| morbo |
| Anyone else get these? Lets hear what you have planned for them if you did. |
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| RAW |
Well 1st of 4 on the go.
More to come as well.
Al |
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| khaosman |
| I haven't ordered them yet due to lack of money. However, I plan on getting some and running them full range for computer speakers :D |
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| JoeBob |
| I was contemplating picking up a couple, but I just ordered a pair of Extremis 6s, so maybe I'll pick up a pair later, after the pre-order. |
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| sbolin |
| They look very nice, but I also ordered a bunch of Extremis. Adire is supposed to be releasing a lot of woofers in the coming weeks, so I will wait to see what they offer. I need the back pair of speakers in a HT setup, I believe these should be pretty good for that. Computer speakers too - good idea. I was thinking about some Auras for that, maybe I will reconsider. |
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| morbo |
Well, Adire better slow down before I have to default on my mortgage ;)
I am looking at running these full range, but after running some tests filtering out everything above 13khz, I'm not sure I will be totally happy with the result. Anyone have any ideas for a tweeter to mate with these? I was thinking maybe something like the Seas 19TFF that's onsale at madisound (http://www.madisound.com/Sale%20Pag...Seas%20H586.pdf) or the Audax Gold Dome micro-tweeter (of which I've seen several versions, but little info) that is available for about the same price at Madisound or Solen. I wonder why no one has reported on this Audax micro, when the polymer version seems to get lots of use. Maybe that should be a sign to me.
One appealingly simple alternative would be to build them into fullrange boxes, then install a top-mounted tweeter if necessary - problem is, I'm not sure if there are any good top mounted tweeters, I've only seen Morel and Hi-Vi models, and haven't seen much info about either. |
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| Grahamt |
| Add me to the "was going to buy them until the Extremis came out" list. I was also thinking of pairing them with the Seas 19TFF or the 19TAF that Tony Gee likes, they look like good choices to me. Creative sound solutions is also designing some MTMS and MT for the Wr125. |
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| JohnG |
Count me in. I ordered 4. No firm plans yet, but I haven't built anything in a long time, and this looks like a good place to start.
John |
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| BAM |
| RAW: Are those Koda 8's in the bass section? Looks nice. |
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| Steven Kephart |
| quote: | Originally posted by morbo
I am looking at running these full range, but after running some tests filtering out everything above 13khz, I'm not sure I will be totally happy with the result. |
I'd recomend trying them full range before you rule it out. As long as the intended application keeps them on-axis, I think you will be surprised at how well they do up high. You can always add a tweeter and crossover later if you aren't happy. ;)
Steven Kephart
Adire Audio |
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| sbolin |
| quote: | Originally posted by Steven Kephart
I'd recomend trying them full range before you rule it out. As long as the intended application keeps them on-axis, I think you will be surprised at how well they do up high. You can always add a tweeter and crossover later if you aren't happy. ;)
Steven Kephart
Adire Audio |
So Steven, will Adire have this (or similar) driver available too? I ordered 7 Extremis 6", and now need two smaller speakers for the rear speakers of my surround, and two for my computer. The CSS 4.5 looks good, but I was hoping for something between CSS and the Extremis for the surround, and smaller (3") for the computer. [Yes, the Extremis would be good, but (1) I keep changing my order, and I am too embarrassed to change it yet again, and (2) the sale is over]. Reading some of Dan's comments on the DIYspeakers mailing list, I doubt I'll see a metal cone Extremis, but it would be pretty nice! |
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| bilbobaggins |
I've ordered 6 for my HT setup. Hopefully, they can beat out the likes of B&W and Celestion.
I'm also interested in a supertweeter down the road. But then again I've had an amp that started rolling off at 10 kHz and were down 3 dB at 20 kHz that still provided great imaging. But then its not really the imaging but the frequency response that I'm after with a supertweeter. |
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| Warren G |
| quote: | Originally posted by Steven Kephart
I'd recomend trying them full range before you rule it out. As long as the intended application keeps them on-axis, I think you will be surprised at how well they do up high. You can always add a tweeter and crossover later if you aren't happy. ;)
Steven Kephart
Adire Audio |
Will these perform good on axis too?? |
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| morbo |
| Good to hear folks.. I guess I will try them full range first, as I do like the 'crossoverless' point source sound (like my TB 871s), but 13khz seems quite low... Also, wouldn't beaming become an issue at higher frequencies? I wonder if you could just put a cap on a tweeter (maybe top-mounted?) and run the woofer full range? |
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| RAW |
Bam.
No they are a OEM version Adire has done for CSS.
As for the crossover anything is possible.
I have done a second order using Solen parts,Silver wire,BH5 in the show samples but all finished will have Ice materail over BH5.
Other than that same xover parts.
And can be ordered (MT)with a twin jumper set of connectors to run the speaker fullrange no tweeter or with the tweeter and network.
Al |
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| morbo |
:cool: There was a package waiting for me when I got home today :D Opened them up... damn these things are fairly heavy! Nice construction, looks a lot like the TB 871, but look a little closer and the quality control is obviously a fair bit better, as well as the frame.
I couldnt wait, so I grabbed a couple small cardboard boxes I had lying around (different sizes even), cut holes in them, and surface mounted the drivers, secured with masking tape. :bigeyes: I know, very high tech :rolleyes:
First test was to substitute the stiffer of the 2 cardboard boxes for my TB871 center channel. In about 5 minutes I was sold on this being my new center channel. In a nutshell, even in the cardboard box, it has same great locking of voices to the screen, with none of the harshness the tangband takes on at higher levels. I tried these at the maximum level I would normally play my HT, no sign of strain whatsoever. Also, I think the lack of sparkle actually helps with dialogue intellegibility, or maybe its the greater dynamics or better tonal balance, but there is no doubt dialogue was a bit easier to make out.
Speaking of sparkle, I hooked them up in a stereo pair nearfield at my computer desk and started listening. I'm still doing so now. Cardboard speakers about just under 3 feet from my head, forming an equilateral triangle. My biggest concern was with the high frequency rolloff. Well, I'm happy to say really isnt that noticeable. I know, I was one of the most skeptical of this claim, and I have fairly extended HF hearing (certianly to 17k or so). But frankly, I don't miss it that much at all. There is still plenty of treble energy and detail. Like I said, for the center channel, I'm going to forget about a tweeter, and if I were using these as bookshelves I might be willing to as well... at least for listening on axis. Really I only notice the lack of sparkle on every fifth recording or so, and it has been fairly benign in all those cases.
If I had to describe the preliminary sound, I'd say it is very dynamic
and very clean. Especially in contrast to the TB 871's I've used in the nearfield, these have a sense of dynamics and speed that the 871s just can't convey. Combined with the excellent imaging and large soundstage (I've heard sounds from well outside the speakers, and some as if from behind me) this makes some sounds and effects quite literally startling. They certainly want to play bass as well, but obviously in this enclosure they are misaligned and the panels are vibrating quite a bit, but its pretty impressive the amount of bass they are trying to put out. All in all, I'm pretty damn impressed! I'll try to post some pictures of the drivers and my 'shoeboxes' in the coming days. |
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| JoeBob |
| These have already been shipped out? Argh, I'm still waiting for my Extremy (or Extremises?). |
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| Warren G |
| anyone recommend some good tweeters with these? would the seas 20tff tweeters sound good? |
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| kwhilden |
I've had the new Creative Sound WR125S 4" fullrange speakers running for a few weeks now. I am very impressed with the sound. I have extensive experience with the Jordan JX92S and have a pair of each running in identical transmission line cabinets.
