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Discussion Starter #1
I recently bought dual PB12-NSDs. For the first hour or so I had them on carpet supported by wood structure (second floor of my home). It didn't take long to realize they were shaking the house way too much! Since then, I've had them on the packing carboard/foam that came with the box. It's actually working pretty well but obviously not attractive enough.


I was considering building my own isolation riser. I looked into some Owens Corning 703 (I was thinking 2 or 4 inches thick) and I was going to attach it to wood to make the riser. All things in, the cheapest I could do this for is probably about $45-60 in total and I'm not exactly sure it would look pretty.


Since the basic foam worked so well, I thought maybe I could just use that same foam from the packing materials and glue THAT to the bottom of some wood covered in fabric. That would be like $15-20 in total but again, it wouldn't look too good.


So that leaves me with the standard Auralex offerings at $99 including shipping for two GRAMMAs. The studs at the bottom of my PB12-NSD are about 22" apart in one direction and 15-16" apart in the other direction. The Auralex GRAMMA measures 15x24" (can anyone confirm this?). My questions are:


-Is the GRAMMA overkill/a ripoff? Should I just make something with wood and generic foam that would perform just as well?

-Since my sub is just a little too big with the studs in for the GRAMMA, would I get good isolation performance if I unscrewed the studs and just laid the subwoofer directly on the surface?


Thanks for any input,

Mike
 

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Discussion Starter #3

Quote:
Originally Posted by Jay1  /t/1418472/isolation-riser-questions#post_22186388


These should work pretty well.
http://www.amazon.com/gp/product/B005JRLQ20/ref=oh_details_o00_s00_i00

Thanks, I hadn't stumbled across those before. Given they are only an inch off the ground, should I be concerned about their effectiveness versus a GRAMMA? If the difference is between 98-99% decoupling, that's fine. I just don't want to settle for something like 70%.
 

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I used 2" thick high density packing foam and spray painted it black. I used 4 - 3" wide by 6" long foam bricks that I cut to that size. Then for the platform I used 3/4" MDF, I went 2 inches bigger than the sub in each direction for mine. Painted the MDF with Flat Black interior paint that I had left from a previous project. Got some Locktight spray adhesive to glue the foam to the MDF.... And Voilla... Isolation Platform. It works great and only cost me about $40 for 2 of them for my dual subs.
 

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Discussion Starter #5

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Originally Posted by flickhtguru  /t/1418472/isolation-riser-questions#post_22187669


I used 2" thick high density packing foam and spray painted it black. I used 4 - 3" wide by 6" long foam bricks that I cut to that size. Then for the platform I used 3/4" MDF, I went 2 inches bigger than the sub in each direction for mine. Painted the MDF with Flat Black interior paint that I had left from a previous project. Got some Locktight spray adhesive to glue the foam to the MDF.... And Voilla... Isolation Platform. It works great and only cost me about $40 for 2 of them for my dual subs.

I actually saw your pictures on that. Nice job! I like that it doesn't really need to be covered in fabric. A few questions:

-Where did you get the MDF? I think you said Home Depot/Lowes but I didn't see any in stock online. Are there substitutes? EDIT: is this it?
http://www.homedepot.com/webapp/catalog/servlet/Search?storeId=10051&langId=-1&catalogId=10053&keyword=mdf%20board&Ns=None&Ntpr=1&Ntpc=1&selectedCatgry=SEARCH+ALL


-Did you cut the MDF or did they cut it to size for you at the store?

-Where did you get the high density packing foam? Is it easy to cut?


I think I may go down this path, and it should look better than a GRAMMA - thanks for any responses!
 

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Quote:
Originally Posted by Jay1  /t/1418472/isolation-riser-questions#post_22186388


These should work pretty well.
http://www.amazon.com/gp/product/B005JRLQ20/ref=oh_details_o00_s00_i00

Thanks for the link to this product. Just cleaned out Amazon's Wherehouse of three of the 4 packs. Going to try and use 6 pads on each of my two JTR Orbit Shifter subs (177lbs each). I'm hoping the 1" height will do the isolation job and not force me to raise my FP screen.
 

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Discussion Starter #7
I found the 2'x4'x3/4" MDF at Home Depot today. I'm making two stands, each 2'x18.5"x3/4" - just bigger than the subs by about 1/2" in each direction. Total cost of the entire piece was $9.99 - I can live with that, and they cut it for me!


There are four pieces of what I would call "high density packing foam" that are perfect squares, about 6"x6"x2" that were in each of the SVS PB-12 NSD boxes. I just had to rip them off some bigger pieces but they're perfect! That worked out well.


Other things I picked up at Home Depot were some glue and some flat black spray paint. Total cost of everything: about $19.


I'm gluing the foam to the boards now. I'll spray paint the boards and foam tomorrow, and that should do it!


Saved me between $80-$100 and it's going to look a hell of a lot better than those ugly charcoal gray GRAMMAs!
 

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Discussion Starter #8
Well I built them, they look great, but the foam that came with the SVS doesn't absorb enough of the low frequency vibration.


To fix this, I just ordered some 4"x2'x4' Owens Corning 703 online. So much for cost savings ($58 with shipping), but it should work and look nice painted black.
 
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