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Is distortion in electronics meaningful ?

mansr

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I don't think "easy" is the right adjective. We only have a handful of DACs and Amps that achieve -120 dBFS and they are all less than 2 years old I think.
-110 dB is easy. Beyond that it starts getting tricky.
 

DonH56

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"Meaningful", yes.

"Audible", probably not. But it depends on the frequency of the distortion, system gain and volume, and so forth.

I remember when -80 dB (0.01%) THD was excellent and considered easily 10x lower than what anyone could hear. Now -100 dB is not enough.

As for ASR, it is nice to have a place to discuss technical aspects, though we don't get too deep too often (I'm as guilty as anyone, too tired for deep technical discussions at the end of a long day), but I think many visitors forget that most of us "geeks" turn off the technical side and just enjoy listening to (or making) the music without analyzing each atom along the way. My processor probably measures horribly compared to the stand-alone DACs, and my amps are certainly not state of the art, but it sounds good (enough) to me.
 
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o2so

o2so

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I am a bit confused. If a SINAD of 130db is equally (in)audible as a SINAD of 90db, or even 80db, why would a DAC designer ever spend any money at all, in a competitive market, to achieve an improvement that no one can hear because of the loudspeaker limitations in terms of distortion (not noise)?
 

Jimbob54

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I am a bit confused. If a SINAD of 130db is equally (in)audible as a SINAD of 90db, or even 80db, why would a DAC designer ever spend any money at all, in a competitive market, to achieve an improvement that no one can hear because of the loudspeaker limitations in terms of distortion (not noise)?

And that is where constant upgrades, marketing and most importantly the press/ media come in ;-)

That, and to a degree, knowing a certain portion of the market will chase the ever increasing numbers
 

BDWoody

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My processor probably measures horribly compared to the stand-alone DACs, and my amps are certainly not state of the art, but it sounds good (enough) to me.

And, what speakers are you using again there Don? :cool:
 

solderdude

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I am a bit confused. If a SINAD of 130db is equally (in)audible as a SINAD of 90db, or even 80db, why would a DAC designer ever spend any money at all, in a competitive market, to achieve an improvement that no one can hear because of the loudspeaker limitations in terms of distortion (not noise)?

New chips are coming out pushing boundaries futher and further. Manufacturers put these chips in new devices that can now boast with even better specs. People look at specs, they buy on specs, recommendations, tests and want the best for the lowest possible price with the right features and connectivity.

As you can see there are no speakers nor their specs involved. Just money and better specs. This has always been the case. There is not much more to it.
 

DonH56

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I am a bit confused. If a SINAD of 130db is equally (in)audible as a SINAD of 90db, or even 80db, why would a DAC designer ever spend any money at all, in a competitive market, to achieve an improvement that no one can hear because of the loudspeaker limitations in terms of distortion (not noise)?

(A) Because he can. Design engineers gotta' design.
(B) Marketing. Which pays for the design engineers to keep designing, 1 additional dB at a time.

My new notebook with a 3.4 GHz multi-threaded CPU and 16 GB memory does not load web pages any faster but it "feels" faster.
 

DonH56

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And, what speakers are you using again there Don? :cool:

Some crappy old towers designed 10+ years ago by some geek with no ears. Or so "they" tell me. :)
 

q3cpma

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(A) Because he can. Design engineers gotta' design.
(B) Marketing. Which pays for the design engineers to keep designing, 1 additional dB at a time.

My new notebook with a 3.4 GHz multi-threaded CPU and 16 GB memory does not load web pages any faster but it "feels" faster.
With modern web pages full of Jabbascript, chances are that it's actually faster. But yeah, SINAD (or better, masking weighted SINAD) is a neurotic number fetish past a certain value.
 

Jimbob54

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DonH56

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Big horn!

1599224487393.png
 

Tks

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As far as I understand. Each device in the chain compounds the distortion quantity. Maybe someone here can chime in on the formula used.

Though this begs the question about how distortion ridden studio setups are with 10s of devices all hooked up and such.

