A pair of lap joints over a butt joint. Sounds good for larger woofers. Did I mention that I tore a 2" tweeter on my Rec's? I'd be worried about weight, and the back is sealed, so I'll probably need to find something else. I'll file this for future use and hope I don't need it.
Koldby,
Wow. very nice stuff. I like the aluminum, although I can't say I'd go there myself, just for the cost, but it sure looks nice. I've been using my Vifa tester speakers as little desktop speakers on a small open baffle in my cube at work. My only complaint is lack of bass as a single driver. The amount of bass that you guys are getting from those 3"ers is making me less apprehensive about using the 5.25's for bass duty.
Speaking of which, about how much of the excursion are you actually using on the Vifas for general movie volumes when the arrays are run full range?
Greg
Greg,
I use 12 Sony 5" woofers per array, the neo ones with blue cone and attached grill. Although they only have 3mm of Xmax, they will give drums some authority when the loudness switch is engaged on the old receiver. I've clipped the receiver power meters at the 80 watt level without any protest from the $4.50 Parts Express closeout woofers, they operate in a sealed box at Vas if that helps. The box is stuffed with poly fill at approx 120 grams per liter (1.5 pounds per cubic foot)
Eventually the garage arrays will have subs but for now, a dozen 5" woofers are a decent stop gap. Any concepts how to stiffen the dust caps? Finger nail polish would be very simple, is light weight and lasts longer than the foam surrounds on the 5.25" full ranges.
I use 12 Sony 5" woofers per array, the neo ones with blue cone and attached grill. Although they only have 3mm of Xmax, they will give drums some authority when the loudness switch is engaged on the old receiver. I've clipped the receiver power meters at the 80 watt level without any protest from the $4.50 Parts Express closeout woofers, they operate in a sealed box at Vas if that helps. The box is stuffed with poly fill at approx 120 grams per liter (1.5 pounds per cubic foot)
Eventually the garage arrays will have subs but for now, a dozen 5" woofers are a decent stop gap. Any concepts how to stiffen the dust caps? Finger nail polish would be very simple, is light weight and lasts longer than the foam surrounds on the 5.25" full ranges.
Fingernail polish is usually just lacquer. Some people have used hairspray with good results and there are different varnishes that work as well, dammar being one that is often used. Others have used different forms of "cone doping" like latex based adhesives, or PVC coatings and so forth.
The right one depends on which properties you're looking for, as they all can produce different results.
Best Regards,
TerryO
Okay, while the whole line array project will be on hold while I work on my new tarkus look-alike, I do have some questions and Ideas.
My line arrays are going to be essentially an H-frame dipole construct, with slot loaded 10" woofers on each side making up the "wings". (slot to front, woofer back towards the inside.
__'''''''''''''''''''''''''''''''''''''''''''''''''''''''' __
|:::: |++++++++++++++++++ |::::|
| \ +++++++++++++++++++/::: |
| { []++++++++++++++++ [] }::|
| / +++++++++++++++++++\::: |
|__|__________|__________| :_|
The opposed forces should cancel as long as I brace from wing to wing fairly well.
I'm..... hoping the response will work out from my napkin math. But I have no sim that I can plug and chug for.
After this I have a real question - How do I get a dipole response from a line of tweeters? a mirror tweeter line out of phase from the front?
Is a dipole tweeter net necessary to integrate with the dipole everything else? I've never worked with them before
My line arrays are going to be essentially an H-frame dipole construct, with slot loaded 10" woofers on each side making up the "wings". (slot to front, woofer back towards the inside.
__'''''''''''''''''''''''''''''''''''''''''''''''''''''''' __
|:::: |++++++++++++++++++ |::::|
| \ +++++++++++++++++++/::: |
| { []++++++++++++++++ [] }::|
| / +++++++++++++++++++\::: |
|__|__________|__________| :_|
The opposed forces should cancel as long as I brace from wing to wing fairly well.
I'm..... hoping the response will work out from my napkin math. But I have no sim that I can plug and chug for.
After this I have a real question - How do I get a dipole response from a line of tweeters? a mirror tweeter line out of phase from the front?
Is a dipole tweeter net necessary to integrate with the dipole everything else? I've never worked with them before
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I thought making two 48 tweeter lines was enough fun in life...
