DIY Barium/PVC turntable mat

[aussievintage]

I was in the mood to experiment and  sounding damping material was talked about earlier today.   Reading further, this stuff https://www.jaycar.com.au/heavy-duty-sound-barrier-damping-material-improved/p/AX3680  seemed very interesting.

 

It is cloth backed PVC with a faux leather look, but the PVC, has 75% Barium in it (by weight).   It sold in rolls 330mm wide and used to line car panels to deaden sound.  I got the idea to make a turntable mat, so I went and bought some.  First surprise - this stuff is HEAVY.  Like those lead coats they sometimes give you to wear when being X-Rayed..

 

I cut a circle of it and put it on  my ROK idler as it has no sound deadening yet.    I will be playing quite a few records tonight, so we'll see how it goes.  In theory it should deaden  ringing in the platter, and also help isolate the record from noise from the idler drive.

 

[pwstereo]

That looks like a great experiment, good thinking.

[aussievintage]

1 minute ago, pwstereo said:

That looks like a great experiment, good thinking.

Certainly sounds like it should work well.   Cheap two, I will get 2 mats from one roll of the stuff, cost $8 per mat.

[aussievintage]

 

Just weighed the mat.  A tad over 300 g.   For comparison, a felt mat was 15 g,  and a thin cork mat was 40 g.

[pwstereo]

16 minutes ago, aussievintage said:

 

Just weighed the mat.  A tad over 300 g.

Your spindle bearing will now wear out in 3000 years instead of 23000 years. You are going to have to look into a super lubricant to compensate for this issue.

[aussievintage]

7 minutes ago, pwstereo said:

Your spindle bearing will now wear out in 3000 years instead of 23000 years. You are going to have to look into a super lubricant to compensate for this issue.

 

     Well, we must remember that they make 220g vinyl records.    Also, most of my turntables, especially this one, were built to play shellac records, and I just weighed a 12" shellac copy of Messiah - 384 g !    

 

So I don't think I need worry and will easily get 20k plus years from the Rek-o-Kut bearing (minus the 65 odd it has already been around for)  

[EV Cali]

Hard to believe it will be any good when it does not cost $500

Can't wait to hear your thoughts.

 

[aussievintage]

2 minutes ago, EV Cali said:

Hard to believe it will be any good when it does not cost $500

Can't wait to hear your thoughts.

 

 

I am forcing myself to wait until I get a few more albums played later tonight.    I have noted so far that the surface of the mat is quite grippy.  The plastic formulation is soft and grips the record well.

[aussievintage]

OK, time for some initial impressions.

 

 

In short  -  it is a lot like having a weighted record clamp without really having one - a virtual clamp

 

 Firstly, the mass is similar to that of some weighted record clamps, but it is distributed out under the whole surface of the record, and so gives more rotational inertia.  On platters less massive than the ROK 16", I think this would provide more benefit than I am getting.  Nevertheless, I have more rotating mass in a form that also damps noise and ringing.    (I think the noise from the idler drive is a little less, but nothing startling)

 

The grippy surface is working like those mats people have made from that rubbery open-weave drawer liner.  The record is held firmly , and this is the other half of the virtual clamp effect. The bonus though is that, it isn't weight coupled to the platter in a way that would induce noise and vibrations to be transmitted through to the record.  

 

Just listening to it, I think I am hearing firmer bass, and a more solid or cohesive presentation generally, compared to the same turntable and setup using a cork mat (no clamp).  However, I am always shy of making too many claims about tweaks and DIY stuff.  We all know about expectation bias and how easy it is to fool ourselves.

 

I definitely like the way it looks like a leather mat.    I still find it weird how heavy this stuff is when I pick up the roll.

 

Here's a closeup of the texture, and the cloth backing.

[audiofeline]

I note an AB arm - what cart is in the headshell?

 

Interesting comments about the mat, with some improvements.  I'm aware that sometimes too much dampening can suck some of the life from the music, have you noticed any of this on your system?

[Colin Rutter]

8 hours ago, audiofeline said:

I note an AB arm - what cart is in the headshell?

 

Interesting comments about the mat, with some improvements.  I'm aware that sometimes too much dampening can suck some of the life from the music, have you noticed any of this on your system?

Can you have to much damping? 

I suspect when peaks we are used to are removed the feeling is the sound has been reduced in "life".

[aussievintage]

9 hours ago, audiofeline said:

I note an AB arm - what cart is in the headshell?

 

It is an AT95 with VM95ML stylus.  I think the heavier tracking force and the stiffer suspension suits the arm.    Also, I don't use the spring on the arm (it was missing anyway).  Tracking force is easily set just by the counterbalance weight.

[aussievintage]

9 hours ago, audiofeline said:

Interesting comments about the mat, with some improvements.  I'm aware that sometimes too much dampening can suck some of the life from the music, have you noticed any of this on your system?

 

 

48 minutes ago, Colin Rutter said:

Can you have to much damping? 

I suspect when peaks we are used to are removed the feeling is the sound has been reduced in "life".