Its also an engineering boundary focus thats being pushed to demonstrate who has competence as well as initiative. Its not enough to have a company simply want to produce better performing devices, yet use engineers that dont know what they're doing. Likewise its not enough just to have talented engineers that get told to hurry up and make pretty boxes in a week or two.

Also, as features start to be more demanded by consumers (as the market of single purpose devices becomes saturated). Being able to keep pefromance high while adding things like DSP or FPGA solutions becomes important. People dont want downgrades as other territories are explored. So it pays to have a baseline thats high.
 

MediumRare

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I am a bit confused. If a SINAD of 130db is equally (in)audible as a SINAD of 90db, or even 80db, why would a DAC designer ever spend any money at all, in a competitive market, to achieve an improvement that no one can hear because of the loudspeaker limitations in terms of distortion (not noise)?
IMO you are hung up on the speaker performance a bit too much. THD+N is not like "everything in any unit below the worst unit doesn't matter". THD+N actually adds tones to the signal at each stage of the process. It's both additive and multiplicative. In other words, the unwanted (added) tones carry over to the next link in the audio chain and then are in turn are multiplied AND added to.

Consider all the amp reviews here which show IMD rising at HF, plus THD rising as the amp clips. A lot of discussion here has been about dynamics requiring 10x the sustained power level for peaks. The cumulative effect across a signal chain can absolutely be audible, especially if your high-end hearing is good (HF noise & clipping) and, in an extreme case, you are using sensitive IEMs.

We call ourselves "Science" but the truth, IMO, is there is still a lot of speculation on what is audible and what isn't. Amir will tell you training enhances your ability to detect the flaws and he DOES hear differences at the end of the chain - unless the FULL chain AFTER addition/multiplication is still "transparent". If Redbook requires 96 dB to be transparent before reaching your speakers that's a tall order.

The real benefit of our approach is to filter out the provable BS and snake-oil and provide visibility of the data. How you interpret the data, your price/value preferences, and your taste for shaping the signal is up to you.
 

Blumlein 88

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When I did 8th generation loop backs noise and distortion increased with each generation. Yet one is hard pressed to hear that. The devices I used were non-exotic. Sinad was eroded by more than 12 db.
 

DonH56

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As far as I understand. Each device in the chain compounds the distortion quantity. Maybe someone here can chime in on the formula used.

Uncorrelated it should RSS -- root-sum-square -- so calculate each distortion term, square it, add all the squared terms, take the square root, and calculate the new distortion. So if the speakers are at -60 dBc and amp at -80 dBc then the distortion is (10^-60*2/20 + 10^-80*2/20) = 0.00000101 (using voltages) and converting back to dBc (20*log) the result is -59.96 dBc -- about 0.04 dB reduction in performance from the amp. A DAC at -130 dBc is in the mud...
 
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MediumRare

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When I did 8th generation loop backs noise and distortion increased with each generation. Yet one is hard pressed to hear that. The devices I used were non-exotic. Sinad was eroded by more than 12 db.
Was your amp near clipping and did you measure the distortion difference at the speakers? That’s where it would be most audible, right?
 

BDWoody

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Some crappy old towers designed 10+ years ago by some geek with no ears. Or so "they" tell me. :)

Don't lose heart...if you work hard, maybe you can have nice things too one day.;)
 

MediumRare

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Uncorrelated it should RSS -- root-sum-square -- so calculate each distortion term, square it, add all the terms, take the square root, and calculate the new distortion. So if the speakers are at -60 dBc and amp at -80 dBc then the distortion is (10^-60*2/20 + 10^-80*2/20) = 0.00000101 (using voltages) and converting back to dBc (20*log) the result is -59.96 dBc -- about 0.04 dB reduction from the amp. A DAC at -130 dBc is in the mud...
So let’s use a real edge case: DAC is a phone at 90 dB, speaker midrange THD is at 2.5% distortion and amp is at 1% (before dynamics). What RSS dB does that give you?
 
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