HT Project: New in-walls + surrounds

[cjd]

edit: I've updated the thread title today as I've now ordered parts and will track this project here. WMTW mains (in-wall) and TM surrounds (in-wall or partially in-wall, not fully fleshed out in my mind yet but I've some ideas). I'm using an acoustically transparent screen, but will probably do a brief measurement test with a horizontally set up WTMW (TM vertically aligned) to put out a crossover for that option as well.

Original first-post below:

My HT room is a little odd in shape and limits me a little when it comes to speakers. I'm in the final planning stages for updating the speakers all around, but am stuck on a design limitation.

I only have room between the screen and the wall to fit a 5 inch wide baffle. I could easily fit the 3" Aura or that nice black 3" Hi-Vi driver PE has on buyout right now in an MTM, but that makes it slightly tricky for a center as I'd really want to keep 2 mids for sensitivity reasons. Still, easily crossed below the point where center spacing and off-axis response problems are really a problem so one possibility.

I could also fit up to a 24" tall speaker under the screen, so I *could* place a small face tweeter snug up against the top of the baffle (or close). No matter what I do, the center will have to be snugged up under the screen like this.

The 3" driver option(s) are interesting in that I *think* I could get away with just a 2-way for surround duty (it'll be very nearfield and probably in-wall and I'll shortly be able to set crossover frequencies separate for surround and mains).

Anyone else have thoughts to help me figure out what direction to go here? How important is getting the mains a little closer to the center of the screen... vs the fun of a near-edge tweeter.

C

[Brian Bunge]

Chris,

How about a center using dual 3" mids side by side with the tweeter directly above them on center? Then add RS150's or 180's on either side of the 3's. The towers could be an issue unless you have a bottom cabinet with angled sides to allow the larger woofers to be mounted on the front.

Or maybe do something similar to those designs that Al Wooley did with the FR125 and the Extremis mounted on the side. You could use the RS125's and the Seas neo tweeter in an MTM configuration with some form of side-firing woofer. Maybe the RS180's or if they'll work well, use the TB 6.5" subwoofers from PE. The downside would be that you would have to have straight 90 degree edges on the front since the RS125's are something like a 4 11/16" diameter. And I'm not sure how nice those TB subs are. I've heard good things about them in car audio use, but don't know how they'd be as purely bass drivers in a 3-way tower.

I was actually thinking about using the TB subs to possibly act as a poor-man's version of the Extremis. I have no idea how they actually compare to the Extremis, but I'd think a pair of them wired in series might work well. I'd like to possibly build a very slim tower with big sound similar to those designs that the Extremis where in.

[cjd]

I've already been considering the MTM with the 3" drivers, probably would use either one of the cheap Dayton tweeters or the D26 with Zaph's mounting technique. If I put that in a separate box I can put it anywhere, including on mains. It probably wouldn't be wider than the width of a woofer cabinet horizontally. There's a lot of merit to this concept I think, though sensitivity would still be low. That would allow me more flexibility on woofer selection too. Maybe a single RS225S-4 per channel across the front.

For that matter, if I cross low enough I think I could put the mid/tweet MTM up on risers for the mains. Hmmm.

C

[Brian Bunge]

What do you mean by "up on risers"? Are you saying have the MTM's mounted up high, maybe with the tweeter centered on the centerline of the screen, and then have bass bins sitting on the floor below? That could be interesting. Others could also have the option of using the MTM's sitting on top of the bass bins, maybe.

[cjd]

What do you mean by "up on risers"? Are you saying have the MTM's mounted up high, maybe with the tweeter centered on the centerline of the screen, and then have bass bins sitting on the floor below? That could be interesting. Others could also have the option of using the MTM's sitting on top of the bass bins, maybe.

Yes. It would be difficult, perhaps, to cross that passively and have it work well consistently but... easy to experiment with. Would be pretty nifty if I can pull it off. And I like what it allows with respect to surround flexibility. My other thoughts were to go RS52 for mid on a narrow baffle, but that requires crossing to woofers at a higher frequency.

It starts to get to the point where I wonder if I'd be better off going with a MMTMM 2.5 way with the 4" Aurasound drivers were they available. When they were around, that was high on my list. The 4" Peerless is an option but would get spendy quite fast at $55 each. So not really an option. T-B has some potentials too but again, price goes up really fast for the better drivers in their collection.

C

[Dennis H]

I wonder if you could fit a Tang Band W4-1337SA on a 5" baffle with a bit of creative work on the inside of the cabinet to ease airflow? I think the frame is a hair under 5" with a 3.75" hole.