Dipole would have another tweeter line firing backwards and wired out of phase.
Maybe you can try a bullet tweeter facing backwards to check out the dipole effect? If you don't mind wiring hundreds of tweeters--go for it!
You're a better man than me!
Dipole would have another tweeter line firing backwards and wired out of phase.
Maybe you can try a bullet tweeter facing backwards to check out the dipole effect? If you don't mind wiring hundreds of tweeters--go for it!
You're a better man than me!
Mitch,
The crossover point for the Apex Jrs is 6KHz as recommended by Audax. They are only 10mm domes so have a rather high Fs of 3000 Hz--no go on a crossover of 3.8KHz.
I crossed my line of 48 of them at 4,350 Hz 3rd order and it does not work very well. It will output something and won't blow but--it really don't get up in volume and flatness until it hits at least 5,500 Hz.
I'm redoing mine with 3" mids so will bump the crossover to 6 KHz 2nd order. Just got done building the bezel panels, at least all the holes are cut. Now to make the mid enclosure, attach it to the bezel, mount the mids, wire them and test them before determining the crossover points and parts required.
It is an exercise in patience while I wait for those rare warm days to cut wood. Weather looks good for Saturday so step 1,811 (out of 1,900) to get the mid enclosures built.
The crossover point for the Apex Jrs is 6KHz as recommended by Audax. They are only 10mm domes so have a rather high Fs of 3000 Hz--no go on a crossover of 3.8KHz.
I crossed my line of 48 of them at 4,350 Hz 3rd order and it does not work very well. It will output something and won't blow but--it really don't get up in volume and flatness until it hits at least 5,500 Hz.
I'm redoing mine with 3" mids so will bump the crossover to 6 KHz 2nd order. Just got done building the bezel panels, at least all the holes are cut. Now to make the mid enclosure, attach it to the bezel, mount the mids, wire them and test them before determining the crossover points and parts required.
It is an exercise in patience while I wait for those rare warm days to cut wood. Weather looks good for Saturday so step 1,811 (out of 1,900) to get the mid enclosures built.
Mitch,
I'd agree with 18, that Apex Jr Tweeter is no good down there. a 1st order @7k sounds good, but honestly dips too low. To put that much power @ 3khz is a lot for those things.
I've just come to an epiphany after picking up a thrift score pair of Bose 301 Series II's (they were cheap, get off my case!)... I may be a bit slow here, it's a concept that's been on the tip of my tongue for some time but that didn't materialize until now... The "Big" sound that Bose speakers have is because of the direct-reflecting design, creating two+ signals reaching your ear at different times. Just like a line array, except a line array does "big" more accurately.
My hypothesis is that "big" sounding things in nature are big; the "imperceptable" differences in sounds eminating from a large surfaces (creating differential differences in signal arrival time). We've trained ourselves to perceive these sounds as being big. Line sources in near-field mimic that. It's technically still inaccurate reproduction (distortion), and we all know that a true point source is more accurate (but flawed until they perfect that plasma arc subwoofer). So the "imperceivable" inaccuracies of a line array's acoustic centers placements are perceivable, just not consiously.
Bose mimics this by having your room help out. Of course it won't be as good because there is a less even distribution of relative distances (one close wall, one far wall, as opposed to 28 drivers all at slightly different distances, mounted so that their diaphragms are nearly continuous). So this whole line array thing is really little better than Bose? Not quite. And of course the line array is a flawed means to an end (power handling, dynamics, distortion control).
Has everyone else figured this out already?
FYI, if you ever get a Bose 301 Series II speaker and hate the super muddy bass, stuff a rolled up sock in the port. It REALLY helps. They're not great, but good for $35/pr.
Greg
I'd agree with 18, that Apex Jr Tweeter is no good down there. a 1st order @7k sounds good, but honestly dips too low. To put that much power @ 3khz is a lot for those things.
I've just come to an epiphany after picking up a thrift score pair of Bose 301 Series II's (they were cheap, get off my case!)... I may be a bit slow here, it's a concept that's been on the tip of my tongue for some time but that didn't materialize until now... The "Big" sound that Bose speakers have is because of the direct-reflecting design, creating two+ signals reaching your ear at different times. Just like a line array, except a line array does "big" more accurately.
