I apologize that this is long, but I tried to anticipate and answer some questions upfront. If you read this, thanks!
I'm ready to try my hand at building some speakers and was hoping to get some advice from those who have heard a number of different designs. I've read quite a bit over the past few decades but have been too poor and itinerant to be able to invest in the hobby, or even to listen to more than my headphones (which actually are pretty sweet). I've never actually heard a full range speaker or even heard the effect of different box designs, and I live in the boonies, so it's a bit difficult to audition commercial designs. That said, based on theory and philosophy, I would like to build some FR speakers for my new home, but I am wavering on some design options.
The ultimate goal is to outfit a new room (18' x 14'front with a 10ft open back wall) with a 7.2 surround system for music and HT. I don't need astonishing volume. I plan on driving the front 2 ch with a 60wpc SS amp(1st G Densen Beat B100, owned) and the surrounds with an NAD C245BEE (not currently owned), though other thoughts and input would be welcome. The source will be an HTPC which unbuilt, but I think I'm going to use a Xonar Essence card for output. Having the computer as the source is not optional.
My original thought was to use the Alpair 10 G2 all-around, but I have no idea when those will be available or if they'd even be suitable. I've read about the fellow who used the Mark Audio Alpair 12 for a similar purpose, so copying that is a possibility. The room is pre-wired through the walls, so I would like to build wall-mounted surrounds if they would work. Which brings me to my barrage of questions:
1) I've seen the CHR70 sealed wall-mount designs--has anyone heard these? Would they produce adequate SPL, 6 ft from the listening position?
2) How about an Alpair 7 in a similar sealed wall-mount for the surrounds? Overkill for a surround channel?
3) Understanding it would be theoretically easier for the driver and the amp, has anyone heard if adding a sub/woofer audibly improves the overall sound quality, over just supplements the low end? Or, stated differently, should I cut the off the FR somewhere (200hz?--probably needs 2 woofers; 80hz?--too low but could maybe use one sub)? I'm a bit afraid to build a big horn.
4) Probably better asked elsewhere, but if I use a woofer/sub, does anyone know using the LFE cutoff on the soundcard would be an adequate crossover? My impression is that, for bass frequencies, it doesn't really matter.
I'm ready to try my hand at building some speakers and was hoping to get some advice from those who have heard a number of different designs. I've read quite a bit over the past few decades but have been too poor and itinerant to be able to invest in the hobby, or even to listen to more than my headphones (which actually are pretty sweet). I've never actually heard a full range speaker or even heard the effect of different box designs, and I live in the boonies, so it's a bit difficult to audition commercial designs. That said, based on theory and philosophy, I would like to build some FR speakers for my new home, but I am wavering on some design options.
The ultimate goal is to outfit a new room (18' x 14'front with a 10ft open back wall) with a 7.2 surround system for music and HT. I don't need astonishing volume. I plan on driving the front 2 ch with a 60wpc SS amp(1st G Densen Beat B100, owned) and the surrounds with an NAD C245BEE (not currently owned), though other thoughts and input would be welcome. The source will be an HTPC which unbuilt, but I think I'm going to use a Xonar Essence card for output. Having the computer as the source is not optional.
My original thought was to use the Alpair 10 G2 all-around, but I have no idea when those will be available or if they'd even be suitable. I've read about the fellow who used the Mark Audio Alpair 12 for a similar purpose, so copying that is a possibility. The room is pre-wired through the walls, so I would like to build wall-mounted surrounds if they would work. Which brings me to my barrage of questions:
1) I've seen the CHR70 sealed wall-mount designs--has anyone heard these? Would they produce adequate SPL, 6 ft from the listening position?
2) How about an Alpair 7 in a similar sealed wall-mount for the surrounds? Overkill for a surround channel?
3) Understanding it would be theoretically easier for the driver and the amp, has anyone heard if adding a sub/woofer audibly improves the overall sound quality, over just supplements the low end? Or, stated differently, should I cut the off the FR somewhere (200hz?--probably needs 2 woofers; 80hz?--too low but could maybe use one sub)? I'm a bit afraid to build a big horn.
4) Probably better asked elsewhere, but if I use a woofer/sub, does anyone know using the LFE cutoff on the soundcard would be an adequate crossover? My impression is that, for bass frequencies, it doesn't really matter.
