Pad to stop viberation?

[GotNoRice]

I have a stereo setup of almost entirely vintage components. 3 Pairs of Vintage JBLs each with their own Vintage Yamaha Amplifier controlled by a Vintage Yamaha Preamp.

130dB is the max reading the SPL meter is capable of

My problem, as can be seen in the 2nd picture, is that when played loud, those JBL 4412s up top want to vibrate right off the top of the other speaker. It's capable of a pretty amazing amount of bass given the age of the components and the lack of a sub-woofer. I need to find some kind of rubber pad that I can place under the speaker that will stop it from moving, ideally without messing up the wood of the speaker above or below. Any ideas?

 

[counterpoint]

Woah dude! Very short periods of 130dB sound can permanently damage your hearing! Please be careful and take care of yourself! Use hearing protection if you're just testing!

 

[spaceman]

Honestly a bit of decently thick memory foam will do the trick. Or a pair of Auralex SUBDUDE pads made for subwoofers but are perfect for this too.

You are using hearing protection at that db though right? I would think someone with a db meter would but just checking.

 

[GotNoRice]

Woah dude! Very short periods of 130dB sound can permanently damage your hearing! Please be careful and take care of yourself! Use hearing protection if you're just testing!

Thanks, I really do appreciate the advice, and do care about my hearing.

Human hearing is not equally sensitive across the audible sound spectrum. There is a notable range, about 1-5Khz that humans are most sensitive to. For the most part, this corresponds to the frequency range of human speech.

My prefered EQ settings tend to have a lot in common with the Fletcher Munson curve

The 130dB reading in this case is the result of extra EQ on the bass end for the most part, and you can see on the meter that it is measuring with the C scale.

But the bottom line is that it has to be loud enough that I can sing along while I'm shitfaced drunk and not be able to hear my own voice

 

[spaceman]

lol

Ok then! Yeah so what I mentioned has worked for me in the past. The subdude will change your bass signature though. The bass sounds more "audiophile" than boomy.

 

[RedWagnum]

My problem, as can be seen in the 2nd picture, is that when played loud, those JBL 4412s up top want to vibrate right off the top of the other speaker. It's capable of a pretty amazing amount of bass given the age of the components and the lack of a sub-woofer. I need to find some kind of rubber pad that I can place under the speaker that will stop it from moving, ideally without messing up the wood of the speaker above or below. Any ideas?

Mouse Pads! Cheapest generic rubber ones you can find. The thick ones (3/16" - 1/4") with the cloth top should work well. Get one, quarter it, and stick a piece on each corner of the speaker. If the cloth surface proves to be too slick and you still get movement get another mouse pad, quarter it, and glue them together, cloth side to cloth side.

Did this with a PC that sat on top of a file cabinet. The fans and HDs created a resonance in the file cabinet. Put the mouse pads under it and the resonance went away -and- the PC was almost impossible to move without picking it up.

 

[John721]

Could look into nonslip shelf/cabinet liner mats.

Something like this, getting whichever size best meets your needs.

 

[atarione]

bahahaha...

i'm not sure about the "presentation" exactly but as a fellow vintage fan... I love some of you gear the (the JBL speakers and that Yamaha M-2?)


also if you where my neighbor I may well have murdered you by now..

and yeah.. there is NO reason to have 130db going.. you are insane ....sorry but

a. check for hearing loss from this / whatever else now... because I can speak at first hand I have a bit of hearing loss (grew up hunting and around farm equipment which is loud as ****) and tinnitus and it sucks... If you are not careful you could really screw yourself as you get older and or (assuming it is not to late) wind up with really irritating at time near constant ringing in your ears.

b. I think you should put the JBL 4412's on shelves on the walls (with mats as previously suggested.)


but mainly you are going to wreck you hearing entirely if you don't chill

 

[B00nie]

Like others here said that kind of sound pressures _will_ damage your hearing despite any equalization you may have.

You're not probably even looking for a hi-fi sound, but if you do here's some pointers:

When you put several speakers to play the same audio frequencies they produce something that's called the 'comb filter' effect. When sound waves originate from positions further than half wavelength, some waves will match in phase producing double sound, some waves will sum each others out. That is why you should never ever have anything than just one properly designed speaker playing an audio channel at a time. That is, if you want the sound to be even remotely hi-fi.

