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Ladies & Gents as we know noise floors are normal and nothing to worry about. Noise needs to be -85dB below the signal to be inaudible.

Even so I'd love to hear about how our noise floors compare in our different setups, it might tell us a few things!

If you can turn your system on and with no music playing stick your ear against each driver, try at different volumes because that will help identify/eliminate where the noise is coming from. Describe what you hear and tell us a bit about your setup.

My setup:- Akubarik Exakt (old DAC) with Akurate system hub (DSM). I have standard kettle lead power cables on the speakers which are plugged directly into the wall. There's cheap basic filtering of the wall supply in the power strip which the system hub is connected to, the power strip has a switch and wifi access point plugged into it as well. All this is on a dedicated spur.

My loudest driver is the tweeter I can hear very faint white noise, it's barely audible when I'm 5cm away, I have to press right up to the tweeter to hear it properly. The super tweeter has an even fainter higher frequency white noise.

The mid has even quieter white noise which sounds a tiny big mechanical (makes me wonder if there's still a small ground loop in the house somewhere). I can't hear anything from the mid if I'm more than 1cm away from it.

Upper base is quieter still, I have to press my ear against it to hear anything. I'm not going to bother trying with the lower bass...

when I'm sat at my listening position I can't hear any noise at all, when music plays there's nothing I can hear.

@Paulssurround and @akamatsu really keen to hear from both of you!

@Paulssurround interested if the Katalyst DAC improves the noise floor at all, not sure I can think of an easy way to tell without having both our speakers next to each other. Any ideas?

Edited by Phobic
Ladies as well!

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Very interesting @Phobic My tweeter too gives off the most white noise although inaudible more than a few centimetres away. Both bass drivers are only slightly audible with my ear right up against the unit. Amplifier volume change doesn't alter the white noise sound at all, unless I have the turntable switched on and that input selected on the ASH. But I assume that's normal behaviour?

Akurate System Hub, Akurate Exaktbox-I and Ninkas. K600 speaker cable and no power conditioning unit, just standard Linn power cables into a 6 socket extension into the wall socket. I don't know how many separate electrical spurs I have, if any.

Mike.

Edited by SnapperMike
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1 hour ago, Phobic said:

the power strip has a switch and wifi access point plugged into it as well. All this is on a dedicated spur.

Is the Linn System also connected there? A power strip with a switch is the worst thing you can do.

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2 minutes ago, Johannes said:

Is the Linn System also connected there? A power strip with a switch is the worst thing you can do.

I reckon pouring petrol over the speakers and setting fire to them may just edge it for being worse...

(Switches aren't going to have some sort of catastrophic effect.)

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1 hour ago, Phobic said:

Gents ...

Aren't you making a bit of an assumption here? :)

1 hour ago, Phobic said:

noise floors are normal and nothing to worry about. Noise needs to be -85dB below the signal to be inaudible.

Noise floors are surely more than "normal"; they are inevitable, because there is no such thing as a Hi-Fi system that is completely noise-free. And whether we can separately detect the noise as noise may, depending on circumstances, not be the important issue.

As I understand recent developments in our understanding of how the mind (conscious and unconscious) works, we more readily and rapidly detect that there is a change in the set of sensory signals we are receiving than we identify what that change actually is. In the particular case of our hearing, the sensors (our ears) each receive only one - complex - 'waveform' of pressure variations; the brain then processes that waveform to identify the constituent 'sounds'. Clearly, pattern recognition plays an important part in this process; anything that "doesn't fit" requires more processing effort so that it can be identified and remembered as necessary. This process was no doubt a survival adaptation; our great ape ancestors were threatened by predators who could outrun them, and needed to identify any actual or potential threat before it got too close. If any change couldn't be immediately identified, it was best to run first and do the thinking in a place of safety. So we perceive that there is  a change before we put in the brain effort to know what it is. 

The need for additional processing represents extra work for the brain, which is inherently lazy (or, if you prefer, efficient in its use of energy). So the extra work is not enjoyable. If we are listening to music which we unconsciously expect to conform to particular sound patterns, noise, even at levels at which we do not separately identify it as such, is a disturber of our musical enjoyment. I believe that, as a defence mechanism, we unconsciously learn to "factor in" a certain amount of noise when we listen to our Hi-Fi systems, to reduce the processing overhead and thereby make the musical experience more enjoyable.

Thus, while I shall be interested to discover whether others have experimented as you have done, I think that what is even more interesting is the effect of lowering the noise floor of the system. As you know, I had the Karousel bearing fitted to my LP12 a some months ago, and the major claimed benefit of the Karousel is that it lowers the noise floor of the LP12, and therefore of the system as a whole. When Jon Monks came to deliver my new RCM a few weeks ago, he brought with him a high quality (direct cut) jazz LP that he likes to use for testing. You can reasonably expect a manufacturer of RCMs to be pretty sensitive to system noise, and Jon commented that he had never heard the music on that album against such a quiet background. One has to assume that he was "expecting" a certain noise level; when it did not materialise, the reduction in the need for brain effort to process the noise was in some way pleasurable. This reaction seems to be typical among those who hear systems with LP12s fitted with the Karousel. A somewhat similar reaction was also part of the response when people heard Katalyst-based systems for the first time.

So, while the noise you hear when you are listening next to a loudspeaker driver which is powered but receiving no signal is perhaps less interesting than the absence of noise you perceive, at your normal listening distance, when you lower the noise floor. All the same, thanks for starting the topic. It's a good one for us to get our teeth into.

David

Edited by DavidHB
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24 minutes ago, Johannes said:

Is the Linn System also connected there? A power strip with a switch is the worst thing you can do.

the system hub is yes, I don't have any choice at the moment.

