advertisement


DIY Speaker Isolators for Wooden Floors

jimification

pfm Member
I've been messing with different supports for a while trying to mitigate the effects of our suspended floor on our floor / stand mounted speakers. After watching some presentations I was very tempted to try some of the Townsend products but thought I'd have a go at making something myself that would do a similar job but cost less and be less visually obtrusive.

As I understand it, the Townsend springs work by having a strong resonant frequency low enough that audio frequencies are unaffected by it (the same principle as the isolation in an LP12 - a low pass filter), so what I wanted was something that would allow my speakers to resonate at around 4hz. Experiments with various inner tube setups had demonstrated that this idea really worked but I found inner tubes quite problematic with stability and the "29er" MTB tubes that I found worked best looked goofy sticking out from under the things.So I was trying to find something small and neat that would duplicate the same effect. I finally came up with what's shown below. It's just a section of bicycle inner tube stretched over a small cup. The spikes in the integrated speaker stands are replaced with M6 coach bolts (to better distribut the load onto the stretched inner tube surfaces).

In the test version I used some aluminium napkin rings but for the full on blow the budget version I bought some copper tealight candle holders from Debenhams online. The copper cup on the left with the coach bolt on shows how they sit in use (so I have 4 under each speaker)

DSCF5307-X4.jpg


So do they work? Yes - amazingly well actually, when given a gentle push, the speakers rock quite nicely at 4hz, the bass boom is gone, the overall sound is clearer (and, what I didn't expect - quieter) The stereo image, in particular is much, much better defined.

Aesthetically they are almost invisible under the speaker stands expect for a little glint of copper (which goes quite well with the solid maple speaker cabinets) I hope this idea might help some suspended floor sufferers! Cheers!
 
The rocking mode is unlikely to be the most relevant one when it comes to transmitting vibrations into the floor. What is the frequency of the lowest bouncing mode? That is, when you press down evenly on the speakers and let go what frequency do they bounce rather than rock?

I would not expect a strongly stretched inner tube to have a particularly long life. If the bounce test demonstrates that the spring rate is in the right ball park with the inner tube then putting a coil spring in your cup would seem a longer lasting alternative. A better solution might be nonlinear springs that stiffen progressively when compressed since this would help with stability by opposing rocking.
 
How does one measure the 'bouncing frequency' of a speaker cabinet when it's sitting on its isolators?
 
Rubber has internal hysteresis, which contributes damping (the other, essential part of any deliberate introduction of a 'spring')

With only the same reservations about the tube segment life as @h.g. , this is a very tidy bit of lateral thinking for experimenting further. I like it - thanks for sharing :)
 
Thanks Martin :) I note that Townshend has a rubber wrap around his spring - I presume for damping, as you said. The inner tubes are ok so far. Just checking the photo data showed I set these up in June 2018 and they still seem fine. If they do ever "wear out" or lose their elasticity, replacement strips are relatively economical :)
 
I thought they'd just ..perish first , but a year+ is good!

Just freewheeling from here another approach could be, say, a 1" washer locked-down with a nut against the the inverted head of the bolt, to engage with a spring hidden in the tealight holder, the spring perhaps filled with a foam or similar for experimental damping/lossiness. Hmm ...
 
This is a very good scheme. I have a seemingly limitless supply of dead inner tubes. There are only so many plant ties that you need.
 
I like this! I had proper springs made with a 2.4Hz resonance, but 8 of them cost £60. I may well try these for the loft speakers.
I still use the inner tube version up there at the moment.
BTW, I found cheap inner tubes worked best for me, as they are softer and have a lower resonant frequency. Maybe that would be true with this type too.
 
Thanks Martin :) I note that Townshend has a rubber wrap around his spring - I presume for damping, as you said. The inner tubes are ok so far. Just checking the photo data showed I set these up in June 2018 and they still seem fine. If they do ever "wear out" or lose their elasticity, replacement strips are relatively economical :)
The Townshend springs have a small air hole to control the damping. And it might be worth putting a suitable block in each cup a short distance below the loaded feet, so if one does fail it can't fall too far. That's what I will do.
 
I've been messing with different supports for a while trying to mitigate the effects of our suspended floor on our floor / stand mounted speakers. After watching some presentations I was very tempted to try some of the Townsend products but thought I'd have a go at making something myself that would do a similar job but cost less and be less visually obtrusive.

As I understand it, the Townsend springs work by having a strong resonant frequency low enough that audio frequencies are unaffected by it (the same principle as the isolation in an LP12 - a low pass filter), so what I wanted was something that would allow my speakers to resonate at around 4hz. Experiments with various inner tube setups had demonstrated that this idea really worked but I found inner tubes quite problematic with stability and the "29er" MTB tubes that I found worked best looked goofy sticking out from under the things.So I was trying to find something small and neat that would duplicate the same effect. I finally came up with what's shown below. It's just a section of bicycle inner tube stretched over a small cup. The spikes in the integrated speaker stands are replaced with M6 coach bolts (to better distribut the load onto the stretched inner tube surfaces).