The CSS driver does indeed have superior performance. It has better, deeped bass, and more controlled high frequencies. Midrange performance is about the same, with the CSS unit having a more balanced neutral presentation. The Jordan has a midrange peak around 2-3k and this tends to add a little 'shimmer' to the music which some find very seductive and others find annoying. Personally I appreciate the neutrality of the CSS unit and prefer that sound. Nothing sounds bad on the CSS.
Running the CSS in a 7l cabinet tuned to 65Hz provides significantly extrended bass response, to the point of wondering where the subwoofer is hiding! I am quite surprized just how much bass the XBL2 technology provides.
About the only advantage of the Jordan is that it is more efficient than the CSS, but not by a lot. Some may prefer the characteristic sound of a metal cone driver.
In the near future, I will have some commercial products using this driver.
Kevin Whilden |
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| morbo |
Kevin - thanks for taking the time to give us your thoughts. Its good to have my impressions verified by someone with more experience, as I'm a perpetual beginner at this stuff ;) To whatever extent you're comfortable talking about your upcoming products, can you tell me:
a) if you're planning on using a tweeter
b) if so which one and roughly how/where you'll cross to it, and
c) if you've used a tweeter with it, how did you find it effected the imaging and cohesiveness of the speaker?
Thanks again |
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| Steven Kephart |
| quote: | Originally posted by kwhilden
Running the CSS in a 7l cabinet tuned to 65Hz provides significantly extrended bass response, to the point of wondering where the subwoofer is hiding! I am quite surprized just how much bass the XBL2 technology provides.
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Hahahaha. That's the same reaction we always get. We literally have to unplug all the demo subs just to prove they aren't on.
:D
Steven Kephart
Adire Audio |
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| sbolin |
| quote: | Originally posted by Steven Kephart
Hahahaha. That's the same reaction we always get. We literally have to unplug all the demo subs just to prove they aren't on.
:D
Steven Kephart
Adire Audio |
By the way Steven, any word on when the Extremis will be shipping? I have 7 on order for my HT, can't wait to get them. I note that the Extremis page has been updated with distortion measurements, too - looks really good. How about that 4" mini-me Extremis? :D |
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| kwhilden |
| quote: | Originally posted by Steven Kephart
Hahahaha. That's the same reaction we always get. We literally have to unplug all the demo subs just to prove they aren't on.
:D
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Yes, bass is good... for a 4" driver. It doesn't replace a 6.5" driver, in any way, however there are many significant design advantages from a 4" that thumps like that! ;) |
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| Steven Kephart |
| quote: | Originally posted by sbolin
By the way Steven, any word on when the Extremis will be shipping? I have 7 on order for my HT, can't wait to get them. I note that the Extremis page has been updated with distortion measurements, too - looks really good. How about that 4" mini-me Extremis? :D |
Unfortunately I don't know when they will ship. You could e-mail sales@adireaudio.com and ask them. They may be able to get you an answer.
BTW, we have a video of the Extremis 6 under full excursion. Here's a link if you are interested: http://www.adireaudio.com/Files/Extremis6.AVI
Steven Kephart
Adire Audio |
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| bilbobaggins |
| Would using a bucking magnet on these drivers to help with video shielding be OK? Or would that be determental to the point of using XBL driver technology where you are trying to keep the B* L (magnetic flux density * length of the wire in the magnetic field) constant. |
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| khaosman |
| quote: | Originally posted by bilbobaggins
Would using a bucking magnet on these drivers to help with video shielding be OK? Or would that be determental to the point of using XBL driver technology where you are trying to keep the B* L (magnetic flux density * length of the wire in the magnetic field) constant. |
They are already video shielded. Both the CSS 4.5 and the Extremis. |
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| morbo |
I'm hoping to build cabinets for these this weekend, can someone double check my math here?
I'm looking at
~13 litres
17" x 6.5" x 12" external, 3/4" mdf
ported to Fb 45 with 1.5" ID flared port 4" long
seem reasonable for low level listening? |
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| Timn8ter |
I had heard the two previous prototypes and yesterday heard the current model at Adire. The box it was in looked less than 7 liter though I didn't break out my tape measure. I'm getting a pair next weekend if that tells you anything. Dan tipped all the subs in the room to prove none were connected. I may add a supertweeter 'cuz that's how I am. Highly recommended driver!
p.s. This thread should be in the Full Range section.;) |
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| morbo |
| Well I backed off the 13l a little bit, looking at ~10 or so now, 15" x 12" x 6.5" external dimensions, 3/4" MDF. I've added a large amount of my own 'sandwich' damping materials to the walls, so as to take internal volume down even more. Hopefully this will bring them more in line with the ~7l Adire and CSS seem to recommend. Glad to hear you like Tim, let us know how your project with these goes. I'm hoping someone designs a TL with these soon, that would be the killer app for them IMO |
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| morbo |
| oh and you're right about the fullrange section, but IIRC it was started before that section existed, or before I noticed it anyway. But feel free to move it as it is the more appropriate area for it, and this driver seems to be overlooked by the fullrange crowd ATM for whatever reason. |
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| tg3 |
That's amazing. Highly recommended. :nod: |
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| tubesguy |
| That should be "in extremis" - Pat |
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| ABS |
Morbo,
I'd like to know if you could provide an update on your work with the WR125S driver. I'm personally considering using these for an HT setup . . . If you took your own measurements, would you please post them? I'd like to know how close to reality the CSS specs are. Also, I noticed that CSS doesn't have any power handling specs posted, would you have a sense of how much wattage these can handle when running full range? I'm wondering if you've decided to add a tweeter to the setup for a TM configuration or if you've decided to run them as an MTM setup. Also, what size enclosure/tuning did you end up with? Your input is greatly appreciated.
Andy |
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| morbo |
ABS - you're right, an update is overdue. I have 3 of the drivers in house right now. I have cut wood and holes for all 3 speakers (2 nearfield 'monitors' and a centre channel), and all 3 speakers have been in use for about 1 week so far, the boxes and drivers taped together with masking tape for now while I decide how to finish them before final gluing. All of my impressions are based on this unfinished state, so keep that in mind.
To answer your specific questions:
1. I don't have my measurement gear yet so I can't post any measurements, sorry. I should be getting a behringer mic soon and can do some measurements then. I also can't verify the CSS specs for the same reason, however, if it puts your mind at ease at all, the technical paper about the WR125 on the CSS site is written by Dan Wiggins of Adire Audio, who is quite highly regarded and TTBoMK, has never been known to overembellish specs.
2. Power handling - the computer speaker pair are run full range. On all but the most bass-heavy material, their dynamic range seems unlimited in this setup. I can't say how many watts they will 'take', but I'm using a fairly beefy old Carver 60wpc reciever to drive them, and I can't get past 11 o'clock on most material before its too loud. Put it this way - I've played everything from large scale classical to Dr. Dre to drum & bass, and on every occasion, my ears have given out before the speakers showed any sign of strain. Keep in mind however, that this is sitting about 1 foot from the speakers. Still, on most material, even in normal listening positions, these things could fill a small room easily, especially if tuned a bit higher (or better yet, sealed). Which brings me to another point - see point 5 for more on tuning.
The other speaker is used as my centre channel. Same box, same tuning. Here the speaker is run out of my receiver (100wpc pioneer), with I beleive a 2nd order highpass at 100hz. In my small room, it is about 6' from my head. In this setting the speaker is amazing. I have watched several full movies at this point, from The Two Towers to The Hulk to The Big Lebowski (my personal fav. center channel dialogue test). In every case, dialogue has been better than I've ever heard it before. I have played at pretty good levels, although I'm not someone who listens extremely loud. Initially, I got worried at louder passages, but after playing some of those and watching the driver excursion, my concerns have faded. This is a paranoia particular to me; until I've fully learned the limitations of a new speaker, I am always worried I'll blow it. It is not specific to this speaker or driver at all.
