Evolution of Speaker / Electronics Ratio

[fas42]

But a solid state amplifier?

I'm trying to imagine what kind of vibration could cause the changes in RFI/EMI signature of a circuit board.

Tubes, with their microphonics, are different story...

Every bit of equipment will be different - a lot would be due to how the circuit board(s) are supported inside the case - insufficient posts could allow the board to slightly flex, vibrate when the right frequencies are felt, causing some part to modulate its behaviour - I just suggest doing experiments to damp, stabilise things, if you have suspicions - there may be zero effect, or there may be a change. Anything that can rattle easily, inside a case, is not going to be a good thing - it won't hurt to do experiments, and it may help the overall sound ...

 

[watchnerd]

Anything that can rattle easily, inside a case, is not going to be a good thing - it won't hurt to do experiments, and it may help the overall sound ...

If I've got rattling parts inside a solid state amplifier case I've got much bigger problems than Blu Tack can fix.

 

[fas42]

OK, think connecting cables lying every which way, strewn over everything - the degree of movement may not be great, but it may have an audible effect ...

 

[watchnerd]

OK, think connecting cables lying every which way, strewn over everything - the degree of movement may not be great, but it may have an audible effect ...

Yeah, but if I get a jiggly cable, I get hum or static. It's not some subtle thing.

 

[Blumlein 88]

Three ways a moving cable can have an effect. One is moving within a magnetic field which will generate voltage. That effect isn't large enough to get close to the basic noise floor of gear itself with domestic audio. Another way is to move enough it effects the connection at the end. Unless the cable is nearly defective or placing undo strain on where it is plugged in that isn't going to be an issue. The third is the triboelectric effect. Dissimilar materials moving against each other can cause electrical noise to be generated. I have run across some cables that do this. One of the worst are Monoprice Premium XLR cables. If feeding a microphone preamp, moving or bending the cable physically will result in a clear burst of audible noise. However, when I tried finding an effect with the cable sitting or routed statically in various positions with loud music playing nothing could be heard. Even with the 50 db of extra gain form the microphone pre nothing is heard. So again a non-issue for audio reproduction (though not for recording if the vocalist is moving around a microphone attached to such a cable). BTW, probably the worst two materials in regards to triboelectric effect are teflon and silver.

 

[fas42]

Yeah, but if I get a jiggly cable, I get hum or static. It's not some subtle thing.

It's when the system gets to a very level of resolving that one starts to hear these sort of things. It may simply be that the system has a dull, lacking in sparkle, quality about it - and you'll find that rerouting or tying down a cable, solidly, brings the life back. It is subtle - but it can make all the difference ... I've done this type of thing for years now, because every little thing helps.

 

[fas42]

If feeding a microphone preamp, moving or bending the cable physically will result in a clear burst of audible noise. However, when I tried finding an effect with the cable sitting or routed statically in various positions with loud music playing nothing could be heard. Even with the 50 db of extra gain form the microphone pre nothing is heard. So again a non-issue for audio reproduction (though not for recording if the vocalist is moving around a microphone attached to such a cable). BTW, probably the worst two materials in regards to triboelectric effect are teflon and silver.

Would be nice if that were so, but unfortunately not. It's not an audible glitch of noise, but a continuous degrading of sound - think, 16 bit digital, and the bottom 4 bits go bye-bye, you're only running on 12 cylinders, effectively.

 

[Thomas savage]

I love blue tack and use it to stick my speakers down instead of spikes ( who's idea was it to put spikes under speakers ?)

My rack is stuck down to a bamboo plinth with...... Blue tack

My combi boiler is full of ..... Blue tack

I typed in 'I love blue tac ' into yahoo and looked at the resulting image search, won't forget those sights in a hurry

 

[Blumlein 88]

Would be nice if that were so, but unfortunately not. It's not an audible glitch of noise, but a continuous degrading of sound - think, 16 bit digital, and the bottom 4 bits go bye-bye, you're only running on 12 cylinders, effectively.

Except the effects you are pondering don't get anywhere close to even the 16th bit. So no, the cables laying about may not have an audible effect.

 

[watchnerd]

Would be nice if that were so, but unfortunately not. It's not an audible glitch of noise, but a continuous degrading of sound - think, 16 bit digital, and the bottom 4 bits go bye-bye, you're only running on 12 cylinders, effectively.

That leaves me with 12 bits = 72 dB of dynamic range, which puts this effect below the noise floor of most, if not all, recordings.

 

[fas42]

Except the effects you are pondering don't get anywhere close to even the 16th bit. So no, the cables laying about may not have an audible effect.

I'm attempting to give you an idea of what the subjective difference is - and, sorry, they're way above that 16 bit level - sufficient resolution in the the system, easy to hear the impact; poorer resolution, impact is completely masked.

 

[fas42]

That leaves me with 12 bits = 72 dB of dynamic range, which puts this effect below the noise floor of most, if not all, recordings.

This nasty stuff seems to hover in the 60-80dB range - almost inaudible, but you can always tell if it's there, or not there ...

 

[watchnerd]

This nasty stuff seems to hover in the 60-80dB range - almost inaudible, but you can always tell if it's there, or not there ...

So where am I supposed to stick the Blu Tack if I have this latent cable noise issue?

 

[Blumlein 88]

This nasty stuff seems to hover in the 60-80dB range - almost inaudible, but you can always tell if it's there, or not there ...

Okay, so with gear having about 20 bit resolution in terms of noise, how can I uncover this noise in the 60-80 db range? How can I replicate your results?

 

[watchnerd]

That's called diagnosis - you or someone else needs to look at the gear, get an idea where there may be an issue, and experiment. If you look inside some cases it's a nightmare of cables running everywhere - think old school Japanese; and on the inside of some gear considered well of there may be a single circuit board, with very short paths to external connections - the NAD I'm currently using is of this design style, and even in raw form does many things well.

And don't get a hangup on a particular substance to use - plenty of times I just use an everyday hot glue gun to "tie" things together - something cheap, easy to use, easy to undo - experiment, experiment, experiment ...

The noise is the unpleasantness in a recording that you don't like listening to - pick a recording which you consider to have flaws, as in that at certain points there is some artifact or quality that irritates or disturbs you to hear. Now, do a mental somersault - think, that which I don't like is not a recording issue, but actually playback noise, or distortion - once you've got that snippet of a track as a "test signal" try varying the environment in all sorts of ways - how does the quality of that snippet vary?

This is like hearing an MP3 encoding flaw, and then varying the bit rate - how does the artifact change in character as you do this?

Frank, do you mind making a separate Blu Tack thread?

This is getting way off topic...

 

[watchnerd]

Getting back to topic,

Guys...we didn't get back on topic.

I'm going to delete all the posts about ineffable quality and Blu Tack (including my own); Frank, you already have a thread for that which you started.