My hypothesis is that "big" sounding things in nature are big; the "imperceptable" differences in sounds eminating from a large surfaces (creating differential differences in signal arrival time). We've trained ourselves to perceive these sounds as being big. Line sources in near-field mimic that. It's technically still inaccurate reproduction (distortion), and we all know that a true point source is more accurate (but flawed until they perfect that plasma arc subwoofer). So the "imperceivable" inaccuracies of a line array's acoustic centers placements are perceivable, just not consiously.
Bose mimics this by having your room help out. Of course it won't be as good because there is a less even distribution of relative distances (one close wall, one far wall, as opposed to 28 drivers all at slightly different distances, mounted so that their diaphragms are nearly continuous). So this whole line array thing is really little better than Bose? Not quite. And of course the line array is a flawed means to an end (power handling, dynamics, distortion control).
Has everyone else figured this out already?
FYI, if you ever get a Bose 301 Series II speaker and hate the super muddy bass, stuff a rolled up sock in the port. It REALLY helps. They're not great, but good for $35/pr.
Greg
Interesting thought but....
My entire reason for building 6 foot arrays is so they WON'T reflect off the cement floor or ceiling in my garage. My outside walls and roof are metal so if I get any reflection--it will sound like a trash can symphony. Once I get the mid array complete, then assemble the beast using the parts from the 2-way line arrays, my last trick is to put it on a 1 foot tall base so it won't reflect off the floor in the vocal frequencies until it hits the listening position 12 feet away.
In PA, the rule is no more than 20% reflected sound--the more direct sound from the PA main speakers the better. Reflected sound = a blurry image and the vocals turn into a echo mess. I do find it entertaining that Bose advertised the opposite, you want reflected sound! Yeah, if you're stoned in the 70's listening to piles of speakers as Led Zeppelin takes the stage. Keep drinking and smoking until it sounds good.
Line arrays are more "anti-Bose" in that the major point of the design is to limit reflected sound. Since line arrays pre-date Bose, maybe 'ol Amar tried to duplicate their big sound? No.. he just took the Sweet 16 and ran with it--advertised constantly and babbled about research. He did create "the Bose sound" which works great for people with hearing loss at high frequencies and
don't like deep bass frequencies.
Very interesting. What I meant to say was that line arrays sound big because of the tens of differential distances from the listener (remember the small differences that someone calculated and diagrammed some pages ago?). Bose makes the "big" (and empty) sound by bouncing multiple sources off of walls in order to get different arrival times.
On the other hand, line arrays control reflections. My understanding of the way that reflections are controlled is not so much that a line source has less vertical dispersion, just that each source close to the floor or ceiling is much quieter, limiting the effect of speakers near the ceiling.
Or is it that there's a beaming effect caused by the simulated large vertical surface? I've seen all of the vertical dispersion graphs in this thread that seem to show this effect, but I've never been sure if it's just because of the small effect of each driver or beaming/combing above and below the array.
Greg
And BTW, as you know, Bose is FAR from the only one who believes in reflected sound. I don't believe in it, or at least I wouldn't if I never heard the original Martin Logan CLS speakers. I HATE the idea of reflected sound, but those speakers are MAGIC.
Sorry, I felt the need to represent.
Greg
Dipoles, bipoles and open back speakers--depends on what you like. I built some surround speakers that fire full ranges at the back wall to make the sound more diffused, I prefer the surrounds to not be obvious where they are located. They are triangular shaped so it did occur to me I was building something that looked like a 901
The "point" of the triangle is pointed at the listening position so all the full ranges are off axis with half bouncing so I'm guilty! Yes, I hooked them to the receiver as main speakers and fired them into the corners--sounded big but the imaging was lacking. Status of my 3 way conversion has improved, it was warm for a few days so I cut the new bezels, built the mid range enclosures to the bezels, sanded and routered out the holes. This morning there is snow on the ground!
Stain/polyurethane gets pushed to next week and then I can start screwing in the drivers. Testing, ordering crossover parts, installation and final finishing puts me about a month out. After hand sanding 66 mid and woofer holes--my hands were happy when the snow flakes were falling this morning. Mother Nature is always around to inform me to take a break and perfect the next step.