3. I have not yet tried a tweeter. I probably will not add one to the center channel, but I will add one to the computer speakers. This is not because I miss the 'sparkle' at all, I find the current sound most satisfying. However, I use the computer speakers as monitors for mixing music, much of it in mp3 format from various sources. The single most common probelm with carelessy encoded mp3s is high frequency artifacts such as ringing or swishing - often around 16khz. I need to be able to hear these artifacts so I can easily weed out and reject those mp3s which have such problems. If the speakers were not being used in this critical application, I would not bother, the added expense plus the chance of ruining the coherency with a crossover are not worth it IMO. The tweeter I will most likely use is a 10mm Audax gold dome, available at madisound and Solen. I've also thought about using the VifaXT19 or one of the seas 3/4" tweeters. I will not use them in an MTM setup, though I'm sure it would sound great and reduce the reflections from the desk they sit on, its not in my budget. For the center channel, I would not use a horizontal mtm because of dispersion issues. Vertical MTMs would probably be quite appropriate though, and would help with SPL a great deal.
4. My boxes are 12" deep by 15" high/wide (depending on orientation) and 6.5" wide/high (ditto), with a single shelf brace. The port is the 1.5" flared one that CSS sells. This tunes the speaker to ~48-50hz. Port noise is not an issue at all. Internal volume is somewhere around 11-11.5L. All walls are damped with my own DIY material, a sandwich with a first layer of thick mousepads, a second layer of closed cell foam normally used to kill sound underneath that interlocking laminate flooring, and finally matress underpadding. All of these are 'glued' together with Mono 'Acoustical Sealant' caulk (nasty, nasty stuff). This deadens the cabinet very well, and also does a good job soaking up the backwave. The back wall behind the driver is covered in acoustic foam on top of said sandwich. Wherever possible, I used aysmettric placement & orientation of damping material.
I have some pictures of the construction process that I'll try and post later, seem to have misplaced my CF card right now.
My general impressions of the sound, in order of how much they jump out at you:
1. Dynamic
2. Undistorted
3. Precise Imaging
The computer speakers are just amazing, I don't think I've fully absorbed just how high the level of performance is in this role. It really puts my main system to shame in almost every way, probably because the speakers are never getting close to their limits.
The center channel speaker is great as well. I have fairly nice mains, ACI Spirit/Opals, and in the past for solo HT viewing, I would always use the phantom center mode on my receiver, since I was sitting in the sweet spot anyways. Now I don't think I will be doing that anymore. While the phantom center still provides a more seamless front soundstage, this speaker is so obviously of a higher resolution through the midbass and midrange than the ACIs, that I will take the hit in net coeherence to hear the extra detail in the center channel. Dialogue is an order of magnitude clearer than on my old TB871 center, and best of all, I'm not 'riding the remote' (adjusting volume) nearly as much to try and hear quiet without making action sequences unbearably loud. The remote stays at my side throughout the whole movie, which is a BIG plus in my books. The ACIs have a laid back character, whereas the center at times demands your attention. There will be something, like a female vocal, or a few string notes, that really grab you and make you focus in a way the ACIs rarely do. This is another big plus IMO, since the moments when this happens tend to be the big emotional or dramatic bits.
If you want to use these all-around for an HT, I would say you could end up with an extremly coherent system with incredible imaging and very low distortion. However, these are not some miracle speakers that won't need a sub for HT type bass, nor are they going to be SPL kings. Within their limits they are incredible, but its important to respect those limits. Treat them the way you would treat an extremely high quality 5.5" two-way, and you can't go wrong IMO. If you need inspiration, look at the rave reviews that Jim Griffin's Jordan/Aurum Cantus 2 way has recieved, and then consider that the CSS driver has been called as good or better than the Jordan. I hope this helps, if you have more questions let me know and I'll do my best to answer. |
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| morbo |
| center channel unfinished |
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| morbo |
| computer speakers unfinished. I'll post more photos of both when they are properly glued, rounded, and finished. |
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| ABS |
Morbo:
Thanks for the update. Based upon your comments and the comments of others, I ordered a pair of these drivers to play with.
Of note, while modeling the driver with the latest version of WIN ISD, I discovered that using a .3cu.ft. cabinet tuned to 60HZ but adding a first order high pass filter at 100 hz, yields a very nice response curve. Without the high pass filter, there is a +3-4db bump centered around 100hz. The high pass filter subdues the otherwise large peak in output and results in a response curve which is almost directly comparable to a sealed box enclosure of comparable size except the vented setup with the filter appears to have much better control over the cone's excursion and also yields the high group delay values of a ported enclosure.
I've also been investigating inexpensive 3/4" dome tweeters to mate with this driver and so far I've been considering the following (comments/recommendations welcome):
Scanspeak D2008/8512
Scanspeak D2010/8513
Seas 19TAF/D
Seas 19TFF1
Seas 20TFF
Audax TM020j3
Vifa TC20TD05-06
Vifa D19TD-05-08
LPG 19P
Visaton G20SC
Hiquphon OW1
Without hearing the speakers first, it is hard to tell what makes the most sense, but I'm now thinking that the front and center channel configuration which might be best is a TMM configuration with a subwoofer and active high pass set at 100hz. For surrounds I'm thinking that a single driver in a ported enclosure might work well.
I'll post results once I get the drivers in and do some testing.
Andy |
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| tg3 |
| Must be the first time I've seen an OW1 on a list of 'inexpensive' tweeters. |
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| ABS |
Yes, you are correct, the OW1 is not inexpensive, but it is supposed to be extremely good. I supposed it and the Scan-Speak drivers probably do not belong on this list since they are all $50 or more and I had stated I wanted an inexpensive tweeter. However, if these mids are as good as I expect them to be, and the off axis response is as good as has been described, then perhaps a high quality 19/20mm tweeter at the level of the OW1 is in order.
Recommendations, comments, concerns for a good tweeter to mate with this mid/woofer would be appreciated.
Andy |
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| morbo |
ABS - the EQed smaller box seems like a good plan. Just one thing - although the excursion may be kept under control better down to the tuning frequency, keep in mind that below the tuning frequency the driver becomes unloaded and flops around like crazy trying to make output. This is very undesireable in a fullrange driver IMO. This is especially a concern with HT, where some soundtracks route a lot of bass to all channels - a ported speaker (unfiltered that is) will be damaged easier if some really low fr content makes it into the signal. Are you planning on filtering them, and if so what Fr/slope will you use?
Your list of tweeters looks good, though I can't say I've ever used any of them. It pretty much mirrors my own. I am probably going to go with the little Audaxes, because of $$$ concerns and because they should perform very well if crossed high enough, say 6 k or do. I'm not too sure when I will get to that though, too many projects (and most of al,l too much to learn) as is! |
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| ABS |
Morbo:
I looked at some of those Audax tweeters, but none of them "jumped out" at me and made me think they would really shine. I was thinking about tweeter criteria on the airplane today and I realized that if I began to roll-off the tweeter at around 12K with a 1st order x-over, that I would be down 18db by 1.5K (assuming that I also include impedance correction in the circuit. One of my priorities is to have excellent off-axis response out of the tweeter as well as excellent overall sound quality to ensure that the tweeter will mate nicely with the new midrange/woofer. I'd like to know which Audax tweeters you were thinking about using. For about $30, some of those 19/20mm Seas tweeters look pretty good. I'd suggest that we'd want the tweeter to have an Fs of no higher than 1500hz, and of course, anything lower would be better. Some of the top mount Morel tweeters also look interesting.
I fully agree with you regarding the cone excursion issue below the tuning frequency with this mid-woofers. Even a first order high pass filter set between 80-100hz, would make a tremendous difference for power handling. I know that everyone complains about the size of the caps required, but I really don't think this is a big deal, NP electrolytics with a poly bypass should be just fine. I've had great success with Black Gate caps in my amplifiers and I'd probably use those. They sound terrific even without the poly bypass cap. I'm considering making this high pass cap "switchable" so that I can decide on the fly whether or not to activate it. The other options are to just use a built in active x-over either in the pre-amp or in a subwoofer amp.
