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best isolating materials for turntables?
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dogscanskate
Super Member
You have a Linn on granite???
Linn requires a light and rigid support. If you wanna kill the music from the Linn, get soborthane, a nice big sandbox with 100 lbs of sand/lead...Most suspended turntables work better with light stands to dissipate and evacuate the vibrations. Granite rings like heck, not a very good idea.
For those who have Linns that sing, they usually get a MANA (defunct) shelf, Target, sound organizatio, Ikea Lack, Neuance and such products which are proven over and over again.
There is a lot of information you can find, if not here, on AA vinyl asylum, naim forum, Linn...
Linn requires a light and rigid support. If you wanna kill the music from the Linn, get soborthane, a nice big sandbox with 100 lbs of sand/lead...Most suspended turntables work better with light stands to dissipate and evacuate the vibrations. Granite rings like heck, not a very good idea.
For those who have Linns that sing, they usually get a MANA (defunct) shelf, Target, sound organizatio, Ikea Lack, Neuance and such products which are proven over and over again.
There is a lot of information you can find, if not here, on AA vinyl asylum, naim forum, Linn...
Rock6x
2stupid2PostHere
granite
I am also wondering about the buzz on granite. What gives? Is it good for some turntables, and not others? What's the best general purpose surface.
(just fyi - all I currently have is a Technics SL-BD22 to listen with, and I'm having some feedback probs that I'm still in the process of troubleshooting.)
I am also wondering about the buzz on granite. What gives? Is it good for some turntables, and not others? What's the best general purpose surface.
(just fyi - all I currently have is a Technics SL-BD22 to listen with, and I'm having some feedback probs that I'm still in the process of troubleshooting.)
dogscanskate
Super Member
The basic thing is that the more "mass" you put under a component, the lower its resonant frequency becomes. In other words, a very massive support is like installing a nice big "bass trap" underneath your component. Lower frequencies are also "physically" longer (look at the length of a 20 Hz sinewave) and if they have any energy (such as slam, as in a 32 Hz organ tone) do you believe they will dissipate as quickly as a higher frequency? (Does a triangle resonate as long as a string bass?)
The idea is to dissipate the vibrations emitted by the movement of air (sound created by movements of air pressure) on your gear as quickly as possible, it's not rocket science. The price to pay for this is having a resonant frequency within the audio band but try to have them die off as quickly as possible. It's all about making the right compromise. Most suspended turntables have suspensions to deal with those issues but no spring suspended tt is totally immune to these changes in air pressure and frequencies. A light and rigid structure will reject (or filter out) the low energy output theoretically. That's what Linn, even on their website, suggest for their LP-12. They did design the Trampolin to deal with heavier supports.
Rock, when you get feedback problems, it's probably because of the proximity of your deck to the speakers. You can try a cheap tweak like tennis balls under your plinth to alleviate your problem and also try to sit the turntable as far from the speakers as possible.
The idea is to dissipate the vibrations emitted by the movement of air (sound created by movements of air pressure) on your gear as quickly as possible, it's not rocket science. The price to pay for this is having a resonant frequency within the audio band but try to have them die off as quickly as possible. It's all about making the right compromise. Most suspended turntables have suspensions to deal with those issues but no spring suspended tt is totally immune to these changes in air pressure and frequencies. A light and rigid structure will reject (or filter out) the low energy output theoretically. That's what Linn, even on their website, suggest for their LP-12. They did design the Trampolin to deal with heavier supports.
Rock, when you get feedback problems, it's probably because of the proximity of your deck to the speakers. You can try a cheap tweak like tennis balls under your plinth to alleviate your problem and also try to sit the turntable as far from the speakers as possible.
Rock6x
2stupid2PostHere
Thanks dogs. I've actually got a post going about the problem, and received a lot of comments and tips about how to troubleshoot. At the moment, the wife and child are sleeping, so I'm not even trying yet. It is fine at low volumes and w/TD and CDP, but I sometimes want to crank the vinyl.
I like a lot of rock music, so the bass thing you're talking about above makes perfect sense.
I like a lot of rock music, so the bass thing you're talking about above makes perfect sense.
Thanks for all the information so far! I must admit that I havea friend who has a mounted wall frame for his lp12 and things do sound great. As you can see from my low post count I'm still learning!!:scratch2:
My current set-up is not ideal. I have my TT set up in a back bedroom with wooden floor-boards. My speakers are spikes which in turn sits on granite slabs. (I guess this will need to be changed). Am I right in saying that the granite will take off some of the fine detail from the edges of the notes because of the "ringing" sensation, altough I must admit I have not heard this sensation yet. Can anyone describe what characteristics the granite will have to the sound stage?
Thanks in advance.
Rex
My current set-up is not ideal. I have my TT set up in a back bedroom with wooden floor-boards. My speakers are spikes which in turn sits on granite slabs. (I guess this will need to be changed). Am I right in saying that the granite will take off some of the fine detail from the edges of the notes because of the "ringing" sensation, altough I must admit I have not heard this sensation yet. Can anyone describe what characteristics the granite will have to the sound stage?
