Acoustic effects of the audiophile shrine

[TBone]

My TT had (has) a suspended sub-platform and I designed my DIY suspension to have a spring rate well below the TT itself, is that what you mean? If the TT had its own suspension it complicated any after-market mods as I had to ensure the suspensions worked together (which often meant complementary resonances vs. have the whole system "ring" together). In some cases I also modified the suspension of the TT itself. Rarely did I completely "short" or remove the TT's suspension as that would led to higher noise from the motor and such. Since I didn't have good measuring equipment determining spring rates was tricky (strobe, even counting by eye with a stopwatch, etc.) and a lot of empirical testing was required (i.e. trial and error). That's engineering for yuh, not science...

thx ... in the narrow view of my own unique main tt setup.

light spring dampening ...

Building fishing rods taught me about spine orientation; so each spring is marked accordingly (b/c twisting a spring alters overall orientation). Helps when setting up and controlling the platters & arm "bounce", so to speak. Minimal horizontal movement. A fine line, damping is, this particular model has five springs to damp/orientate.

wall mounting resolved past footfall issues.

 

[Sal1950]

Shrines are cool, we all need a place to pray.
Just don't get caught praying to your cables.

 

[DonH56]

I couldn't see the image. For my big DIY mattress-spring isolation platform I flipped alternate ones to change their coil direction, sounds like you did the same. Wall mounting was not an option for me.

Note vibration isolation is not my area of expertise by any means. I actually learned much more on the job long after making those platforms, but they did seem to help. In my case the difference was very obvious (no more skipping with heavy footfalls); in others, it was more subtle, but measurements usually confirmed some improvement. The primary measurement tools I had then were a test record with pink noise, various tones, and a silent track plus a spectrum analyzer. I'd look for added noise playing the silent track, and added or increased spurs on the pink noise and single-tone tracks. I would tap on the support to assess the fundamental resonances of the system and turn on the speakers playing the tones or pink noise to assess airborne transmission (isolation).

At one point I had a DIY phono preamp modified to extend the response to 100 kHz or so. It was interesting to observe cartridge resonances that were often in the 10's of kHz range.

 

[TBone]

sorry Don ... another attempt (different pic).

 

[DonH56]

Yes, exactly. Except I did not use cotton batting if that's what you did. I tried it, since it was a popular suggestion at the time (this was long ago), but found it didn't do too much. Enough of it compressed in would raise the spring rate, of course. I found friction tape wrapped around the wires (a painful process to implement) would dampen HF (relatively) ringing and I used different densities of foam and foam rubber to adjust the spring rate and damping. Finding the optimum balance among spring rate, weight support, etc. was tricky and often required a lot of trial and error on my part. You can also buy springs using different spring wire to achieve the balance of size, damping, spring rate, and weight support you desire. I used some that had different wires interleaved; they were used in vibration control tables and I managed to get a few leftovers after a lab build.

I wish I had videos of some of my failures; the one I remember best was when the TT and it's suspension all oscillated like that old Tacoma Narrows bridge film clip except somehow it all hung together and the measured response was outstanding (virtually no added vibration on the spectrum analyzer). I had my head in the test equipment whilst doing frequency sweeps and cranking the volume louder and louder until the owner suggested I look at the TT... Isolation was great, but I to this day have no idea why the cartridge and tonearm wasn't flapping like crazy wedding relatives doing the chicken dance...

 

[TBone]

Yes, exactly. Except I did not use cotton batting if that's what you did.

Well, not cotton batting, thin tightly woven pads (easily cut) used to remove makeup .

 

[March Audio]

I see that the audio 'Ponzi' scheme that is the Mdac has taken another turn!
Keith.

Sorry this is ot, but ill quickly respond. Sadly it is of no surprise. The guy is incapable of any kind of planning/project management. I hope he is of independent means because anyone in the industry following the debacle would conclude he is unemployable.

So another year on from the fdac we have another development step introduced, which as with the previous changes to the scope of the project, is promised to not cause delays. The USB isolator was due at xmas, no sign of it yet.....

What I find absolutely incredible is the quantity of JW fan boys that just lap it all up, the continual changes to scope, design, the delays and of course the frequent "oh I was working on this till 5 am"..........