I'm still looking for thoughts on the tweeter selection. I'm going to post on the PE and Madisound boards to see if I can get some recommendations.
Andy |
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| ABS |
Grahamt:
Thanks for the link, I hadn't seen that configuration. One thing which concerns me is the woofer's off axis response above 2K. On axis and 15 degrees off axis looks okay up to about 10K, however, the 30 and 45 degree off axis curve don't look nearly as good. I'm guessing that this woofer might do really well mated with a tweeter using only 1st order x-overs with a full 3 octaves in the cross over range. I'm guessing that this would keep the parts count low and might also provide a very smooth transition from tweeter to woofer. Since I don't have the woofers in yet, I'll have to test them once I get them. I suspect that Dan was trying to showcase the high frequency capabilities of the driver and that is the reason why he configured the tweeter the a 4th order cross over and no attenuation on the upper octaves of the woofer . . . |
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| Grahamt |
| quote: | | I suspect that Dan was trying to showcase the high frequency capabilities of the driver and that is the reason why he configured the tweeter the a 4th order cross over and no attenuation on the upper octaves of the woofer . . . |
Yep. He did it this way because you can easily run the driver full range without the tweeter as well. I think he designed this for his car too. |
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| Timn8ter |
| Dan is an ardent believer in high order crossovers. He is especially proud of designs that use 2nd order electrical but yield 6th order acoustical. It would be interesting to see the MLS measurements of this because I'm guessing the WR125S has run out of steam when the tweeter takes over. The XO point bandwidth is probably very small if Dan has stuck to his philosophy. |
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| Kilentra |
| I don't think this is a steep crossover. I think it is intended to preserve the tone of the WR125 (including the declining off axis response) and just correct the lack of high frequency extension. |
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| ABS |
Although I haven't received my woofers yet, I'm still struggling with the theory behind Dan's design . . . From the curves posted on the CSS web site, we know that the woofer doesn't do so well 30-45 degrees off-axis above 2K. That would make sense since this is typically tweeter territory and the woofer is 4.5" after all. It is quite amazing that the woofer has as much on-axis extension as it does. Despite this fact, if we were going to use this driver in a 2-way design, I just don't understand why we wouldn't opt to run the tweeter lower. I'm not suggesting that the tweeter should be run all the way into the vocal range, but maybe (depending on x-over slope) we'd choose to set our x-over point somewhere between 6-12K? It appears that Dan's x-over point is set around 12K (judging by the FRQ curves only) but with an extremely steep x-over since it appears that he is down 24db by 6K. This steep slope really mitigates the effects of the tweeter in the 2-6K region. Perhaps the woofer's off-axis performance in that 2-6K region is actually better than it appears at first glance?
Andy |
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| DanWiggins |
Hi all,
I designed that crossover to do a few things:
1. Allow easy show-off of the 4" full range (which, by the way, works REALLY well for home theater applications, when high passed at 100 Hz and run full range). Simply disconnect the input to the tweeter crossover network and its the woofer full range.
2. Sonics. We experimented with first order, 2nd order, 4th order, and 6th order networks at a variety of crossover points. After listening, the low orders were simply tossed out - too much sonic "mush" from the comb filtering. Wide bandwidth drivers with lots of overlap really call for higher order crossovers.
So it was the 4th order 6th order solutions, or the solution we ended up with. On axis, and even near on-axis (say, 20-30 degrees off) using just the tweeter as a fill at the top end really worked well. So that was ultimately chosen (the second favorite was a 6th order solution at 7 kHz).
3. The Audax tweeter really isn't that bad. It's one of my three favorites under $20. The slight rise in the top end isn't bad at all, easy to work with. And it does have quite a bit of extension on the low end. Plenty of output, fairly low THD/IMD when used with a higher order crossover (and there's lots of good reasons to use a high order crossover for just about any XO situation). There really aren't any other small faceplate, low cost, video shielded good performing tweeters out there.
Anyway, we've got that design solution running in one of our demo rooms, if anyone wants to stop by and take a listen...
Dan Wiggins
Adire Audio |
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| ABS |
Dan,
Thank you for sharing your experiences in developing a "good fit" for the high end with this woofer. Understanding your design goals really helps here. It is also good to know that just using a tweeter for the top frequencies really helps with the off-axis HF dispersion. I do have one question though. When you were testing filters at lower frequencies, such as the one you mentioned at 7K, were you still running the woofer full range or were you filtering its high end as well? I'd like to understand if I should anticipate problems using a low pass filter on the woofer . . . Thanks again.
Andy |
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| DanWiggins |
Andy,
All the other crossovers except for this final one were true two way designs. The 6th order two way at 6 kHz sounded as good as the final solution, so we decided to drop the extra complexity and just go wide open on the mid.
Dan Wiggins
Adire Audio |
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| morbo |
| Dan - thanks for chiming in with your thoughts on this. Very informative. One question - how baffle dependent is this crossover? I have my WR125 in a box already, the drivers are mounted at the top. How best to implement the tweeter then? If I just mount it in an equal width (6.5") 'baffle extension' piece on top of my existing box, as close to the woofer as possible? Or should I start fresh since my baffle size may be different than yours? |
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| Zaph |
| quote: | Originally posted by DanWiggins
2. Sonics. We experimented with first order, 2nd order, 4th order, and 6th order networks at a variety of crossover points. After listening, the low orders were simply tossed out - too much sonic "mush" from the comb filtering. Wide bandwidth drivers with lots of overlap really call for higher order crossovers.
So it was the 4th order 6th order solutions, or the solution we ended up with. On axis, and even near on-axis (say, 20-30 degrees off) using just the tweeter as a fill at the top end really worked well. So that was ultimately chosen (the second favorite was a 6th order solution at 7 kHz).
|
Interesting. A lot of people have the opposite opinion, including me. What about power response, and passing a square wave that looks like a sabertooth saw? Actually, I usually end up going LR4 anyway because it's easier to do with most drivers. But if I had a driver with wide bandwidth, I'd probably go with shallow slopes.
| quote: | Originally posted by DanWiggins
3. The Audax tweeter really isn't that bad. It's one of my three favorites under $20. The slight rise in the top end isn't bad at all, easy to work with. And it does have quite a bit of extension on the low end. Plenty of output, fairly low THD/IMD when used with a higher order crossover (and there's lots of good reasons to use a high order crossover for just about any XO situation). There really aren't any other small faceplate, low cost, video shielded good performing tweeters out there. |
Someone posted a link to a project of mine using the Audax tweeter because I seem to suggest that it's not very good. But the fact is I like it a lot or I wouldn't have posted the project. The only thing about it is that it takes so many components to get it under control, and lately I've come to the conclusion that cheaper tweeters cost more than expensive tweeters because they need more crossover components thrown at them. A $26 Seas can reach a perfect acoustic 4th order with only 2 components, and do it with lower distortion too.
For high quality, wide bandwidth drivers, I highly recommend the Vifa XT19. And if money is tight, the DX19 is nice also. The DX19 has surprising low frequency ability, and 2nd order acoustic slopes at 2500 are no problem. The XT19 can't go quite as low but otherwise it's performance is even better, probably better than the Hiq's.
Bob Reimer was nice enough to send me one of these for evaluation, so I'll be comparing it to other similar size drivers I have in the house, Seas L12 among them. When I was at DIY Chicago, I won a XBL^2 subwoofer as a door prize, so it looks like I'll be giving this technology a good run for it's money. High Xmax never tripped my trigger, but low distortion and smooth response do so I'm curious to see if these live up to it.
