DIY Subwoofer Risers

[crazyBLUE]

Originally Posted by GAWD

That is the main reason I've never gone out and made acoustic panels. I was never 100% sure of the material to use to properly "seal" it. I know burlap and others are good enough..BUT...I don't know. like you said it was meant to be sealed in a wall. the main reason I went the Auralex road.

If you fill the Riser with foam it will help & you don't have those worries . I could go on but then there is big woop-teedo that I will have no part of

[kareface]

If fiberglass is such a concern, which I can't imagine why, you would be better off using a fluffy polyfill over foam. The principle is about the same, but fiberglass would be more effective then both.

[Big Daddy]

Originally Posted by kareface

If fiberglass is such a concern, which I can't imagine why, you would be better off using a fluffy polyfill over foam. The principle is about the same, but fiberglass would be more effective then both.

You have to use a proper mask to handle fiber glass as it is a health hazard.

[jlafrenz]

Originally Posted by kareface

With subs I would suggest an open frame filled with fluffy, lower density fiberglass wrapped in an acoustically transparent material. It'll do a better job of reducing the excess vertical node energy from the sub compared to a box. Also, a sealed box will produce resonance. It is a good idea if you have any box in the room to fill it with something, sand is best but fiberglass is much cheaper. The little shelf that comes on my coffee table actually resonates a great deal when I'm playing movies, I actually have to remove it at some point or get a new coffee table, lol. The main reason I have risers for my speakers is to get the tweeters to ear level, it isn't the same reason why most people raise their subs.

Fiber glass cheaper than sand? 80lbs of sand is 4 bucks. Point us to a place where fiberglass is cheaper than that.

[kareface]

Originally Posted by jlafrenz

Fiber glass cheaper than sand? 80lbs of sand is 4 bucks. Point us to a place where fiberglass is cheaper than that.

It's because of the difference in density. It takes around ~90 lbs of sand to fill a cubic foot. A bag of 9.5" thick r30 insulation, even compressed down will easily fill 12 cubic feet, which will cost you around 10$. To fill the same volume with sand you'd need 22 bags of sand (most bags of sand come in 50lb volumes), even @ 4$ a bag you're looking at 88$. I've never seen 80lb bags, but you might have them local to you. In my case my risers were about twice that volume, ~24 cubic feet.

[kraig1]

I put about 1" legs (about 1/2" diameter) on bottom to give air gap. The one thing I really notice is the amount of vibration the riser absorbs and does not transfer to floor. My checking method is only putting hand on riser and other on floor about 2" from each other and I would say the difference is about 75% less in floor. Now I know this isnt exactly scientific but its doing something.

[jlafrenz]

Originally Posted by kareface

It's because of the difference in density. It takes around ~90 lbs of sand to fill a cubic foot. A bag of 9.5" thick r30 insulation, even compressed down will easily fill 12 cubic feet, which will cost you around 10$. To fill the same volume with sand you'd need 22 bags of sand (most bags of sand come in 50lb volumes), even @ 4$ a bag you're looking at 88$. I've never seen 80lb bags, but you might have them local to you. In my case my risers were about twice that volume, ~24 cubic feet.

Head over to your local Wal-Mart or hardware store. A tube of sand is $4

[kareface]

Originally Posted by jlafrenz

Head over to your local Wal-Mart or hardware store. A tube of sand is $4

I'm unable to find any sand at all on their website, but I'll take you at your word. Even 80lb @ 4$ a tube would cost much more per foot^3 then r30 would.

[jlafrenz]

Originally Posted by kareface

I'm unable to find any sand at all on their website, but I'll take you at your word. Even 80lb @ 4$ a tube would cost much more per foot^3 then r30 would.

Do you happen to have a link to the r30? I am curious about it now.

The sand you probably won't find on the website. Is it seasonal and usually carried during the winter to throw in the back of trucks. The hardware store may carry it year round.

[kareface]

http://www.homedepot.com/Building-Ma...atalogId=10053

You might be able to get it cheaper then that even, I just happened to pick mine up from home depot when I went to buy the materials for the front stage.

[Driver_King]

Originally Posted by kareface

It's because of the difference in density. It takes around ~90 lbs of sand to fill a cubic foot. A bag of 9.5" thick r30 insulation, even compressed down will easily fill 12 cubic feet, which will cost you around 10$. To fill the same volume with sand you'd need 22 bags of sand (most bags of sand come in 50lb volumes), even @ 4$ a bag you're looking at 88$. I've never seen 80lb bags, but you might have them local to you. In my case my risers were about twice that volume, ~24 cubic feet.

