Audiophile Paranoia

Anto68 posted:

my question is with Naim's philosophy of leaving always on 24/7 ,this micro noise could stress the speakers?

No. 

I looked at your profile; the answer given by an Electronics Engineer reassures me 

thank you

The very low signal described causing the diaphagm to move by a microscopic amount is nothing to either the crossover components or the drive units - if it were the life of speakers would likely be very short if played enthusiastically, which patently is not the case. However, relative to being completely off, the signal will cause the driver to heat up, rising from switch on (or cooling from music playing) to a steady state at which the rate of heat loss into the room equals the rate of heat gain from the signal - but the increase compared to no signal will be unmeasurable except under laboratory conditions with very sensitive equipment.

Bigger stresses to speakers come from gravity, exerting a constant unidirectional force compressing the diaphagm suspension at the bottom and stretching it at the top (in conventional forward-firing drivers). This is a very real force, though undoubtedly the effect of it will vary according to driver design. One technique for minimising the effect is to remove, invert and refit the drivers periodically. There is an argument partial rotation rather than simply inverting each time, keeping the compression/expansion wear as uniform as possible, and probably an algorithm for determining by how much. (All this of course subject to any limitations arising from the driver's shape and mounting holes, and it is important to ensure that sealing of driver to baffle is not affected.) Alternatively you could invert the entire speaker when not in use...

This is not saying it is necessary to address the gravity issue, but if you want to pander to paranoia...

+1 for IB's very complete yet fairly succinct answer.

Yes, nicely put IB.

Ribbon tweeters tend to hiss louder than normal ones by a fair margin I noticed.

Any idea why?  In theory, this should just be related to the devices sensitivity.

It is the Russians listening. Speakers work the other way around as well, in this particular case they act as microphones. The very sensitive drivers notice the incoming sound waves against the outgoing sound waves and send them to the Amplifier as a variation in impedance. Your lovely SU will broadcast it to Moscow because it is 24/7 switched on.

This is why they need to be switched on always. It was decided on one of the Bilderberg conferences.

Never ever put a SU in your bedroom. You'll end up like Trump having the American press chasing you.

And remember, just because you're paranoid, it doesn't necessarily follow that in reality they aren't out to get you!

I know. I grew up in the Eighties, so for me it are the Russians.

These days, it are the Chinese. They have already opened a 'Restaurant' in my town. There is a large antenna on their building.

I'm not sure this stereotyping is entirely helpful. 

Dan.S posted:

Ribbon tweeters tend to hiss louder than normal ones by a fair margin I noticed.

What model vs what model? Same system? Volume control on zero, if not on, same setting for both?

and is it actually louder, or just different because of the different characteristics of the drivers (e.g one smoother sounding than the other) making one subjectively sound louder?

If genuinely louder, then as Huge says, the immediately anticipated logical answer is sensitivity:  assuming same amps and room, with volume set to zero, the more sensitive would have louder hiss.

Otherwise, and the root cause in what follows is purely speculative as I'm unsure if it is feasible in the circuitry involved (others with better knowledge of different volume controls and surrounding circuitry may be able to confirm):- if with the volume not at zero but at the level used for playing - e.g between playing music - and having been playing both speakers at the same sound level In the same system, the volume control setting would have been different for each speaker. In this case, if (some of) the hiss arises from interaction of the volume control with the circuitry, such that the setting of the control increases that hiss disproprtionately compared to the effect on signal level, it would be possible for a higher level of  hiss to be sent to the less sensitive speaker, and if higher by more than the difference in sensitivity the kess sensitive one could hiss louder than the more sensitive during quiescent periods.

Hungryhalibut posted:

I'm not sure this stereotyping is entirely helpful. 

If you don't use a stereo type system, then you'll either get mono sound reproduction or multi-channel.

Hungryhalibut posted:

I'm not sure this stereotyping is entirely helpful. 

No, as you may miss the real buggers (if that is an allowable term for people placing bugs, which is how I mean it): just as likely to be big conglomerates seeking more info on you, or cybercriminals (is your system connected to the internet?), or even your neighbours... Check that the TV screen can't 'see' as well as display.

Thank's for your feed back,  I read with interest the Innocent B answer, although with a bit of effort to understanding, English is not my native language.

So you don't take precautions with your expensive speakers leaving the amps always on !!

