[bigshot]

I would think that the sound measuring stuff by MiniDSP would be at least in the ballpark of correct for noise floor. I can't see the image though. What was the reading?

 

[Strangelove424]

I find that computers are really a troublesome source of ambient noise, and we are all using them now for media consumption. I struggled to build a desktop computer that was inaudible from listening range at low/medium work loads. The loudest component is the PSU, and it's not fan noise, just hum. I'm very happy with what I accomplished, partially by using fans that shift the noise to a lower, less detectable frequency. But even though I dropped the computer a few db, I still have a minimum ambient of 31db in my house because of the damn roads nearby. In rush hour it gets to 35db, but when there is little traffic I can occasionally see noise floors just below 30db. That's not with an expensive mic though, so the numbers might be off.

Anyway, if anybody wants any help with computer cooling, feel free to PM me, I love the subject matter, and am always happy to give people some pointers on lowering computer ambient noise.

 

[KeithEmo]

Honestly, I want to sit down and do it right, and I haven't had a chance yet.
I promise I will do so over the long weekend and report my results.

I'll also state publicly something that I already said in one of our PMs......
I am NOT especially confident that I'll be able to distinguish major differences, or tell for sure which is which, among samples of music I'm not familiar with.

I'm going to use one last analogy to image processing here.....
If you were to show me two different images, on two different monitors, I may not necessarily be able to tell which one is correct if they look different.
The reason I calibrate my monitors is so that I KNOW which one is correct.
So, even if I can't tell which of two monitors is "right" or "better" I still prefer taking steps to ensure that the monitor I'm using is correct - rather than not - and I don't have to worry whether it is or not.
(I do not accept the logic that "if I can't tell which is which then it doesn't matter".)

How are you finding the lossy tracks above 128 in the listening test I sent you? Have you determined your threshold for the three codecs there yet? When you're done, I'll let you know what other people have found. There is a range but it's narrower than you would expect.

 

[KeithEmo]

I do have a quick suggestion there......

The computer I currently use to play music is a Raspberry Pi.... running Volumio.
It's about three times the size of a deck of cards.... and totally silent (no fans or other moving parts).
I have a USB hard drive connected directly to it; and it's connected to my pre/pro via USB.
(Volumio plays FLAC and all the other popular formats..... )

Volumio is free, and the Raspberry Pi (including a case and power supply) is about $60 total.

For a minimalist, and totally silent, solution it really is hard to beat.

I find that computers are really a troublesome source of ambient noise, and we are all using them now for media consumption. I struggled to build a desktop computer that was inaudible from listening range at low/medium work loads. The loudest component is the PSU, and it's not fan noise, just hum. I'm very happy with what I accomplished, partially by using fans that shift the noise to a lower, less detectable frequency. But even though I dropped the computer a few db, I still have a minimum ambient of 31db in my house because of the damn roads nearby. In rush hour it gets to 35db, but when there is little traffic I can occasionally see noise floors just below 30db. That's not with an expensive mic though, so the numbers might be off.

Anyway, if anybody wants any help with computer cooling, feel free to PM me, I love the subject matter, and am always happy to give people some pointers on lowering computer ambient noise.

 

[bigshot]

There is a broad range of rates and codecs there. The point is to find your level of transparency. Artifacts are artifacts. They are either there or they aren’t. The differences between the samples aren’t a graduated scale like frequency imbalances or distortion levels. We’re talking here about either/or... either there are artifacts, or there is sufficient bandwidth to reproduce the sound transparently. You will be able to tell if it doesn’t matter or not.

When the test is done, you can pull the file apart and A/B them against the known lossless file using foobar, but if there are no artifacts, the results will be the same.

 

[Strangelove424]

I do have a quick suggestion there......

The computer I currently use to play music is a Raspberry Pi.... running Volumio.
It's about three times the size of a deck of cards.... and totally silent (no fans or other moving parts).
I have a USB hard drive connected directly to it; and it's connected to my pre/pro via USB.
(Volumio plays FLAC and all the other popular formats..... )

Volumio is free, and the Raspberry Pi (including a case and power supply) is about $60 total.

