General debate thread about audio measurements

[Dismayed]

I don't have that measurement. I meant, in general. I can go look at SBAF for a specific plot, if you insist. My point is that no one is seeing or reacting as strongly as Amir is to Schiit. (Okay, maybe JA, but he got a bad taste in his mouth on Ragnarok.)

You are the one making the claim, so, yes, we do insist that you provide supporting evidence.

 

[FrivolsListener]

POWERFUL!

I just looked and it is rated for 375 watts or 1/2 hp. Noticed another curious thing. It lists AC frequency as 26-60 hz.

Did anyone ever use anything less than 50 hz?

16 Hz for electrified railroads. Wasn't Tesla's Niagra Falls plant something like 25 Hz?

 

[FrivolsListener]

I react pretty strongly to Schiit because I owned a couple of their products. The Bifrost DAC would pass noise through to my headphones when there was disc activity on my computer. Sorry, but their engineering is crap.

Sorry you had that experience. Did they tell you to pound sand, or that it was normal?

My experience hasn't been perfect. But it has been good. What it has NOT been is uniformly, consistently bad.

 

[FrivolsListener]

I can and so can you. But again, that is not the point. You brought up the topic of measurements. You said he doesn't complain about measurements but I do implying I find problems he doesn't. I showed you how he is showing horrible performance yet you didn't even notice it because he did a horrible job of explaining it as such, and paper over it for good measure. So are we done with my measurements not being good and me complaining for no reason?

You are looking at the measurement of the least significant bit going from 1 to 0 to -1. Part of being able to make measurements was to read them. You are looking at noise down at the inaudible threshold.

So, I searched for "modi" by user atomicbob over there, and didn't find it. At least, when I'm asked for links (like back at the beginning of discussion), I try to provide.

 

[FrivolsListener]

You are the one making the claim, so, yes, we do insist that you provide supporting evidence.

Which? About the Lyr? I didn't have a specific example in mind, but I can go and dig up a link on a measurement article of a Schiit product by atomicbob. Hold that thought.

 

[amirm]

You are looking at the measurement of the least significant bit going from 1 to 0 to -1. Part of being able to make measurements was to read them. You are looking at noise down at the inaudible threshold.

You keep mixing the two topics. By your standard abob should not be making any measurements either. So please don't keep confusing the two topics. The purpose of measurements are to provide reliable data as to how well a product is designed. If such a measurement shows poor performance, it needs to be stated so. For you to defend the guy who doesn't educate you on what the test is, and papers over any issues while complaining about me who does neither, is improper.

So, I searched for "modi" by user atomicbob over there, and didn't find it. At least, when I'm asked for links (like back at the beginning of discussion), I try to provide.

Huh? You didn't ask me for a link. Here it is: http://www.superbestaudiofriends.org/index.php?threads/schiit-modi-mb-technical-measurements.2603/

 

[FrivolsListener]

Huh? You didn't ask me for a link. Here it is: http://www.superbestaudiofriends.org/index.php?threads/schiit-modi-mb-technical-measurements.2603/

Could you link to the post itself, please? I'd like to read the full thing.

 

[FrivolsListener]

You keep mixing the two topics. By your standard abob should not be making any measurements either. So please don't keep confusing the two topics. The purpose of measurements are to provide reliable data as to how well a product is designed. If such a measurement shows poor performance, it needs to be stated so. For you to defend the guy who doesn't educate you on what the test is, and papers over any issues while complaining about me who does neither, is improper.

No, you are drawing a conclusion from something I didn't say.

You displayed a plot of a sine wave at -90 dBFS. By definition, that's down in the noise, and at the very edge of what a 16 bit DAC can show. It showed something resembling a waveform at that scale. What would a theoretical perfect 16 bit DAC show in that case? A square wave? A "mayan temple" wave with 3 steps in it?

My conclusion is that it's not good, but that it not being good is not all that relevant.

