Once I get round to it (I've got a lot of projects on the go as well as moving to Uni) I was thinking about mounting speakers on some kind of air suspension device - a small pad of some kind.
Any thoughts on this idea?
(I might try your spring idea some time too)
Any thoughts on this idea?
(I might try your spring idea some time too)
Probably similar to mounting the cabinet on a flat surface - ie the bottom panel of the cab is damped.
By using cones or springs you can choose nodal minima or maxima points and allow the bottom panel to run free.
Eric.
By using cones or springs you can choose nodal minima or maxima points and allow the bottom panel to run free.
Eric.
annex666 said:
You mean like <a href="http://www.townshendaudio.com/prod04.htm">this?</a>
<img src=http://www.townshendaudio.com/images/rega.jpg>
Cheers
Brett
Throwing Pearls To Swine !
I've tried Bubble Wrap too, and it worked quite well, but I still prefer the bottom panel of the cabinet to be undamped, and the valve springs are better.
Somebody try it and report back to the forum - suggestions so far have been speculation of how it can't work, or alternatives but so far nobody has run with the information that these springs are available in quantity for free if you just politely ask the right people (engine shops and auto wreckers).
You guys are looking a gift horse in the mouth !
Eric.
I've tried Bubble Wrap too, and it worked quite well, but I still prefer the bottom panel of the cabinet to be undamped, and the valve springs are better.
Somebody try it and report back to the forum - suggestions so far have been speculation of how it can't work, or alternatives but so far nobody has run with the information that these springs are available in quantity for free if you just politely ask the right people (engine shops and auto wreckers).
You guys are looking a gift horse in the mouth !
Eric.
Springs and dampers are what the pros use!
There is a company called GERB who are German (therefore quite extreme engineers) who produce mountings based on a metal spring and elastomer damper which are used for protecting buildings against earthquake vibrations, and for soundproofing rooms to near total isolation. This approach does not appear to be used that much in the speaker building industry, which seems curious. Resting speakers on pins reduces the amount of coupling of the cabinet to the floor, but they are still of course coupled. I would have thought that the improvement in sound achieved by pins spikes or cones is down to the fact that the floor does not resonate as part of the cabinet, allowing the speaker and cabinet to perform as the designers intended it to (they can't know the properties of everybody's floor). The audiophile cone is quite an amazing piece of marketing, I have seen them sold for as much as £100 for a set of three pieces of milled brass. Somebody is sitting there with a lathe basically printing money by selling the emperor's new clothes! Sitting speakers on pads of material with a high damping factor and a bit of elastic movement provides a nice barrier for vibration. Connecting them to the floor with rigid points does not, as the kid's experiment with two paper cups connected with a bit of string (or even worse, a hard thin stick) will prove. No matter how pointy your pins are your floor will shake. The stiffer the material the better the transmission. So what I want to know is this. Spring man is on the right track as far as I can work out, and I would be interested to see if there is a way of modifying car/motorbike suspension to hang a PA from to prevent mechanical transmission of sound to the building and therefore neighbours.
If you want to read something really weird on this subject check out this link: http://www.soundstage.com/yfiles/yfiles200007.htm
There is a company called GERB who are German (therefore quite extreme engineers) who produce mountings based on a metal spring and elastomer damper which are used for protecting buildings against earthquake vibrations, and for soundproofing rooms to near total isolation. This approach does not appear to be used that much in the speaker building industry, which seems curious. Resting speakers on pins reduces the amount of coupling of the cabinet to the floor, but they are still of course coupled. I would have thought that the improvement in sound achieved by pins spikes or cones is down to the fact that the floor does not resonate as part of the cabinet, allowing the speaker and cabinet to perform as the designers intended it to (they can't know the properties of everybody's floor). The audiophile cone is quite an amazing piece of marketing, I have seen them sold for as much as £100 for a set of three pieces of milled brass. Somebody is sitting there with a lathe basically printing money by selling the emperor's new clothes! Sitting speakers on pads of material with a high damping factor and a bit of elastic movement provides a nice barrier for vibration. Connecting them to the floor with rigid points does not, as the kid's experiment with two paper cups connected with a bit of string (or even worse, a hard thin stick) will prove. No matter how pointy your pins are your floor will shake. The stiffer the material the better the transmission. So what I want to know is this. Spring man is on the right track as far as I can work out, and I would be interested to see if there is a way of modifying car/motorbike suspension to hang a PA from to prevent mechanical transmission of sound to the building and therefore neighbours.
If you want to read something really weird on this subject check out this link: http://www.soundstage.com/yfiles/yfiles200007.htm
reading this reminds me of how we stop feedback through the decks in a club with a nightmare room
ash trays and elastic bands!
about ten thick rubber bands streched across an ash tray then placed under each foot
works a treat completely removing any feedback and really opens up the room - scratch dj's hate us tho ;-)
was wondering if you could replace the feet with a cone, spike up, and sit your speakers on top?
ash trays and elastic bands!
about ten thick rubber bands streched across an ash tray then placed under each foot
works a treat completely removing any feedback and really opens up the room - scratch dj's hate us tho ;-)
was wondering if you could replace the feet with a cone, spike up, and sit your speakers on top?
The BBC's studios are mounted on springs, to prevent low frequency traffic noise entering the room. One friend was an acoustic engineer, and this was one method to prevent the conduction of vibration, which is just like low frequency sound, but structurally borne rather than air borne. I've always thought that spikes are an odd idea, they still conduct vibration. Another friend uses concrete paving slabs to provide a very high mass to absorb the vibration. Otherwise, the floor will vibrate and consequently radiate sound, with its own frequency response etc.
Its enough that the room is part of the speaker at low frequencies, without the floor being part of the cone.
Its enough that the room is part of the speaker at low frequencies, without the floor being part of the cone.
but that's the problem isn't it the more solid an object is the easier it conducts sound/vibrations
the least conductive medium of all is a vacumm followed by air itself
before adopting the elastic bands we used to take a tip from earthquake proof buildings
they've got foundation pillars of rubber sandwiched between sheets of steel
the steel giving the rigidity upon which to build the rubber damping out any vibrations
we used to sandwich varying densities of foam between paving slabs and hardboard it did the trick but nowhere near as well as the elastic bands
the least conductive medium of all is a vacumm followed by air itself
before adopting the elastic bands we used to take a tip from earthquake proof buildings
they've got foundation pillars of rubber sandwiched between sheets of steel
the steel giving the rigidity upon which to build the rubber damping out any vibrations
we used to sandwich varying densities of foam between paving slabs and hardboard it did the trick but nowhere near as well as the elastic bands
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