On the data out, you measured that didn't you? Funny my computer loads software and rips CD's without all this. See you guys later, I'm leaving this thread.
It is not the tape itself that can change a lot the resonating/vibrating behavior of a panel. Not heavy enough. But, glued between, by example, a mobile shelf and its frame / support, it avoids the noise that can make two hard surfaces vibrating against each other. This also creates damping of the panel itself by bonding it to the mass of the support / wall.
Small foam balls cut in half also make excellent anti-vibration feet under the different elements of your hi-fi system.
Nothing mysterious, nothing esoteric.
Properly placed carpets, rugs, tapestry with fleece on some walls will greatly assist in the acoustic dampening of the listening room. As well as fabric sofas, bookcases filled with books, etc. Everyone knows that.
No. I measured the signal on the head motor itself as i said. How to measure the 'datas' out of an audio CD player ?
Well, can-you believe ? My 'audio' CD player was working as well as your computer before. More or less, under guaranty.
Just, it was working better after: less error corrections. You are strange, sometimes. When you rip a CD, you read datas, at variable speeds. Not an audio stream.
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The tape damps acoustic resonances not by mass damping but by unequal resonant modes. It also reduces acoustic reradiation.
Better mass damping can be obtained by mass such as sand that has nonresonant modes. Even lead sheets have some modes.
Book shelves and the like break up standing waves and thus resonances in a manner different than absorption.
The three basic methods are absorption by depth of fuzzy stuff, absorption by diaphragmatic absorption and reflective dispersion.
??? Résonnant mode of a tape of foam ?
Just hit a lead sheet with what you want, your finger or a hammer ;-) (at room temperature)
My personal speakers enclosures are made with chipboard, with a 2mm lead sheet glued on its outside and wood plating glued on the lead. Not perfect (resonances modes still exists but at much lower frequency and very quickly damped.)
And, inside, tar. of course, panels of glass wool for acoustic damping in the middle of each volume (where is maximum speed).
More efficient, for sure than the same overall thickness (impossible) with sand.
They are VERY HEAVY, it help for the instant dynamic.
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Foam tape effectively breaks up the typical case thin steel panel into several smaller resonant panels. Try a bit of tape on a panel and tap it!
Yes even soft lead sheets have resonances. Generally low frequency and due to the high mass well damped. When you measure studio wall isolation it shows up at low frequencies. A material like sand shifts from the low frequency energy and effectively changes the energy to a higher frequency where it is more readily absorb. Classic example when sand is better than lead is reducing noise from trains or other steel rail vehicles.
Lead is very useful for conserving space. When studio space is high rent, lead sheets are great. They tie up almost no additional floor space. But for floor and ceiling particular fill works better.
Yes even soft lead sheets have resonances. Generally low frequency and due to the high mass well damped. When you measure studio wall isolation it shows up at low frequencies. A material like sand shifts from the low frequency energy and effectively changes the energy to a higher frequency where it is more readily absorb. Classic example when sand is better than lead is reducing noise from trains or other steel rail vehicles.
Lead is very useful for conserving space. When studio space is high rent, lead sheets are great. They tie up almost no additional floor space. But for floor and ceiling particular fill works better.
Now this is a subject that needs addressing, you know uncontrolled vibration in audio systems. First, we often think of the speaker cabinets, and rightly too! They almost always seriously vibrate at their unique set of frequencies. Many years ago, perhaps 50, I originally thought that a super strong and thick wooden cabinet, like we used with the Grateful Dead was the answer, but it was only partially the answer, because the cabinets still vibrated, just at a higher frequency due to the added stiffness of the thick birch plywood that we made them from. A few papers at the London AES in 1975 set me straight about this. Some of those papers are among the best ever presented, in my opinion.
Of course, Dave Wilson really tried to damp his speaker cabinets. Originally he lead-lined them, and they were pretty darn damped. Later, he found special damping materials, better than wood to make his cabinets. The darn stuff dulled his saws (or whatever he used to cut them) and the individual pieces had to be made to very high tolerances, because there was just no 'give' like wood might have if you mismatched the dimensions of the pieces, even a little bit. Now you might have some added understanding why his speakers cost so much. They are expensive to build, but the cabinets don't audibly resonate!