That sounds like a good idea for "stuffing" for my next subwoofer riser that I'll be making for my larger sub. Do you know of any materials that could decouple the riser from the ground, like an affordable rubber mat or something, large enough to span about 50" x 25"? I haven't really looked into it but was curious since you have made a furniture riser before.

[kareface]

Originally Posted by Driver_King

That sounds like a good idea for "stuffing" for my next subwoofer riser that I'll be making for my larger sub. Do you know of any materials that could decouple the riser from the ground, like an affordable rubber mat or something, large enough to span about 50" x 25"? I haven't really looked into it but was curious since you have made a furniture riser before.

If you plan to use it for furniture I wouldn't try and isolate it. If you are trying to use it to raise the subwoofer I'd use rubber feet. The less surface area the better, but obviously you want enough that it can support your riser. I'd suggest something like:
http://www.parts-express.com/pe/show...ource=googleps

Don't spend much on them, almost all resins, epoxies and rubbers act the same so spending 25$ per foot isn't going to result in a huge improvement. I don't know if those will be large enough for your purpose tho.

[jlafrenz]

Originally Posted by kareface

If you plan to use it for furniture I wouldn't try and isolate it. If you are trying to use it to raise the subwoofer I'd use rubber feet. The less surface area the better, but obviously you want enough that it can support your riser. I'd suggest something like:
http://www.parts-express.com/pe/show...ource=googleps

Don't spend much on them, almost all resins, epoxies and rubbers act the same so spending 25$ per foot isn't going to result in a huge improvement. I don't know if those will be large enough for your purpose tho.

When I built my platform, I looked at those very same feet. I would suggest going to a local sporting goods store and picking up some hockey pucks. Just about the same size and only $2 each. Should save you a few bucks and do the trick. Works for me anyway.

Another option for a full mat would be that snap together garage flooring. It would be possible to make it the size you desire. I remember seeing it at Harbor Freight, but can't seem to find the link and don't remember the price.

[kareface]

Originally Posted by jlafrenz

When I built my platform, I looked at those very same feet. I would suggest going to a local sporting goods store and picking up some hockey pucks. Just about the same size and only $2 each. Should save you a few bucks and do the trick. Works for me anyway.

Another option for a full mat would be that snap together garage flooring. It would be possible to make it the size you desire. I remember seeing it at Harbor Freight, but can't seem to find the link and don't remember the price.

I think most hockey pucks are plastic or made from rubber that contains other trace materials to strengthen them. A pure rubber solution would be best, but absolutely don't get the plastic pucks, the rubber ones would be much better.

[Driver_King]

Originally Posted by kareface

I think most hockey pucks are plastic or made from rubber that contains other trace materials to strengthen them. A pure rubber solution would be best, but absolutely don't get the plastic pucks, the rubber ones would be much better.

That sounds like it'd be a good idea. I'd probably have to get six or eight of them to support the weight of the riser and subwoofer (which would be in excess of 300-400lbs). By the way, the subwoofer will probably be lying flat on the riser because of the weight. Would I be fine just with carpeting on top?

[jlafrenz]

Originally Posted by kareface

I think most hockey pucks are plastic or made from rubber that contains other trace materials to strengthen them. A pure rubber solution would be best, but absolutely don't get the plastic pucks, the rubber ones would be much better.

I got standard issue/regulation hockey pucks. I actually called Parts Express about those feet when I was looking at them. They told me they were pretty hard as they were designed to go on the bottom of a cabinet or some kind of gear that would be used in live music to travel with.

[kareface]

Originally Posted by jlafrenz

I got standard issue/regulation hockey pucks. I actually called Parts Express about those feet when I was looking at them. They told me they were pretty hard as they were designed to go on the bottom of a cabinet or some kind of gear that would be used in live music to travel with.

Good to know. I'll be looking into this issue once I start work on my risers. This, as I mentioned, has been put on the back burner until for the time being. I know there are a few good products for computer cases that aren't too expensive. However I've got too many other things to keep me occupied for the moment, lol.

[kareface]

I posted a video to help people better understand nodes, I thought I'd link it here as it's related to what I was discussing above:

https://forum.blu-ray.com/audio-theo...ml#post2943830

[duder1234]

Hey Guys,

Will these rubber "feet" work for the bottom of a sub riser and/or speaker stands?

Thanks!

[Fors*]

Originally Posted by duder1234

Hey Guys,

Will these rubber "feet" work for the bottom of a sub riser and/or speaker stands?

Thanks!

Anything that can help with decoupling the sub from the floor can't hurt. Give it a try and let us know.