What actually is a noise floor, technically and subjectively?

It’s a term that gets used and perhaps often abused a lot - so what really is it?

On the technical side, you’ll have to wait for the experts. Subjectively, I have understood a low noise floor to imply that a listener can pick out small and quiet details in a complex mix. Eg. Can I hear the breath control of a flautist playing pp during a loud orchestral crescendo? My current system allows me to do this and is noted for having a low noise floor, so I guess at least some other people use the term “noise floor” in this sense.

Unfortunately I currently have exceptionally low noise from my system as I am sitting in the dark during an extended power cut waiting for the lights and power to come back on.

Roger

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Simple explanation : all electronics produces noise. The noise of the combined electronics in the signal is the noise floor. Any recorded sound would have to be above the noise floor to be audible, so in general the lower the noise floor the better, otherwise it can mask ambient sounds from the recording venue, or even the quietest parts of music.

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Good explanations above. I’ve found that it’s hard to appreciate until you upgrade and details are revealed that have been previously masked by noise. I’m now starting to appreciate this having added some power supplies to my SN2 and NDX2, which have dropped the noise floor.

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Simply it’s the level of noise in a system which defines the system resolution. That is if the signal changes or resolution are less than the level of the noise floor then they won’t be determinable and effectively hidden and be inaudible.

You sometimes see a term noise margin, which is the level above the noise floor.

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The above comments resonates with my perception. I hear a descriptive term used a lot when audio reviewers are praising a new product. In fact, it was used a lot when the trickled down DR technologies were passed on to NAP Amps.

I keep destroying the term, but I think it is Dark Inky quietness! But I feel it is related to a quiet low noise floor!

What I don’t understand, is there a spec that measures the noise floor?

And is distortion noise?

Less than .00008 % distortion @ …

I really don’t have a clue😕

8 x 10 raised to the minus 5th is a very small #.

Can anyone help my flawed understanding?

Thanks In Advance!

I think you are confusing this with signal-to-noise ratio. Which isn’t a mile away from noise floor but SN ratio is measured at one point (usually the output of a function) in a chain.

Noise floor would be more like the ratio of source signal at source input against noise at final speaker output. Which is not measurable easily as functions like amplitude and frequency normalisation would technically be noise if you tried to reconcile them to the source input (which is also an immeasurable value).

We try and fail to articulate noise floor. Everything from “inky blackness” to “separation” etc. But how do you accurately describe what you can’t accurately measure? Until we come up with something, our Ears are all we have.

Thanks Zen, that was in the back of my brain!

PS. Inky Blackness!

Its not all bad to have some noise.

A higher noise floor can also hide problems earlier in the chain and allow you to focus on the music.

Is that kind of like a 282 can mask some of problems within a system that a 252/552 might reveal!

But assuming the playing field is even and tweaked out to the nth degree, isn’t a lower noise floor better?

:confused::confused::confused:

I’m not Engineer, measure above/below etc… I guess the more confusion the better, just accept what we say, and buy our product!

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I heard it explained in laymen terms like this…

If you were in a busy bar listening to a band play but everyone is talking and laughing, you can still hear the music but…

If you were in the same scenario without all the people and it was just you in the room with the band you would have a perfect black background enabling you to hear all the lovely details being masked by all the noise.

Regards

Popeye

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One thing I really like about my system, which has improved a lot since I improved my mains arrangements, is that when the music stops - it’s particularly obvious with solo piano - it falls away into an absolutely silent background. This is the infamous inky blackness. My thought is that if it is this silent when the music stops the system itself must be that silent when the music is actually playing, and therefore letting more music through. I suppose that’s a low noise floor, though I’ve never really thought about it before.

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I agree with both of you gents, Thanks popeye, I will remember that analogy.

Also since I been back, the most profound and mind altering statement, that changed my perception of all the tweaking, expensive ICs and the likes that take place on the forum came from the Darke Bear:

"I tried it and learned what to do. I think these things are not easy to convince others about other than they hear it for themselves.

DB."

Naim Fraim, is it really worth it

The funny thing, it was all accidental.

A corian shelf underneath my CDX2, and two standard shelves which further isolated my system from Naim’s ‘infamous’ Hum!

That’s right HH, that reduced my Humming by an staggering 85%, if not more. I have to focus hard, to see if my system is powered on!

My point! Now I can enjoy those passages where that ‘Dark Inky Blackness’ can shine through my system! Getting long winded! :wave::wave::wave:

PS. I had to tag it: Dark Inky Blackness!

I recently upgraded my speakers and got a tibia plus power cord in the exchange. When comparing the oem power cord to the tibia plus I achieved what I believe to be a lowering of the noise floor, at least that’s how I see (hear) it. It’s like a layer of noise has been removed (floor lowered) to reveal a new layer of music detail.

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From an acoustician’s perspective noise is unwanted sound.

The noisefloor is what Naim strive to achieve, removing as much extraneous electronic noise as possible.

They achieve this quite well, then blow it out of the windows by making power supplies that gently buzz away to themselves with varying degrees of intrusion.

I have two separate power supplies - a 300PS and a PS555DR - and one in my Nat05 tuner. All three are totally silent.

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When I bought mine the dealer warned me that some will emit a buzzing noise that varies over time from non-existent to noticeable. Mine is usually at the lower end, today it’s a slightly miffed bluefly. Also 300PS & 555PS.

Mine are silent also. Have on a couple of occasions if the mains Is dirty for some reason then I may get a bit of hum but it never lasts.
I also know that this transformer hum is not transmitted into the system music and has no bearing on the noise floor.