Can't believe I missed this post! I've been rebuilding my PC using SSD's and a new Asus Xonar Essence ST to use it as mediacenter with the Vifa arrays.
The reason I've not been on here for a while and that I've missed the email update.
Great to read they are delivering! I was waiting for the weather to improve to start my build and I think that's not to far off anymore. I'm tempted to use the aluminium, they look great!
I plan to use the PC/Xonar ST for EQ with regular audio and the Behringer 24/96 for other sources.
It seems you have not EQ-ed the bottom end as far as Mr. Russel dared to do...
Hi wesayso.
I am playing in a large room ( > 60 sqmeters) and my best sounding amp right now is a 2x25W OTL tube amp and it clips badly if I compensate too much in the bottom.
I have had a 700 W ClassD hypex amp on them and compensated them down to 20 Hz and I thought the Vifas were bottoming, but later I have been thinking maybe I was hearing digital overload instead.
Still I prefer the weight and authority of a couple of 18" subs. But thats just me!
Koldby
I am playing in a large room ( > 60 sqmeters) and my best sounding amp right now is a 2x25W OTL tube amp and it clips badly if I compensate too much in the bottom.
I have had a 700 W ClassD hypex amp on them and compensated them down to 20 Hz and I thought the Vifas were bottoming, but later I have been thinking maybe I was hearing digital overload instead.
Still I prefer the weight and authority of a couple of 18" subs. But thats just me!
Koldby
Thanks for the reply Koldby,
I was planning on extending the lows to about 25/30 Hz for music with a 250 watt amp. For music that should be enough for me, my current speakers do 30 Hz but they have 15" bass speakers. I guess I'll have to find out.
I think I''m going with my original design but make the front baffle out of aluminum mounting the speakers from behind or even as a sandwich. A friend of mine could do the required machining and I'll use water cutting for the wood (thinking of multiply).
If the budget allows it of coarse, but I like the back side mounting with these Vifa's.
I was planning on extending the lows to about 25/30 Hz for music with a 250 watt amp. For music that should be enough for me, my current speakers do 30 Hz but they have 15" bass speakers. I guess I'll have to find out.
I think I''m going with my original design but make the front baffle out of aluminum mounting the speakers from behind or even as a sandwich. A friend of mine could do the required machining and I'll use water cutting for the wood (thinking of multiply).
If the budget allows it of coarse, but I like the back side mounting with these Vifa's.
Mounting from behind is a very good solution with the Vifas.
It looks very neat and clean and it is the best way to avoid reflections and refractions from the baffle.
Sounds like a good solution to make the baffle only out of alu - especially as a sandwich. That could be a very dead mountingplatform for the drivers.
Do not forget to post pictures of the result, though!!!
A freind of my uses 16 of these Vifas in a corner line array much like the Murphy Corner Array in a smallish room and he has compensated them all the way down.
He has used them with 50 Watts and even 25 Watts and sayes that he is not missing anything in the bottom. Actually he is very surprised how well the play bass and how small the movement of the drivers are even when playing loud. Of course you get a helping hand from the room whith corner loaded line arrays.
I havent heard his system yet, though.
Klodby
It looks very neat and clean and it is the best way to avoid reflections and refractions from the baffle.
Sounds like a good solution to make the baffle only out of alu - especially as a sandwich. That could be a very dead mountingplatform for the drivers.
Do not forget to post pictures of the result, though!!!
A freind of my uses 16 of these Vifas in a corner line array much like the Murphy Corner Array in a smallish room and he has compensated them all the way down.
He has used them with 50 Watts and even 25 Watts and sayes that he is not missing anything in the bottom. Actually he is very surprised how well the play bass and how small the movement of the drivers are even when playing loud. Of course you get a helping hand from the room whith corner loaded line arrays.
I havent heard his system yet, though.
Klodby
So, before I jump into construction, I've decided to mount the Vifas on a (really) crude open baffle. Just been listening to Pandora after everyone else has gone home. I decided today to switch them out for the Aura NS3's, and I have to say, I'm wishing this would STOP. They sound so similar in direct comparison, but after a month or two of just the Vifas, this is painful. I take that back, they're not that bad, but they are muddy, and have a lot of higher register distortion. Also, I think that they'd be better mids than they are full-range because the mud would go away, and the high end can be smoothed. I'd still guess that they are relatively slow drivers, which isn't going away.