For a minimalist, and totally silent, solution it really is hard to beat.

For a dedicated media player, the Raspberry Pis are great. Low power consumption, easy to mount, wireless/HDMI capable. I have one too, complete with LEGO case! I use my media computer for a few different things though, including my sim racing rig, so it’s a bit of a beast.

 

[Whazzzup]

dedicated external music server running roon core via ssd is the best component i purchased in absolute sq enjoyment.

 

[castleofargh]

I have a fanless weak crap I bought second hand for almost nothing, I got it just to play music. but in practice I almost always end up using the other computer anyway, for all the important stuff like telling that somebody is wrong on the web and other vital stuff like playing games(siriouz biznezz). so the fanless craputer has about as much use as my CD player nowadays, almost none.

the glass is half full: good thing about the fans making noise is that I never get to complain about my speakers hissing even so slightly(I need to get close to notice).

 

[castleofargh]

I would think that the sound measuring stuff by MiniDSP would be at least in the ballpark of correct for noise floor. I can't see the image though. What was the reading?

it just suggests that the self generated noise is really close to the noise in the room despite measuring close to the computer, so not a "quiet" room. I don't get much improvement from a physical seal and isolation of the mic(of all the mic not only the opening for the capsule). I'm using a Behringer EMC8000 and someone reported it to have 32dBA of noise floor. which is weirdly in line with what I just got(mine isn't weighted).
I've come to a point of self skepticism where getting the expected result makes me even more suspicious ^_^.

 

[KeithEmo]

Obviously we simply look at the same thing from opposite directions (or we interpret the semantics differently).

To me, when you're talking about lossy compression, there are ALWAYS artifacts (by definition ANY detectable or measurable variation from the original is an artifact).
I can convert a WAV file to a FLAC, then back to a WAV, and there will be NO differences between the "before" and "after" file - thus no artifacts.
However, if I do the same with MP3, or AAC, I will be unable to get back my original WAV file (when I compare the before and after there will be differences; those differences are artifacts; binary statement there).
(I don't need to do any complicated tests - a simple bit-compare will tell me with absolute certainty whether there are artifacts or not.... )
Therefore, the only question is whether I am able to NOTICE the artifacts/errors under a specific situation or not (or perhaps, assuming I notice them, whether I consider them significant or not).

If I am totally unable to pick out the artifacts, I will have proven is that, with that particular sample, one particular human (myself), was unable to notice the artifacts.
Of course, since I'm probably not the human with the best hearing on the planet, that won't prove that nobody else can hear them.
And, even if nobody else can hear them, that still won't prove that they don't exist - just that nobody can hear them.

The biggest difference between you and I seems to be the way we interpret the data.
To me, there is absolute data - for example, a copy of a file either is or is not bit perfect.
And there are an infinite number of ways in which it can be IMPERFECT, some of them more obvious than others, but only one "100% right".
And, while we can debate whether a given flaw is or is not noticeable, there is no doubt that "perfect is perfect" - which is why, to me, it's just easier to stick with perfect.
Note that, for the sake of this discussion, I'm assuming that whatever version of music I acquire is "my local master", so my only goal is to maintain that copy without degrading it.

However, the term "transparent" is more a flexible term, based on some sort of opinion......
An optics expert will tell you that there is no such thing as a transparent sheet of glass - because all glass absorbs somewhat more than 0.000% of the light passing through it.
Therefore, what you're really defining is "transparent enough" or "so transparent I personally cannot see the flaws".

There is a broad range of rates and codecs there. The point is to find your level of transparency. Artifacts are artifacts. They are either there or they aren’t. The differences between the samples aren’t a graduated scale like frequency imbalances or distortion levels. We’re talking here about either/or... either there are artifacts, or there is sufficient bandwidth to reproduce the sound transparently. You will be able to tell if it doesn’t matter or not.