I'm currently looking at his Bifrost MB measurements (link: http://www.superbestaudiofriends.org/index.php?threads/schiit-bifrost-mb-technical-measurements.235/) and it, too, shows an atrocious waveform not resembling anything useful at -90 dBFS. -70 dBFS is much more interesting in that it has more than 1 or 2 significant bits to construct a waveform from, and the distortion products are potentially audible there.

 

[March Audio]

I beg to differ. Personally, I'm not worried about distortion spikes that are 100+ dB down from the signal. Twice as inaudible is still inaudible.

Differ about what?

I have made no statement about what is ultimately audible. In fact I am very much of the mind that people can't hear what they like to think they can.

That doesn't take anything away from the fact that the Schiit products don't technically perform well compared to many cheaper competitors. So armed with that knowledge up front why would you buy them?

Obviously people who have bought the products will defend them, as will the manufacturer.

BTW your personal subjective uncontrolled opinion regarding what is audible has little relevance or meaning.

 

[amirm]

No, you are drawing a conclusion from something I didn't say.

You displayed a plot of a sine wave at -90 dBFS. By definition, that's down in the noise, and at the very edge of what a 16 bit DAC can show. It showed something resembling a waveform at that scale. What would a theoretical perfect 16 bit DAC show in that case? A square wave? A "mayan temple" wave with 3 steps in it?

Hmmm. Seems like you have not read much of my reviews as I show and explain that signal in everyone. Here it is from my latest review: https://www.audiosciencereview.com/...gemini-2000-dac-and-headphone-amplifier.2556/

The one on the left is what it is supposed to look like.

Now compare that to the Schiit Modi 2 Multibit from abob. And you tell me if you did a review and got that, you would say nothing.

 

[March Audio]

Unlikely to be THAT problem, yes, but switchers are noisy. You have to work hard to get a clean switcher. Some designers choose to avoid them altogether.

Well your point was specifically about low mains supply voltage.

So, yet again, as other manufacturers have no major issue making products work well with switching supplies, what can we conclude if its now down to general switching noise?

Schiit design is deficient.

 

[Blumlein 88]

No, you are drawing a conclusion from something I didn't say.

You displayed a plot of a sine wave at -90 dBFS. By definition, that's down in the noise, and at the very edge of what a 16 bit DAC can show. It showed something resembling a waveform at that scale. What would a theoretical perfect 16 bit DAC show in that case? A square wave? A "mayan temple" wave with 3 steps in it?

My conclusion is that it's not good, but that it not being good is not all that relevant.

I'm currently looking at his Bifrost MB measurements (link: http://www.superbestaudiofriends.org/index.php?threads/schiit-bifrost-mb-technical-measurements.235/) and it, too, shows an atrocious waveform not resembling anything useful at -90 dBFS. -70 dBFS is much more interesting in that it has more than 1 or 2 significant bits to construct a waveform from, and the distortion products are potentially audible there.

Maybe this for 16 bit. The Bifrost looks nothing like this -90.3 dbFS waveshape in Atomic Bob's view of it.

 

[Wombat]

So just another keyboard expert know it all pretending to have credentials................................

A typical forum blow-in.

Like most I have my strong, and otherwise, knowledge and experience specialties.

I am used to dealing in facts where they are relevant. That is one aspect of ASR that I strongly support.

 

[March Audio]

Hmmm. Seems like you have not read much of my reviews as I show and explain that signal in everyone. Here it is from my latest review: https://www.audiosciencereview.com/...gemini-2000-dac-and-headphone-amplifier.2556/

The one on the left is what it is supposed to look like.

Now compare that to the Schiit Modi 2 Multibit from abob. And you tell me if you did a review and got that, you would say nothing.

Ill take the fuzzy distorted one

 

[Wombat]

POWERFUL!

I just looked and it is rated for 375 watts or 1/2 hp. Noticed another curious thing. It lists AC frequency as 26-60 hz.

Did anyone ever use anything less than 50 hz?

In my early career days I worked as a power station controller/operator. The old part of the power station had 25 Hz generators.

See Newport A in this article: https://en.wikipedia.org/wiki/Newport_Power_Station
Two of the main customers were the Melbourne City Council and the Victorian Railways. At some later time a rotating Synchronous Converter was installed to connect the 25Hz and 50Hz busses.