Your electronic components will 'age' more than your speakers (hence the need for example, of capacitor replacement on the naim kit). It's really nothing to worry about.

I'd be more concerned about the wasteful use of electricity with a system continually powered but that's another thread ... 

Anto68 posted:

Thank's for your feed back,  I read with interest the Innocent B answer, although with a bit of effort to understanding, English is not my native language.

So you don't take precautions with your expensive speakers leaving the amps always on !!

Personally I normally turn my power amp off when not in use, just putting on an hour or so before using, but that not for any consideration of residual output signal.

In the eighties every Naim amp hissed quite much putting ears close to speakers

Nowadays range it seem much less or zero, maybe age related too

Innocent Bystander posted:

Anto68 posted:

Thank's for your feed back,  I read with interest the Innocent B answer, although with a bit of effort to understanding, English is not my native language.

So you don't take precautions with your expensive speakers leaving the amps always on !!

Personally I normally turn my power amp off when not in use, just putting on an hour or so before using, but that not for any consideration of residual output signal.

I do exactly the same, as advised by the manufacturer of my amplifiers.

I understand the concept behind leaving amps switched on 24/7, but surely doing so will have a significantly adverse impact on the longevity of components such as capacitors in the amp.

Am I wrong?  

b_lund posted:

In the eighties every Naim amp hissed quite much putting ears close to speakers

Nowadays range it seem much less or zero, maybe age related too

Yours or the amp's?

Hmack posted:

 

I understand the concept behind leaving amps switched on 24/7, but surely doing so will have a significantly adverse impact on the longevity of components such as capacitors in the amp.

Am I wrong?  

There is an argument both ways, one that it stresses them more to heat up and cool down, with associated expansion and contraction, and the instantaneous effect of switch-on surges, and the other that in general people listen for an average of only a small proprtion of time, so turning off minimises the continuing stress of high voltages and elevated temperatures. Which over-rides which, I don't know.

There can be a minor difference in sound between warm and cold circuits, but in the case of Naim amps it is claimed to take days to stabilise, which I think is their primary reason for advising as they do, not the stress side of things. Whether most people would notice a difference if they warmed up for an hour on one occasion or a week on opanother I have no idea.

Some power amps out there in the wild don't even go off when turned off, even off off, to turn off off off you'll need to pull out the plug from the wall and then wait 12 hours for the battery to discharge.

None of this has explained the OPs issue for me.  Does it relate to noise, heat or philosophy?

Anto68 - what you are hearing is best described in simple terms as your 'mains' polution. Noise induced by other devices, interference in the mains.

I use to have exactly the same problem, even when my SU was on mute. How did I cure it? Dedicated mains with proper earthing solved the problem.

It will not harm your speakers.

Adam Zielinski posted:

Anto68 - what you are hearing is best described in simple terms as your 'mains' polution. Noise induced by other devices, interference in the mains.

I use to have exactly the same problem, even when my SU was on mute. How did I cure it? Dedicated mains with proper earthing solved the problem.

It will not harm your speakers.

Exactly what Adam says. If the noise is OTT then a dedicated mains supply is the answer.

The Strat (Fender) posted:

None of this has explained the OPs issue for me.  Does it relate to noise, heat or philosophy?

The hiss was not a problem, but the OP was concerned whether it would harm his speakers. That was answered early on in the thread.

Wugged Woy posted:

Adam Zielinski posted:

Anto68 - what you are hearing is best described in simple terms as your 'mains' polution. Noise induced by other devices, interference in the mains.

I use to have exactly the same problem, even when my SU was on mute. How did I cure it? Dedicated mains with proper earthing solved the problem.

It will not harm your speakers.

Exactly what Adam says. If the noise is OTT then a dedicated mains supply is the answer.

The noise was not OTT: "impossible to hear normally but only if I put my ear very very close to the speaker". Wholly consistent with  normal random thermionic noise from electronic circuitry, at a very low level, and nothing to do with mains pollution.

It is likely that on the majority of systems a feint hiss can be heard if the ear is placed very close to the tweeters when connecred and power amp on, and it will differ from system to system as according to the individual amplifier - it could even vary between samples - and the sensitivity of the speaker (and indeed the sensitivity of the person listening. Unless loud enough to be audible at the listening position it is of no consequence, though with very sensitive loundspeakers that can occur. My recollection of valve amps a few decades ago was that it was commonly more audible from them, but that might not apply to modern designs.