Of course, Dave Wilson really tried to damp his speaker cabinets. Originally he lead-lined them, and they were pretty darn damped. Later, he found special damping materials, better than wood to make his cabinets. The darn stuff dulled his saws (or whatever he used to cut them) and the individual pieces had to be made to very high tolerances, because there was just no 'give' like wood might have if you mismatched the dimensions of the pieces, even a little bit. Now you might have some added understanding why his speakers cost so much. They are expensive to build, but the cabinets don't audibly resonate!
White pages or Yellow Pages ?
.I tried placing a house brick on top of my cd player.
It turned out to be directional......iron rich clay brick.
Dan.
It seems obvious that anything that reduces the vibrations of the CD transport can only bring benefit.
I believe Scott confused the purpose of my trick (increasing of the inertia of the spring suspended transport assembly) with something magical I don't agree with, like those special feet (cones etc) that some like to put under their solid state amps or pre-amps.
Good solid state components are not supposed to be microphonic ( it is enough to record the output line when you hit-it with a hammer to ensure-it).
If so, it is time to look for the dried up welding or faulty component.
My horns are made from a turned massive piece of wood. They are beautiful and It is incredible how it damps the vibrations: Knocking on it with your finger sounds like you did it on the wall of a blockhaus: you just hurt your finger.
My first prototype was in epoxy resin: the difference in sound quality is huge and worth the price.
Nothing esoteric either.
I believe Scott confused the purpose of my trick (increasing of the inertia of the spring suspended transport assembly) with something magical I don't agree with, like those special feet (cones etc) that some like to put under their solid state amps or pre-amps.
Good solid state components are not supposed to be microphonic ( it is enough to record the output line when you hit-it with a hammer to ensure-it).
If so, it is time to look for the dried up welding or faulty component.
My horns are made from a turned massive piece of wood. They are beautiful and It is incredible how it damps the vibrations: Knocking on it with your finger sounds like you did it on the wall of a blockhaus: you just hurt your finger.
My first prototype was in epoxy resin: the difference in sound quality is huge and worth the price.
Nothing esoteric either.
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White pages or Yellow Pages ?
White.
In Switzerland, the yellow pages have much lower mass.
Happy to find someone who still remembers these extinct species.
I have paid their extortionist rates for Yellow pages column cm....something like $500 for 3cm or so IIRC.White.
In Switzerland, the yellow pages have much lower mass.
Happy to find someone who still remembers these extinct species.
Telephone books have also gone extinct because the trees to print them on have gone extinct......
It seems like every house in the 'western world' got copies, just like the Ikea catalogues that most people don't read.
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Sorry to see Scott got frustrated. I think some of the engineers just don't want this thread to descend into audiophoolery stuff, and I think we have all seen useless audio sites where that has happened. It may not take too much of that before this looks like a safe place for any claim at all. On the issue of vibration damping, IME, it can help a lot when used selectively.
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Anyone here got a pair of KEF LS50’s? If you have MET7’s or what ever they are called, it’s well worth ditching them and spending a bit more ($1400 or £800 in store price) for these which are a really decent speakers (add $200/£150 for stands). Beer money for the performance on offer and superb in a smallish listening room. Lots of reviews and measurements on line.
Let’s at least get decent with our speakers.
Scott, 10 watts ? Shaking my head in disbelief here. C’mon man!
Let’s at least get decent with our speakers.
Scott, 10 watts ? Shaking my head in disbelief here. C’mon man!
True. Adding that the acoustic of the hall is just day and night. Every people involved with P.A systems knows this.
For John, who was involved in this extraordinary adventure of the "Wall of sound", an anecdote.
Because of this change in the acoustic, it was difficult to equalize properly PA systems with sliding frequencies with the audience inside the hall, and the first curves made in the empty hall were often far to be optimal once the hall crowded.
So I imagined a trick. You know we often use a music tape playing some music at low volume while the audience is entering the concert hall. I recorded a tune, highly compressed and limited, in order to have all its crests at the same level, whatever the frequencies. I used-it with a memorized 1/3 octave analyzer as the last tune of this program, and at higher level to cover enough the noise of the crowd. With the advantage that this was catching the attention of the audience, creating some kind of a suspense and more silence. Followed by a silence, long enough to give the time to tune the equalization. Then, the show could start in good conditions.
The way I see it, this thead is about exploring the unknown, with requires some heresy/black magic/snake oil, e.g. flat earth -> round earth -> orbital mechanics.
Otherwise, do you think it's fun talking about the application of old receipes from dusty textbooks?
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