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D.I.Y "shock absorbers" for my Turntable.

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Domsmith1970

Member
My neighbours suck. They slam their front door and boom...skips my TT. Other than building a suspended shelving unit do you guys have any ideas as to what I can do? And yes...I have told them to stop slamming the door. My TT currently sits on the top shelf of a media unit above my reciever and cd player. All crazy and quirky ideas will be much appreciated! Thanks for your time.
 
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There are numerous threads on AK and other sites addressing turntable isolation--do a little searching as there are too many suggestions to even try to re-iterate here.

Sounds like your media center is not all that stable, and having the TT on the very top of the rack might not be the best place for it (top floors of a skyscraper sway way more than the ground floor).

Some of the most common suggestions/solutions are isolation blocks, hockey pucks, marble/granite slabs, inner-tubes and even "sandboxes".

Good Luck!
 
The run of the mill currently sold media racks are poorly constructed/designed when it comes to installing turntables. Most are so unstable that they are marginal for even your average CD/DVD player. I'd opt for a DIY wall shelf or a vintage Target turntable wall shelf, either way no more skipping records.
 
TT Isolation

I live in a slab house so there are no real floor issues when walking past my Table, even when it was on top of a modified 1940's oak bookshelf. I did put some butyl "isolators" under the legs to minimize some speaker vibration I was getting.

I installed a cheapo bookshelf on the wall above my audio stuff to put the table on. I made some DIY alterations to level it. It has helped minimize even more of the speaker vibration.

Getting tables on a wall shelf is one of the cheapest and easiest way to stabilize them. If I had more money, I would buy one of the wall shelves from Music Direct or Audio Advisors. I have seen some nice steel ones for under $200.
 
I'd think that if their door slamming is causing skips, the wall shelf will not yield the results you're looking for.

Are you in a house or an apartment? Can you tell us about the construction? Upstairs neighbors or next door? Anything else affect the tt?

What about suspending a platform from the ceiling? That can be done for less than $20 in parts - some chain, a few springs, and some eye hooks, as well as some plywood. Should insulate from just about anything. Aesthetics may be a bit out there, but it's effective.
 
jgordon said:
I'd think that if their door slamming is causing skips, the wall shelf will not yield the results you're looking for...
Click to expand...

I can definitely state that if you share a wall with your neighbors and they slam the door it WILL make your turntable skip even with a wall shelf.

I put up a wall mount shelf and it works great... except when someone slams the door to my bath... I never thought about the location until then! I put up a sign on the bathroom door to remind people not to slam the door. No problems after that. Good thing too! I was going to take the bathroom door off if I had to!

In my case, the wall that has the bath door in it intersects the other wall at a right angle close to where the shelf is mounted (on the other side of the wall). Hope that makes sense....
 
Best location for the wall shelf is an outside wall away from doors. Look up the Arcorob DIY wall shelf that can be constructed for under $50, also looked terrific as he installed the shelf.
 
Find the most rigid, supported part of your apartment. You know, where the solid exterior walls are, or the vertical supports underneath the floor are, and place your TT there. Get it lower to the ground on its own support, not high up where lateral movement will be amplified.
 
I had some similar issues - trouble is there is no one size fits all solution....

Let me explain - your problem is caused by vibrations being transmitted from floor/wall to the stand/furniture on which your turntable sits.

There are basically two methods of removing the vibrations:
1) Damping - the vibration is "received" but you absorb it by converting it to heat/friction
2) isolation - find a way for the TT to reject the vibration

in reality most solutions are a combination of the two.

Isolation is usually achieved through some form of "springs" - Sorbothane, various other elastomers, MagLev, or actual springs - they all behave as a spring.

Springs tend transmit/pass through frequencies below their resonance, and to a varying degree absorb frequencies above their resonance...

So if you want to isolate you need to know the frequencies you are trying to isolate from, and the resonant frequency of your "sprung system".
The softer the springs, the lower the resonant frequency for the same mass....
Raising the mass will also lower the resonant frequency (up until the point it totally squashes the spring, after which it no longer isolates at all! - it no longer acts as a spring)

Typically footfall, door slams and such tend to be in the 2Hz to 3Hz range roughly.

An easy way to measure the problem, is to (gently) lower the needle onto the plinth or a stationary record (turn off the motor, assuming you table allows you to do this without muting the arm/cartridge!) - or lower it gently onto the TT plinth.

Then do the door slamming/stomping whatever it is that you are trying to isolate from - and record it . (no fancy stuff needed for the recording, a laptop line/mic input is fine, and take the output from your phono stage)
Then analyse it with a bit of FFT software so you get a spectrum of the recorded track - this will show you what frequency the problems are at.

The same method can then be used to test different "shock absorbers"/springs until you find the combination that works best.

My optimum solution was as follows (took a couple of weekends of working through various permutations and combinations !)

At the base - a 60cm x 60cm 36kg concrete paver sitting on 5 sorbothane pucks (I chose the sorbothan pucks so that the total mass on top of them would be towards the top end of their weight allowance - ie: get the resonant F as low as possible!) - Sorbothane also acts as a damper - so some of the energy is also absorbed and transmuted to heat.
Then the rack sits on the pave
Then the TT platform sits on 4 MagLev feet, then the TT itself is on 5 isolating rubber feet, and the TT plinth has been filled with 3.5kg of plasticine (both adding mass to lower the res. F, and acting as a damper for frequencies between 300Hz and 3kHz)

hope this helps

bye for now

David
 
I can bang on the shelf and hear nothing on the turntable. Cheap and easy.
Four Raquet balls.
Piece of MDF board or any hard wood.
A butcher block
Some "Blu Tac" - like Play Doe

You can use small napkin rings orashtrays or anything to keep the balls from rolling.
I use 1 board then put silicone caulking and stuck the butcher block to it.
Then I put it all on the balls
make sure it's all level and BAM !
I get NO vibrations at all. It was pretty stable before but it's made a difference on the sound by isolating the table so well.

Some people do the same kind of thing but just put the wood on top of a semi inflated bike inner tube.
Some people cut the balls in half but I didn't and love my results.
Good luck.....
 

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I found that putting the TT on heavy furniture helps. When I had my TT upstairs, it skipped all the time when I walked around the room. After I put an IKEA Expedit unit loaded with LP's under the TT there was no more skipping
 
I renovated an art-deco phonograph/radio console a few years back; bringing it from the early 30's, to the mid-50's hifi standards. The console has an onboard speaker in it. The speaker caused feedback in my testing. I tested both suspended and non-suspended Tt's by placing them on top of the console cabinet, and playing music through the system. The suspended TT did not feedback at all; the non-suspended deck howled with feedback at no more than half volume.
So to counter the onboard speaker, I built a massive birch ply plinth for the TT, that was to be hidden within the console. The massive birch ply plinth would be suspended on four Superballs (those lively high bouncing balls of our youth).
The result was total isolation of the tt and speaker. I can turn this unit up to its maximum level, and not feedback. So ultimately, the Superballs did a good job in isolation.

early construction:
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You can see the shine of the super balls, ^^, between the plinth plywood leaves, and the built-in TT plinth shelf

closer to finished:
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renovated console:
attachment.php


the tt plinth, ^^, fills the space below the TT top plate, and to just above the amplifier opening.
 

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Oh yeah,…. This, ^^, probably won't do anything for hard footfalls, slamming doors, and such, on a joisted floor system. I'm on a concrete slab, and not effected by any such anomalies.
 
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