Subwoofer pad/absorber?? Help

[masak_aer]

Hi,
I'm in desperate help. I got my HK subwoofer not too long ago. I live in a condo building and I knew this is going to happen sooner or later. The tenant right below my condo is knocking on my door saying that she can hear my bass reverberating through her ceiling and it's annoying her. I told her from the door,"I don't think i put it too loud." (it's true) and she agreed with me. She said it sounded nice but she could hear it. It was a soft instrumental music that i played through the DVD with ocassional strong bass sound.
Well, I've tried to be a good neighbor by not putting it too loud. I was so mad yesterday cuz i know it's not loud at all but i said nothing. I just said i'd turn it down a lil' and hope it'd help. I actually did decide if she still came, i'd tell her to call the police and let them decide.
Now, is there anything i can use to overcome this problem? I know the sub speaker is facing down my floor. Is there any pad or subwoofer raiser (raise it up from the floor with the pad so the vibration is not directly going through the floor)? If so, where can i purchase it? Thank you so much for all the help i can get....

 

[bongobob]

I live in an apartment so I feel your pain. I use an Auralex Gramma Pad found here:
http://www.auralex.com/sound_isolation_gramma/sound_isolation_gramma.asp
I use one on my bass guitar Amp as well. Tightens things up considerably as a bonus too!

 

[masak_aer]

Thank you for the quick reply. I think i'm going to get me one of this. I hope it works.

 

[WmAx]

Hi,
I'm in desperate help. I got my HK subwoofer not too long ago. I live in a condo building and I knew this is going to happen sooner or later. The tenant right below my condo is knocking on my door saying that she can hear my bass reverberating through her ceiling and it's annoying her. I told her from the door,"I don't think i put it too loud." (it's true) and she agreed with me. She said it sounded nice but she could hear it. It was a soft instrumental music that i played through the DVD with ocassional strong bass sound.
Well, I've tried to be a good neighbor by not putting it too loud. I was so mad yesterday cuz i know it's not loud at all but i said nothing. I just said i'd turn it down a lil' and hope it'd help. I actually did decide if she still came, i'd tell her to call the police and let them decide.
Now, is there anything i can use to overcome this problem? I know the sub speaker is facing down my floor. Is there any pad or subwoofer raiser (raise it up from the floor with the pad so the vibration is not directly going through the floor)? If so, where can i purchase it? Thank you so much for all the help i can get....

A physical isolator that effectively decouples the cabinet vibration from the floor will help a very small amount. But not much. The best solution is to use a parameteric equalizer and reduce the amplitude of the primary resonance of the floor structure. To get the most accurate results will require the cooperation of the neighboring tenant. You will have run a high SPL sweep through your subwoofer and at the same time meausure the frequency response of this sweep from within your neighbor's dwelling. Using this data, you can effectively reduce the bass to the neighbor while still having some bass in your dwelling. This will obviously result in degrdation of audio quality, but it is a compromise you can chosse to make.

-Chris

 

[bongobob]

A physical isolator that effectively decouples the cabinet vibration from the floor will help a very small amount. But not much. The best solution is to use a parameteric equalizer and reduce the amplitude of the primary resonance of the floor structure. To get the most accurate results will require the cooperation of the neighboring tenant. You will have run a high SPL sweep through your subwoofer and at the same time meausure the frequency response of this sweep from within your neighbor's dwelling. Using this data, you can effectively reduce the bass to the neighbor while still having some bass in your dwelling. This will obviously result in degrdation of audio quality, but it is a compromise you can chosse to make.

-Chris

While your solution is probably the best route Chris, I have to point out that the Gramma does an excellent job of eliminating floor resonances. It has foam diffusion underneath the platform much like the wall treatments in a recording studio. It was designed to lift stage amps off the wood floor to kill noise transferance. Bottom line is that I used to get banging on the wall and once I lifted the sub, no more bangin! - Bob

 

[BARRACUDA1968]

would something like this make a difference in my basement? on carpet over a cement floor? I'm having a heck of a time getting my Velodyne tuned in. If this would help me tighten it up I would try it.