How are these going to fit around the screen exactly? Flush with the front of the screen's frame or will they stick out farther, leaving the possibility of a wider baffle with the back of the cabinet notched down to 5" to fit in the hole?

Is it a DIY screen that could be cut down a touch? I just hate to see you compromise on the sound with dinky speakers when a couple more inches could make all the difference.

[Brian Bunge]

The TB 4" drivers have the exact same frame size as the RS125's so either of those could be possibilities. While the 125's may not (or maybe they do?) have similar midrange capabilities as the 1337's, they would be a much lower cost option if you wanted to to save some bucks.

[---k---]

C,
I've been in your basement, and I'm not sure I can picture what you're doing. Are you talking about just the center or the mains also? It sounds like your new anamorphic screen is bigger than your old one, and you want to squeeze the speakers into the small space between the edge of the wall and the screen. - No acoustically transparent screen, huh?

I know your room is very (very) small and doesn't require much. But man, I would hate to see you compromise with little 3" drivers or such.

Like we tell everyone else, how about some pictures or a sketch.

[cjd]

If I'm spending $50 per mid, the Peerless are a better option for the box limitations.

The room is oddly shaped. There's a soffit above the screen and a 5' high "shelf" on the back behind the couch. Layout attached. Behind the screen wall is about 24" to the actual basement wall, with the main water shutoff in the "bump" to the far right of the room (facing the screen) and the house sump back there as well. The IB is manifold mounted into this space roughly centered with the screen.

I have a curved 2.35:1 screen, 96.5"x41" + 3.5 on each side for the border. Speakers would have to sit in front of the screen. There is a little room between the screen and the wall, but I can't really move the screen much. Acoustically transparent is an option but I can't find a source on material any more. The one guy that used to ship to the DIY community has gone commercial. But, maybe I should look again - that *would* be the way to go in my room, really.

If I move the screen over much more I have to worry about the projection angle no longer reaching the left side of the screen due to the stair wall, not to mention the left side of the couch (which also becomes the "good seat" being visually removed (and audibly!) from the left of the screen.

Watching the 2nd Matrix the other night, there were moments I swear the cement floor was rattling, and my MTM's (currently placed horizontally below the screen) are doing fine with -28 on the H/K AVR-35 (ancient tech, I know! ) So filling the room adequately is nowhere near a problem IMHO.

But, you perhaps see my quandary.

I'll see if I can find a source on JUST screen material that's acoustically transparent.

C

[cjd]

Hmm. Seymore AV sells what looks like a good material for an AT screen - would run about $200 if I do a 12 degree angle (anti-moire) on the 63" (need 9 linear feet of that). Or about $300 if I do the 98" (10 feet) to have a little more flexibility on that angle.

[JonW]

Chris,

If you’re looking for “acoustically transparent” cloth, my screen is made from “coated celtic cloth” I bought from Dazian. Available pretty wide. I think it was something like $50 shipped for mine. It works fine. There were various posts about it over on avsforum. There are better AT options out there, for more cash. But I’m less critical about sound when watching movies versus just listening to music. It lets a little light through which is bad for the video but good for the audio. You’re welcome to stop by and see for yourself if you’re ever down here. I’m using a Modula MT for a center speaker. Again, it works fine, but there is probably better sound out there. My screen is a temporary situation. If I ever get my next speaker project done, I’ll make a dedicated separate movie room and get a fancy reflecting screen and maybe a different center speaker. For now though, I'm more into trying to build some excellent speakers for music.

-Jon

[joecarrow]

I have to say, I just saw Beowulf on IMAX last night, and now I'm completely re-sold on the benefits of excess in cinema. Don't sell yourself short on max SPL, even if you think you don't need it. A 2.5 way might be the best way to get enough volume. Sorry I can't search more right now, but I kind of got interrupted by housework & etc.

[augerpro]

Chris with a room that size maybe you should get put two little speaker on the left and right side of the couch like a drive-in movie :B

[---k---]

Just saw Beowulf today. First time in a theater in a long time, but figured I would see what the 3D was all about. Pretty cool. And yeah, I was impressed with the sound. Rivaled my home setup.

[---k---]

C,

Are you sure that screen isn't too big for your room.

I don't think I'm smart enough to come up with anything you haven't thoguht of already. Man, that room is tough.

[cjd]

Screen is perfect. It's constant height, so narrower for 16:9

I'm still pondering.

C

[dlneubec]

C

I picked up some of those Hi Vi 3" buyouts. The measure up pretty nicely. I think they are the RS90 we heard about a year or so ago.