 

[March Audio]

As mentioned previously I will be going through vibration measurements on stands and equipment which I hope will be helpful to people to see what is actually going on.

It may be in a week or so as I have been somewhat distracted with my speaker project, subject for another thread

 

[Purité Audio]

Sorry this is ot, but ill quickly respond. Sadly it is of no surprise. The guy is incapable of any kind of planning/project management. I hope he is of independent means because anyone in the industry following the debacle would conclude he is unemployable.

So another year on from the fdac we have another development step introduced, which as with the previous changes to the scope of the project, is promised to not cause delays. The USB isolator was due at xmas, no sign of it yet.....

What I find absolutely incredible is the quantity of JW fan boys that just lap it all up, the continual changes to scope, design, the delays and of course the frequent "oh I was working on this till 5 am"..........

Yup I find it incredible, and if anyone does have the temerity to ask actually what is being produced they are harangued by the fanboys, I am sure that thread is his main source of income ,I really wonder whether anything will ever be produced.
Keith.

 

[Thomas savage]

Iv been covering my 'shrine' with a blanket as I was getting a annoying reflection off it, today I repositioned the power leads and interconnects to facilitate the moving of my rack tight up against the back wall ( basically 3-4 inches back from where it was) .

This has eradicated the reflection and removed any need for a blanket..

What I was thinking is why equipment designers don't consider audible reflections when they design the boxes? The are all square ish flat surfaces with sharp corners.. Not ideal?

 

[watchnerd]

What I was thinking is why equipment designers don't consider audible reflections when the design the boxes? The are all square ish flat surfaces with sharp corners.. Not ideal?

I think we need to create a Kickstart project to make a bunch of random stick-on shapes (we could probably use Mr Potato Head parts) that you can apply to improve diffusion.

As for worrying about the shrine: you are effing crazy to worry about it.

Have you seen all the crap that lies between the multiple speakers on a monitor bridge in studio? And these are guys who get *paid* to worry about imaging.

 

[Thomas savage]

Well I might be crazy but the audible reflection that was disturbing my peaceful listening is now gone... we are not talking about imaging nuance more a beam of sound at a certain frequency coming off my CDP. It was distracting, as was the reflection I used to get off my radiators..

I was more than happy to remove these ailments on a volunteer basis

 

[watchnerd]

Well I might be crazy but the audible reflection that was disturbing my peaceful listening is now gone... we are not talking about imaging nuance more a beam of sound at a certain frequency coming off my CDP. It was distracting, as was the reflection I used to get off my radiators..

I was more than happy to remove these ailments on a volunteer basis

You should sell your magic towel for $500, claim it has some special mix of fibers.

 

[Thomas savage]

You should sell your magic towel for $500, claim it has some special mix of fibers.

Err... You've seen my eBay add then....

 

[watchnerd]

Err... You've seen my eBay add then....

 

[Sal1950]

Iv been covering my 'shrine' with a blanket as I was getting a annoying reflection off it, today I repositioned the power leads and interconnects to facilitate the moving of my rack tight up against the back wall ( basically 3-4 inches back from where it was) .
This has eradicated the reflection and removed any need for a blanket..

Your not coming down with another case of audiophilia nervosa are you Thomas?
You've been down this road before, remember.
No idea how you could introduce a blind testing session here but maybe somehow time for a reality check.

 

[watchnerd]

Your not coming down with another case of audiophilia nervosa are you Thomas?
You've been down this road before, remember.
No idea how you could introduce a blind testing session here but maybe somehow time for a reality check.

Blind fold over the eyes.

 

[Thomas savage]

Your not coming down with another case of audiophilia nervosa are you Thomas?
You've been down this road before, remember.
No idea how you could introduce a blind testing session here but maybe somehow time for a reality check.

Nope, it was definitely a issue.

 

[watchnerd]

Nope, it was definitely a issue.

I heard it, so it must be true?

 

[Thomas savage]

I heard it, so it must be true?

Well it was kinda bad tbh.. Not a ' blacker blacks ' moment.

But whatever, if you guys don't believe large square metal objects right in the middle of the listening area can cause audible reflection anomalies I'm ok with that

I'm coming to America soon, maybe we can get together and do some tests.. I'd love that...