 

I have not noticed anything negative.    I am not sure I like the idea that the turntable contributes to the sound in a way that could be "deadened" by damping.  That would make it too much like a musical instrument in it's own right. 

 

The AB tonearm is rubber mounted, as are other arms like the SME3009 I have.  This would appear to be an attempt to decouple the tonearm/record interaction from the turntable.   Thinking about the AR/Linn idea of suspending a minimal frame, to me, suggests not much contribution from the turntable.

 

I am thinking out loud here a bit.  I have mixed feelings about this subject  

[andyr]

15 minutes ago, aussievintage said:

 

I am not sure I like the idea that the turntable contributes to the sound in a way that could be "deadened" by damping.  That would make it too much like a musical instrument in it's own right. 

 

 

The Linn line has always been that - although the platter and the pressed-steel subchassis are known to 'ring', applying any deadening material to the underside of either of these components ... kills the magic.

 

Andy

 

[aussievintage]

5 minutes ago, andyr said:

 

The Linn line has always been that - although the platter and the pressed-steel subchassis are known to 'ring', applying any deadening material to the underside of either of these components ... kills the magic.

 

Andy

 

I know it's not good to step over the Linn line...       but is this not a resonance in the audible frequency range?  It's something we try hard to avoid between the cart and tonearm. I know devices are sold to enhance Linns - such as platter damping rings.

 

Anyway, I don't want this to be a Linn argument thread.  The Rek-o-Kut could not be further from it.  It's base is so solid you could drive the proverbial truck over it.  The platter does ring a little however, and this mat would indeed dampen it  a bit.

[audiofeline]

3 hours ago, Colin Rutter said:

Can you have to much damping? 

I suspect when peaks we are used to are removed the feeling is the sound has been reduced in "life".

I've played with dampening a turntable (not high-end), and over-dampened.  It sounded horrible.  Removed most of it, and it sounded OK again.

[pwstereo]

I've had good success with this device for dampening things (not just turntables).

[audiofeline]

3 hours ago, aussievintage said:

...I don't use the spring on the [AB] arm (it was missing anyway).  Tracking force is easily set just by the counterbalance weight.

FUI, the spring can be used to apply anti-skate on the arm, by slightly twisting the spring's mount on the arm tube.

[aussievintage]

18 minutes ago, audiofeline said:

FUI, the spring can be used to apply anti-skate on the arm, by slightly twisting the spring's mount on the arm tube.

Good tip, thank you.  Maybe worth getting a light spring to experiment with.

 

[aussievintage]

44 minutes ago, audiofeline said:

I've played with dampening a turntable (not high-end), and over-dampened.  It sounded horrible.  Removed most of it, and it sounded OK again.

 

Not seeing any problems like that with this system.  The music is somehow more exact, if anything.  Toes are tapping to Daddy Cool right now  

 

I have a theory that, particularly with less massive turntables, some resonances due to under damping, are perceived as an improvement.  That it sounds better, might be a fair observation. 

 

The problem I have with that is, when you switch over to digital (I do play both through my system), you lose all that.  I would venture that striving for accuracy might also produce a perceived improvement, just in a different direction.

[Colin Rutter]

7 hours ago, andyr said:

 

The Linn line has always been that - although the platter and the pressed-steel subchassis are known to 'ring', applying any deadening material to the underside of either of these components ... kills the magic.

 

Andy

 

Don't agree.

I prefer the sub chassis damped.

 

[aussievintage]

38 minutes ago, Colin Rutter said:

Don't agree.

I prefer the sub chassis damped.

 

I never had a Linn, although I did audition an Ariston once.   I did have an AR-XB and at that time people were adding damping.

 

Anyway, as I said, I don't think a turntable could be much more different from the ROK.   

[andyr]

1 hour ago, Colin Rutter said:

Don't agree.

I prefer the sub chassis damped.

 

I never tried damping it myself.  I preferred the Cetech CF-composite subchassis.    (Because this didn't ring, it enabled you to bolt the armboard to the subchassis - providing a rigid coupling between arm and platter that the stock LP12 didn't achieve until Linn brought out the Keel.)

 

Andy

 

[aussievintage]

 

Well, I definitely like this mat.  In fact I am going to make another for my CEC/Peak idler table.  I normally use a cork/neoprene mat on that, with a weighted record clamp.    I think this mat will work even better, as the platter, while still heavy, is not as heavy as the ROK 16", so the distributed weight will give a bigger percentage increase in rotating mass.

 

I would be interesting if some other people would make one just to try it on different systems.  C'mon guys - it's a cheap experiment.

 

[Peter-E]

On 08/05/2020 at 3:29 PM, aussievintage said:

 

Well, I definitely like this mat.  In fact I am going to make another for my CEC/Peak idler table.  I normally use a cork/neoprene mat on that, with a weighted record clamp.    I think this mat will work even better, as the platter, while still heavy, is not as heavy as the ROK 16", so the distributed weight will give a bigger percentage increase in rotating mass.

 

I would be interesting if some other people would make one just to try it on different systems.  C'mon guys - it's a cheap experiment.

 

I made one of these today. Nice and heavy and the surface certainly stops any chance of slippage.