Thanks in advance.
Rex
dogscanskate
Super Member
You have a very good system imho 
! As you'll see, fine tuning a system is not necessarily an irreversible project. Since your Linn has the Trampolin, it was designed for a more massive shelf as we can't all have light and rigid stands.
All materials have a resonant frequency and will vibrate when that frequency is excited. They also have an absorption/reflection ratio. When they vibrate, they are "ringing". Whether it be a speaker cabinet, a granite slab, a capacitor in the amp or a clock or even a wall, they all vibrate at their resonant frequency.
As you can see, it's quite easy to smear the musical performance even through the finest components available. We all have to deal with the laws of acoustics and much needs to be learned so we can at least choose a viable compromise.
Here's my take on it. A vibrating cabinet or wall acts in the same manner a speaker cone works, it goes back and forth and emits sound. Even a clock or transistor can vibrate and ring.
There's also the part where the signal from vibrating structures will be fed back through the system. Your cartridge is a transducer and will act like a microphone. Since vacuum tubes are known to be microphonic, I think transistor based amps are too but to a lesser degree.
How does it affect the sound? I believe when all these negative effects are added to the signal, they have a tendency to compress the output signal much like FM radio compression. All audio frequencies are affected by resonant vibrations. We get lingering bass notes, buzzing bass... shouty and sibilant mids, harsh highs...It's more difficult to separate instruments, voices...as if they were lumped and averaged out. Just like FM radio, the output signal seems louder. It smears the leading edge of a note and decay is longer too. This masks the finer inner detail of the performance where you can separate instruments or micro dynamics as we might say. When the output signal is lumped, you have no sense of separating two voices and they rarely start at exactly the same time, these few micro/milliseconds are lost. You lose the flow of the performance and its timing...
Using the right materials to evacuate/dissipate the acoustic energy that can paralyze a good system is more a "trial and error" scheme than our ability to set-up gear based on scientific fact. There are too many variables in the equation sadly. I happen to think that metal structures have a detrimental effect on the musical performance but most audio racks offered are metal. We still haven't found directional dissipation acoustic products. If we did, that would be a giant leap in musical enjoyment. How well do we understand coupling/decoupling techniques?
So all you have to do is try it and hear for yourself, you learn more this way. Trust me, I've made more mistakes than most here.
http://www.concertsoundusa.com/hifi_history/documents/rehedeko_recommendations.pdf
This link is one man's opinion on metal stands. He also sells a wood stand so beware! But the point he makes is still something to consider. In my opinion, metal vibrations are easily fed back into the system through the speakers and electronics. But that's just my opinion.
Hope this helps, you can all bash it, I'm gone for a few days so I don't mind. There is still so much to learn from acoustical behavior of materials/components and I'm no expert. Just my unashamed opinion.
! As you'll see, fine tuning a system is not necessarily an irreversible project. Since your Linn has the Trampolin, it was designed for a more massive shelf as we can't all have light and rigid stands.All materials have a resonant frequency and will vibrate when that frequency is excited. They also have an absorption/reflection ratio. When they vibrate, they are "ringing". Whether it be a speaker cabinet, a granite slab, a capacitor in the amp or a clock or even a wall, they all vibrate at their resonant frequency.
As you can see, it's quite easy to smear the musical performance even through the finest components available. We all have to deal with the laws of acoustics and much needs to be learned so we can at least choose a viable compromise.
Here's my take on it. A vibrating cabinet or wall acts in the same manner a speaker cone works, it goes back and forth and emits sound. Even a clock or transistor can vibrate and ring.
There's also the part where the signal from vibrating structures will be fed back through the system. Your cartridge is a transducer and will act like a microphone. Since vacuum tubes are known to be microphonic, I think transistor based amps are too but to a lesser degree.
How does it affect the sound? I believe when all these negative effects are added to the signal, they have a tendency to compress the output signal much like FM radio compression. All audio frequencies are affected by resonant vibrations. We get lingering bass notes, buzzing bass... shouty and sibilant mids, harsh highs...It's more difficult to separate instruments, voices...as if they were lumped and averaged out. Just like FM radio, the output signal seems louder. It smears the leading edge of a note and decay is longer too. This masks the finer inner detail of the performance where you can separate instruments or micro dynamics as we might say. When the output signal is lumped, you have no sense of separating two voices and they rarely start at exactly the same time, these few micro/milliseconds are lost. You lose the flow of the performance and its timing...
Using the right materials to evacuate/dissipate the acoustic energy that can paralyze a good system is more a "trial and error" scheme than our ability to set-up gear based on scientific fact. There are too many variables in the equation sadly. I happen to think that metal structures have a detrimental effect on the musical performance but most audio racks offered are metal. We still haven't found directional dissipation acoustic products. If we did, that would be a giant leap in musical enjoyment. How well do we understand coupling/decoupling techniques?