Second thing - you should place most speakers as far away as possible from any reflective surfaces i.e. floors, walls or ceilings (yes, that includes the back wall too). If you have small speakers you should put them on tall stands so that the tweeter is about on ear level at your listening position. Your speakers should be symmetrically positioned in the room and your listening position should be in the bottom position of a 'listening triangle' in order to get proper stereo imaging.

Thirdly you should put heavy furniture (heavy built sofa(s), book shelf full of books etc.) to your listening room to dampen low frequency standing waves. Thick rugs and curtains or 'wall carpets' on wall help with early reflections. Most optimally your listening room should be wooden in structure to let low frequencies pass through them. Concrete and audio = problems.

OTOH if all you're aiming for is to blast out your ears while you're drunk (and alone since no woman is surely not going to join you in that self destruction) you can pretty much continue looking for the damping pads. Oh, and subscribe to the hearing aid and tinnitus news groups while you're at it!

 

[GotNoRice]

i'm not sure about the "presentation" exactly but as a fellow vintage fan... I love some of you gear the (the JBL speakers and that Yamaha M-2?)

I'm running a C-80 Preamp (1984) with a Yamaha M-2 amp (1979-1982), two Yamaha P2201 amps (1976). A pair of JBL L150s (1979-82), L100Ts (1985-1988), and 4412s (~1986).

but mainly you are going to wreck you hearing entirely if you don't chill

Seems like everyone wants to give hearing loss advice. A few things:

The two common weighting filters used for measuring SPL levels do not measure the same across the frequency spectrum. "A-weighting" heavily favors the same frequencies that human hearing is extra sensitive to, as shown in the Fletcher Munson curve earlier. This makes sense in that, like I said before, human hearing is not equally sensitive across the entire frequency spectrum. Damage does not occur at the same SPL regardless of frequency. Someone screaming in a bullhorn aimed at your ear is going to create much more potential for hearing loss than someone at a subwoofer competition. This is why hearing loss guidelines generally use the A-scale. Most of that 130dBC was bass and suffice it to say that if I had measured using the A-scale instead of the C-scale, the reading would have been lower. Taking a reading made using the C-Scale and trying to apply hearing loss criteria created using the A-scale doesn't really make sense, especially if the content is bass heavy.

The 2nd thing is that you can see the meter was set to "Max hold", which holds at the peak reading that it takes. That means it peaked to 130dB at least one but not that it's constantly at that level.

If I was listening at 130dBA, constantly, I probably would be deaf by now. That is not the case.

OTOH if all you're aiming for is to blast out your ears while you're drunk (and alone since no woman is surely not going to join you in that self destruction) you can pretty much continue looking for the damping pads.

I think you'd be surprised the number of couples who get drunk every night and also love their music.

 

[B00nie]

I'm running a C-80 Preamp (1984) with a Yamaha M-2 amp (1979-1982), two Yamaha P2201 amps (1976). A pair of JBL L150s (1979-82), L100Ts (1985-1988), and 4412s (~1986).



Seems like everyone wants to give hearing loss advice. A few things:

The two common weighting filters used for measuring SPL levels do not measure the same across the frequency spectrum. "A-weighting" heavily favors the same frequencies that human hearing is extra sensitive to, as shown in the Fletcher Munson curve earlier. This makes sense in that, like I said before, human hearing is not equally sensitive across the entire frequency spectrum. Damage does not occur at the same SPL regardless of frequency. Someone screaming in a bullhorn aimed at your ear is going to create much more potential for hearing loss than someone at a subwoofer competition. This is why hearing loss guidelines generally use the A-scale. Most of that 130dBC was bass and suffice it to say that if I had measured using the A-scale instead of the C-scale, the reading would have been lower. Taking a reading made using the C-Scale and trying to apply hearing loss criteria created using the A-scale doesn't really make sense, especially if the content is bass heavy.