 

[masak_aer]

Gramma thingy

I just bought the Gramma thingy for $49.95 at the Guitar Center on my way home from the office. I asked them to match the internet price (I printed out from the internet). I tried it with my Matrix Reloaded dvd. No banging yet so far but i don't know if it's the absorber or because the old lady downstairs isn't home. I'll try again whenever i have a chance. Two hours passed by and still no banging on my door. May be she just passed out from the sub's wave.
WMax idea is going to work for sure but it's gonna be such a hassle but i'll somehow have to do it if she still complains. I think this Gramma thing will work both on concrete/tile and or carpet since the pad uses some kind of sponge material much like your bed but harder. From the look of it, I think it can absorb the vibration.
I'll let you know if it works. I'll give it a week.

 

[SKINNER]

While your solution is probably the best route Chris, I have to point out that the Gramma does an excellent job of eliminating floor resonances. It has foam diffusion underneath the platform much like the wall treatments in a recording studio. It was designed to lift stage amps off the wood floor to kill noise transferance. Bottom line is that I used to get banging on the wall and once I lifted the sub, no more bangin! - Bob

What did this do in terms of sound quality? Do you still have the same amounts of bass just with less floor resonance?? I'm really interested....

 

[bongobob]

What did this do in terms of sound quality? Do you still have the same amounts of bass just with less floor resonance?? I'm really interested....

I found a tighter punch and no quality loss. Subjective of course. Thie Gramma was recommended by a friend who does a lot of studio work. I listen mostly to music so I'm interested to see what Masak thinks. There could be different results from different sub configurations. Mine uses a semi-sealed, ported front firing bandpass design. I'd like to know how a downward radiating sub reacts... Not WAF friendly though as it's more designed for stage use. - Bob

 

[KeithT]

The gramma did wonders for my situation, the PB2ultra would vibrate on
hardwood flooring on a slab and rattle everything within 40ft of the sub.
The riser tamed all the rattles and stopped vibration against the floor.
I thought it sounded better with it added, but that was subjective. So I got
out my SPL and did some measurements, no easy task with a 190lb box!

 

[SKINNER]

The gramma did wonders for my situation, the PB2ultra would vibrate on
hardwood flooring on a slab and rattle everything within 40ft of the sub.
The riser tamed all the rattles and stopped vibration against the floor.
I thought it sounded better with it added, but that was subjective. So I got
out my SPL and did some measurements, no easy task with a 190lb box!

wow. I guess you can't argue with the numbers. Maybe you can answer my question---I've got a Mirage Omni S12 (12" driver, front firing woofer, dual down firing ports). The problem I'm having is with my fireplace...I've got a gas fireplace and it vibrates under even moderate volume levels. I've already removed the fireplace and have begun welding braces to the sheet metal body. Do you think one of these isolation pads will help?

 

[Sheep]

wow. I guess you can't argue with the numbers. Maybe you can answer my question---I've got a Mirage Omni S12 (12" driver, front firing woofer, dual down firing ports). The problem I'm having is with my fireplace...I've got a gas fireplace and it vibrates under even moderate volume levels. I've already removed the fireplace and have begun welding braces to the sheet metal body. Do you think one of these isolation pads will help?

If you look closely, it didn't do a whole lot 80Hz down, which is where most of us run our subs.

SheepStar

 

[SKINNER]

If you look closely, it didn't do a whole lot 80Hz down, which is where most of us run our subs.

SheepStar

I'm not sure I understand, you said it didn't do a whole lot below 80hz. A whole lot of what?

I wasn't looking for it to do "anything". I was more curious to see if output would be compromised to any degree with the use of the isolation pad. From the numbers, the sub plays at the same DB level with or without the pad - - this is good, No??

The thing I need the isolation pad for is to take resonance out of the floor in an attempt to stop my fireplace from trying to self-destruct....POS fireplace....damn canadians....can't even build an F'n fireplace....sorry, I digress.

 

[Sheep]

I'm not sure I understand, you said it didn't do a whole lot below 80hz. A whole lot of what?

I wasn't looking for it to do "anything". I was more curious if the sound is degraded to any degree with the use of the isolation pad. From the numbers, the sub plays at the same DB level with or without the pad - - this is good, No??

The thing I need the isolation pad for is to take resonance out of the floor in an attempt to stop my fireplace from trying to self-destruct....POS fireplace....damn canadians....can't even build an F'n fireplace....sorry, I digress.

Thats why I use a REAL fireplace, where I burn trees. Never rattles. I don't see how this can stop rattleing. If the sub is isolated from the floor, it can still rattle things with the energized air...

SheepStar

 

[SKINNER]

Thats why I use a REAL fireplace, where I burn trees. Never rattles. I don't see how this can stop rattleing. If the sub is isolated from the floor, it can still rattle things with the energized air...