In the test version I used some aluminium napkin rings but for the full on blow the budget version I bought some copper tealight candle holders from Debenhams online. The copper cup on the left with the coach bolt on shows how they sit in use (so I have 4 under each speaker)

DSCF5307-X4.jpg


So do they work? Yes - amazingly well actually, when given a gentle push, the speakers rock quite nicely at 4hz, the bass boom is gone, the overall sound is clearer (and, what I didn't expect - quieter) The stereo image, in particular is much, much better defined.

Aesthetically they are almost invisible under the speaker stands expect for a little glint of copper (which goes quite well with the solid maple speaker cabinets) I hope this idea might help some suspended floor sufferers! Cheers!
I have carpets on floorboards so suspended i think, it creaks when i walk on it. How do you fasten the rubber to the metal copper tea light things. And don't they rock under the stands and my speaker bolts are 10mm so unual thickness.
 
I have carpets on floorboards so suspended i think, it creaks when i walk on it. How do you fasten the rubber to the metal copper tea light things. And don't they rock under the stands and my speaker bolts are 10mm so unual thickness.
There's a photo above that shows how it works. This is the diy section, a willingness to experiment for yourself and carry out your own light engineering and problem solving is expected. If you want a turnkey system that suits your exaxt requirements and you aren't prepared to do your own development work then this may not be for you.
 
Excuse my ignorance but are these isolating the speakers from resonance transmitted from the floor. In that case would they be of no use with a wooden block parquet floor on granite and ultimately concrete. I don´t need to remove bass boom but improving the imaging would be nice.
 
There's a photo above that shows how it works. This is the diy section, a willingness to experiment for yourself and carry out your own light engineering and problem solving is expected. If you want a turnkey system that suits your exaxt requirements and you aren't prepared to do your own development work then this may not be for you.
I guess your right as i look at the instabilities of a system and this one lookks okay but heavy weighted stands would just seem to unstable for this to work efficiently. Plus they would give or add some height to my already tallish stand/speakers.
 
Excuse my ignorance but are these isolating the speakers from resonance transmitted from the floor. In that case would they be of no use with a wooden block parquet floor on granite and ultimately concrete. I don´t need to remove bass boom but improving the imaging would be nice.
Yes they are isolating the speakers from the floor. Any noise has to go along the floor, up the cup, and then cross the rubber suspension to the attachment to the speaker. The rubber is the key. To demonstrate this, get a hammer and hit your hand. Off you go to hospital. Now isolate your hand with a rubber tyre and hit the tyre. This time you don't break your hand. That's isolation.
 
I guess your right as i look at the instabilities of a system and this one lookks okay but heavy weighted stands would just seem to unstable for this to work efficiently. Plus they would give or add some height to my already tallish stand/speakers.
OK, so have a think about an alternative. A folded towel would work. A polystyrene tile would work. So might a rubber sheet. These solutions cost pennies. Build a system into your stand that addresses your objections. There's no one answer here. Over to you.

Alternatively, hand over a hefty sum to Townsend for a system with all the development work done.
 
we can argue the maths and physics of how it might work forever, starts to read like a hifi review written by someone who regurgitates specs rather than listening.
The important thing here is - does it work.
Clearly it does, the maker is happy with his results, so much so he has shared his ideas with us.
All sorts of other versions are possible, its up to our imaginations.
 
Yes they are isolating the speakers from the floor. Any noise has to go along the floor, up the cup, and then cross the rubber suspension to the attachment to the speaker.

So, assuming my solid floor is not transmitting any noise into my speakers and possibly affecting my pin-point imaging (not) I need to take any noise generated away from my boxes by coupling them with spikes whose only function in practise seems to be turning my floor into a dartboard. But if the walls of my boxes seem to be totally inert and impervious to even the strongest bass beats then it is presumably the air inside that is vibrating and affecting my drivers which need to be isolated from its toxic effect. Should I buy some old Roksans with tweeters dangling from springs ? But my tweeters are Seas Millenniums which are not open backed and certainly look to be virtually bomb - proof from behind. So the real culprits are the fixing screws on the drivers which should be made of jelly
I guess we should implant our speakers into reinforced concrete walls.
 
Excuse my ignorance but are these isolating the speakers from resonance transmitted from the floor. In that case would they be of no use with a wooden block parquet floor on granite and ultimately concrete. I don´t need to remove bass boom but improving the imaging would be nice.
My floor is solid oak glued to concrete, and Townshend type springs still improve the sound.
 


advertisement


Back
Top