When the test is done, you can pull the file apart and A/B them against the known lossless file using foobar, but if there are no artifacts, the results will be the same.

 

[bigshot]

Audibly transparent means that the quality of the sound exceeds your ability to hear it. Beyond that point, better quality doesn't matter because it can't be heard. If you can't hear something, it's irrelevant to your enjoyment of recorded music. No one wants to pay more or suffer inconvenience because of stuff that doesn't matter.

You see, there's a difference here... I've spent a great deal of time to try to carefully document my perception. I spent two weeks straining to hear differences between a wide range of rates and codecs and a wide range of different kinds of music. I've also invested a great deal of time sharing this test with a wide range of people and I know the results of those tests. You just have a concept of sound purity that you have faith in, but you haven't made much effort to see if it's a valid concept. I understand how you can't be sure where the line of transparency lies. And I'm sure you can understand how I can be pretty sure.

To know something, you have to want to know. At least half the time, I hand out this test and I never hear back from the people. They aren't really interested enough to put their ears on the line like this. Ignorance is more comfortable to them because they can remain the same and their thinking won't have to change. Changing your mind can hurt. Other people will fudge the text reports from Foobar or cherry pick their tests to make it look the way they want it to look or engage in logical fallacies to prop up their weak theories. That goes beyond ignorance into disingenuousness. But we're in Sound Science here. We enjoy finding out. We don't want to prop ourselves up and pat ourselves on the back. We just want to know so we can apply that knowledge to get better sound out of our audio systems.

If you make the effort to find out the truth, you don't need to depend on faith. Knowing what matters and what doesn't is the highest level of understanding.

 

[RollsDownWindowsManually]

ABX testing is not fun to me, especially when you're close to the threshold of audibility and really have to strain to hear any difference. I can see why some people wouldn't like to do it. For me that starts to happen at 128 kbps LAME MP3; at that point I can hear the difference clearly on some songs (hard rock) but not at all on others (rap). At 96 I can hear the difference clearly on almost anything without even listening carefully. I think it's mostly a function of the high frequency cutoff - I can only hear up to about 18.5 khz and 96 kbps MP3 starts to roll off a little below that I think whereas 128 goes right up to about 18.5 iirc.


Did 16 more trials of 24/96 vs V2 VBR MP3 and and got 3/8 followed by 5/8, so I'm batting right at about .500 - same as I would be just guessing I reckon.

 

[bigshot]

ABX testing is not fun to me, especially when you're close to the threshold of audibility and really have to strain to hear any difference.

If you have to strain to hear a difference, you're in the neighborhood of your line of audible transparency. You don't have to strain. The goal is to determine what matters and what doesn't, not to force yourself to hear the unhearable. Call that your line, bump up your encoding one notch so you're sure you're on the other side of the line, add VBR so your files are efficient and go with it. No reason to look back.

By the way, your findings are pretty typical. For some people (and with some kinds of music) the line might be a notch higher than yours, but you are in the majority. If you go two notches up, no one can hear a difference with any kind of music.

Congrats! There are a lot of people around here who are much less self aware of their hearing limits than you are.

 

[pinnahertz]

I would think that the sound measuring stuff by MiniDSP would be at least in the ballpark of correct for noise floor. I can't see the image though. What was the reading?

It's not. All of those mics, and even really good measurement mics like the Earthworks M30 ($700), are too noisy for good room noise measurements. It's the 1/4" capsules. The good low noise measurement mics, like the B&K 4179 capsule, are all 1" capsules and very expensive. But then you get -5.5dBA. Otherwise all the 1/2" stuff is 14-18dBA, and the 1/4" stuff is in the 20+ range.

 

[bigshot]

You're going to have a higher noise floor than 20dB in your living room anyway most likely. 20dB is like a recording booth. My $100 SPL meter came up with between 35 and 40dB in my room, and that sounds totally in line with what I would expect. There's a place for "close enough for government work" measurements.