In-wall version of Delta Max

Discussion in 'DIY Speakers and Subwoofers' started by tuxedocivic, Dec 12, 2012.

  1. NOTE: This is a variation of the Delta Max. I am not using the same cross over.

    I built an AT screen so wanted to take advantage of it.

    Cut a hole in the wall. No going back.

    I stuffed the space with insulation, even more than shown. The wall is 6" deep including the drywall. The Delta10a has about 1.5" of clearange, which is just enough imo because it has a pole vent. The SEOS12 and DNA-350 just fit. This would NOT work on a 4" wall. That's what I thought I had and was considering 6" woofer ideas until I did some investigating and realized it was 6".

    Built a baffle out of scrap MDF. Who cares what it looks like, cause it won't be seen.

    Here it is. L and R to come.

    Because I designed the delta max already, I was already a step ahead. Finding a cross over that works did not take me long. I've now listened to a 950hz cross over and a 1200hz cross over. Both are very very good and I'm very happy I'm building this as my permanent centre channel (well, permanent is a vague term, right :eek: ). The sound is excellent for both cross overs. I'll take measurements soon. It's going to be tough to properly measure in some ways, because I'm confined to indoors. But it'll also make nearfield measurements quite useful being that it's in-wall.

    Nice to look at my wall and all you see is a screen. Lurking behind only I know how much power there is.
  2. How did you internally brace the 'cab'?

  3. There isn't any bracing... yet. Other than being screwed down to the studs which is really quite rigid. There is a couple cross braces above and below across the studs. It's why there is a hole cutout above, so I could feed the wire past the braces. So there is the rear panel which is drywall, haha. And the baffle is unbraced. Sides, top, and bottom should be fine though.

    Once I've worked out the details of the cross over and satisfied myself with the design, I'll take it all out and I'll:

    1. Brace it and maybe even totally build a box into the wall. Or I might "rib" the baffle. Not sure yet.
    2. Seal it all around. Right now it's just MDF flush to the drywall. No seal. That seems to be ok right now, but not something I want to leave permanently.
    3. Paint everything black so any stray light passing through my screen is absorbed.

    Believe it or not, I hear "less box" like this than I did with my Delta Max test box. Which admittedly wasn't braced like a permanent build should be, but had a 1" baffle and the usual side to side bracing with a brace front to back between the woofer and waveguide. This inwall version is quite "silent". Maybe it's well damped, because it isn't well braced. Could also be I can't hear the rear panel of drywall, and the baffle is so large and screwed so well to the studs that it doesn't resonate. I don't know, but I was sort of expecting some audible problems. Actually I'd like to hear them so I can know how to go about making the permanent version.
  4. Very nice.
    You going to toe-in your L&R? ;D
  5. No.. he's going to toe-in the wall. :eek: :p
  6. Ha, ya, I don't think toe in will be happening. I've thought about how I could do it, but it's basically impossible. 8)
  7. Tux, you are amazing!!. Very cool.

    What screen are you using?
  8. DIY spandex. I'll be measuring with and without the screen.
  9. Here is an on axis FR spliced with a nearfield around 250hz. Reasonable to do this considering this is in -wall so no baffle step being washed away from that.


    Here is the difference from my screen.


    So the blue line is what I've been hearing. And it's very good. If there was no screen, I'd probably attenuate the tweeter a little, which there is an easy way to do that.

    Will post more details soon. This cross over is fairly simple/cheap :)
  10. nice one, Tux
  11. Cross over available via pm. Please provide an email address and donate $5 to DIYsoundGroup or a registered charity. Thanks.
  12. Excellent work Tux. Did you like doing an in-wall?

    I don't know if I missed it but how far is your screen from the baffles?

    I saw you mentioned it sounding less "boxy". I'm not sure the boxy sound is always due to the box per se. I've noticed it is more a product of baffle diffraction at lower midrange frequencies. By using a baffle wall you mitigate this issue. Others use very small baffles or open baffles to alter the "boxy" effect. Of course, this is tough to prove and is just my observation. I'm a huge fan of baffle walls when it is feasible.
  13. Coctostan, doing an in-wall was awesome. If I ever move I'm going to have to find a way to do it again. The advantages of the flush baffle are amazing. Really happy with the turn out.

    The screen is about an inch away from the drivers. I haven't tried to pull it away cause I can't really.

    You're probably right that the less "boxy" sound is because there's no diffraction. Either way, it worked and its great. One of those major improvement type things that don't happen very often.
  14. Tux, can you get a better shot directly in front of your inwall design? I'm trying to figure out how to implement this into a kit with the baffle.

    I'm thinking about a 1" thick baffle with some really big roundovers. Or maybe an actual subbaffle that fit's between the studs, with a cross brace between the waveguide and woofer, then attaching to the outer baffle.

    Also, how far out from the wall can we go without messing up the crossover?
  15. Like this?


    Not sure that helps.

    Ya, not sure how to implement this as a kit. Having a pre-cut baffle would help people. Something like this is tricky cause it's quite application dependent. It would work the way I've done it, or if someone made a false wall, or surrounds built into the wall, etc.

    I think you'd be safe at 1". Maybe even further. The further out the more diffraction is all. You could use this cross over in a box, except it would have diffraction and baffle step and wouldn't sound as good as a result.
  16. I want to hear more about this screen.....details/pics?

  17. It's just a DIY spandex. Smokarz has built one and done some testing as well. Pretty slick setup if I can brag. Just a screen on the wall. Wish I had IB subs and then my setup would take less space than a plasma tv.
  18. I think it could work for a lot of people because studs have pretty much been spaced out the same for 100 years. The issue about depth could be fixed with an extra baffle to build it out a little.