4/ for HT bass is usually <120 Hz. When dealing with room modes a minimum of 2 subs (running mono) are indicated
3/ HTPC should have bass management, allowing you to cut off the mains/surrounds at 80-100 Hz or so. Freedom from expending themselves producing bass, this sweetens the FR's capacity to produce mid & top.
2/ Alpair 7 is definitely better than CHR on absolute grounds, but will show the warts on a lesser amplifier. Further, surrounds have a daunting task when it comes to optimum dispersion. For surrounds 2 CHR per surround probably win out over a single A7 because of this. (see the splayed sealed surround in the microTower Home Theatre appendix document)
1/ not those specific designs but the milliSize sealed box they are based on. Simple, with outstanding performance at very low cost. The mMarS produce ample volume (for me) in my room at 12' distance.
0/ Madisound is selling CHR70 for an obscenely low price. I suggest grabbing a pair and stuffing them into anything handy that is 5-7 litres and get a feel for the sound.
dave
3/ HTPC should have bass management, allowing you to cut off the mains/surrounds at 80-100 Hz or so. Freedom from expending themselves producing bass, this sweetens the FR's capacity to produce mid & top.
2/ Alpair 7 is definitely better than CHR on absolute grounds, but will show the warts on a lesser amplifier. Further, surrounds have a daunting task when it comes to optimum dispersion. For surrounds 2 CHR per surround probably win out over a single A7 because of this. (see the splayed sealed surround in the microTower Home Theatre appendix document)
1/ not those specific designs but the milliSize sealed box they are based on. Simple, with outstanding performance at very low cost. The mMarS produce ample volume (for me) in my room at 12' distance.
0/ Madisound is selling CHR70 for an obscenely low price. I suggest grabbing a pair and stuffing them into anything handy that is 5-7 litres and get a feel for the sound.
dave
Thanks for your reply. I had actually already downloaded your mMarS plan (thanks for publishing all of those designs BTW), but was worried about exceeding the power limit of the CHR70. I was planning on buying some of those drivers anyway while I experiment and build some woodworking skills. I'll try and share my experience, but it could be a while (in addition to a driver, I have to choose a saw).
I noted you're building a 2-way with 4x SDX-7 for the low end. Can you explain your decision. I assume you chose the 7 so that it can cross high, but why do you feel you need four? I had been thinking of using one SDX-10 per side. Any thought on or experience with that?
I noted you're building a 2-way with 4x SDX-7 for the low end. Can you explain your decision. I assume you chose the 7 so that it can cross high, but why do you feel you need four? I had been thinking of using one SDX-10 per side. Any thought on or experience with that?
Actually, SDX7 doesn't go all that high for its size... it starts falling at 1-1.1k. Something i use to advantage. Once treated they do well up to there and roll off smoothly.
I really like the woofer (once at least simple mods are performed), it performs on par with larger drivers, and works very well in a simple sealed enclosure.
But the real reason is pragmatic (and overkill -- but to hit 20 Hz with authority, some subwoofers probably still needed). I ended up with quite a few and they are a hard sell.
I want to make this design a statement... like the cost of a house commercial offerings (but better 🙂)
Althou all of the concepts in the design were coming together already, the KEF Blade and a loonngg listening session with the Alpair 7 really gelled what had been a loosly defined project.
I'd like to present both ative & passive XOs. If it works out i know 2 vendors stitting on drivers that would enable a <$1k parts investment (a bit more fully tarted up) to get parlayed into something that would cost 5, maybe 6 figures at your local hifi emporium.
dave
Well, now that I'm doomed to remain covetous and dissatisfied with anything I build...
I ordered some CHR70s--I think I'll try some mMarS, Castle-Micro-Tower and Pensil R70
I hope this isn't addicting.
I ordered some CHR70s--I think I'll try some mMarS, Castle-Micro-Tower and Pensil R70
I hope this isn't addicting.
Remember the story of the cookie... it is awefully hard to eat just 1... and it sounds like you already have 3 on your plate 😀
dave
Greets!
Your Qs imply that you're not 'up to speed' on what it takes to design a successful HT, so FWIW here's a response I made to another recently:
>>>The original 5.1 specs limited the center/surrounds to ~100-7 kHz with, but nowadays all channels are supposed to be 20-20 kHz. Browsing THX certified cinema or consumer systems tells a different story though with ~80-20 kHz being required to meet the top of the line THX Ultra with ~42-20 kHz for the mains.
