DIY Subwoofer Risers

[Big Daddy]

Originally Posted by Driver_King

Big Daddy, have you gotten around to building some risers or something of that nature for your fronts? If so, post pictures and give us an idea of how it sounds. If not, get to it!

The Definitive Technology Super Towers are already too tall (52"). The center of the built-in subs is about 2 feet above the floor. In addition, by putting them on a riser, the tweeters will be higher than my ears when I am sitting dowN. They came with spikes. I never used them until recently because I was afraid of scratching the wood floor. A couple of months ago, I finally decided to use them and put silver dollars under them. Unfortunately, they were not very even and stable. I finally orderd these 8 spike pads from Ebay for about $22. The speakers are very stable now and difficult to knock over. In my opinin, they were a great investment.

http://shop.ebay.com/?_from=R40&_trk...All-Categories

[liquidice]

downloaded the real traps mp3's, and gave them spin before. I think I need to reburn with no gaps between the tracks because when it switches, it send a signal to my other speakers, and they sound like they are going to blow! Lost track of what frequency I was at (probably around 35hz), and I thought my head was going to cave in! My little 8" sub was shoving so much air out of it, it was like a blowdryer! My 12" could feel air by the port, but not like the smaller 8" cabinet. I thought it was making a rattling sound at first, but it was more of just the air blasting out of the front port that sounded so strange. I've got the Rives Audio cd2 around here somewhere, gonna pull that out, and also try re-burning the real traps one. I forgot they made the Rives to work perfectly with the Radioshack SPL meter (whatever that means) so I'll definately need to get one now. Time to blow some stuff up!!!

[Big Daddy]

Originally Posted by liquidice

downloaded the real traps mp3's, and gave them spin before. I think I need to reburn with no gaps between the tracks because when it switches, it send a signal to my other speakers, and they sound like they are going to blow! Lost track of what frequency I was at (probably around 35hz), and I thought my head was going to cave in! My little 8" sub was shoving so much air out of it, it was like a blowdryer! My 12" could feel air by the port, but not like the smaller 8" cabinet. I thought it was making a rattling sound at first, but it was more of just the air blasting out of the front port that sounded so strange. I've got the Rives Audio cd2 around here somewhere, gonna pull that out, and also try re-burning the real traps one. I forgot they made the Rives to work perfectly with the Radioshack SPL meter (whatever that means) so I'll definately need to get one now. Time to blow some stuff up!!!

Anytime you play test tones, lower the volume. At certain low frequencies, your room starts vibrating. Mine happens at 25Hz.

[liquidice]

I'm pretty sure I can't even get that low. I think about maybe 30hz is when I start to hear things rattling without even hearing any bass...very little. Kind of cool actually. Just found my Rives test disc2, and was reading the track listing. I'm gonna mess with this for a minute, just to see whats going on. I did realize with these tests that I truely have my subs in the right locations. When seated in optimal viewing spot, the bass is great. When I walk over to the corner with no subwoofer, there is so much built up energy, I either feel like I'm going to turn into the Fly, or possibly teleport somewhere in the world or time.

[erict]

BD, I have a question. When building a riser, does it give any isolation from the floor? For example, if the sub rattles the floor and makes objects rattle (pictures, glasses, etc) would a riser also help with this? Or do I need something like a subdude to address this?

Here is a quick sketch of the type of riser I will build.
RISER.jpg

[jomari]

Originally Posted by erict

BD, I have a question. When building a riser, does it give any isolation from the floor? For example, if the sub rattles the floor and makes objects rattle (pictures, glasses, etc) would a riser also help with this? Or do I need something like a subdude to address this?

Here is a quick sketch of the type of riser I will build.
Attachment 5802

you can have a riser, and thats it. or you can have a isolator, and not have to address the vertical axis of the room mode.

OR you can have both. might as well right?

personally, the isolation should start with the platform itself, either made of carpet (which others have chosen), then isolating that factor with rubber feet if you'd care for.

id also suggest to have it a tad higher. BD gave a good formula as the height being 25% of the height of the room, in most cases rooms generally are at 8ft. so, 25% is 2 feet. some, like me, have other factors to consider, including a vaulted ceiling. i personally cant end up building jack because i live in an apartment, and will be moving out in a month or two towards our new home. i will make the appropriate measurements then.

[JJ]

Originally Posted by Big Daddy

http://shop.ebay.com/?_from=R40&_trk...All-Categories

That's a great idea, I need something like those for my B&Ws.

[erict]

Originally Posted by jomari

you can have a riser, and thats it. or you can have a isolator, and not have to address the vertical axis of the room mode.

OR you can have both. might as well right?

personally, the isolation should start with the platform itself, either made of carpet (which others have chosen), then isolating that factor with rubber feet if you'd care for.

id also suggest to have it a tad higher. BD gave a good formula as the height being 25% of the height of the room, in most cases rooms generally are at 8ft. so, 25% is 2 feet. some, like me, have other factors to consider, including a vaulted ceiling. i personally cant end up building jack because i live in an apartment, and will be moving out in a month or two towards our new home. i will make the appropriate measurements then.

I'm not sure I can find the answer here. One thing though is the wife would never go for a 2' riser.

