"Wall-integrated" corner loaded line array with Vifa TC9 drivers

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Lots of updates to share!

The house is coming along. Still a long way to go (~Jan completion), but it's coming along.

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Here's a simpler version of the line arrays built into the walls:
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Also, signal chain wise, I decided to go simple for now and then consider other options after evaluating the simple. So I got a factory renewed XMC-1 for processing duties. The turntable will feed into this through a PS audio phono preamp/ADC along with all the other various digital sources. This way, I'll be able to evaluate manual PEQ, Dirac, and also play with convolution through "pre-convolved" files to see what I might be missing.
 
Another shift in plan... The studs that I was hoping could move to accommodate my volume requirements actually can't move. Also, this is going to be a shear wall with plywood under the drywall. However, I still plan on putting the drivers as close to the corner as possible and building in the required volume IN the ceiling joists by having an opening at the top of the tower and sealing off the requisite space with an additional 2x10 plus some caulking. Still need to think through some of the details but I think the concept is sound at least. Probably won't get to actually building until the end of the year, but the house is on track.
 
There's a need for some space behind the drivers, a little breathing room, and also a great place to add stuffing and reduce the back wave.

Adding volume on top does not replace the volume needed behind the drivers.

Does it have to be 45 degrees corners? Couldn't you do 20 degrees and add a straight board to extend the volume?
 
It doesn't need to be 45 degrees. And actually, the original Murphy corner loaded array that originally inspired this is more like what you're suggesting. That's the fall back option, but I would like to keep the drivers as close to the corner as practical to maximize the corner loading effect, taking into account your comments around stuffing and breathing room. It might be more by feel than by science though unless there are guidelines around these design parameters that are out there that I haven't heard about yet.
 
Quick update:

The house is coming along. Solar panels are up. Rough electrical and plumbing are nearly done. (I have two separate circuits for power and signal... not that I really believe I'll be able to tell a difference.) The speaker wires and signal cables are being routed for a 7.2.4 Atmos setup although I don't have an Atmos receiver yet. That said I got a refurbished XMC-1 that I might upgrade at some point. Looking forward to getting the line arrays built probably sometime in February at this point.

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Lots of updates to share!

The house is coming along. Still a long way to go (~Jan completion), but it's coming along.

28549341722_94c969740a_z.jpg


Here's a simpler version of the line arrays built into the walls:
28550089642_bb83edf38e_z.jpg


Also, signal chain wise, I decided to go simple for now and then consider other options after evaluating the simple. So I got a factory renewed XMC-1 for processing duties. The turntable will feed into this through a PS audio phono preamp/ADC along with all the other various digital sources. This way, I'll be able to evaluate manual PEQ, Dirac, and also play with convolution through "pre-convolved" files to see what I might be missing.

What you need to do is have your engineer look at this picture before proceeding with your addition! That lower translam is no where near to code in supporting a three story structure as you've shown later in the thread! That's one hot mess dude!
 
What you need to do is have your engineer look at this picture before proceeding with your addition! That lower translam is no where near to code in supporting a three story structure as you've shown later in the thread! That's one hot mess dude!

There's a bunch of other support throughout. It's actually ridiculously over designed. You don't see the plethora of other translam as well as I Beam and hardy panels and shear walls and tie downs and foundation reinforcement etc.
 
The first floor is starting to come together with the drywall and hardwood. I might be able to get 28 of the TC9 in each array. If so, four groups of 7 for a 14 ohm nominal load seems reasonable. Any other ideas for something better? (I'm driving these with Ncore 400.)

There's a chance I may need to go to 27 drivers. And that makes for a more difficult decision (24 or 2.7 ohm.). The nCore are capable of driving a 2Ohm load without any problem but I might be in trouble if I need to change amps for some reason down the line.

The other option is to go to 25 drivers for a 5x5 for a 8 ohm load. But that would leave a few inch gap in the array on the top and bottom. Or I suppose I can space the drivers out a little bit to fill the gap.

What do you all think?
 
DO NOT space out the drivers. That will just make the combing worse.

Having a few inches gaps between the floor and the ceiling is fine. The line arrays need to fill 75% of the wall to get the floor and ceiling imaginary mirror images.

I'd go with 25 drivers and not worry about load.
 
I agree, just go with 25. Center the array on the wall to have equal drivers below your seated position and above for standing up. That would probably mean having about an equal distance above and below the array.
I don't reach my ceiling, nor my floor:
LineArray.jpg

Standing up I have 7 drivers above my ear level. Sitting down I have about 9. Still the sound is balanced between these positions. Avoid having sharp edges near the arrays.
 
Thinking about the cabinet design and will likely follow the shape of the Murphy corner arrays.

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The difference is that I am planning on just building them directly into the wall so I'm considering just using pocket holes/screws and mounting the "sides" directly to the sheet rock and plywood behind the sheet rock (these are all shear walls so there's no problem having something for the screws to grab onto.) I probably don't need to, but I'll probably caulk the corners and then use foam tape to seal the sides to the sheet rock.

Any thoughts?
 
The enclosure size would influence what you can get out of it, EQ the bottom end down to low frequencies or not... The (outside) enclosure (or baffle/wall) shape would determine sensitivity to diffraction/reflection... it's your choice ultimately.

I've said before: I'd opt for having no sharp corners, I'll add that I'd aim for at least 2 litre enclosure volume for each driver (to be able to boost the lows).

Treatment inside the enclosure would be a third factor of importance.
 
Yah, RA7 had said that he wanted to make his as much like a horn loaded driver as possible so he had just setup the one baffle. I had originally planned on hiding extra enclosure volume in the wall before it had to become a shear wall. So now I probably should be cutting into it although it probably wouldn't make that much of a difference.

I like the idea of horn loading and I also like the relatively easy of construction. Another thought is to have the baffle be concave instead of convex. In other words, instead of having the side pieces angle in towards the wall to create a 90 degree angle, they can angle away from the wall and perhaps meet the wall at a 20 degree angle or some such. That would create more volume and also create more of a horn design. I'll draw up a sketch that would meet the 2L+ volume spec.

Would the wave simulators be able to model this? Which ones would you recommend?
 
Hmm, hornresp is PC only unfortunately. I'm thinking other factors will be more important than anything the modeling might show anyway.

In any case, here's a rough mockup of what I was thinking.
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And now that I've sketched it out, I'm thinking keeping it simple like RA7 might be the better approach overall.
 
Yes, everything is important. But compromises must be made! ;)

I like the thinking on flexible wings. I was trying to get the drivers as close to the corner as possible while maintaining the appropriate volume. And this wouldn't be that hard to build actually since I have the luxury of screwing directly into the walls. But it just didn't seem all that different from the straight 45 degree baffle. I do like the look though. And the concept even if I may not be able to actually hear a difference. Plus, RA7 already did the 45 degree baffle thing so this would be unique at least.

What final volume did you design for and what was the rationale? I think I had calculated shooting for 2.5L per driver a while back based on the driver specs. Also, I had read someone had separated five drivers at a time in their own enclosure for some reason. It was something about making sure the drivers that were wired in series didn't share the same space as the others. I'm not sure why this would make a difference though. Minimizing the standing waves going up and down the column is the only thing I was thinking would be a design consideration. So I'm missing something.
 
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