Anyway, depends on what level of performance you want: Consumer Home Entertainment Home Theater THX.com
Of more interest to the serious DIYer is the Dolby tech library where you can find all the recording/playback details for the various formats: http://www.dolby.com/professional/technology/index.html<<<
GM
Your Qs imply that you're not 'up to speed' on what it takes to design a successful HT, so FWIW here's a response I made to another recently:
>>>The original 5.1 specs limited the center/surrounds to ~100-7 kHz with, but nowadays all channels are supposed to be 20-20 kHz. Browsing THX certified cinema or consumer systems tells a different story though with ~80-20 kHz being required to meet the top of the line THX Ultra with ~42-20 kHz for the mains.
Anyway, depends on what level of performance you want: Consumer Home Entertainment Home Theater THX.com
Of more interest to the serious DIYer is the Dolby tech library where you can find all the recording/playback details for the various formats: http://www.dolby.com/professional/technology/index.html<<<
GM
I'm not really interested in designing an actual home theater at this time, 'though maybe a few years in the future. Trying to keep up with THX specifications, I feel would just add complexity and ruin the fun. Anyway, for this room I didn't want side or rear speakers anywhere but on the wall, so (and maybe I'm wrong) I didn't think I'd be able to get decent bottom range without cutting them off to the front.
That's not what you indicated in either your thread's title or first post.
Keeping up?! The basics of THX haven't changed fundamentally since the advent of discrete surround channels or almost two decades now, so have no idea what you're referring to. Regardless, I can understand one not wanting to delve into the 'nuts n' bolts' of HT that one gets at the Dolby site and why I said it's only for the 'serious' DIYer, but the THX site is designed predominately for folks like you that just wants to experience surround sound with their video, i.e. guidelines, not 'cast in stone' requirements.
I mean how many HTs, not to mention full size cinemas, have 'full-range' surrounds? Statistically, i.e. the percentage referenced to the total, I've seen none! They all use bass management to re-direct any LF to the LFE system or the L/R mains if there isn't one, but if you don't have surrounds or CC that go low enough for the bass management to work correctly..........
Ruin the fun?! The info that's buried in my post answers many of your Qs and volumes more you haven't either voiced or thought of yet, so if 're-inventing the wheel' is your idea of 'fun' as you imply, that's fine, to each his own, but then why are you wasting our time that could be better spent helping folks who aren't? Seems like you're missing a lot of fun by not building/tweaking/testing, then maybe scrapping it and starting all over with what you learned...........
GM
I'm sorry if my attitude came across as inflammatory. I think I may have poorly expressed my skill limitations. Yes, I know that what I'm talking about doing will not be as capable when it comes to HT as some other options, but I feel that starting with a FR driver offers me the best chance of actually completing my first DIY project. Also, I don't see any theoretical reason that I wouldn't actually be happy with the results, but, as stated, I've never heard a FR speaker, so I was asking for input from those who have. Regarding the "ruin the fun" statement--the comment was just reflecting the fact that if a quality THX home theater were my real goal, it would be much more efficient for to buy one.
If I wasted anyone's time, I apologize, but it was my understanding that responses were voluntary.
If I wasted anyone's time, I apologize, but it was my understanding that responses were voluntary.
😕
I was just wondering if there was some special over at Madisound that I was missing. But Dave's got a point, it does seem like a great price for the quality of this driver.
Quite; I nearly fell out of my chair when I saw the price-list, but they seem happy enough with it, & if Bob's selling them at the same price, it's a win-win situation for potential buyers.
Possibly, but THX is slightly wooly in terms of requirements, so there's also a lot of junk out there.
Regardless, it boils down to what you want / value. GM's post's are actually rather useful to you, but he won't 'hold your hand' as it were; he'll give you the information you need to go & figure it out for yourself, just as the best teachers do.
Anyway, FR based HT is something of a compromise in terms of dynamic bandwidth; they'll never reach THX or Dolby spec. but if you're just after 'good enough' surround, like the majority, rather than a 'serious' HT setup, it'll probably do OK; certainly as a first go at creating a multi-channel system as there's less to go wrong. Sticking with one make of driver (whatever you settle on) should help as they're generally voiced in a similar way, even if they're different sizes. FWIW, I'd be inclined toward multiple subs. for the bottom end rather than a single & I'd be inclined to keep the BW on all channels as wide as practical.
