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

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That is a much better idea! It's not as clean looking on the front but the trade off is well worth it. Besides, I'd probably mess up enough holes where I would need to do this in those holes anyway and then I'd have a pock marked baffle. :)

That is true but it is much easier and can provide a slightly industrial look.

Think I need additional washers on the nut side if I use silicone o rings to isolate the driver from the bolt? And do yo think counterbore is necesssary? An M3 button head socket is pretty small.

I would say don't bother with the counterbore grommets and socket heads on the front if it is too much hassle.

Instead use button head cap screws as they will be better from a diffraction point of view, use neoprene as a gasket between the driver and the baffle and on the back use a grommet or small square of neoprene between the driver and the nut. I would use a flat washer as it will spread the load better, M3 nuts have a pretty small surface area.

You can choose between black bolts or stainless depending on what you think looks best. I would probably avoid zinc plated as it doesn't blend as well with raw aluminium to me.
 
I've ordered some M3x16mm button heads and found some nylon nuts as well, both in black oxide. Also found some o-rings for between the nuts and the drivers and 3" o-rings that I think will work between the baffle and the drivers. It may not be so easy to keep them in position while tightening but we'll see. May need to put together a small assembly jig. I also got MLV and a dynamat type material to decouple the MVL from the baffle. Finally, I found some 1/2" wide, 1/4" thick neoprene to go between the baffle and the wall. There's a lot of accessorizing going on for this baffle!

Still need to buy the wool felt for both the inside and outside, grill cloth if I can't convince the wife otherwise, and the actual aluminum itself. Speaking of which, I'm considering going with an 8" wide baffle now to give a better chance of having enough enclosure volume to go close to flat to ~20-40Hz without having to cut into the walls. That's the compromise I've made in size to performance given all the other considerations. And I can still cut into the walls if I need to. As a test, I'm also considering the idea of just disconnecting perhaps the top 10 drivers or so to get volume per active driver around 2.0L to see how they test. Another option is to build in volume from the FRONT of the enclosure by leaving one of the driver holes open and connecting a box to get to 2.0L/driver. Again, just to test and see if more "heroic" adjustments should be taken.
 
I've ordered some M3x16mm button heads and found some nylon nuts as well, both in black oxide. Also found some o-rings for between the nuts and the drivers and 3" o-rings that I think will work between the baffle and the drivers. It may not be so easy to keep them in position while tightening but we'll see. May need to put together a small assembly jig. I also got MLV and a dynamat type material to decouple the MVL from the baffle. Finally, I found some 1/2" wide, 1/4" thick neoprene to go between the baffle and the wall. There's a lot of accessorizing going on for this baffle!

You are well on your way, good to see some decisions being made.
I would put a little bit of clear silicone sealer/glue on the baffle to hold the o ring in place and then let it dry, use a small disposable syringe with a small opening and that will help to not get it everywhere.

Speaking of which, I'm considering going with an 8" wide baffle now to give a better chance of having enough enclosure volume to go close to flat to ~20-40Hz without having to cut into the walls. That's the compromise I've made in size to performance given all the other considerations. And I can still cut into the walls if I need to.

That dimension with a 1/4" baffle will give you this.

Screen Shot 2017-02-14 at 12.19.58 pm.png

I think that is enough to allow you to get down to between 20 to 40Hz with EQ but you lose a bit of output volume potential. You have a couple of pretty big subs so you should be able to get that back by relaxing the eq when the subs are on. I'll run a sim in Jeff bagby's woofer designer as that has a linkwitz transform simulator. Room gain and corner loading won't be included though so it isn't a complete picture.

As a test, I'm also considering the idea of just disconnecting perhaps the top 10 drivers or so to get volume per active driver around 2.0L to see how they test. Another option is to build in volume from the FRONT of the enclosure by leaving one of the driver holes open and connecting a box to get to 2.0L/driver. Again, just to test and see if more "heroic" adjustments should be taken.

Remember to short the drivers and not just disconnect them.
You will need to have some way to hold the damping material in place as over time it will compress from the weight of itself if it is not braced. A Few triangular shelves will help to hold it in place and stop the material on the top from compressing that at the bottom.
 
Thanks for the ideas and the bassboxx model. I feel like things are coming together nicely so thanks for all the input and feedback. House probably won't be ready for making aluminum chips until April so still have some time to plan though. The beauty of this build is that almost all of the physical work is in the baffle itself. If only I had a little CNC at home. I suppose I could look into farming it out. I have a feeling it would be above my price point. And it's not really as much diy as I like anyway. Maybe worth pricing out just for kicks. Anyone have an online tool that can rough estimate quickly?
 
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You will need to have some way to hold the damping material in place as over time it will compress from the weight of itself if it is not braced. A Few triangular shelves will help to hold it in place and stop the material on the top from compressing that at the bottom.