 

[junki]

Can you hear that resolution at -90 dB? That hash between -INF and -88 dB down is inaudible. Unless you're a dog or cat.

Like I said in my original response to you many pages back, what measurements show vs. what you hear is a bridge too far to cross in most cases, and you should editorialize all the signals to suit your own needs. Perhaps you care 99% what it sounds like, and just 1% what it measures. That's fine. There's not right or wrong in this. Some people buy a car mostly because of the feeling they get behind the wheel. Others buy a car for the status it may impart. Still others buy a car based off of the engine, drivetrain, and specs. It doesn't really matter, as long as you derive delight from your purchase.

However, what does a 1KHz at -90 dB say about a DAC? The lowest bitdepth of audio most of us listen to is 16-bit music, typically sampled at 44.1 KHz. That's what I listen to. 16-bits means -96 dB amplitudes, max. Another words, the maximum dynamic range of 16-bit audio is 96 dB. If a DAC can't reconstruct analog signals with 90 dB amplitudes, that means, factually, it cannot accurately reconstruct an analog signal whose amplitude requires 15-bits to encode, less 16-bits. By far, most audio signals, regardless of bitdepth, don't use all 16-bits, especially in today's age of more and more compressed music. It's also very quiet down there, so it's unlikely anyone can hear it. But the factual reality remains, and that's all it means. It doesn't say if one can hear those highly distorted bits, if present; or perhaps those highly distorted bits create a subtle euphonic character over the sound for you. Who knows. All we can conclude from that measurement is the Bimby cannot accurately reconstruct 96dB of dynamic range, as supported by 16-bit encoded audio.

So let's just try to be measured in our interpretations. Arguing that a 1 KHz -90 dB linearity measurement shouldn't matter because it's inaudible to you is similar to arguing that one person's complaints about the peak performance of a car's disc brakes not being to spec shouldn't matter because you feel great behind the wheel. It's not helpful to anyone, is pretentious, and doesn't make any sense.

In the end, know your preferences. Know what metrics mean, and the extent to what they mean. Finally, be internally consistent. Don't be an audiofool with 32-bit 384 KHz music and a several thousand dollar R2R DAC with 18 effective bits because omg it sounds organic.

 

[Cosmik]

I've not been following this thread for a while, but a brief dip in now reveals that the exact mains voltage is being questioned?!! It might make a difference as to whether a regulator is or is not dropping out..??!!! I am having trouble in expressing my disbelief. It is cognitive dissonance or something, where a discussion is taking place in all seriousness about something that no engineer would ever have trouble with when designing a low power device that runs on the mains. Why does audiophilia result in 'designs' that are so amateurish and shambolic that people might even raise it as an issue?

 

[Wombat]

I've not been following this thread for a while, but a brief dip in now reveals that the exact mains voltage is being questioned?!! It might make a difference as to whether a regulator is or is not dropping out..??!!! I am having trouble in expressing my disbelief. It is cognitive dissonance or something, where a discussion is taking place in all seriousness about something that no engineer would ever have trouble with when designing a low power device that runs on the mains. Why does audiophilia result in 'designs' that are so amateurish and shambolic that people might even raise it as an issue?

Lots of dangerous amateurs after kudos and/or a buck. I once pointed out to a low volume SET maker that his products did not comply with the US Amplifier Rule Regulation. His reply was that he didn't believe in regulations.

 

[Blumlein 88]

Lots of dangerous amateurs after kudos and/or a buck. I once pointed out to a low volume SET maker that his products did not comply with the US Amplifier Rule Regulation. His reply was that he didn't believe in regulations.

Makes sense to me. His design was about beliefs.

 

[FrivolsListener]

Differ about what?

Amir spazzing out.

BTW your personal subjective uncontrolled opinion regarding what is audible has little relevance or meaning.

True enough; it is an opinion. So tell me: Can you provide peer reviewed research that -90 dBm signals can be heard on any transducer by a human? Or not heard by a human?