ZAPH Audio ZA5.3 in wall theater build

Hi All -

This is a great forum. I have never built speakers before but I do everything DIY so I'm jumping in! I have a couple questions:

I'm building a theater/multi purpose room in my basement and after much research I have settled on an in-wall speaker set up for the L-C-R channels behind an acoustically transparent screen. Going in-wall with the speakers saved me some space and, had high WAF. I didnt think a regular in-wall speaker would sound good enough so I decided I would build enclosures and build them into the wall. I have stud walls up at this stage and no drywall yet so now was the time. I decided I would use the Zaph audio ZA5.3c MTM speakers oriented vertically for all 3 L-C-R channels but with the in-wall cross over in all of them. The center channel configuration of this seems best suited because its front ported while the standard L-R cabinets use rear ports. I built a .7 cubic ft(20L) enclosure that was thin enough to fit my wall. This is the volume John Krutke recommends for this speaker.
This is what my enclosures look like. The center part is where I will put the drivers after the drywall is up.




This is my theater wall with the opening made for the center channel


This is all 3 openings with the enclosures in their almost final position


Close up of the center channel enclosure


The drywall will lay over the whole enclosure and then I will roto-zip the opening. Question: How should I attach the enclosure to the wall/studs? Should I try and isolate it from the studs with some insulation or, should I screw and glue? I guess I dont know about vibration transfer to the wall itself and if thats a good or bad thing.

Hmm... I aligned the tweeter with the average ear height..., guess I cant do much about that now.

I was going to stuff the enclosure with insulation. Isnt this the same as lining with dampening material?

Whats a waveguide?

Tuxedocivic - I looked at your thread. Thats a real nice build! The wave guide is interesting. Unfortunately I am not as talented or creative as you and I dont know as much about freq response. So that is why my design is as close to what Zaph specifies as I can possibly get it. I assumed Zaph makes a good product and they make a crossover dedicated to in-wall speakers. And the kits from Madisound look like a pretty good value. I also found that I could adapt his enclosure to in-wall use and should end up with a no compromise in-wall setup: i.e the L-C-R channels are all set vertically and they are all the same speakers and in-wall cross overs. There has been several times where I have been glad that what I'm building is not going to be seen. Hopefully it will sound good. Thanks for the replies. I'll keep this thread updated as I go.

Update: Drywall is up and I'm working on finishing it. Here is a couple pics of the enclosure openings under drywall





Devon S: My internal dimensions are 17.5"W x 20.5"H x 3.5" Deep. This is maintaining as close to
the original volume of the ZA 5.3c in-wall as possible.
The guy I spoke with at madisound confirmed my choice of crossover: The L-R in-wall crossover
for the ZA5.3 (not the center channel crossover!) for all
three L-C-R speakers in the way I am going to mount them.

Hi Lowpoly - Yes I read the ZA5 info page. His detailed explanations and the good price is what made me decide to use them. Reference the port length; I know its going to be tight but if I get the parts and its too long for my enclosure I'll deal with it then. I figure there is more important design considerations to be made then modifying a big part of my plans around a plastic tube. If it fits great! If not, I'll cut it to the appropriate length and put a 45 on it. I actually considered this problem and mentioned it to Madisound and they suggested that solution like it was no big deal. Time will tell. Thanks for the advice.

DevonS - I used 3/4" particle board for the enclosures that are in the wall. For the baffle, I'll use some good plywood since they could be visible if the screen is not on the wall. Also, I made my box 3.5" deep on the inside so the outside depth is actually 5". The only reason I could do this is because my stud wall (standard 2x4's) sits away from my concrete basement wall about an inch and a half. In a standard 2x4 wall, this box depth would be too deep to mount flush.

I'm having second thoughts about the in-wall crossover. IIRC (I should go back and read the ZA5 page) the in wall x-over is for an infinite baffle. My box is essentially a sealed enclosure of the same internal volume as the standard ZA5. I dont see why I couldnt just use the normal x-over for the ZA5? It doesnt have any baffle step compensation which I dont need because the speakers are at the wall, and its designed for a .7cu/ft enclosure. I guess I'll have to call Madisound and talk it over.

I called Madisound today and talked with "Brian". I told him how I had built my enclosures: Basically they were in-wall enclosures of the same volume as the ZA5.3 speaker design; .70ft3. All three were going to be front ported like the ZA5.3c center channel design. I asked him which crossover to use since the in-wall crossover was for a large volume enclosure (a wall cavity) but the normal crossover was for the enclosure volume that I had built in my wall. He said to use the in-wall crossover because it does not have baffle step compensation! That was kinda my design goal when I started so I must have done something right.

So, to summarize for anyone attempting something similar; I have 3 Zaph audio ZA5.3 enclosures built vertically into my walls each with volume equal to the normal speaker cabinet. The front baffles will all be exactly like the center channel configuration. All three L-C-R speakers will be using the ZA5.3 in-wall crossovers and the baffles will be flush with the wall. The only thing I'm using from the center channel configuration is the baffle design because I need the front porting.

Hooked em up, installed and tested em last night! I'm very happy with them! Dont have time right now for a detailed description, gotta go to work but here are some photos:

Well so far they are working out better than I expected. Bass response is surprisingly good but still needs a subwoofer. The port is about 1" longer than optimum as it's less than a full diameter away from the back of the enclosure. But I think it will be fine since I don't intend on driving these to their limit. I wanted clear dialog for movies and good music performance and, above all matching vertical L-C-R speakers in a clean install. I used the in wall cross overs which I think are supposed to be for an infinite baffle I.e. a wall cavity but I installed them in sealed, matched enclosures. Whether the x-over was used with an IB or ported enclosure it's main advantage is no baffle step compensation. On Madisound's website, there are 2 different port flares associated with these speakers. The one I got was shorter than I planned on but actually worked out better with my shallow enclosure because it was shorter. Madisound was very helpful and I want to thank them for putting up with my frequent panicked phone calls. These were the first speakers I ever built and I wonder if I could have screwed up to the point that I wouldn't have been happy or, if it's just easy to achieve good results with a little research and planning? Don't know. I'll use them for a while, build a subwoofer fine tune my setup and just be happy with it.