# My DIY absorption panels



## kadijk

After a lot of reading and "listening" here on HTS and the GIK website, and a couple others including Rives Audio, I have begun the journey of room treatment. I understand that measurement and analysis is important to this process, and do intend to do that at some time in the future, however, for now, I am working on assumed generalizations and best practices observed in others experience. 

OC 703 seems impossible to acquire easily here in Canada, so Roxul RHT40 became the material to use...and that wasn't easy to get either. I decided on building first reflection panels to begin with, 3 for each side because my seating is around 14' back and the side wall is quite long. One concern is the reflection from a frame material like 1x4, and so my intent was to drill holes in the sides to allow for wave transmission. That plan only lasted for the prototype, because each piece after that first one decided to split and crack. I decided to compromise and allow some side reflection, to save the integrity of the panel structure. I also wanted to have a standoff gap, keeping the panels 2" away from the wall surface to allow for absorption from behind, basically doubling the effect(I believe that's the result in theory).

prototype frame with holes and rear standoffs attached








panel ready to upholster 








1st coat of spray paint on the standoff blocks








it was tougher than I thought to stretch the fabric evenly








2 panels ready to install








finished backside with single hook for hanging and bumpers on the standoffs








mirror placement measurement by yours truly








finished and looking good. I didn't want to see the standoffs, just a shadow or gap.Mission accomplished








All in all, an easy carpentry project, simple upholstery ( I bought black broadcloth-poly cotton), and some planning to allow for a single attachment point to the wall to minimize holes that might need to be repaired later. Now...on to corner bass trap panels


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## bpape

Looking good. My only suggestion would be to put some sort of pad on the rear of the standoff so you don't ever get any rattling of the 2 hard surfaces. Something as simple as little felt stick on pads used on the bottom of lamps, etc. would do the job.

Bryan


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## kadijk

Thanks Bryan. I was considering felt pads, but opted for what looks like a large version of a rubber cabinet door bumper. I was thinking that these would stop any lateral sliding or moving caused by vibration, because they are a little stickier on the wall surface than felt. If they rattle, and they haven't yet, I will try the felt pads instead. So far so good.


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## robbo266317

They look good. Have you noticed any improvement in the sound?


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## kadijk

Absolutely. Sound is vastly improved. I can't wait until I have the gear to actually test with REW. The front soundstage is really defined now, dialogue is clearer, movement from right to left and vice versa is very good, and everything is more detailed. I can also "hear" my surrounds now, where before they were lost in all the sound. Knowing what I know now, if I couldn't make panels, I would buy them. The change is incredible.


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## bpape

If what you have is working for the pads, don't fix what's not broken :dumbcrazy:

You're hearing what good reflection control can do. Wait til you really tweak it with some targeted bass control. Dialog will get even better. Bottom end will tighten up and become more extended. Lots of other things.

Bryan


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## Big Dave

Hello Kadijk, fellow Albertan! They look great, as does your room. You said you can now hear your surrounds? I run two sets of bipoles as surrounds and I thought the whole idea was "not" to hear, or should I say be able to pinpoint their location. Are you going to add panels directly behind the mains as well? I am just about to treat my room as you have. I figured I would do the bass treatment to try and smooth out the humps first before I go ahead and get a BFD Parametric Equalizer.


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## kadijk

Hey Dave! Welcome to HTS. I am planning on panels behind the front mains, they just won't have the standoff gap and I'll make them 4" thick( that's the plan anyways). As far as the surrounds go...by "hear" I mean I'm now getting that surround feeling. Call it "detailed immersive" where before it was more like sound applesauce. Thanks for looking and the comments, by the way.


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## Prof.

Kadijk,

Nice job on the panels..:T Any reason for not putting in bass traps?


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## kadijk

Thanks Prof. Bass trap panels are in the works, for the rear corners. I have the materials, and the design...just need some time. I'll post the construction as a continuation of this thread.


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## vann_d

Hey those look really nice! I'm in the process of making some of my own (using 2-in Ultra Touch) . What type of fabric did you choose? I've tried regular cotton and a burlap. Not sure which I like better and still looking for options.


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## kadijk

I went to the fabric store asking for black "muslin". The sales lady looked surprised, told me they don't have black muslin, and it would be quite expensive. She said how about black broadcloth, and that's what I got...$3.99/ meter 60" wide...and I used 1.5 meters per panel. It's poly-cotton, won't shrink, and isn't too stretchy, and is thin enough for sound transmission.


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## vann_d

Hey thanks! I tried the broadcloth. It is much nicer to work with in terms of stretching than regular cotton fabric or the burlap. Finished product generally looks better. The fabric weave is much tighter, however, than either of the two afore mentioned and does not pass the "breathe through" test as well. Makes me question the HF transparency somewhat. Hmm...


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## kadijk

Vann_d... I assumed that the broadcloth would pass the test and so didn't test it at the time. Today I did the test and it does pass. Breath can be felt by a hand, and a Kleenex will move if it's where a hand would be. So the stuff I bought is ok.


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