The 2nd thing is that you can see the meter was set to "Max hold", which holds at the peak reading that it takes. That means it peaked to 130dB at least one but not that it's constantly at that level.

If I was listening at 130dBA, constantly, I probably would be deaf by now. That is not the case.



I think you'd be surprised the number of couples who get drunk every night and also love their music.

The curves show the sensitivity and pain thresholds, not the damaging effect the sound is going to have. 130db even as a peak is way too much, especially considering your remark of that being as high as the tool will go, indicating your peak volumes were even higher.

 

[GotNoRice]

The curves show the sensitivity and pain thresholds, not the damaging effect the sound is going to have. 130db even as a peak is way too much, especially considering your remark of that being as high as the tool will go, indicating your peak volumes were even higher.

You're not taking into account the differences between A-scale and C-scale. In the bass frequencies, the discrepancy between the two can be as large as 20-30dB. Subtract 20-30 from 130, and you begin to get the picture of what my last post was trying to explain...

 

[B00nie]

You're not taking into account the differences between A-scale and C-scale. In the bass frequencies, the discrepancy between the two can be as large as 20-30dB. Subtract 20-30 from 130, and you begin to get the picture of what my last post was trying to explain...

The difference between A and C scale are that when measuring on A scale the tool will mimic the ear sensitivity where on C scale it goes pretty much flat on lower frequencies.

The C scale will more accurately show the sound pressure your ears are subjected to. Lower frequencies are arguably worst since they travel all the way to the back of the eardrum, affecting the hairs of all spectrums of hearing.

 

[GotNoRice]

The C scale will more accurately show the sound pressure your ears are subjected to.

http://www.osha.gov/dts/osta/otm/noise/health_effects/physics.html#weighting

It has been found that the A-network gives a better estimation of the threat to human hearing than the other networks. The A-network is required by OSHA for measuring noise in the workplace and is widely used in describing occupational and environmental noise.

 

[jojo69]

jeez, lot of ninnies in here

I used to run 210W into 6 12" drivers in my guitar rig and I can still hear sirens and train horns just fine.

setup looks bumpin' dude

 

[GotNoRice]

Mouse Pads! Cheapest generic rubber ones you can find. The thick ones (3/16" - 1/4") with the cloth top should work well. Get one, quarter it, and stick a piece on each corner of the speaker. If the cloth surface proves to be too slick and you still get movement get another mouse pad, quarter it, and glue them together, cloth side to cloth side.

Did this with a PC that sat on top of a file cabinet. The fans and HDs created a resonance in the file cabinet. Put the mouse pads under it and the resonance went away -and- the PC was almost impossible to move without picking it up.

Cool I just scrounged a bunch of old mouse pads and it looks like this might work. Thanks for the suggestion!

setup looks bumpin' dude

Thanks

 

[B00nie]

http://www.osha.gov/dts/osta/otm/noise/health_effects/physics.html#weighting

And from your own site:

C-network readings are also necessary when determining the amount of attenuation from hearing protection.

It's quite futile to try to defend those sound pressures. High SPL != quality sound.

Your ears bud...

 

[GotNoRice]

It's quite futile to try to defend those sound pressures. High SPL != quality sound.

Your ears bud...

I'm flattered by your concern for my ears, but not sure why you keep obsessively derailing my thread

I've made no claims of having obtained nor do I seek any sort of audiophile nirvana. I know what I like from my music, and have constructed my system to deliver exactly that: Powerful, fast, & accurate bass. The combined 6 12" woofers are quite capable in that regard. The only reason I was measuring with C-scale in the first place was to give a better representation of the bass output. I've also made no claims about the duration at which I listen at loud volumes (due to it being irrelevant to the subject of the thread).

My listening is done within the bounds of the Permissible Noise Exposure as dictated by OSHA and using standard A-scale readings which rarely peak above 110dBA.

With certain songs it only takes about 5 seconds for the JBL 4412s up top to rattle far enough that I feel like I have to run over and catch them. This is a problem that still occurs even with short-duration listening.

 

[B00nie]

Well the easyest solution is what I gave you earlyer. Use only a single pair of high quality speakers for 2ch audio. Solves many problems in one go.