SheepStar

Unfortunately, there's not a whole lot I can do about that...maybe 3 months ago when it was built, but not now.

I understand that the air can still cause it to vibrate. However, I'm confident that the majority of the vib's are coming from the subs output into my floor joists. If I pick the sub up it pretty much goes away. My home has a crawlspace foundation which allows for vib's to more easily be passed through the floor.

I'm curious if one of these would soak the vib's up at all...

 

[masak_aer]

Thats why I use a REAL fireplace, where I burn trees. Never rattles. I don't see how this can stop rattleing. If the sub is isolated from the floor, it can still rattle things with the energized air...

SheepStar

In my all nite experience with it, the rattling floor is less since i use it. It is quite logical as you put a pretty thick "soft" padding underneath your sub. The vibration from the sub without the padding is more intense since it travels all along your floor and to the wall. With the gramma thing, most of the vibration is absorbed by the padding hence less vibration to the floor.
As of the sound quality, i don't hear much different (still subjective). The product claim that it creates clearer sound but i haven't heard it just yet.
More scientific reports are welcomed...

 

[bongobob]

I understand that the air can still cause it to vibrate. However, I'm confident that the majority of the vib's are coming from the subs output into my floor joists. If I pick the sub up it pretty much goes away. My home has a crawlspace foundation which allows for vib's to more easily be passed through the floor.

I'm curious if one of these would soak the vib's up at all...

I have a crawlspace under me as well. I felt it eliminated transferance to the floor while not compromising sound quality in any way that I can tell. It was a simple, inexpensive solution to a neighbors anger. - Bob

 

[WmAx]

While your solution is probably the best route Chris, I have to point out that the Gramma does an excellent job of eliminating floor resonances. It has foam diffusion underneath the platform much like the wall treatments in a recording studio. It was designed to lift stage amps off the wood floor to kill noise transferance. Bottom line is that I used to get banging on the wall and once I lifted the sub, no more bangin! - Bob

I use an isolation/suspension system or my speakers, as the floor on which they are located has a primary resonant frequency around 65Hz. However, when measuring the difference that only isolation creates in the room below this, the effect is only a few dB, and while an audible difference, is not very much difference. The main purpose of my suspension system is to reduce colorations of the floor resonance in the actual listening room and to reduce felt vibration in the floor(the vibrating floor annoys me when listening). The primary resonance(s) being transmitted need to be attenuated with a line level filter for an appreciable difference.

-Chris

 

[WmAx]

Unfortunately, there's not a whole lot I can do about that...maybe 3 months ago when it was built, but not now.

I understand that the air can still cause it to vibrate. However, I'm confident that the majority of the vib's are coming from the subs output into my floor joists. If I pick the sub up it pretty much goes away. My home has a crawlspace foundation which allows for vib's to more easily be passed through the floor.

I'm curious if one of these would soak the vib's up at all...

It depends on the specific circumstances. If you have a very high Q resonance that is a result of a direct mechanical stimulation, and the mechanical stimulation(speaker cabinet) is directly contacting the point of resonance, this would be signifcantly reduced by removing the direct mechanical stimulation. However, in a normal situation, the majority of stimulus comes from the acousticly born energy.

-Chris

 

[bongobob]

I use an isolation/suspension system or my speakers, as the floor on which they are located has a primary resonant frequency around 65Hz. However, when measuring the difference that only isolation creates in the room below this, the effect is only a few dB, and while an audible difference, is not very much difference. The main purpose of my suspension system is to reduce colorations of the floor resonance in the actual listening room and to reduce felt vibration in the floor(the vibrating floor annoys me when listening). The primary resonance(s) being transmitted need to be attenuated with a line level filter for an appreciable difference.

-Chris

Actually, my neighbors are not below but next door to me. Perhaps the fact that we're sharing the same joists caused the problem? In any case, I was thanked for the change and that's what important to me. I already had acoustic foam along the adjoining wall but it was the sub shaking the flooring that was the issue. So it's not a matter of dB's produced by the unit but the resonances produced when coupled to a crappy floor. I suppose that's why the performace\ studio room where I work was constructed as a concrete slab "floating" a few inches above the rest of the second floor of the building (Don't ask me how it was made because I didn't get the details but it cost a ridiculous amount of scratch). There's also an anechoic chamber in there that had to be isolated from resonance from machinery in the building. Sort of the same principle. I'll ask our acoustcal engineer to elaborate and comment as well. - Bob