Axiom Home Page Forums General Discussion Home Theater Lets plan a theater space

Looks great, the rack is beautiful great work.
We're all going to want your top notch work. Big difference from the starting photos.

Thanks!

I wish I had a little more garage time to get the diffusers done. Sounds like 15cm of blowing now overnight. Here, 15cm can be anything from a trace to a couple feet. Please not another winter like last year......

Hope you guys over there have a mild one this year.
Over here in van. it was actually 0 to-4 and dry for a few days,
now were back to the normal 10ish and rain rain rain.

I might have missed it somewhere, but have you noticed much improvement after adding the poly diffusers? I know that you added them on 08/30/2015 and there were other treatments, but I am not sure if there was ever a "yeah, I think that they were worth it" or not comment from you.

Whoa! The thread awakens. Thought my spring rear wall diffuser update would be it.

The sidewall polys were installed prior to the sidewall absorbers. The absorbers made a much more impactful benefit to listening. That said, I am happy I went with the polys for esthetic reasons. At the time it was hard for me to quantify with measurements or give a definitive subjective impression. The room was still pretty lively.

One thing the polys did do was take the ring out of that sidewall to sidewall area in the room when testing rt60 with balloon pops. It was impressive actually how much it improved flutter issues. Gone even before absorbers.

If I revisit these areas I will do a shallow QRD design for the sidewalls and wrap in AT fabric. People say QRD diffusers dont work in small rooms, or they arent beneficial compared to absorbtion. In my experience they are a great solution when trying to preserve room energy. They sure are a lot of work compared to polys though.

If you are thinking of an overhaul while shifting your sidewalls and mains around I would encourage any diffusion. A deep front wall QRD was an incredible improvement for my setup.

I'm not very good at concise answers.... If you are ever on the island you are welcome for a listen.

Not that you need a primer, Nick, but here is a good vid for those interested directly comparing and explaining different diffusers vs absorbers. Headphones work best when viewing the vid for comparison. Hope it's helpful.

https://m.youtube.com/watch?v=vb30CICG68c

I am planning an slight overhaul in my theater. Mainly to get my front main speakers a little bit wider (which means tearing down the false wall and moving it about a foot further into the room), and then the moving of my side surround a bit more forward, and the rear surrounds a bit wider too. At the same time I plan to map out a different wall panel layout. Something that is a bit more aesthetic as well as functional, and it will require me adding two more 2 foot x 4 foot panels that are 3.5" thick.

This is where I am toying with adding diffusion. 3.5" isn't very thick, and most QRD diffusers need at least 7-8" of depth, so those are out. I was thinking about a poly diffuser because I can work with the size to get a 30 degree arc and if sized right still have it fit in that 3.5" space. I just don't know how much it will help. Not saying that diffusion doesn't help, but that due to the restriction in depth, it could be a waste.

Of course, I could make the 2 additional panels absorption like the others, but I am really getting close to that 20% max absorption number so I thought that I would look back into diffusion.

I just watched Ethan's video over my lunch break just today, but have a bit of planning to figure out. He says that 3" is the minimum depth, but also that they should be further away from the MLP than what might work for me, so we'll see. As he mentions, absorption can solve all acoustical problems, but also make the room seem smaller.

The new panels will be the last thing that I do, so I am in no rush, but I will be looking to tackle everything else in about 10 days when I have a 3 day weekend.

The rear wall beckons... "Finish me....." Then a ring wraith shreek. Planning begins.

Back for an update. How are y'all? Missed yous guys.

Here is how the back wall shaped up.





In the end I went ahead with a modified fractal design from Arqen (A1-LF). I used foamular EPS insulation from home depot and made a hot wire foam cutter to dice it up. This made the project affordable and not weigh a ton. The slices are glued together with 3M super 77 spray adhesive. Wow what a time saver. Had to wear gloves, specs and a mask though. Almost as intense as the spray foam day!



Mocked up before gluing on hot wire bench.



Spraying.


Pretty happy with the way it turned out. Building the hot wire foam cutter was fun too. Now to see how it all sounds....

Here's a shot to give an idea of the "texture" and depth of these things. They weigh a whopping 3 pounds each I'm guessing. Learned to cut the weight when building the other QRD.