So all you have to do is try it and hear for yourself, you learn more this way. Trust me, I've made more mistakes than most here.
http://www.concertsoundusa.com/hifi_history/documents/rehedeko_recommendations.pdf
This link is one man's opinion on metal stands. He also sells a wood stand so beware
! But the point he makes is still something to consider. In my opinion, metal vibrations are easily fed back into the system through the speakers and electronics. But that's just my opinion.Hope this helps, you can all bash it, I'm gone for a few days so I don't mind. There is still so much to learn from acoustical behavior of materials/components and I'm no expert. Just my unashamed opinion.
Vinyl-Addict
Manufacturer
Rex, You can eliminate the ringing by using a constrained layer approach. I have posted a couple of pics so you can see how I did it. They are posted 3 messages down. I built a very heavy duty wall stand to isolate my table. I then constructed an MDF shelf/EAR Isodamp layer (blue in colour)/granite sandwich to support the table which weighs approx. 120 pounds. This combination does not ring the slightest and the turntable performs far better than it ever did mounted on a standard rack.
Brett a
~◦●○o0o○●◦~
My unsuspended Pioneer PL-550 has been helped greatly by a sandbox supported by racquetball halves. (Photos in signature)
The sandbox, I figure, helps drain vibration away from the table while also isolating it from incoming vibrations. (I used a very lightweight 1/4" MDF panel between the TT and sand) The racquetballs lower the resonant frequency of the whole rig to about 6 cps.
The end result has been a lower noise floor, clearer, better defined bass (I can now clearly hear the bass player grooving along behind Steve Miller on "Fly Like an Eagle". I mean clearly.) It also improved the already good 3-dimensionality of the soundstage.
There's a thread on sandboxes here: (you can see mine at posts #'s 30 and 34
http://www.audiokarma.org/forums/showthread.php?t=159775&highlight=sandbox
The sandbox, I figure, helps drain vibration away from the table while also isolating it from incoming vibrations. (I used a very lightweight 1/4" MDF panel between the TT and sand) The racquetballs lower the resonant frequency of the whole rig to about 6 cps.
The end result has been a lower noise floor, clearer, better defined bass (I can now clearly hear the bass player grooving along behind Steve Miller on "Fly Like an Eagle". I mean clearly.) It also improved the already good 3-dimensionality of the soundstage.
There's a thread on sandboxes here: (you can see mine at posts #'s 30 and 34
http://www.audiokarma.org/forums/showthread.php?t=159775&highlight=sandbox
Vinyl-Addict
Manufacturer
Vinyl-Addict
Manufacturer
Images should be there now.
OK so basic idea for the LP12, wall mount the thing, ideally some tubular steel construction, then MDF / sandwhich layer / granite. Isolate anything coming into the TT from the ground and then isolate the ground for anything coming from the TT. Thanks again, I also managed to listen to a few LP's without the Granite /Velstone combo I had under the LP12 and all I can say is that I now understand why the LP12 "sings", it's very very difficult to put into words, things don't seem as clipped / shortened any more and the music seems to "flow" if thats the correct term? Piano's seem clearer altough I think I have lost a little bass definition???
dogscanskate
Super Member
The basic idea for the Linn is a light and rigid shelf such as this one:http://s307.photobucket.com/albums/nn317/dogscanskate/?action=view¤t=Picture025.jpg
The shelf is a Neuance on which the Linn sits, it is very light and rigid. The rack is an Apollo wall mount rack. As you can see the spikes, whose points seem to penetrate the Neuance shelf, which means that the shelf/tt deck are decoupled from the rack. The shelf itself is very light, I don't think it weighs 1lb. It can evacuate vibrations though. It's resonant frequency will be higher than any constrained layer structure that outweighs it by a huge margin.
Were it another record player, I wouldn't argue the point. There are so many references you can get on a Linn from its owners and how they were set up for ideal music reproduction. Just have fun with it.
The shelf is a Neuance on which the Linn sits, it is very light and rigid. The rack is an Apollo wall mount rack. As you can see the spikes, whose points seem to penetrate the Neuance shelf, which means that the shelf/tt deck are decoupled from the rack. The shelf itself is very light, I don't think it weighs 1lb. It can evacuate vibrations though. It's resonant frequency will be higher than any constrained layer structure that outweighs it by a huge margin.
Were it another record player, I wouldn't argue the point. There are so many references you can get on a Linn from its owners and how they were set up for ideal music reproduction. Just have fun with it.
Thanks for the excellent pictures. I have had a week listening to the Linn without all my previous attempts at isolation and the music sounds a little "thin" and some of the punch has been lost, I'm about to try 1 week with all the stuff back in again and see what differences I find. Thanks once again!
dogscanskate
Super Member
Usually the best are mass and composite (sandwich) construction with elastomer's of varying density
You may prefer "mass" but it is not necessarily "the best" option for vibration damping and evacuation, that's your opinion and I respect it but in no way share or agree with your view on this. I agree with constrained layer damping, and it can be done in "massive" or "light and rigid" platforms. I have no problem with someone going against the flow and achieving good results, there is always room for the contrarian approach. Some components prefer massive structures to sit on while others work better on a light and rigid structure. Knowledge of the gear we own can dictate the course of action as to which is preferable. The proof is in the listening.