[jomari]

Originally Posted by erict

I'm not sure I can find the answer here. One thing though is the wife would never go for a 2' riser.

hmm. ive confused a number of people with this posting, so im going to say it as simple as i can.

an isolator decouples your speaker from the room, while a riser ADDRESSES the vertical axis of the room mode.

a isolator/decoupler is a passive solution, while a riser is an active solution.

two different functions, which can of course be combined.

a riser can be an isolator, and an isolator can be a riser.

you can create a decent decoupler, and eliminate most of the rattle caused in the room, and you can also make it INTO a riser by adding legs on it, improving its response to the room vertically. which is another way to address rattle in your room.

or you can use blu-tak and address the glass fixtures and even glasses.

[erict]

Originally Posted by jomari

hmm. ive confused a number of people with this posting, so im going to say it as simple as i can.

an isolator decouples your speaker from the room, while a riser ADDRESSES the vertical axis of the room mode.

a isolator/decoupler is a passive solution, while a riser is an active solution.

two different functions, which can of course be combined.

a riser can be an isolator, and an isolator can be a riser.

you can create a decent decoupler, and eliminate most of the rattle caused in the room, and you can also make it INTO a riser by adding legs on it, improving its response to the room vertically. which is another way to address rattle in your room.

or you can use blu-tak and address the glass fixtures and even glasses.

I think It's starting to penetrate my thick skull Now if I got it right, the riser I want to build will not isolate unless I add something like rubber feet to the legs, right? My riser design plans on having a box frame instead of feet.

[jomari]

Originally Posted by erict

I think It's starting to penetrate my thick skull Now if I got it right, the riser I want to build will not isolate unless I add something like rubber feet to the legs, right? My riser design plans on having a box frame instead of feet.

it can work, but id rather have some rubber feet on them to make sure it decouples from the floor. better yet, you can also add carpeting on the inside of your 'box' to accomodate the sub.

when you do make your box frame, also consider reinforcing it to avoid rattle...

[erict]

Originally Posted by jomari

it can work, but id rather have some rubber feet on them to make sure it decouples from the floor. better yet, you can also add carpeting on the inside of your 'box' to accomodate the sub.

when you do make your box frame, also consider reinforcing it to avoid rattle...

I guess I could still use the box frame design but also put a rubber foot on each corner of the frame. I do plan on adding four corner braces and also it will be screwed and glued so that should eliminate any rattles down the road. One thing I didn't mention is this will be on a carpet floor.

[Big Daddy]

Originally Posted by erict

I guess I could still use the box frame design but also put a rubber foot on each corner of the frame. I do plan on adding four corner braces and also it will be screwed and glued so that should eliminate any rattles down the road. One thing I didn't mention is this will be on a carpet floor.

If you put the riser on carpet and dampen the area below it with as much dampening material such as foam, it will decouple the sub from the floor. Also make sure it is as steady as possible and not wobbly.

[liquidice]

I'll tell you whats interesting: today I suddenly remembered that I like the Crystal Method, so out come two of their discs, and in the PS3 they go. After a quick receiver tweek (usually my music would always revert to strero through multi-channel, but today I actually had to set it on stereo?..), I began enjoying the wonderful electronic sounds of Crystal Method nice and loud. I flipped to PHD, one of my favorite "bass heavy" tracks, and started cleaning up my house. While I was in the very next room, my dining room, I noticed how much bass was traveling through the floor. Standing right in the middle of the room, the bass was very noticable, more so than ever before! Strange how my riser/isolator seemed to make the bass travel farther?!?!

[erict]

Originally Posted by Big Daddy

If you put the riser on carpet and dampen the area below it with as much dampening material such foam, it will decouple the sub from the floor. Also make sure it is as steady as possible and not wobbly.

So are you saying, no rubber feet needed? I will be filling the whole box frame cavity completely with dampening material.

[crazyBLUE]

Originally Posted by erict

So are you saying, no rubber feet needed? I will be filling the whole box frame cavity completely with dampening material.

erict , the grampa I built has A solid piece of foam completely filling the underneath between the legs ! In fact the foam is about 1/4" taller so the stand is actually compressing it some !
I cannot feel any transfer to the floor even when the sub is doing its job !!

[erict]

Originally Posted by crazyBLUE

erict , the grampa I built has A solid piece of foam completely filling the underneath between the legs ! In fact the foam is about 1/4" taller so the stand is actually compressing it some !
I cannot feel any transfer to the floor even when the sub is doing its job !!

looks good. Do you have any close up shots? Also where and what type of foam did you use?

[liquidice]

dude, I totally missed that you replaced your center with another BA. You've got to much money!

[crazyBLUE]

Originally Posted by erict

looks good. Do you have any close up shots? Also where and what type of foam did you use?

I just have the 2 pics. of the stand ! The foam is just solid pieces of foam ~ 12" x 12" x 2" thick . I used 3 pieces put together for 6" of foam !!

[crazyBLUE]

Originally Posted by liquidice

dude, I totally missed that you replaced your center with another BA. You've got to much money!

I wish I had to much money ice ! The front's would probably be the new line of BA at about $1,600. each !