    I've seen those metal mesh type paintable grills and I bet I could get some custom made.
  19. Yes, 16" spacing since north america switched from log houses to wood framed :D

    The depth is pretty ok, which is why I stuck with the 10" woofer. I have clearance for the waveguide too. Only issue is if it's built into a box into the wall, then the CD may bump the back of the box. The woofer will still be mostly ok. I'd use 1/2" for the back panel.

    Something like this plate at the bottom of the wall might be handy for people to run wire down between the studs to this plate.
  20. Re: In-wall version of Delta Max (Fusion-10 Max)

    My boss would like to build these in his basement.
    The wall is an exterior one with 4" studs, so he's going to build out some framing of a spandex screen another 6" to get it in front of the speakers that stick out.

    I think he'll buy the front baffle, pay for the design and SEOS-12, and then buy the drivers crossover parts from Parts Express.

    Has anyone else built this yet?

    Where should the blocking be behind the wall, above and below the drivers, to set the "cabinet" volume?
  21. Re: In-Wall Surrounds

    What would be good suggestions for in-wall side- surrounds? He wants all the speakers hidden.
    The surround backs will be in-ceiling.

    Would there be a good version of one of the existing smaller designs like with the EOS-8, that with a few crossover tweaks would work in-wall?

    Or what would y'all use as an-wall surround if you absolutely had to?
    I was browsing Paradigm, Definitive Technology, Triad, Klipsch sites and AVS posts about such.
    I think we should keep the sensitivity in at least the 90s, so some of those were too low in the 80s.

    I think $400+ is too expensive per speaker for his application. That makes Triad tough. Klipsch has some models that don't have boxes. Are any of the commercial speakers (JBL, Tannoy, EV, etc.) anything you'd consider using with your SEOS speakers?
  22. Hey Eyleron,

    No one else has built these. I haven't even been asked for the xo. Surprising to me, I kind of thought in-wall speakers would be more popular. And there's been lots of interest in them. None the less, KyleLovesBass has heard it. He was impressed. He also heard my Jack of All Trades in wall. I haven't measured that or documented it yet. He wasn't to thrilled with those, but was looking for something very high end sounding. The Fusion Pure/Max is to big for his application though.

    Ok, anyways, installation would be somewhat user built. If your boss is crafty, it really shouldn't be hard to do. Just requires sawing into your drywall ! I kind of stood there stunned before doing it. I hate drywall work and didn't want to create more work than necessary. If it needs to stick out beyond the wall, it may be a good idea to make a 2" wide chamfer to transition from baffle to wall.

    This design will run your boss around the $230 mark. Don't worry about a design fee. I don't take fees. Just ask him to make a donation to a charity, or if he already does, as him to write a review you can post. Good or bad. Honestly, not to worried about this one. It really blows me away it's so good. And I gotta tell you, seeing nothing but a screen on the wall is very sleek. When people come over and we hang out in the basement, after about 10 minutes they'll point and say, "what's that". "Oh it's my TV"... Haha. Then I point out the "end tables" and say, those are my subs. They're pretty blown away how WAF it is.

    As for surrounds... I'll eventually document the in-wall version of Jack of all Trades. But it is a $95 speaker. If he wants something a little more diffused sounding and higher end, zaph has an in-wall. But again, that's only 86db. If you want in-wall and 90+db, it's gonna be tough to find. Hence why I thought this would be a pretty popular design. If he has anything specific in mind, let me know and I might be able to figure something out.
  23. Thanks! He's pretty excited.

    Since his wall is 4" deep, he was going to build out the entire wall another 3.5", but I suggested just building it out behind the planned screen, so it sounds like he'll do that to save construction time.

    Looking at your photos again, it appears the baffle needs to be much wider than Erich's kit baffle, to provide enough meat to brace against the drywall and studs to the side of the speaker.

    He sounds nervous being guinea piggish, but I told him I trusted your designs and ears since you've done so much!


    For the surrounds, when you say "higher-end" are you meaning the low end extends to 40hz and the treble to 25kHz?
    What do you think the sensitivity is of the Jack of All Trades In-Wall (JAT-IW)?
  24. I see what you mean building out the wall behind the screen. That would work good.

    The stock baffles could work if you boxed in the studs. That's actually what I did for my L&R. Just slide a piece of 2x4 in there and screw in to the inside of the studs. Do both sides and the cativy goes from 16" to 13". I believe the stock baffle is 14.5" so you'll have 3/4" of over hang. Not much, but workable.

    If he's nervous about being a first timer, he could at least pm kylelovesbass for a second opinion. Kyle came over a week ago to hear my L&R and he liked the center.

    As for surrounds, by high end I just mean better performance. They're called the Jack of All Trades for a reason. They do it all pretty good. But nothing outstanding. I could probably get them to yield a flatter response, but it would take to many parts. And the waveguide is very short, giving some advantages, but taking away from others. It's also got a lot of diffraction in the waveguide. Higher end would use the EOS8. But, no in-wall xo.

    It's about 91 or 92db/w/m and an easy load to drive.
  25. Hmm, apparently I misunderstood my boss on the phone last night. I thought he was talking about building out from the wall the entire dimensions of the 130" screen (a bump-out behind the screen). But in fact he was talking about just building out where the speakers were, such that they'd be sitting proud of the surrounding drywall by 3.5" with the screen placed just in front of them.
    Doesn't that make them semi-in-walls?

    What sort of diffraction effects would you expect with the 14" x 21" speaker baffle being in front of the surrounding wall by several inches? To make them be "flush-enough" acoustically, how big should the baffle be built out to? 3' x 2'? Or more?

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