John |
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| sbolin |
| quote: | Originally posted by Zaph
For high quality, wide bandwidth drivers, I highly recommend the Vifa XT19. And if money is tight, the DX19 is nice also. The DX19 has surprising low frequency ability, and 2nd order acoustic slopes at 2500 are no problem. The XT19 can't go quite as low but otherwise it's performance is even better, probably better than the Hiq's.
Bob Reimer was nice enough to send me one of these for evaluation, so I'll be comparing it to other similar size drivers I have in the house, Seas L12 among them. When I was at DIY Chicago, I won a XBL^2 subwoofer as a door prize, so it looks like I'll be giving this technology a good run for it's money. High Xmax never tripped my trigger, but low distortion and smooth response do so I'm curious to see if these live up to it.
John |
Not to derail the thread, but how do you find the Vifa XT19 and DX19 compared to the Seas 27TDFC?
Also, do you mean you will be testing the WR125 along with the other 3" drivers? If so, I really look forward to the results - a lot of good speakers on that list. |
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| Zaph |
| quote: | Originally posted by sbolin
Not to derail the thread, but how do you find the Vifa XT19 and DX19 compared to the Seas 27TDFC?
Also, do you mean you will be testing the WR125 along with the other 3" drivers? If so, I really look forward to the results - a lot of good speakers on that list. |
The XT19 is a better tweeter to use in a 3-way or for supplementing the high end of a wide range driver. Above 4Khz, I don't think there's a better tweeter. It's built with a copper faraday ring and the rear chamber is well designed, so distortion is very low in the range that it is intended to be used. Right at about 2Khz, 2nd order harmonic distortion starts to rise sharply, so those using this tweeter should really cross over much higher. 2nd order at 3000 or 4th order at 2500 are my recommendations. I'm currently using the XT19 with a GR M130, a driver that has extended response out to 10kHz. I affectionately call this system the MBOW-None. I would guess that the CSS WR125 would be good in a similar system.
I wasn't going to test the WR125 with the other 3" drivers because it's really in a different class, both price and size-wise. If things go well, I'll be testing the 3" this weekend. The guy who was going to send me the Fostex didn't come through, so now the list is:
TB W3-871
TB W2-880S
Aurasound NSW1-205-8A
Aurasound NSW2-326-8A
Aurasound NS3-193-8A
Aurasound NS3-194-8E (New model)
Hi-Vi B3S
Hi-Vi A2S
MCM 54-606
MCM 54-609 |
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| Zaph |
| For everyone's reference, here's some test data of the Vifa XT and DX19. The DX would probably be the worlds best 3/4" tweeter if it weren't for a slightly higher energy storage at 4kHz. For $23 US, it's still a great value however. I'm using it with a Vifa TC14. |
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| BAM |
| I've been contemplating a mini-monitor using this woofer and a B+G Neo3 ribbon tweeter. Lack of impedance curves and FR data for the Neo3 would need to be remedied before I could, though. I'd probably use Speakerworkshop to model the crossover. |
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| DanWiggins |
Zaph wrote:| quote: | | Interesting. A lot of people have the opposite opinion, including me. What about power response, and passing a square wave that looks like a sabertooth saw? Actually, I usually end up going LR4 anyway because it's easier to do with most drivers. But if I had a driver with wide bandwidth, I'd probably go with shallow slopes. |
Well, using a critically damped filter (Q=0.5) you get flat power and frequency response at the crossover point.
Passing a square wave really only happens easily with a first order filter, and then only at a prescribed small sweet spot. You can do higher order linear phase networks, but they do get quite tricky above 2nd order. The goal of linear phase is admirable, but the scientific community is still undecided about the audibility of linear phase (note that this is whether you can even hear it, let alone if it's required for good perceived sound).
HOWEVER, with a first (or even a second) order filter, you automatically accept:
- higher THD
- higher IMD
- higher power compression
- worse off axis response
- smaller sweet spot
- higher component count
relative to a higher order crossover. Many of these artifacts ARE known to be audible and detrimental to the perceived results of the speaker.
So, in my mind, it's either shoot for a potentially good thing at the expense of many known pitfalls, or eliminate one potentially good thing and avoid many known pitfalls. Since I see engineering as the art of making the perfect set of compromises, I usually go for higher order. Rarely do I do a speaker with lower than 4th order (usually 6th or 8th).
Just my design philosophy! I've done first and second order networks when the client requests it, but if they don't state a specific requirement for crossover order, I go high...:
| quote: | Someone posted a link to a project of mine using the Audax tweeter because I seem to suggest that it's not very good. But the fact is I like it a lot or I wouldn't have posted the project. The only thing about it is that it takes so many components to get it under control, and lately I've come to the conclusion that cheaper tweeters cost more than expensive tweeters because they need more crossover components thrown at them. A $26 Seas can reach a perfect acoustic 4th order with only 2 components, and do it with lower distortion too.
For high quality, wide bandwidth drivers, I highly recommend the Vifa XT19. And if money is tight, the DX19 is nice also. The DX19 has surprising low frequency ability, and 2nd order acoustic slopes at 2500 are no problem. The XT19 can't go quite as low but otherwise it's performance is even better, probably better than the Hiq's. |
Good information! I'll have to consider those... Another reason I used the Audax was I have a supply of them here...;) I know Bob has some other kit designs for the WR125S coming out, with different tweeters, but I put one out for general info that used tweeters I had.
| quote: |
Bob Reimer was nice enough to send me one of these for evaluation, so I'll be comparing it to other similar size drivers I have in the house, Seas L12 among them. When I was at DIY Chicago, I won a XBL^2 subwoofer as a door prize, so it looks like I'll be giving this technology a good run for it's money. High Xmax never tripped my trigger, but low distortion and smooth response do so I'm curious to see if these live up to it. |
I look forward to your feedback! We're picking up new OEMs weekly after playing with XBL^2 drivers. One new convert (a very skeptical engineer) wrote us that "The quality of bass and even lower midrange was different, less muffled and less congested. Quite noticeable difference" for an 8" subwoofer we designed for him.
Dan Wiggins
Adire Audio |
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| morbo |
Interesting posts about the various tweeters Zaph.. I got the impression from your comments after testing that the DX19 is a pretty mediocre tweeter... it is fairly cheap here, so if it is that good, I may try that out as well. The XT19 is a bit much for me $$$ wise I think. Would crossing above 5 or 6k ameliorate the stored energy @ 4k issue much?
The other tweeter I've had my eye on (mainly because of cost) is the little Audax 10mm gold dome:
It would also allow for very tight driver-driver spacing, although it would need a relatively high XO, but thats something the WR125 can help with I think ;)
A question - if I'm listening very close, ie 1-2 feet away from the speakers, how much do I need to worry about what they do @ 30-45 deg. off axis? |
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| HeatMiser |
| quote: | Originally posted by morbo
A question - if I'm listening very close, ie 1-2 feet away from the speakers, how much do I need to worry about what they do @ 30-45 deg. off axis? |
I asked the same question in another thread about the WR125S and somebody helpfully pointed out the way rather simple geometry suggests an answer: at 1 foot, moving your head 6 inches to the side puts you 30 degrees off axis; at 10 feet, you're not 30 degrees off until you move 5 feet. Looked at another way, the same 6 inches puts you less than 3 degrees off axis when seated at my hypothetical 10 foot distance. That right there suggests off-axis response might be especially critical in the near field.
It seems to me that there are other factors at play though. Depending on your listening habits, you might tend to stay in one spot at your computer such that a 6 inch sweet spot is not unreasonable. Also, in the near field the problem of power response is mostly avoided so in that sense the off-axis response as reflected from walls and ceiling needs not be a factor.
