The latest BS from that crazy guy 
Audio Tweaks, Damping, Vibration Isolation, Room Acoustics, Crystals
Audio Tweaks, Damping, Vibration Isolation, Room Acoustics, Crystals
🙄
I think he left the "m" out of the- super intelligent chip for bluray- titling...
It's a funny link!
The latest BS from that crazy guy
Audio Tweaks, Damping, Vibration Isolation, Room Acoustics, Crystals
I think he left the "m" out of the- super intelligent chip for bluray- titling...
It's a funny link!
The latest BS from that crazy guy
Audio Tweaks, Damping, Vibration Isolation, Room Acoustics, Crystals
These sorts of businesses do stay around though.
Maybe the placebo effect becomes very convincing following financial investment.
Ford V8 Valve Springs And Kitchen Top Granite...
Audio Tweak, Vibration Isolation, Resonance Control, Anti Vibration,
I have been using this for decades....works very well.
Dan.
Audio Tweak, Vibration Isolation, Resonance Control, Anti Vibration,
I have been using this for decades....works very well.
Dan.
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You have no damping only springs that can resonate, have a look at AV (anti vibration ) mounts, there is always a lossy element.
Looks smart. I think it would resonate, as Marce writes, but at such a low frequency as be a very good isolator from its perch.
Zero Cost Isolation....
However, in this case the mechanical resonance frequency is less than 1Hz.
My system does not go low enough to excite that resonance.... ie the system 'floats'.
Dan.
Sure.
However, in this case the mechanical resonance frequency is less than 1Hz.
My system does not go low enough to excite that resonance.... ie the system 'floats'.
Dan.
The latest BS from that crazy guy
Audio Tweaks, Damping, Vibration Isolation, Room Acoustics, Crystals
He is not crazy. He's cynical, deliberate, and skilled.
Max, we had some very large granite proof blocks that had internal ringing like crazy. You might want to place a mic right over the surface and ping the center of your slab out of curiosity. Our blocks were 4" thick and could not be damped, the AC excited one resonance and a very high power microscope placed on top was useless at high magnification. The block was on a very expensive pneumaticly isolated set of legs.
This was a classic case of asking the wrong person to order the best isolation setup you can buy.
Hi Scott.
The kitchen top stone that I have used is about 1'' thick, and yes it does ring like a slab of glass when tapped with a hard object.
In my usage I used three layers of stone...shelf/springs/stone/draw liner/stone/CDP/draw liner/stone in order to increase overall mass, and get platform assembly vertical resonance frequency way down.
Squares of the draw liner were also placed under the CDP feet.
This overall combination did not ring, and did give very useful isolation from the wooden flooring....maybe not good enough for your microscope, but very adequate for this application.
Placing the speakers on four such springs also kept mechanically coupled vibration out of the wood flooring very effectively.
I have also placed bass guitar quad boxes on four such springs, and this made FOH mixing duty much easier by markedly reducing excitation of the typically light (12mm form ply) stage flooring, which then bleeds into every other mic on stage.
Dan.
The kitchen top stone that I have used is about 1'' thick, and yes it does ring like a slab of glass when tapped with a hard object.
In my usage I used three layers of stone...shelf/springs/stone/draw liner/stone/CDP/draw liner/stone in order to increase overall mass, and get platform assembly vertical resonance frequency way down.
Squares of the draw liner were also placed under the CDP feet.
This overall combination did not ring, and did give very useful isolation from the wooden flooring....maybe not good enough for your microscope, but very adequate for this application.
Placing the speakers on four such springs also kept mechanically coupled vibration out of the wood flooring very effectively.
I have also placed bass guitar quad boxes on four such springs, and this made FOH mixing duty much easier by markedly reducing excitation of the typically light (12mm form ply) stage flooring, which then bleeds into every other mic on stage.
Dan.
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Mic bleeding through the floor never thought of that one. This isolation stuff is interesting, BTW by AC I meant the air conditioning ducts and fans. I have a 400Hz fan resonance in my office that is a pain to eliminate below the noise floor. Looking at noise spectra is one thing I suspect these resonances if large enough modulate everything when say for instance playing LP's.
I measured my mic noise floor by burying it in 300lb of sand, sand is very lossy acousticly and even the commuter rail about 50ft away only gave problems at very low frequencies when everything was obviously shaking. Pretty easy to measure between trains. 🙂
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Yeah, typical light weight raised stages act as a big loudspeaker cone, with lots of resonances and distortion products.
All that gets picked up by mics and causes muddy/boomy/hanging bass through the PA.
Isolating the speaker cabs helps bigtime....another item I should market/patent !.
AC system resonances are a big problem imo....likely a big part of the 'sick building syndrome' I suspect.
I have been in buildings with HUGE very LF/subsonic resonance, enough to drive the occupants nuts....400Hz would drive me out of the room also.
I have seen a turntable stand mounted to the ground and protruding up through a hole in the floor and filled with half a ton of dry silica sand....no acoustic feedback whatsoever in that case.