Here's a different idea. Use them or another 3"-4" driver in a sealed MTM or MMTMM, 5" wide on each side of the screen with one of the neo tweets. Include a high pass in your crossover for the 3"ers so they don't have to do any work below maybe 180-220hz or so. They would probably work for surrounds as well. Since you have room under your sceen, you could design a center channel/sub that uses two 3" drivers in the same vertical MTM arrangement flanked on each side by RSS265HF's or RSS210HF's in a passive design, run it full range (large), but also set your reciever to send all your LFE to the center channel.

[cjd]

Interesting thought. Definitely would not work with my current receiver, but the one I'm eyeing could manage that. LFE to the CC is a no go but I think just setting the CC to "large" and the rest to "small" would work, with LFE going to the real sub (there's an IB on that front wall)

[---k---]

continuing on Dan's idea: There is a lot of low bass in the mains that I think you would miss with just having your IB connected to the LFE. I think you would want to mix in an active crossover somewhere. All the bass would then get sent to the center, where an active would split it between the RS265's and the IB. I guess if you did this, it wouldn't matter if your center or your mains was set to large.

However, in that small of a room and with room gain, I bet a pair of sealed RS265 would be more than adequate. (But who wants adequate???? )

Didn't you ponder this once upon a time?

[cjd]

The more I think about this, the more I like these 3" drivers even if I go in-wall and an AT screen... Especially if these are, in fact, what was at one time called the RS90. AT screen is even very very tempting since there's a source for just the material again. I just hate stretching the stuff! Maybe I should get a new stapler if I do that.

C

[cjd]

ahh crap. PE sold out of the 3" Hi-Vi's already!

[aduljr]

ahh crap. PE sold out of the 3" Hi-Vi's already!

madisound stalks them to.

http://www.madisound.com/catalog/product_info.php?manufacturers_id=136&products_id=1502&osCsid=1255fa005a522a3f51ce219ac31a4310

http://www.madisound.com/catalog/product_info.php?manufacturers_id=136&products_id=1503&osCsid=1255fa005a522a3f51ce219ac31a4310

slightly different

[Brian Bunge]

The buyout units from PE had a black aluminum cone. I assume that's the main reason Chris wanted to use them.

[cjd]

Aluminum cone, cast frame, black cone. If they're not behind the screen, I want black. This is helpful in a FP setup. But, I think at this point I will probably find myself with an AT screen and a new in-wall design. Maybe a simple TMW (or MTW), maybe a WMTMW.

TMW would possibly be the 4ohm RS drivers (150/225), WMTMW would possibly be the 8ohm but that leaves me with a tweeter quandary due to the sensitivity. Even the 4ohm drivers would probably take something like a BG Neo3 (non PDR) once we count the loss from the screen. And I think I'd have plenty of power handling in this system - the downside is an F3 of 60 vs 50Hz compared to the 8ohm versions... but higher sensitivity. I could go with RS52 as well, but that doesn't lend itself as well to a simplified version for surround duty - it does help the off-axis problems for surround if I go 3-way though, and RS180 could be swapped for RS225 in the back...

It's a mess.

C

[aduljr]

Aluminum cone, cast frame, black cone. If they're not behind the screen, I want black. This is helpful in a FP setup. But, I think at this point I will probably find myself with an AT screen and a new in-wall design. Maybe a simple TMW (or MTW), maybe a WMTMW.

TMW would possibly be the 4ohm RS drivers (150/225), WMTMW would possibly be the 8ohm but that leaves me with a tweeter quandary due to the sensitivity. Even the 4ohm drivers would probably take something like a BG Neo3 (non PDR) once we count the loss from the screen. And I think I'd have plenty of power handling in this system - the downside is an F3 of 60 vs 50Hz compared to the 8ohm versions... but higher sensitivity. I could go with RS52 as well, but that doesn't lend itself as well to a simplified version for surround duty - it does help the off-axis problems for surround if I go 3-way though, and RS180 could be swapped for RS225 in the back...

It's a mess.

C

But choices are great to have

[cjd]

Well... if I can find a tweeter (Seas 29TFF/W is a candidate as is the Neo3) that works with the required sensitivity I think I may be going in-wall WMTMW with RS225/RS150 4 ohm versions wired up in series. I'd like a little extra sensitivity available on the tweeter to counter the normal attenuation an acoustically transparent screen presents, and that's proving to be an interesting quandary.

C

[---k---]

Well... if I can find a tweeter (Seas 29TFF/W is a candidate as is the Neo3) that works with the required sensitivity I think I may be going in-wall WMTMW with RS225/RS150 4 ohm versions wired up in series. I'd like a little extra sensitivity available on the tweeter to counter the normal attenuation an acoustically transparent screen presents, and that's proving to be an interesting quandary.

