Phobic

Practical solutions to identify issues and reduce the noise floor

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19 minutes ago, Phobic said:

shouldn't you be spotting this in a demo before you buy?

if you can't hear it, is it a problem? 

that's a different thing to - would you notice it if it were missing....

Scatter gun will sort out both, but it's a blunt tool. 

Does your system sound better at midnight? 

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11 minutes ago, Blackmetalboon said:

It does seem to, but I don’t think it’s for the reasons you have suggested.

One of the biggest differences in listening late at night is the lower ambient noise level. Try a decibel meter in your listening area at six in the evening and at midnight. If you want 'noise floor' you don't need electrical noise to find the biggest culprit.

And that's leaving aside the obvious psychological aspects of listening late at night versus early evening or even worse, during the daytime.

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13 minutes ago, rabski said:

One of the biggest differences in listening late at night is the lower ambient noise level. Try a decibel meter in your listening area at six in the evening and at midnight. If you want 'noise floor' you don't need electrical noise to find the biggest culprit.

And that's leaving aside the obvious psychological aspects of listening late at night versus early evening or even worse, during the daytime.

...and rum.

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On 16/10/2020 at 06:25, Fourlegs said:

but can you get out to dealers? Griff500 has done that in another thread (PMC - Twenty5.24 vs Fact 8) and so has heard the ATC40 actives and loves them (I think) despite an ex ATC dealer on here trying to rubbish them based on graphs and measurements. And hence why perhaps studying graphs and measurements will only serve to give you preconceptions.

I agree that if one doesn't know how one's preferred sound translates into measurements then choosing based on good measurements is a mistake.

Good measurements equate to accuracy or how faithfully the signal is read, converted, amplified and transduced.

And the problem is that one may not like accuracy.

Some types of distortion are pleasing to some people and the exaggeration or attenuation of specific bands of the audible range will produce particular effects which will have an impact on the overal balance (i.e. cold/warm, full/thin, etc.).

And even if one can achieve reasonable correlation with speakers there's no avoiding the need to listen.

Measurements are really good for shorlisting and tracking down aspects we don't like in a particular piece of equipment; they complement listening but do not replace it. And vice versa.

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1 hour ago, Phobic said:

if you can't hear it, is it a problem?

Noise can affect performance or even stability, even if it isn't audible. For example the noise-shaping used in DSD to push the noise to ultra-sonic frequencies may affect wide-bandwidth amplifiers or perhaps even occasionally trigger the breakup resonance of a tweeter.

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15 hours ago, tuga said:

Noise can affect performance or even stability, even if it isn't audible. For example the noise-shaping used in DSD to push the noise to ultra-sonic frequencies may affect wide-bandwidth amplifiers or perhaps even occasionally trigger the breakup resonance of a tweeter.

you'd hear the effects then though wouldn't you? might be hard to understand the cause of it though.

Parking the usual pointer of just sit back and enjoy the music, I guess I'm pondering on how far you go to chase improvements, laws of diminishing returns an all that...however when you have a well sorted system any improvement is going to be small, these marginal gains do all add up though.

I've generally gravitated towards getting the basics right and have until recently avoided things where there is debate especially when there appears to be a lack of clear rationale to back things up. I think though that a few recent examples have made start to re-look into a few areas, isolation feet and noise on ethernet cables which aren't directly connected to the hifi being the 2 things that spring to mind.

I'm still inclined to just try to keep this to quick/easy/cheap things to try rather than starting to chase potential snakeoil, however until recently I I'd perceived isolation feet to probably be snakeoil, think I better understand that now and my mind's changed as I can see the difference £20 pads make.

not sure there's any real point to this post, just a bit of a ramble on where my head's at I think.

Edited by Phobic

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1 hour ago, Phobic said:

you'd hear the effects then though wouldn't you? might be hard to understand the cause of it though.

You wouldn't hear the noise but you might hear the effects. You'd have to know how to identify those problems through listening assessment and then be able to track down the cause(s) in order to get rid of them.