Acoustic feedback is a much neglected/denied/unrealised system problem ime.
Ceramic/stone floor tiles done properly are glued down with a glue/cement containing rubber particles (used car tyres ?) and this makes a very useful very lossy material for isolation/damping.
Dan.
This has gone to court here stopping some wind farms during sleeping hours. In some cases the local LF noise is off the charts.
Interesting, and correlates with my thoughts.
There have been media reports here of land owners/residents becoming sick /stressed since wind farms are installed.
The 'authorities' of course deny that there is any problem, and further suggest that the complainants are crazy and/or vexatious litigants.
Years ago, there was a loose expansion joint on a freeway bridge about two miles away that caused a very LF boom throughout the suburb.
It took phone calls, a letter and my promise of involving the likes of '60 Minutes' to get the problem solved.
Dan.
There have been media reports here of land owners/residents becoming sick /stressed since wind farms are installed.
The 'authorities' of course deny that there is any problem, and further suggest that the complainants are crazy and/or vexatious litigants.
Years ago, there was a loose expansion joint on a freeway bridge about two miles away that caused a very LF boom throughout the suburb.
It took phone calls, a letter and my promise of involving the likes of '60 Minutes' to get the problem solved.
Dan.
My angle is damping, damping, damping ... I want zero movement, and if I can't get it then the vibrational energy must be transferred to a very, very high mass object, or converted to heat as fast as possible.
How do you effect the transfer of vibrations?
Squishy pucks, or some form of cones?
If cones, pointed up, or down to your mass sink?
I've tried aluminium cones, cardas blocks, carbon fibre cones, and vibrapods, as well as sorbothane.
My favourite is now some cheap plastic painters tetrahedrons between the component and maple butcher block, with good old rubber hockey pucks between these and plywood shelving.
I still use Audioquest sorbothane under the turntable , however .
Phase this?
I was recently very impressed with the clean sound of an actively crossed over system, and am trying out an inexpensive active crossover myself.
While the 4th order crossover points are variable, they are fixed relative to high/ low signals.
I would like the ability to vary the gap between high and lowpass, but it doesn't seem bothersome.
I thought this would eliminate phase angle issues, which seem to come with passive crossovers,but I'm reading this is not the case.
Any links on how to fix this, or is it even worth concern ?
The speakers are sounding about as good as I'd hoped ; I'm just wondering if there's more to be had with these drivers, which I've crossed at 2000 hz.
Dynavox 6 1/2" ers , and Heli AMT tweeters.
Heli is not a misprint. They are decent eBay tweeters.
Couldn't find anything specific to this on Multiway, but I'm having to do this on a cellphone these days.
I was recently very impressed with the clean sound of an actively crossed over system, and am trying out an inexpensive active crossover myself.
While the 4th order crossover points are variable, they are fixed relative to high/ low signals.
I would like the ability to vary the gap between high and lowpass, but it doesn't seem bothersome.
I thought this would eliminate phase angle issues, which seem to come with passive crossovers,but I'm reading this is not the case.
Any links on how to fix this, or is it even worth concern ?
The speakers are sounding about as good as I'd hoped ; I'm just wondering if there's more to be had with these drivers, which I've crossed at 2000 hz.
Dynavox 6 1/2" ers , and Heli AMT tweeters.
Heli is not a misprint. They are decent eBay tweeters.
Couldn't find anything specific to this on Multiway, but I'm having to do this on a cellphone these days.
Two separate things happening: one is transfer of the vibrations, the other is damping, converting the energy of movement into heat - and very different techniques are needed for the two.
To effect transfer, the two masses need to be very tightly coupled, at the frequencies that matter - bolted, cemented or welded together, so to speak. Dan's turntable stand in a previous post, mounted directly on the ground is an example of that - if the stand wants to shake then all the ground that it's set in also wants to shake, which is not gonna happen!
To effect damping, the correct material in the picture has viscoelastic properties, sorbothane is the classic example, but all sorts of memory foams and such are around at the moment, it's easy to find something cheap to try experiments with. I have a blanket of high quality, quite dense memory foam that I cut chunks off, and play with, gives me instant feedback - I used such under the good Yamaha CD player I have, for example.
If the material used is purely elastic, then only the nature of the vibrations alters, and no damping of energy occurs - which may or may not help, depending upon everything.
My first serious experiment, 30 years ago, was with basic but decent bookshelf speakers - I built a stand out of concrete blocks, glued together, filled with sand, so high mass. Very sharp spikes were inset, glued into the base, so tightly coupled here. The spikes were forced to punch through the carpet and underlay, and made hard contact with the concrete slab of the house - so now the speaker stand was coupled strongly with that huge mass. Finally, the speakers were coupled the top of the stand with Blu-Tack - a little bit of viscoelastic effect, but mostly tight coupling, a form of gluing, effectively.
This gave me excellent, super tight bass, and the first glimpse of the convincing sound I've been chasing ever since - most "bass" of conventional, monster speakers after that I found quite laughable - "blubbery" is the word that often came to mind, 😀 ...
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