That does bring me back to my trying to be cheap again. I'm considering building a mini-array of 8 on each side (8ohms), accompanied by 16 tweets and 4 5.25's, and use them as desktop speakers (big desktop speakers) or side/rears. My thought is this: line arrays are as good or better as surrounds than fronts because the nearfield volume levels are much more even than point source speakers. This means that the person on the right side of the couch will not be blasted by the rear right and not hear the rear left at all (my current problem as I have a pair of old Infinitys literally touching the back of my couch). I think that most people's side and rear satellites are much closer to the main viewing location. Also, if the woofers are left out of the picture, the NS3's can still hit 150Hz well, so the amp can set the high pass there and a simple passive x-over for the mid-tweet can be implimented. Again, since the speakers will be closer to the listener, even little tweets like the Apex Jr. tweeter can be used at somewhat lower frequencies because the SPL output of each of the 16 units will be very low.
Seemed ingenious at the time.
Greg
That does bring me back to my trying to be cheap again. I'm considering building a mini-array of 8 on each side (8ohms), accompanied by 16 tweets and 4 5.25's, and use them as desktop speakers (big desktop speakers) or side/rears. My thought is this: line arrays are as good or better as surrounds than fronts because the nearfield volume levels are much more even than point source speakers. This means that the person on the right side of the couch will not be blasted by the rear right and not hear the rear left at all (my current problem as I have a pair of old Infinitys literally touching the back of my couch). I think that most people's side and rear satellites are much closer to the main viewing location. Also, if the woofers are left out of the picture, the NS3's can still hit 150Hz well, so the amp can set the high pass there and a simple passive x-over for the mid-tweet can be implimented. Again, since the speakers will be closer to the listener, even little tweets like the Apex Jr. tweeter can be used at somewhat lower frequencies because the SPL output of each of the 16 units will be very low.
Seemed ingenious at the time.
Greg
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Thanks for the update, Greg
I'm waiting for the magic box O parts to arrive--the more you need them, the more likely they will arrive late.
As you know, I'm using the NS3's as mids in the 400Hz to 6,000 Hz range--I chose that range since the speaker's distortion charts indicate that is the sweet spot--and it fits the recommended XO for the Apex Jrs. Good to hear I was on the right track with the little guys since I'm not building them again. I'm thinking of using my 4 speaker test boxes wired for 16 ohms and throwing a spare Apex Jr. tweeter in the front with a single cap crossing at around 9KHz. Something to play around with as surround speakers when coupled with my 8 ohms surrounds just to fire into the ceiling and hear what it sounds like. To prevent excessive distortion, a "bass blocker" cap will be used at around 150 Hz since they XO at 80Hz.
If you see a FedEx guy obviously lost and carrying around a box of stuff from Parts Express--send him my way.
Thanks for the update, Greg
I'm waiting for the magic box O parts to arrive--the more you need them, the more likely they will arrive late.
Haha, didn't mean to sound so down on them, don't sound so down about it!
I do support their use as a midrange though. I think that if i compared the NS3 vs. the Vifas with the bass and treble turned to a minimum I would find a lot less difference, but I wasn't willing to hear that earlier today. I think you're right about the 400 being a minimum, but I'm a lot less worried about distortion at low volume levels, the kind expected at 1/8 power.
Then again, 8 NS3's = 15W power handling and 88 dB/W... toss that idea.
BTW, has anyone seen/listened to these:
Peerless 830986 3" Full Range Woofer 264-1056
or the inverted surround version:
Peerless 830986 3" Full Range Woofer 264-1056
Maybe I've just not been paying attention, here's a slightly smaller driver with much lower FS (at least according to the cut sheet). 1mm less xmax, but if everyone with the big line arrays says that they're amazed by how little the drivers move, then who cares. Very flat response. North of $1,000/pair for a full line kinda kicks it out of this forum topic, but not that bad if they're good drivers. The Vifa is really making me want to go full range though.
Greg