C

??? Isn't a WMTMW with the RS225/RS150 what you just completed somewhere else? Why the change to the RS150 4ohm and tweeter?

[cjd]

I may just go TMW, but... sensitivity. it'd be 94dB with the 8ohm variants and that's not happenin in tweeter land. No baffle step, see...

C

[Brian Bunge]

??? Isn't a WMTMW with the RS225/RS150 what you just completed somewhere else? Why the change to the RS150 4ohm and tweeter?

I assume the added sensitivity and 8 ohm nominal impedance?

[cjd]

actually, it's *less* sensitivity I'm after. Don't care about impedance.

C

[---k---]

I may just go TMW, but... sensitivity. it'd be 94dB with the 8ohm variants and that's not happenin in tweeter land. No baffle step, see...

C

Holy cow my friend. A few months back you were posting about maybe doing a modular setup. Yesterday you say maybe a wmtmw. Today, you're all maybe a tmw.

Stop torturing yourself and just pick something! You know the other day, I took one of my extra scrap driver cutouts and put all the names of the place to eat around my office on it and put a spinner on it. Makes life much simpler at lunch time when a bunch of us are going out to eat. Maybe you should consider doing this for speaker designs.

If you don't stop, you're going to have my center channel done before you begin on your own. Just pick something!!!

[cjd]

oh, maybe i should go rs52 after all

C

[cjd]

oh, or maybe the Ti TB drivers...

[cjd]

Though the thought of a little more forgiving cone, say, paper or bamboo, has its merits in a system where I'm likely to really crank it up loud...

[Brian Bunge]

Oy Vey! You sound like me. I'm waffling back and forth between the RS52 and a pair of W4-1337's.

[---k---]

Though the thought of a little more forgiving cone, say, paper or bamboo, has its merits in a system where I'm likely to really crank it up loud...

Blasphemy!

You better watch it or you might get banned. The mods here are pretty strict.

[cjd]

Well, I think I've settled on a WTMW with a pair of 4ohm RS180's, single RS150, and Seas 27TDFC. Parts for 3 should run ~$700-ish and net me 90dB sensitivity and 4ohm nominal, with a slight rising response from 2k+ (simply by tweaking a single series resistor value this can be increased or decreased - probably will land between .5ohm and 1ohm. I should be able to cross to a sub between 60 and 70Hz (my IB is front-wall mounted). This is an in-wall concept and will be a go assuming I'm able to secure the acoustically transparent screen material.

C

[Hdale85]

Have you looked at SMX? Stuff is supposed to be very good.

[Brian Bunge]

Chris,

So no RS52 huh? Too efficient?

[Hdale85]

http://www.smxscreen.com/

Shoot them an email they used to sell material thats how they started out.

[cjd]

Eh. RS52 is still on the back-burner. Ill mess with it a little before I decide for sure, but this way I can do TM's for surround with exactly the same drivers and simply bump the crossover frequency to the sub a little higher. A little tweaking and I shaved a hundred bucks while improving integration at the same time. Crazy, i'n'nit?

SMX is what I had planned. Seymour AV reportedly sells the same stuff to DIYers still, but I have to remember to call them.

C

[---k---]

I need to dig into this more to understand what you're doing. I don't understand why you are telling me to order the RS180-8 and RS150-8 while you are ordering the -4 versions. Maybe you can repeat yourself real s_l_o_w_l_y for me.

Also, I put it in a PM before I saw this, why the SEAS over the RS28?

[jkrutke]

I picked up some of those Hi Vi 3" buyouts. The measure up pretty nicely. I think they are the RS90 we heard about a year or so ago.

If you post an impedance curve, we could probably see if they are in fact the RS90. The RS90 had almost no inductive impedance rise. Very low distortion too.

[Spanky Ham]

http://www.smxscreen.com/
Shoot them an email they used to sell material thats how they started out.

I think you can still buy the material from AVS. Rueben says he started out DIY, but quickly turned manufacturer. :roll: Seymour might be an acceptable substitution as I don't think you can get the Phifer cheaper in smaller sizes.

cjd,
When I get settled again, I will probably put three speakers under the screen. If I can go with the Neos, then I am not sure if I would align them vertically or horizontally. I am not a big fan of AT screens otherwise I would put speakers behind a screen. Plus, I really want to try out a large Torus screen.

[cjd]

My AT screen looks like it may show up today! Gotta order me some drivers.