I was thinking about trying to do this in a way that doesn't take much volume away from the enclosure. One idea is to use some old wool sweaters cut into triangles that would be a "shelf" by just stapling to the walls. Another idea is to have a lattice of fishing line suspended from the ceiling to form a web of support. Open to other brainstorms, wacky or not!
 
For the felt on the inside of the enclosure, I'm considering something like this 1/4"x12" F13 pressed wool sheet. It would go top to bottom and I'm thinking I would stuff fiberglass both behind and in front of it. Or maybe just behind in the center but both in front and behind it at the left and right corners to keep the fiberglass neatly tucked away from the drivers. It could be stuffed densely enough so that when I placed the baffle and drivers against it, the drivers would slightly press against the felt so a small pocket was formed around the magnet. I can test a couple iterations of this when the time comes. But this seems like a reasonable approach given wesayso's experience.
 
If it were up to me, as you haven't ordered any alu slab yet, I'd go with a slightly thicker baffle. No, scap that, in fact I'd go with a double baffle like I did :D. To make use of it acting as a CLD assembly. I do think your current choice is on the thin side. I've held both in my hands, a 10 mm baffle and a 6 mm one, both with almost equal size holes.
If the aluminium were part of a profile with bends it would be different. You decide, I just feel obligated to warn you. Do what you want with it.
 
Thanks wesayso. I considered it. And decided to go my route knowing that I can always add a layer after the fact. Also, I kind of want to see the result anyway. Call it morbid curiosity. For the other constraining layer, does CLD theory say it should be the same material? Or can it be something different? Like perhaps 1/4" MDF?
 
Ive seen dissimilar materials being used. I decided to use the same materials. The shear layer deserves serious consideration too. I'm quite happy with the butyl. There's a lot of theory available should you decide to go that route. Personally I wouldn't opt for MDF. I'd go with a stiffer material to match the aluminium.

Advantage of the double baffle is no tiny bolts have to be visible on the outside baffle. The way member koldby did his no visible bolts were used at all. I didn't mind a slightly industrial look. It was the easiest way to cover all my important considerations, the CLD baffle, the wave guide but also mounting drivers and baffle (somewhat) isolated from the enclosure. Even coupling the drivers to the back baffle was a deliberate decision. I wanted some weight behind them, but keep the enclosure free from resonances. It seems to work out for me. But something simpler might have done it too. :)

I didn't skimp on hours or materials. Figuring every detail counts. I wanted to create something I could believe in. And I still do believe in it. I'd do it again, just like that. Even the stacking part, though next time I'd make sure to hack it up in pieces like I ended up doing anyway.
 
If only I had a little CNC at home. I suppose I could look into farming it out. I have a feeling it would be above my price point. And it's not really as much diy as I like anyway. Maybe worth pricing out just for kicks. Anyone have an online tool that can rough estimate quickly?

Now you have a 3D model you can create drawings from it. Include all the holes you want make and mark all the important dimensions. Most CNC operators will provide you a free quote if you send them a CAD drawing. Do one with and without the roundovers. Cutting straight holes is much easier and will take much less time on the machine, you can then satisfy your DIY fetish with making the roundovers.

Whilst it is less DIY, the end result will be better and a lot less work as long as you are willing to pay the cost. I tend to think of just how much of my time it would take and decide if my time is worth more to me than the cost.

When I checked my CNC panels I realised just how long it would have taken me to make them and that I would not have been able to get everything as accurate no matter how much I tried. To me it was money well spent.

Do not underestimate how much effort it is to mark and drill 100 small holes besides the main cutouts and just how difficult it is to get them exactly in the right position. That is not even taking into consideration the roundovers and any chamfering on the rear.

Even with the greatest care, marking fluid, centre punches and a drill press I am sometimes disappointed with the accuracy of my drilling. It is only off by a fraction of a mm but when there are enough holes in a line it is surprising how easy it is to spot. Well for someone who is a bit OCD about these things like I am ;) I am always very happy when I have something machined to my drawings as it is perfect, unless I drew it wrong!
 
I was thinking about trying to do this in a way that doesn't take much volume away from the enclosure. One idea is to use some old wool sweaters cut into triangles that would be a "shelf" by just stapling to the walls. Another idea is to have a lattice of fishing line suspended from the ceiling to form a web of support. Open to other brainstorms, wacky or not!

All reasonable ideas, something like fly screen mesh stretched would work, staple it to some thin ply strips and screw that to the walls or you could cut the damping the whole length of the cabinet and fix it at the top, over time it might still migrate to the bottom though so thin shelves of some kind seems the better plan.
 
Well, as with every repeat job: use templates. Hardly anyone who sees my baffles believe I made them with hand tools. Templates were my ticket. The one that's out of view is as nice as the other with its custom roundovers etc.