It's an interesting question, and I think more discussion could be useful for those of us wanting to build computer speakers or nearfield monitors. |
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| Zaph |
| quote: | Originally posted by morbo
Interesting posts about the various tweeters Zaph.. I got the impression from your comments after testing that the DX19 is a pretty mediocre tweeter... it is fairly cheap here, so if it is that good, I may try that out as well. The XT19 is a bit much for me $$$ wise I think. Would crossing above 5 or 6k ameliorate the stored energy @ 4k issue much?
The other tweeter I've had my eye on (mainly because of cost) is the little Audax 10mm gold dome:
It would also allow for very tight driver-driver spacing, although it would need a relatively high XO, but thats something the WR125 can help with I think ;)
A question - if I'm listening very close, ie 1-2 feet away from the speakers, how much do I need to worry about what they do @ 30-45 deg. off axis? |
For another opinion on the DX19, look here:
http://206.13.113.199/ncdiyaudio/ma...9/vifa_dx19.htm
His results pretty much agree with mine. The ridge at 4kHz on Mark's waterfall looks pretty scary, but he's got a whopping 40db of range on that chart. I generally only show 30 db of range, since below that energy storage issues are off the radar. Ironincally, it was my tweeter too that I borrowed to him for testing. I have several DX19's laying around since they perform decently and are cheap. Don't worry too much about the little bit of energy storage at 4Khz. There have been worse offenses in tweeters costing 5 times as much. I've been listening to these for a while, and it's a great tweeter for the price. Don't feel like you need to cross over above 4kHz on these.
I've got a few of those little audax laying around, both flanged and press fit style. They aren't very good. On one of them, I jammed a pen into the dome for no reason. That kinda says something about them. :D
HeatMiser's point about avoiding power response issues in the near field is a good one. In the near field, room reflections are down a ways compared to far field, where the power response contributes a lot to the tonal balance. The vertical sweet spot is what you have to worry about. With 2 way and a high crossover point, you may only have an inch or two before a big null shows up at the crossover frequency. Woofer off axis response becomes an issue also if it's not aimed directly at you. For this reason, small full range drivers work best as near field monitors. To this day I still have a pair or W3-871's at my desk. |
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| ABS |
Zaph:
Just wondering if you'd had a chance to either test or listen to any of the Seas 19/20mm tweeters? From the specs posted on the Seas web site, they look as though they could be really good, but I'm hesitant to make the jump without more information about them . . . I know that some of the 27mm non-Excel Seas tweeters have received very good reviews. The DX19 looks as though it could be a really good option, but that extra energy at 4K does disturb me . . . If I were to cross the tweeter low enough, I would guess that I would hear that extra energy. I do like the off-axis response of the Vifa though. Thanks for sharing your comments and feedback.
On side note, one thing which really strikes me in this discussion is that the proper selection of a tweeter to mate up with the WR125S will probably be really important. If everything I've heard about this mid-woofer is true, then I would guess having a really high-end tweeter is almost a requirement. The ability for the tweeter to play very low may not be the priority, but low distortion, high dispersion and excellent overall detail, balance and accuracy would probably be high riorities . . . I suppose my point is that the cheapest solution may not be the best solution.
In the prior discussion about linear phase cross-overs, I couldn't help but think about using a top mount tweeter such as the Morel MDT-44. This "should" allow for the tweeter to be "phase aligned" simply by mounting it in the correct location. Have you tested any of those by chance?
Regards,
Andy |
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| Zaph |
| quote: | Originally posted by ABS
Just wondering if you'd had a chance to either test or listen to any of the Seas 19/20mm tweeters? |
It's been a long time since I used a Seas 3/4" dome. Too long for me to remember if it's any good or not. I'll say that I never understood why Seas discontinued the 20TFF. It looked like a better tweeter, with better surround and a hollow polepiece. If you can still get it, I'd go for that over the 19.
I didn't do any comparison yet, but I ran some quick tests of the WR125s. On the good side, what I found so far is a very smooth and low distortion midrange. There was some high frequency breakup, but it looks controllable. On the bad side, Qts was nearly 1 and efficiency was low.
I've attached some data - Frequency response, on axis and 30 degrees off axis, T/S parameters, a CSD chart and exported Z and SPL for modelers to mess with. Don't trust the drive level, but it's supposed to be 1 watt measured at 1/2 m. These are all infinite baffle measurements, so don't forget to sum in the baffle step to get a real in-box response.
In my opinion, these need a tweeter and a crossover. Also, the effective corner frequency and shaping of the baffle step compensation could help minimize the midbass peaking from high Qts. What's left is dealing with the low efficiency. It's probably fine if you have a decent power solid state amp and you use a subwoofer, but these are probably too inefficient to use as a midrange in a passive 3-way unless you double up to a MTMW or a MMTMMW or something.
I'll let you guys know when I do more complete testing and a comparison to other drivers. |
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| CSS/XBL |
I have forwarded the results to Dan Wiggins the designer of the driver and am awaiting input from him before responding.
Bob |
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| sbolin |
| Zaph- what kind of break in did you do? The CSD looks sort of nasty, too, with a lot of ridges. I sure wouldn't use it beyond 5k or so, that is for sure. Still, up to 5k it is quite smooth. Making me a little nervous about my Extremis order :( |
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| Zaph |
Breakin was a few hours at high Xmax.
The CSD, in my opinion is very good. Yes, there are ridges, but nothing large, and notice how through the midrange the signal immediately drops off almost 20db. Measurements like this are unfortunately not very usefull unless you have a point of comparison. Hold off on judgement of the CSD until there are side by side comparisons.
But if you need a quick example of bad, here it is. :eek: |
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| Zaph |
| quote: | Originally posted by Bob Reimer
I have forwarded the results to Dan Wiggins the designer of the driver and am awaiting input from him before responding.
Bob |
Bob, thanks for the test sample. I expect to finish up testing this coming Sunday or Monday, then I can send it back. Or if you'd like, I can send the driver onwards to another person for evaluation. There's a few guys over on the Madisound forum who would love to test this driver out.
John |
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| johnmark |
It looks like this driver would work nicely in a 1.5 or 2.5 way design.
This would avoid the need to apply baffle step circuit, since the driver is not very efficient. If a woofer with a first or second order filter were brought in at a frequency made to offset the falling baffle response of the enclosure, then a resonable efficiency could result. This would preferably be an active crossover which would mean bi-amping. But I think a simple passive coil could work OK.
This is what I am planning to do, and add a tweeter if needed.
I was going to use the Adire Extemis as the .5 woofer.
Now, if I could only predict in advance what the exact crossover point and slope of the .5 speaker should be. Someday I'll buy a good modelling package.
Looking at the data that Zaph posted (thanks a million !) it looks like the reponse up to 10K is pretty decent. |
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| johnmark |
| like the attached |
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| ABS |
I just received my WR125's tonight and briefly listening to them, I am extremely impressed. Yes, they do beam in the upper frequencies, but on-axis, they sound extremely good. Placing them loosely in the end of a plastic enclosure of roughly 4 liters resulted in suprisingly good bass output. Overall I am impressed. I did notice some LF distortion at what was a moderate SPL (this occurred free air). I fully agree that a 2.5 setup with a separate subwoofer or some variant of that concept such as a TMMWW, TMMW, MTMWW or MTMW configuration might be the best way to go.
Zaph: Thanks for the feedback and thoughts regarding those Seas tweeters and thank you VERY much for turning me onto those DX19 tweeters. After careful consideration of the test results, I now agree that those DX19's do look very good, especially considering their price point. I'm planning to pick up a couple . . .