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15 minutes ago, DavidHB said:

Aren't you making a bit of an assumption here? :)

Noise floors are surely more than "normal"; they are inevitable, because there is no such thing as a Hi-Fi system that is completely noise-free. And whether we can separately detect the noise as noise may, depending on circumstances, not be the important issue.

As I understand recent developments in our understanding of how the mind (conscious and unconscious) works, we more readily and rapidly detect that there is a change in the set of sensory signals we are receiving than we identify what that change actually is. In the particular case of our hearing, the sensors (our ears) each receive only one - complex - 'waveform' of pressure variations; the brain then processes that waveform to identify the constituent 'sounds'. Clearly, pattern recognition plays an important part in this process; anything that "doesn't fit" requires more processing effort so that it can be identified and remembered as necessary. This process was no doubt a survival adaptation; our great ape ancestors were threatened by predators who could outrun them, and needed to identify any actual or potential threat before it got too close. If any change couldn't be immediately identified, it was best to run first and do the thinking in a place of safety. So we perceive that there is  a change before we put in the brain effort to know what it is. 

The need for additional processing represents extra work for the brain, which is inherently lazy (or, if you prefer, efficient in its use of energy). So the extra work is not enjoyable. If we are listening to music which we unconsciously expect to conform to particular sound patterns, noise, even at levels at which we do not separately identify it as such, is a disturber of our musical enjoyment. I believe that, as a defence mechanism, we unconsciously learn to "factor in" a certain amount of noise when we listen to our Hi-Fi systems, to reduce the processing overhead and thereby make the musical experience more enjoyable.

Thus, while I shall be interested to discover whether others have experimented as you have done, I think that what is even more interesting is the effect of lowering the noise floor of the system. As you know, I had the Karousel bearing fitted to my LP12 a some months ago, and the major claimed benefit of the Karousel is that it lowers the noise floor of the LP12, and therefore of the system as a whole. When Jon Monks came to deliver my new RCM a few weeks ago, he brought with him a high quality (direct cut) jazz LP that he likes to use for testing. You can reasonably expect a manufacturer of RCMs to be pretty sensitive to system noise, and Jon commented that he had never heard the music on that album against such a quiet background. One has to assume that he was "expecting" a certain noise level; when it did not materialise, the reduction in the need for brain effort to process the noise was in some way pleasurable. This reaction seems to be typical among those who hear systems with LP12s fitted with the Karousel. A somewhat similar reaction was also part of the response when people heard Katalyst-based systems for the first time.

So, while the noise you hear when you are listening next to a loudspeaker driver which is powered but receiving no signal is perhaps less interesting than the absence of noise you perceive, at your normal listening distance, when you lower the noise floor. All the same, thanks for starting the topic. It's a good one for us to get our teeth into.

David

Well written & good points David

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35 minutes ago, Johannes said:

I've listened with the K-Hub switched off and then switched on to full volume, and I can hear absolutely nothing at either. No noise than when they are switched off.

Thanks Johannes, can you tell us a little about your setup please.

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Apologies if this has been mentioned and I've missed it but I think there is an important distinction to be made between random noise (like tweeter hiss) and tonal noise (like tranformer hum or a low level 50 Hz signal reaching the speakers. I believe random noise is easier to 'hear through' as your brain sort of averages it out.

FWIW in my non-Linn system I can hear some hiss with my ear very close to the tweeter and an even quieter noise from close to the mid/bass drivers. Nothing is audible at the listening position though. For music volume control is in the digital domain so this makes no difference, and I suspect the output of my streamer/DSP/DAC/pre may actually be muted with nothing playing anyway. It's the power amp that is the source of the noise.

Note that audibility of tweeter noise will be affected by who is listening as well as the system, as particularly sensitivity to the highest frequencies can vary a lot from one person to the next. One person saying they hear no hiss doesn't necessarily mean that their system produces less noise that a different person's system where they do hear some hiss.

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Super Wammer

I’ve a hunch that background noise in a typical home is dominated by distant traffic rumble, wind noise from outside, and devices operating elsewhere, like refrigerators and central heating pumps.  Obviously I’m excluding noisy children and TVs in adjacent rooms!

I don’t think this ambient noise is anything like -85dB, but nearer -65 or so.  I believe it’s often a problem in recoding venues where they will choose to record at night to minimise the issue.  Incidentally, the mains might well be cleaner at night due to the reduction in other users. 

My system is silent on all inputs except Phono, where there’s a slight hiss and even slighter hum at a loud setting but with nothing playing, ear to speaker.  There’s a trace of transformer buzz from the amp, audible a few cm away.  Nothing whatever at the listening position. 

On my crude iPhone app the living room currently measures about 31dB on the Z weighting.  So that would need a 96dB peak with the 65 range I had assumed. It is quite windy outside, and we are double-glazed.  

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The noise floor I can measure with my UMIK-1 is higher than -85dB re. my typical listening volumes but I can't tell if that's due to background acoustic noise of the noise floor of the microphone itself. My hunch is the latter though.

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55 minutes ago, MartinC said:

Apologies if this has been mentioned and I've missed it but I think there is an important distinction to be made between random noise (like tweeter hiss) and tonal noise (like tranformer hum or a low level 50 Hz signal reaching the speakers. I believe random noise is easier to 'hear through' as your brain sort of averages it out.

exactly, in fact part of the reason for asking people to describe what they hear is we should be able to help steer them to sources and potential fixes e.g. a ground loop has quite a distinct hum to it

agree measuring it is going to be tricky, maybe doing it at night with things switched off might help

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