Topic: Interest in Acoustic Treatment?

[scervin]

Hey there,
     
        As I'm nearly complete with my new room and have made a few wall panels, I was wondering if there is any interest in these?  I checked the Realtraps page and they charge around $170 for a 2'x4' panel.  I figure I canmake them for around $100 or so. This could be less if you didn't want the premium fabric.  If there ia interest let me know.  When I am complete with mine I will take pictures to show the finished product.  Can make in custom sizes and thickness.

SC

[Lil Kim Jong-Il]

are you using the Owens Corning sheets?

I got a table saw this weekend, so I'm starting my panel project next weekend.

[scervin]

I'm using Knauf Duct liner 1".  I got a 100' roll of the stuff.  Where did you find the OC 703 or 705 panels??

[Lil Kim Jong-Il]

Local builders supply.  They have 2x4 sheets of the 703, so I'm making two panels for the first reflection points behind the speakers as a first attempt. 

pine frame, 703, polyester batting, fabric cover, removable pine footer incase I decide to hang them.

thanks for getting me fired up.

[jpschust]

ive been working on what i think are some new designs for those who live in apartments, want their apartments to look classy, but cant drill into their walls for placement.  im hoping to scan some plans this weekend, but for now they have been just brief doodles while i have a down minute or two at work

[Lil Kim Jong-Il]

I just got back from the builder supply.  The OC703 was at another yard, so they made me a good price on some Knauf 6lb 2x4 sheets that were left over from a project.  These things are sweet.  They are very dense and light.  Covered with batting and fabric, it will be no problem suspending these on the wall or from the cieling using regular picture hooks.  They are rigid enough that you don't need a frame.  If you are in the DC area, I got them from Capitol Building Supply.  I got the last box of over stock but the regular price is $1.00/sqft for 6lb and $0.75/sqft for the 3lb sheets.  Thats not bad.  I'm thinking less $25 per panel when it's all done with nice fabric.  :-)

[scervin]

Are these going to be corner bass traps? 

[Lil Kim Jong-Il]

These are for the upper band absorption panels to kill the echo.  Tube traps will come later. 

This weekend I'm just building two free standing upright panels and then some panels to hang on the walls.

These sheets would be perfect for built-in corner traps.  But doing that or hanging diffuser panels is out of the question in my current living arrangement.

[jpschust]

scott, im really focusing on corner traps since thats where apartments really have their worst problems.  bass traps can be next. 

[scervin]

Bass traps are more or less corner traps.  There are room mode calculators to determine what modes and where they fall are most likely in a specified room size.  I'll try and pull it up and post it.   Please let me know how these work for echo and the upper band.  I found those panels worked much beter for bass due to the density.  I've had better luck with the blanket type for echo as there is not a reflective face.  Did the Knauf come with one side faced and the other not? 

[Lil Kim Jong-Il]

I got the deal on the panels with no facing.  But this morning I found out they loaded the wrong box.  I have 3# FSK faced panels.  I'm going to have to wait until next week now.  The 6lb has much better absorption across the range where I want the effect.  The plain sheets at 6# 2" have a 1.0 absorbtion coefficient.  What they gave me is only .75.  So I have to take this back to get the panels I want.  I guess I'll just build the frames this weekend.

this is what I'm using:

http://www.knaufusa.com/index.cfm?fuseaction=prd.dspProdDetail&ID=12

[Lil Kim Jong-Il]

This isn't the completed product, because I still need to construct the stands and install the wooden facades to cover the fabric joint along the vertical sides.  Also my previous cost estimation was a little off.  All done, they will be about $85 in parts to complete since I'm going with furniture grade hardwood for the trim and stand.  I ended up using the knauf they sold me because they did not have the 6# unfaced.  The 3# FSK is about 65% of the performance, but if you remove the facing the numbers go up quite a bit.  Since I uphostered the panels on all faces, I didn't care about removing the insulation facing.  I still have four panels so the next project is to build lightweight panels with white burlap for ceiling suspended panels (we have a high ceiling).  Then the bass traps. 

The room is pretty bad.  Lots of echo and no symetry.  So even though the image spreads about 2ft wide of the speakers, it's a little bit muddled.  My first impression is that with the panels in place as shown, the image is a little cleaner.  I think that I have to go a lot further to get what I'm after, but this first little experiment seems to have been worth the effort.  If anyone has any interest in doing this, I documented the assembly.  It's not difficult but if you can get someone to build them for you for $100, do it!



 

[scervin]

Looking good!  The other night I dove into room response.  Overall, I'm really happy with what I have to start with.  My brother and I had his laptop and using trueRTA we got the response.  The crappy mic he has gave us problems from around 60Hz and below, but from 200Hz to 6800Hz I was nearly perfectly flat!!  Had a couple points that were a dB or 2 down, but I'm happy.  Using the Rat Shack SPL meter and test tones from 20Hz-120Hz stepping every 5Hz my rom has a pretty bad null around 30-35Hz, mostly flat from 40-75 ad another nul at 80Hz.  I'm going to make some cylinder bass traps as the wife said no to anything hanging on the wall.  BTW, play with sub placement because I have played with 5 locations and have had different curves each time.  I've now found one that will work best for my situation and hoping the parametric EQ will help smoth out the rest.
SC