I also wanted to let everyone know that the outside diameter of the metal frame of the WR125S is approximately 5" and the distance between the outer edges of the rubber surround measures approximately 4". |
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| ABS |
Well, I finally got the DX19 tweeters and my PE .25 cu. ft. boxes in over the weekend. So far, I have tested the WR125S in the box both sealed and ported. The sealed version sounded very nice but not nearly as good as the ported. I am using a 2"x7.5" port which, according to WINISD, should bring the F3 in at around 50-55hz. With this setup, the bass is surprisingly good. Far better than one would ever expect from a 4.5" inch driver, and really much more like the output from a 5.5" or 6". I would point out that my 2-way Scan-Speak setup with the 7" carbon fiber woofer has much more low end authority than the WR125S, but the 4.5" driver does hold its own when in the ported configuration.
I also briefly tested the DX19 tweeter with only a 3.3uF capacitor installed. This "should" give a theoretical x-over point around 12K, but without impedance compensation in place, I'm not so sure about that. There is no question that this tweeter sounds very nice and it has amazing off-axis response. Although the 3.3uF x-over point is certainly too high.
My next step is to take measurements and begin modeling in Speaker Workshop. At the end of the day, I think these will be awesome mini-monitors.
Andy |
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| dvdvideo |
This driver sounds like it is amazing. I would love to pair this up with a Bohlender Neo3 tweeter (heard the NEO3 on the Bohlender A-1 and loved it), maybe even swap the 125 for the new larger extremis 6 and have no need for a subwoofer. Alas, it's all a pipedream.....I have no woodmaking experience, no soldering, no anything.
Still it is tempting to just dive in....... |
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| Zaph |
I've completed a comparison of 3 similar size woofers.
Seas L12 vs Dayton RS125S vs CSS WR125S
Three Quality 125mm Midwoofers
No losers in this group, these are all great woofers. Each has it's good points and bad points, but I could be happy with any of them. Note that the WR125S Qts has been updated slightly from my previously posted T/S parameters, thanks to a faulty DCR number spotted by Bob Reimer. It still is high, but not quite as high as I previously stated.
Also note this test page is temporary. I'm out of web space and I need to post another project, so I'll need to remove this soon.
Regards,
John |
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| morbo |
I have now finished my center channel after going through painting hell with it. The sound is still great. The computer speakers are still pending painting, though I've glued them together now. After letting them break in for a while and extended listening, I am starting to feel that on some material they are a bit midbass heavy. Nothing major, but I will definately be doing some measurements soon, and then using the Kxproject drivers to do some EQing and eventually a crossover to a tweeter.
Yet again I find myself thanking John K for testing these drivers and providing great information! For those of us that cannot afford to try all these different drivers for a variety of reasons, this is invaluable!
Thanks for posting your impressions with the tweeter Andy, keep us posted, I havent' got the time or $$$ to follow suit just yet but I will most likely follow in your footsteps sometime soon, although with a DSP crossover instead of passive. |
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| ABS |
John:
Thanks for testing these and publishing your results. What is your take on the large amount of low frequency distortion on the WR125S. To be honest, I am surprised by it - the large xmax of the driver should be helping to reduce the linear distortion at low frequencies, but I guess it's not. On the other hand, the distortion levels about 200hz appear to be extremely good, I am guessing that this is part of the reason why the midrange clarity of this driver is so good . . . What I'm struggling with evaluating is just how much of an issue the low frequency distortion really is . . . Do you have a sense of how this driver compares to other drivers which use either a polypropylene cone or a paper cone? Perhaps what we are seeing is just a paper vs. metal cone issue. Any chance of comparing the highly regarded Vifa P13 poly cone driver too? I know it is a 5.5" (slightly larger), but I believe it also falls into this category . . .
Andrew |
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| kappa546 |
| why do you suggest crossing the xt19 over so high? seems like it would be a capable driver for a low xover. i've wanted to try this tweet for a while now so i just want some input |
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| 454Casull |
| XT19? Don't you mean the DX19? |
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| ABS |
454Casull is correct, I am designing a x-over for the DX19 with the WR125S. I am not looking at the XT19 mostly due to cost constraints. So far my listening impressions of the DX19 are extremely positive. The waterfall plots I've previously viewed showed some excess energy around 4K. It might be desirable to x-over above that frequency to reduce as much as possible the limited damping at that frequency. In addition, the WR125S has extremely good HF extension and so the desire to take advantage of a single driver through the mid-band to the greatest extent possible is also a desirable goal in the overall speaker design. However, this particular goal must be balanced with off-axis response as well. As the WR125S starts reaching higher frequencies, it also begins to "beam". Finding a good balance is the key.
Andy |
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| Irwin AR |
Just wanna say thanx to John (Zaph) for providing us with the
Three Quality 125mm Midwoofers which i found very useful for
pre-evaluating all three mids.
I was just curious if theres is other measured data on the off-axis
of these three babies for referrence.
especially those done by John would be great as to compliment his previous measurements |
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| dvdvideo |
| How are these off axis vs on axis? Do the bean the treble a lot? |
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| nate |
I have four 8ohm and two 16ohm drivers. They are going to be my new home theater! I'm still working out which tweeter to buy. The cabinets are in homage to the 47labs design. Wide, tall and shallow. They are covered in cherry and the baffles are curly redwood. They are not done yet but I will post some pics this coming week.
nate |
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| ABS |
Folks:
I know it has been a long time since I've updated this thread, but I finally found the time to engineer a crossover for the WR125S and DX19 in a Parts Express .25 cu ft enclosure.
The tweeter is mounted slightly off axis and I used a baffle diffraction simulator to determine the "optimal" baffle location for the tweeter.
I used SpeakerWorkshop to perform all my measurements (impedance and frequency response) I ended up with a 2nd order x-over on the woofer and a 1st order crossover on the tweeter. I have a somewhat minimilistic approach to x-over design. It was my goal to keep the parts count and cross over orders as low as possible.
The woofer x-over uses impedance correction circuitry to reduce the rise in impedance with increasing frequency. The tweeter uses impedance correction tuned to the tweeter's resonance frequency.
Tweeter polarity is reversed to avoid a rapid swing in phase response and a negative impact to the frequency response. The frequency response testing I performed, with the woofer mounted in it's final position, on the baffle and installed in the enclosure, showed a big dip centered around 5K in the woofer's output and a lot of extra energy in the 8-10K region. Initial testing indicates that the second order x-over combined with the impedance correction does a good job of subduing the extra energy above 8K and provides a smooth roll-off in overall response above 5K.
Since the woofer has output up so high, I was able to begin the tweeter roll-off at a fairly high frequency (somewhere around 10K).
Listening to the speaker I can state that it sounds very balanced, natural, detailed yet easy to listen to and has tremendous off-axis response and imaging.
I need to finish testing and tweaking, but once complete, I think this design will definitely be a winner. I would be willing to share my design if there is interest.
Regards,
Andrew |
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| audiobomber |
| quote: | Originally posted by ABS
I would be willing to share my design if there is interest.
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You certainly have my interest Andrew. This is a most fascinating thread, and I like your design philosophy. |
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| audiobomber |
http://www.us.alegriaaudio.com/Ling.htm
http://www.rawacoustics.ca
http://www.creativesound.ca/details.php?model=KIT41
All these designs are very similar, but with different tweeters and/or HF crossovers. I've ordered the Raw Acoustics version (RAW-1F), with no tweeter. Here's my plan... You fine speaker makers are forgiven for laughing at my Frankenstein design. Any advice is welcomed:
I have a Marchand XM44-3, a pair of Rocket UFW10 subs, a pair of Usher 9950's and a pair of Energy 22 Ref Con speakers. The plan is to sit the RAW-1F cab on top of the Energy cab, secured with blu-tack. I think the size and colour (piano-black on matte black) will make this visually acceptable, and the Energy cabinet is double-thick wall, so it should be a decent support. The Usher will be mounted in place of the Energy tweeter.
