To spike, or not to spike, that is the question:

dogwan

dogwan

Dogwan
In the past I've seen reasoned answers for both pro and con of whether spikes have an appropriate place as feet on suspended tables. Both made sense to me. I wish I had saved links to the threads at the time or printed them out. Now it seems I would have to re-invest hours of research and frankly I don't have time.

My mid-80's AR The Turntable at one point had spikes on it. At the time I thought it was a positive. Currently it is back to compliant feet (semi-hard rubber feet). Unfortunately I made so many changes when the feet were changed I cannot tell if and how much difference the feet made.

I would suppose that the answer is dependent on where the TT is mounted, of course. I would tell you exactly what my turntable is on, except that I have several TT's that rotate through various rooms. I am mostly concerned with a general take on spikes on suspended decks.

What are everyone's thoughts?
If you're using spikes what do you feel are the advantages?
If you think it's a bad idea tell me why.

-Dogwan
 
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I have a TD125 with 3 spikes and it seems to me the difference was tighter bass. I can't remember for sure but that is what comes to mind. It is fixed on a wall shelf. Oh and Divotdog made me put them on :D
 
You could just make a separate plinth from a square cut of mdf and spike that to whatever your turntable currently sits on instead.

Another good platform to support a turntable (fixed or suspended) is a regular concrete pavement (sidewalk) or garden slab. Ugly but effective...
 
dogwan said:
In the past I've seen reasoned answers for both pro and con of whether spikes have an appropriate place as feet on suspended tables. Both made sense to me. I wish I had saved links to the threads at the time or printed them out. Now it seems I would have to re-invest hours of research and frankly I don't have time.

My mid-80's AR The Turntable at one point had spikes on it. At the time I thought it was a positive. Currently it is back to compliant feet (semi-hard rubber feet). Unfortunately I made so many changes when the feet were changed I cannot tell if and how much difference the feet made.

I would suppose that the answer is dependent on where the TT is mounted, of course. I would tell you exactly what my turntable is on, except that I have several TT's that rotate through various rooms. I am mostly concerned with a general take on spikes on suspended decks.

What are everyone's thoughts?
If you're using spikes what do you feel are the advantages?
If you think it's a bad idea tell me why.

-Dogwan
Click to expand...

To me spikes on a suspended table is the only scenario where they are a good thing. They don´t have a low frequency resonance that would interfere with the suspension´s resonance. The high frequencies generated or transmitted by the spikes would be filtered out, which is the reason to have a suspension in the first place.
gusten
 
On the AR, first thing is to remove the bottom cover. Then mount the plinth on sand bags. What ever the sand bags sit on has to be non reflective, non wobbly. The sand bags will allow the plinth a large area to sink energy into.
 
I just started going to spikes on suspended tables a couple of years ago and have found an improvement over compliant feet, we used them on Bsujeeps TD 125 and more recently used them on my latest TD 150 project so far I like them, Marc brings up an important point also, I have started to make my bottom covers with a more open area in them rather than closed, this give the energy somewhere to dissipate instead of just floating around within the plinth.
 
The purpose of feet for a suspended TT is to be 'non compliant' IMO. If compliant the risk of interfering with the suspension is obvious. Spikes are of course just a name, hard feet could be a better name.
gusten
 
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Divotdog said:
I just started going to spikes on suspended tables a couple of years ago and have found an improvement over compliant feet, we used them on Bsujeeps TD 125 and more recently used them on my latest TD 150 project so far I like them, Marc brings up an important point also, I have started to make my bottom covers with a more open area in them rather than closed, this give the energy somewhere to dissipate instead of just floating around within the plinth.
Click to expand...

Right, a sealed bottom only allows the plinth to be a sound box. Any internal noise from say the motor bounces around in there as well as it acting like an oil drum to acoustic energy passing into the plinth. Which is why I mentioned the shelf has to be non reflective as well. If spikes drained (multi-frequency) energy like sand bags do, competition shooters would shoot off spikes instead of bags.
 
Divotdog said:
I just started going to spikes on suspended tables a couple of years ago and have found an improvement over compliant feet, we used them on Bsujeeps TD 125 and more recently used them on my latest TD 150 project so far I like them, Marc brings up an important point also, I have started to make my bottom covers with a more open area in them rather than closed, this give the energy somewhere to dissipate instead of just floating around within the plinth.
Click to expand...


.... so it you cut three holes in the bottom board that served as hand access holes to the suspension springs, could these holes also meet the requirement you are addressing to dissipate internal energy with the plinth?
 
Here is what what I am doing now.

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Sorry, not a very good pic but it is the only one I have of the bottom plate, I will be doing a TD 145 soon and I will try to go into this a little more and shoot some better pics. :thmbsp:
 

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marcmorin said:
Right, a sealed bottom only allows the plinth to be a sound box. Any internal noise from say the motor bounces around in there as well as it acting like an oil drum to acoustic energy passing into the plinth. Which is why I mentioned the shelf has to be non reflective as well. If spikes drained (multi-frequency) energy like sand bags do, competition shooters would shoot off spikes instead of bags.
Click to expand...

Exactly Marc, I haven’t tried sand bags under one but it makes perfect sense, I hope the grandkids don’t notice me out in their sandbox later...

:naughty:
 
marcmorin said:
On the AR, first thing is to remove the bottom cover. Then mount the plinth on sand bags. What ever the sand bags sit on has to be non reflective, non wobbly. The sand bags will allow the plinth a large area to sink energy into.
Click to expand...

Would adding some sort of damping inside the plinth help at all?
 
KrisM said:
Would adding some sort of damping inside the plinth help at all?
Click to expand...

Only if it's sound absorbing. Simply setting the table down on carpet padding does wonders if the table it sits on is reflective. Right now I'm in the middle of rehabbing a fellow AKer's XB. My mount for testing them is simply a couple of end scraps of cedar rail 3 X 5 laid on the carpeted floor with a towel draped over them. Dead quiet. The bending over and squating down gets old though :sigh:
 
Thanks. I was thinking of something for the inside because of the looks factor. I guess I would need something that is absorbing, but thin enough that it won't get in the way of the working parts.
 
KrisM said:
Thanks. I was thinking of something for the inside because of the looks factor. I guess I would need something that is absorbing, but thin enough that it won't get in the way of the working parts.
Click to expand...

That would be my thought as well. I have no material added to any of my ARs internally to absorb noise. Although I do have a pod I designed for the motor (XA/XB) that stops the top plate from becoming a soundboard for the motor noise. That's a simple bolt on attachment. Setting a table on something like my kitchen table and turning it on, the kitchen table becomes like a soundboard on an acoustic guitar and amplifies noise. Setting the turntable on carpet foam underlayment on the kitchen table, and I get almost no noise.
 
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