The same CD record can sound "harsh" and tiring in one system and "smooth" and fatigue-free in another. The cause of  "harsh" and tiring sound can originate in the player/DAC, in the amplifier, in the speakers, or in a combination of.

Edited by tuga
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16 hours ago, tuga said:

Measurements are really good for shorlisting and tracking down aspects we don't like in a particular piece of equipment; they complement listening but do not replace it. And vice versa.

And following on from your later posts regarding noise and its effect on the music signal creating harshness or a fatiguing sound it is more than likely that will not be picked up in any published measurements

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8 minutes ago, Fourlegs said:

And following on from your later posts regarding noise and its effect on the music signal creating harshness or a fatiguing sound it is more than likely that will not be picked up in any published measurements

Simplistic measurements yield simplistic results.

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7 minutes ago, tuga said:

Simplistic measurements yield simplistic results.

so what sorts of measurement are you thinking about?

is this something the home gamer can do with REW and a umik-1 mic for example?

I've never bothered trying to measure my speakers, have only done things at the listening position.

I've just done a small upgrade on my system which has helped improve my noise floor but I'm not sure I can think of a way that it could be measured with a mic.

My Linn active speakers connect to the streamer via an Ethernet cable, the connection is digital. Logic might suggest that provided these cables are of a decent enough quality you'll get good quality sound out. Linn recommend explicitly to not use shielded cables here because it can effect the timing signal which will degrade sound quality.

I've just bought some "audio" ethernet cables based on a recommendation who's done lots of testing, these were relatively cheap at £30 each, and I'm very happy that under A+B testing I can tell an improvement, there's less graininess/harshness and better clarity with these cables.

I'd find it hard to spot the graininess without that A+B test though - very interested in how you might try to measure something like this 

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23 minutes ago, Fourlegs said:

And following on from your later posts regarding noise and its effect on the music signal creating harshness or a fatiguing sound it is more than likely that will not be picked up in any published measurements

I should add that an objective listening assessment is listening (observation) for problems.

Tasting, or listening for pleasure, is a different task with a distinct goal (or no goal at all).

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15 minutes ago, Phobic said:

so what sorts of measurement are you thinking about?

is this something the home gamer can do with REW and a umik-1 mic for example?

I've never bothered trying to measure my speakers, have only done things at the listening position.

I've just done a small upgrade on my system which has helped improve my noise floor but I'm not sure I can think of a way that it could be measured with a mic.

My Linn active speakers connect to the streamer via an Ethernet cable, the connection is digital. Logic might suggest that provided these cables are of a decent enough quality you'll get good quality sound out. Linn recommend explicitly to not use shielded cables here because it can effect the timing signal which will degrade sound quality.

I've just bought some "audio" ethernet cables based on a recommendation who's done lots of testing, these were relatively cheap at £30 each, and I'm very happy that under A+B testing I can tell an improvement, there's less graininess/harshness and better clarity with these cables.

I'd find it hard to spot the graininess without that A+B test though - very interested in how you might try to measure something like this 

Basic measurements will paint a basic picture of the equipment's performance.

Some shortcomings, audible and inaudible, may not be captured by those measurements, but perhaps their cause will show somewhere and yet be below the threshold of audibility. What to do?

This is why an as comprehensive as possible set of measurements should always be presented. And also an objective listening assessment, but they're as rare as hen's teeth...

A cabinet resonance may show in the impedance plot but not in the frequency response measurement or the harmonic distortion graph. Is it audible?

THD is high but is it low-, even-, high-, odd-order, at what frequency and Q-factor?

Right tool and right measurement. Measure the effects of your tweak at the output of your DAC or amplifier, not at the listening spot.

Edited by tuga

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Here's an example of noise measurements:

A Look At The Computer USB +5V Noise...

https://archimago.blogspot.com/2018/05/measurements-computer-usb-5v-power.html

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Super Dealer

err, so? Careful not to become a Keith and just post links without saying what your thoughts are. xD

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