DIY Townsend derivative bouncy bouncy speaker stands.
- Thread starter Chris
- Start date
Chris
pfm Member
Maybe because on spikes the box was moving and now isn’t or at least not so much. That’s what Is implied by Mr. Townsend’s thoughts on the subject. I’m not a seismograph person but I hope I know what I think I’m now hearing.
John Phillips
pfm Member
I think it may be a question of "what frequency are we discussing?"
AIUI the appropriate wobble frequency for decoupling audio vibrations from 20 Hz upwards is about 2 Hz (as pointed out earlier by @awkwardbydesign). About one tenth of the lowest frequency to be decoupled. That (about 2 Hz) is where the resonance of the "spring-weight" stand/loudspeaker system must be designed; that's the frequency where the stand does not decouple at all (indeed it makes coupling worse); and that's where it wobbles.
Above that resonance frequency the decoupling increases (and wobble decreases) second-order so that by 20 Hz there is useful decoupling. And by the time you get up to tweeter frequencies any wobble at tweeter frequencies should be well suppressed. AFAICS there's going to be no significant impact on tweeter output.
I have very limited experience here beyond having read some basic theory (example here, see figures 2, 3 and 4) so I am open to being contradicted.
awkwardbydesign
Officially Awesome
Quite. And as an aside, Max's video of using his pods with and without damping looks flawed, to my way of thinking. He uses a continuous and constant frequency vibration to demonstrate the value of his damping. I don't believe that is a real world situation, unlike on a motor vehicle. But I would be interested if someone could investigate that.
I have also hung the HF/MF cabinets on a previous build from a supporting cage, using cotton* ropes, so that they were free to swing back and forth. I expected the higher frequency definition to improve, but to my surprise it was the bass that showed a very noticeable improvement. I think that is probably because what we think of as bass has a lot of higher frequencies involved ("bass transients" actually being much higher in frequency), so cleaning up those actually cleans up the bass.
* I picked cotton thinking there might be less transmission of resonances through them than through metal or plastic. I didn't test that, BTW, as the improvement was enough for me to be happy with it and move on.
awkwardbydesign
Officially Awesome
Spikes will couple*, and nothing, not even solid rock, is totally inert. Vibrations will occur and be transmitted back and forth, but the Stella stands, and derivatives, will break (or reduce) that link above resonance.
* Which frequencies are coupled, and which are filtered, would be a nice experiment for someone, if it hasn't already been done. That may well explain the different results people get.
awkwardbydesign
Officially Awesome
Old answer. Max Townshend's original isolation platforms used them, then he tried urethane elastomers (bicycle front fork dampers) and now springs. I never tried the elastomers, as they were hard to get by the time I wanted them), but inner tubes work well, although they slowly deflate and eventually perish. But they are cheap, versatile and very easy to DIY.
Chris
pfm Member
With my very limited understanding of what constitutes a 2hz resonant frequency filter, Is this an nvitation to experiment with various degrees of wobbliness to find an even better result when listening to my speakers. I have no doubt that bass has improved and will proceed to check treble quantity, the quality is already much improved. In actual fact I discovered that my Valhalla Tech isolation pads are for a combined weight of 120lbs per speaker which is roughly double their real weight so maybe things can de improved by getting sets for a total of 60lbs each, presumably making the platforms a tad more jelly-like. on the videos the Townsend jobs seem to wobble a fair bit more than mine do at present. Am I right in hoping that more wobbly = possibly more treble level ?
Last edited:
Chris
pfm Member
Have now fitted the correct density feet between stand/platform and speakers which now seem to dance in a more balanced and controlled way. As I said bass is deffo improved and the general mise en scene seems wider,deeper and more relaxed but maybe that´s me after lifting the b........