Crossovers will be 60 Hz and 250 Hz (2nd-order). I'm not sure how to cross over to the tweeter, since neither the tweeter nor the RAW-1F is here yet. That's why I'm interested in Andrew's spec. |
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| tiroth |
| I had a very bad experience with RAW acoustics and would not recommend them. |
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| planet10 |
| quote: | Originally posted by tiroth
[I had a very bad experience with RAW acoustics and would not recommend them. |
From what i've seen an isolated issue, and from the discussion on both sides not completely in Al's control. And i'm sure he learned from the experience.
dave |
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| johnmark |
Andrew that is an unusual combination of 2nd order on woofer and 1st on tweeter, so you are thinking outside the box!
I would like to see any measurements that you have taken- particularly off axis. I was going to use the WR125 "naked" for my center channel but for my mains I was going to go full boat with tweeter, and active crossover to a pair of woofers. However, maybe re-think and put that tweeter in the center speaker as well if it really improves off-axis highs and doesn't mess with voice intelligibility .
Are you using that 2 way for your center now?
I like the idea of a compact cabinet for the speaker, but what about the baffle step? Your cab must have a drop off in response between 800hz and 200hz . Do you just use your receivers bass control to boost? |
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| Timn8ter |
| quote: | | I like the idea of a compact cabinet for the speaker, but what about the baffle step? Your cab must have a drop off in response between 800hz and 200hz . Do you just use your receivers bass control to boost? |
I'm going to guess that by employing the 2nd order XO on the woofer he's built in BSC. I think this is an excellent example of good design work. |
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| badman |
| A lot of designers refuse to combine crossover orders, but I find that it's an effective design tool. It's especially handy in mid-tweet interfaces, if you get a mid that has a smooth rolloff and sounds good near the rolloff, you can use the acoustic response in conjunction with a lower-order XO to get a steep slope with fewer parts, and then use a higher order tweeter xo. It's all a function of designing around the driver, not coming up with an abstract design goals and expecting the drivers to sound good in what configuration *you* say they should. Flexible design will lead to better results than trying to force drivers to behave the way you want. |
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| audiobomber |
| quote: | Originally posted by badman
... if you get a mid that has a smooth rolloff and sounds good near the rolloff, you can use the acoustic response in conjunction with a lower-order XO to get a steep slope with fewer parts, and then use a higher order tweeter xo. |
That would lead to a first or second-order on the mid-woofer and a third or fourth-order on the tweeter. I thought that was a fairly common design? Second-order on the woofer and first-order on the tweeter as Andrew is suggesting sounds unusual to me (novice that I am). |
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| dvdvideo |
I was looking the infinate baffle frequency graph on zaphaudio and correct me if I am wrong, but does it seem like this driver has baffle step compensation already built in? It seem up about 4 or 5 db in the bass range.......which would be toned down in an enclosure, correct?
Am I right in saying the driver does not really need a baffle step correcting circuit like most do? |
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| konut |
| I've read this thread a couple of times and come up with an idea that I'd like some feedback on. Usually I know enough about audio to be dangerous, but when it comes to designing speakers, I know just enough to appear stupid. Be gentle. What I'd like to do is use two WR125STs(16 ohm version) in a small enclosure like the RAW-1F(there appears to be enough room for this due to the cutoff on the diameter of the mounting flange). I would like to mount a tweeter at the acoustic center on the top of the cabinet(weather the cabinet will be used vertically or horizontally will be determined after listening tests). I would like the enclosure volume to maximise linearity to 80hz, and then fall off as steeply as possible as I will be using a sub for frequencies below 80hz. My questions are 1. At what frequency will comb filtering effects start to set in, assuming the 125s are right next to each other? (This will determine the crossover point) 2. As the RAW enclosure is 12" tall and 7.5" wide, how deep would the enclosure need to be to get the best linearity to 80hz? Correct me if I'm wrong but a sealed enclosure will yield a steeper rolloff than a ported enclosure. 3. Would stuffing the enclosure with cotton or fiberglass, and putting a pressure release vent(aperiodic loading) be enough of a compensation to purhaps use the stock RAW cabinet(10" deep) to achieve the loading I am looking for? Thanks in advance for your responses. |
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| Timn8ter |
Use a .5 cu ft cabinet. With the truncated frames comb filtering is going to be minimal enough to be a non-issue. I did a TL with them and the results were excellent.
http://www.us.alegriaaudio.com/Rosa.htm
I really need to do something about that picture. :o |
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| planet10 |
| quote: | Originally posted by Timn8ter
[B]Use a .5 cu ft cabinet. With the truncated frames comb filtering is going to be minimal enough to be a non-issue. I did a TL with them and the results were excellent. |
Or you could build a bi-pole and not have any comb filtering -- or baffle-step issues at all....
dave
(i just know Tim saw this post coming :)) |
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| Timn8ter |
Of course. I figgered between the two of us we'd get it covered. :D
If the goal is to have an early natural roll-off the closed box idea would probably work well. I can't say with definite certainty but I think you'll need at least 14 liters sealed to get down to 80Hz. |
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| konut |
| Thanks for the input. I dont like the bi-pole idea at all as I've had experience with planars and while the sound is captivating and exciting initially ultimately its too much of a hassle to get realistic imaging. Everything has to be just so, and the sweet spot is limited. I just wanted to confirm that comb filtering would not be a problem as I had planned to use one of the Morel top mounted units at about 4khz, as thats where the WR125 starts to get directional, and the Morel maintains great spread past 10khz. If I get the right one I shouldnt even have to pad it. I'll be using an analogue electronic crossover with a 4th order slope, and graphic equalization to fine tune. |
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| planet10 |
| quote: | Originally posted by konut
bi-pole -- planars |
keep in mind that planars are dipoles & a different animal
dave |
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| ABS |
Folks, I appreciate all the good discussion regarding the x-over design I'm developing. I don't claim to be an expert when it comes to speaker design, and I am certainly willing to take any criticisms and/or recommendations more experienced individuals have.
The frequency response testing I performed was "on-axis" and with both drivers mounted in their final locations on the baffle and with the baffle installed on the enclosure. I am shooting for as close to a flat frequency response as possible for on-axis response. Tweeter and woofer measurements were both taken with the mic and enclosure in the same physical position to avoid phase issues and to compensate for driver off-sets.
The second order x-over on the woofer was needed because the woofer's output, while mounted on the baffle, is not flat up to 10/12k. My testing showed a big dip in the 4-7k region and then a big bump in the 9-11k region. To deal with these issues, I needed to take advantage of the roll-off beginning around 4k and then also reduce the output dramatically around 10k. The second order x-over does this nicely and results in a very smooth and natural roll-off while damping the 10k bump.
Testing the tweeter on the baffle shows that it also has some significant bumps in output, notably around 15k and also around 5k. Of note, the bump in output from the tweeter around 5k helps to compensate for the dip in the woofer output at around the same frequency.
Initial testing of the x-over shows the total combined output to be very flat in the mid-band from around 500 hz to around 5k and then the output rises steadily up to about 12k with a big bump around 15k. Listening tests also confirm that the tweeter is running a little "hot". I suspect that I need to increase the attenuation in my l-pad x-over circuit to regain a more natural balance above 5k. I may also choose to introduce a notch at around 15k to quell the big bump in output centered at that frequency. I will have to determine if this is necessary.
Overall, the system is extremely natural and clean sounding. Vocals are incredibly clear and detailed. I would say that both efficiency and power handling are low, but that was to be expected. Once this design is complete, I may consider building a TMM with the same drivers to help resolve some of the efficiency and power handling issues. I think this little mid-woofer would be really terrific as a dedicated midrange in a 3-way design with a properly tuned sealed enclosure.
When compared to my two way Scan S | | | |