Possibly, but THX is slightly wooly in terms of requirements, so there's also a lot of junk out there.
Regardless, it boils down to what you want / value. GM's post's are actually rather useful to you, but he won't 'hold your hand' as it were; he'll give you the information you need to go & figure it out for yourself, just as the best teachers do.
Anyway, FR based HT is something of a compromise in terms of dynamic bandwidth; they'll never reach THX or Dolby spec. but if you're just after 'good enough' surround, like the majority, rather than a 'serious' HT setup, it'll probably do OK; certainly as a first go at creating a multi-channel system as there's less to go wrong. Sticking with one make of driver (whatever you settle on) should help as they're generally voiced in a similar way, even if they're different sizes. FWIW, I'd be inclined toward multiple subs. for the bottom end rather than a single & I'd be inclined to keep the BW on all channels as wide as practical.
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Another source of some good research on the subject would be the recent Floyd Toole text:
Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms: Amazon.ca: Floyd Toole: Books
He spends much time outlining the evolution of of multi-channel sound reproduction, including ever increasing sophistication of cinema surround sound, and the requirements of home audio equipment - particularly loudspeaker placement/directivity/bass management and room treatment required to emulate that experience in the much smaller venue of a average domestic venue. Now, if your name is Mike Malinoswki then such practicalities might not be of such concern 😛
6moons audio reviews: The Room
The mind boggles at what Mike's "no limit" HT rig might entail.
Anyway, it's probably fair to say that there are many ways to skin a cat, and there would be re as many "solutions" to the OP's question as voices in the conversation.
Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms: Amazon.ca: Floyd Toole: Books
He spends much time outlining the evolution of of multi-channel sound reproduction, including ever increasing sophistication of cinema surround sound, and the requirements of home audio equipment - particularly loudspeaker placement/directivity/bass management and room treatment required to emulate that experience in the much smaller venue of a average domestic venue. Now, if your name is Mike Malinoswki then such practicalities might not be of such concern 😛
6moons audio reviews: The Room
The mind boggles at what Mike's "no limit" HT rig might entail.
Anyway, it's probably fair to say that there are many ways to skin a cat, and there would be re as many "solutions" to the OP's question as voices in the conversation.
I have been seriously considering building a 5.1 system based on the CHR-70 for my TV room which is rather small ( perhaps 15'x20'). My receiver is a Panasonic SA-XR55S.
I recently completed a tapped horn subwoofer based on the TangBand W6-1139. It should be good up to 80Hz and perhaps 100Hz.
My original plan was to go with the half-tower design all round (floor standing in front, wall mount in back) on the theory that more bandwidth is better, and I have the space for it. With a ported design I could use the lower crossover point on the receiver.
But the suggestions on this thread seem to be leaning toward a sealed box for the CHR-70. Any thoughts?
I recently completed a tapped horn subwoofer based on the TangBand W6-1139. It should be good up to 80Hz and perhaps 100Hz.
My original plan was to go with the half-tower design all round (floor standing in front, wall mount in back) on the theory that more bandwidth is better, and I have the space for it. With a ported design I could use the lower crossover point on the receiver.
But the suggestions on this thread seem to be leaning toward a sealed box for the CHR-70. Any thoughts?
If you want small boxes then sealed... if you can go larger then vented is fine, i just don't like to see these in too small a ported box -- by itself causing a bump at the bottom, which is then exaggerated if wall mounted.
dave
dave
You probably already knew this, but some interesting ideas for "half tower" would be either something like the Pensil R70 (page 8):
http://homepage.mac.com/tlinespeakers/FAL/downloads/Pensil-Series-maps-180710.pdf
or half micro tower (page 6):
http://homepage.mac.com/tlinespeakers/FAL/downloads/microTower-maps-150909.pdf
and for surrounds:
http://homepage.mac.com/tlinespeakers/FAL/downloads/MT-HT-Appendix-191209.pdf
I've heard both the CHR / EL70 sound fine in mid sized vented boxes as per the first two above; but for small enclosures, sealed or highly resistive venting seems to give the most natural low end roll off
The half micro tower is the one I was considering, in both its floor-mount and wall mount forms.
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