Can't say it was a sane thing to do or easy for that matter. If I would have had the money, the CNC or waterjet firm would have gotten the biggest part of the job (cutting and drilling).

I'm still proud of how they turned out though. Nobody can take that away from me. ;)
 
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Well, as with every repeat job: use templates. Hardly anyone who sees my baffles believe I made them with hand tools. Templates were my ticket.

A very good point, as it is easier to make a few holes in a template more accurately, still surprising how things can creep though.

You did have a couple of templates cut by machine to a CAD drawing though for other uses :D

Also the distance you would view the completed arrays from will make it harder to pick up on any slight inaccuracies, my experience was more related to equipment enclosures and connector holes. If you look from far away you can't see it but right up close you can.

I do have an issue with perfectionism though.....

None of that is to take anything away from your build, truly awesome and shows just what can be achieved by hand given enough time and effort to get it right. An inspiration to line array builders everywhere :worship::worship:

Who knows maybe one day I will get to see it with my own eyes (and ears) :)
 
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All very good thoughts. I'll have to mull this over a bit. If I was back to drilling and tapping the holes, I think the CNC route might have been a must. With clearance holes, the precision isn't as critical. But over 28 drivers, the sequence of events as well as the precision will be important to make sure errors don't multiply. A drilling template for the mounting holes would be a good idea. Perhaps also including the pilot hole for the hole saw would work well too. And I could use a solid rod instead of a drill bit when using the hole saw for better locating precision. Designing such a template with some drilling bushings would be easy enough. I can even machine it myself given I have a small mini mill. Not practical for the whole baffle, but doable for a template. I could also design it to locate from the holes previously drilled. With how many people use these drivers, we should have a community one made that is just shipped around the world! :D

In other news, I bought JRiver today and installed Wine and DRC Designer on my old MacBook pro. So reading up on how that all should work together. I also bought a DisplayPort --> HDMI dongle. A few questions... sorry if this is basic.

1. Do you use REW to generate Parametric EQ filters first. And then use DRC Designer to generate convolution filters? Or does the convolution take care of everything all at once?
2. I noticed there are two banks for Parametric EQ... why is that? I assume the first bank can only take so many filters and so you can add via the second bank?
3. I tried to use Netflix but got some errors. I think I read that JRiver doesn't work with Netflix any more but I found it weird that the option was still even available.
 
YouTube seems to work as does Google video (on my old MacBook Pro).

A few more questions...
1. Do you just use 96000 Hz as the sample rate and let JRiver automatically adjust with that one file?
2. Are there "preferred" filter types do you use or is it personal preference?
3. Same for the load target... is the preferred tilt personal preference as well?
 
1. Do you use REW to generate Parametric EQ filters first. And then use DRC Designer to generate convolution filters? Or does the convolution take care of everything all at once?
2. I noticed there are two banks for Parametric EQ... why is that? I assume the first bank can only take so many filters and so you can add via the second bank?
3. I tried to use Netflix but got some errors. I think I read that JRiver doesn't work with Netflix any more but I found it weird that the option was still even available.

1) I do use pré EQ, and no problem to do it in REW first to get a starting point. I do advise to remove any high Q correction REW might suggest. Using global EQ to get the FR results within the correction frame of DRC would be enough.

2) I never bumped into any limit of usable PEQ slots. I used to use the first bank to do Pré EQ, have convolution setup between the two banks and used the second bank to do my edits after the convolution. (lowering energy at a dip on the low left frequencies and adding to the right to compensate. Some tonal balance tweaks etc.)
I have since moved the pré EQ to a separate plugin. I'm now using the first bank to separate my stereo signal to multiple channels for ambient and anti cross talk stuff. Keeps it organised.

3) I can run Netflix with the WMD driver in Windows. But I have to manually add video delay each time I want to play a movie like that.

YouTube seems to work as does Google video (on my old MacBook Pro).

A few more questions...
1. Do you just use 96000 Hz as the sample rate and let JRiver automatically adjust with that one file?
2. Are there "preferred" filter types do you use or is it personal preference?
3. Same for the load target... is the preferred tilt personal preference as well?

1. I use the native sample rate for each file I play up to 96000. Above that I run into my limit of the SP/dif and have to adjust. I let JRiver adjust automatically. I did check my chain with a loop back to make sure 44100 was showing a clean pulse. Lots of sound cards do 48000 way better as it was meant to play at that rate. My Asus is an exception.

2. No idea what you're getting at.

3. I grew into a room target over time. Though I do have mid/side EQ making it harder to state what I have. The mid (or phantom centre) signal follows a normal target. The side signal is adjusted. It's complicated to explain (lol). The room target I ended up with pretty much matched preferred targets in literature.

This story by Mitch might help: http://www.computeraudiophile.com/content/744-dynaudio-focus-600-xd-loudspeaker-review/
 
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