SINAD as an overall figure of merit

[RickS]

Wow, tough crowd. Why be so unfriendly? A thought a little technical discussion would be fun. Oh well, thanks for posting Amir’s paper. That should help with the questions I’m asking.

You are welcome. ASR can be a tough crowd.

Did not help that your OP threw in "I am wondering why we believe this single number represents enough of the device's performance roll-up to truly say that one is better than another." So, take some ownership in why you may have provoked some other members that are wary and worn over the barrage of comparable posts here.

 

[rjp]

Why do you think that SINAD is limited to DACs? Or are you particularly concerned with DACs?

I understand SINAD applies to any signal anywhere, not just DACs. For that matter, not just electronics. It is actually a general metric of signal purity, basically the ratio of desired signal to everything else that’s not signal, ie, noise and any interference including the harmonics of the desired signal or external sources like oscillators. It was popular in early telephony. At least that’s where I first used it.

The reason I mentioned DACs is because it looked like a lot or most of the devices in the chart were DACs. And I am particularly interested in DACs now, yes.

 

[Oddball]

I understand SINAD applies to any signal anywhere, not just DACs. For that matter, not just electronics. It is actually a general metric of signal purity, basically the ratio of desired signal to everything else that’s not signal, ie, noise and any interference including the harmonics of the desired signal or external sources like oscillators. It was popular in early telephony. At least that’s where I first used it.

The reason I mentioned DACs is because it looked like a lot or most of the devices in the chart were DACs. And I am particularly interested in DACs now, yes.

Well people get jumpy - you should remember that posts are open to members that have tremendous engineering knowledge on top of decades of their audio experience. I am certainly lacking the first.

You are poking at a narrow and probably not that relevant hole given how transparent the gear got. Just to land some bigger picture, there is the room that makes most of the performance, then there are the speakers, then there is (at least IMO) room correction, and then there are gear spec including SINAD. So overall, there is much bigger fish to fry, but yes, eventually DACs need to be ranked and this appears to be a convenient way to do so for ones that know how to read into all of the above.

If you figured out all of the above and now down to SINAD, hat down. I am way behind you.

 

[rjp]

You are welcome. ASR can be a tough crowd.

Did not help that your OP threw in "I am wondering why we believe this single number represents enough of the device's performance roll-up to truly say that one is better than another." So, take some ownership in why you may have provoked some other members that are wary and worn over the barrage of comparable posts here.

Fair enough. I suppose I could have phrased my OP better. My apologies.

I’m sure that we can all learn from one another even when we disagree. I would hope that should not be an impediment to progress, but instead an opportunity for respectful scientific debate.

 

[rjp]

Well people get jumpy - you should remember that posts are open to members that have tremendous engineering knowledge on top of decades of their audio experience. I am certainly lacking the first.

You are poking at a narrow and probably not that relevant hole given how transparent the gear got. Just to land some bigger picture, there is the room that makes most of the performance, then there are the speakers, then there is (at least IMO) room correction, and then there are gear spec including SINAD. So overall, there is much bigger fish to fry, but yes, eventually DACs need to be ranked and this appears to be a convenient way to do so for ones that know how to read into all of the above.

If you figured out all of the above and now to SINAD, hat down. I am way beyond you.

100% agree with you that the room dominates everything. That’s actually why I’m dipping my toes into room correction again. I tried it years ago and wasn’t satisfied. using minidsp 2x4hd at the time it was new.

 

[solderdude]

gives the impression that DACS up the top are better.

Technically the highest numbers perform better (at 1kHz at 2V/4V).
At this point it is all moot and inconsequential but that's where we are ... measurement limits.
Amir is reaching the practical maximum (for 2/4V) unless Amir starts using a special pre-amp.
You can get even better SINAD at higher voltages ... because of the noise floor.
If the rest (filters, frequency response, distortion in low and high freq and IM is OK and other aspects too you have a top performing DAC.

There will always be people claiming those sound boring, clinical, cold, digital and what not and they prefer the 'poor SINAD' devices because of magical components.
So be it.

Over many years of reading comments here I do get the impression it is sometimes viewed that way.

Well some readers most likely do. There are folks getting teary eyes when they read this or that device has a slightly higher SINAD, sell what they have and buy the latest and greatest. If that is what sets their mind at ease...

In more 'subjective' forums the word SINAD is synonym for 'plot gazers with no ears' and 'misguided people with poor gear'.
It is used as a stick to beat Amir and ASR with.

Partly some of the SINAD critics are even right ... in most cases (as long as it is not noise dominated) 80 SINAD is already fine. In certain cases 100+ may be needed..

 

[Barrelhouse Solly]

Technical question regarding quantitative analysis and ranking..

I saw recently that the WiiM Ultra streamer DAC measure a very high 115 dB SINAD, which is great compared to the hundreds of other DACs measured here.

But why is this SINAD used as an overall metric of quality? The DACs reported in the colored chart seem to be ranked exclusively by this number.

To my understanding the SINAD reported was measured only at a single frequency, 1000 Hz, and only at a single amplitude. What about performance at other frequencies and other power levels?

I am wondering why we believe this single number represents enough of the device's performance roll-up to truly say that one is better than another.

If there has been some prior discussion/technical justification for this please send a link. I would love to read and understand.

Thank you!

Like as lot of tests and measurements the real question is, "Does this help you to make a decision?" Like baseball batting average, SINAD is limited but gives you a fair amount of insight into the overall question of quality.

 

[ahofer]

Why be so unfriendly?

That may be you reading into it. As I said, this accusation about SINAD being all we consider is an incredibly common strawman used by this site’s critics, so you are likely sensing frustration with that, rather than you in particular. When people have strong reactions to an argument, it’s hard not to see it as personal, even if it isn’t.

In fact, people get more upset about these things when they come from the in-group. Humans being social animals. “Et tu?”

 

[rjp]

In more 'subjective' forums the word SINAD is synonym for 'plot gazers with no ears' and 'misguided people with poor gear'.
It is used as a stick to beat Amir and ASR with.

Ah, I see. I didn’t realize it was such a hot button issue. Guess I just stepped in it.

I’m not here to bash anyone for SINAD. It’s a very important metric, but like I’m hearing now, it’s just part of the bigger picture. I was actually wondering if we could measure it at more frequencies and make some sort of composite figure? Just thinking out loud here. Please don’t take it as criticism.

The only problem I find I have with SINAD is how difficult it is to type so many capital letters with one finger

 

[MaxwellsEq]

Ah, I see. I didn’t realize it was such a hot button issue. Guess I just stepped in it

All you needed to do was search. Perhaps it's too much effort to learn from past discussions? Perhaps you are just trying to find a raw nerve with all your current posts ( @RickS ) in order to get a response? Who knows? Oh, you do...

I've spent my life as and EE in signal analysis and an familiar with the term

Ohhhh now this IS interesting. So you actually have sufficient knowledge to know that NONE of us Electronic Engineers on ASR EVER depend on one measure. So are you trying to just trigger a response?