Indentical measurments = Identical performance?


I’ve been doing A LOT of thinking lately. In particular, about the importance of audio measurments for source components like DACs and CD players.

 

Let us first assume that we have 2 identical DACs or 2 identical CD players. You wouldn’t dare suggest that the same models sound inherently different, now would you? Well we can prove that the output of each device in this scenario is identical by doing a null test. We capature the output of the DACs and CD players and learn that their waveforms (let’s say a 30 second clip) are identical. The only time we might see a difference is in an engineering/manufacturing hiccup...and that is RARE considering we have globalization in the modern world today followed by quality control standards that are not necessarily difficult to get right.

 

And so, if put to practice, any 2 digital audio components that have similar enough measurements should sound identical. For example, a DAC with a SINAD or SNR or 120 dB vs one with a SINAD or SNR of 123. Tiny differences in linarity and frequency response above 20 KHz are not audible to us humans anyway.

Because most of our listening dare not go up to 110 dB, which is the threshold of discomfort. You could only listen for up to about 30 minutes at this level without risking hearing loss! For this reason, the ideal listening level is below that!

 

Should we forget about what companies try to sell us as high-end and focus purely on measurements with respect to accurately reproducing digital audio?

 

Here’s what’s really funny. The Chord DAVE performed worse with respect to measurments than the Chord Hugo TT2! Just see audio science review.

 

Lastly, I consider ASR the best objective website on the internet, bar none. Because if Amir really had a business relationship with any of these audio companies, their flagship or most expensive products would always perform at the very top; we see that is not the case and measured performance is all over the place!

 

Looking forward to hearing from you guys. Let’s not turn this discussion into a flame war. If you disagree with what I’ve written, just tell me why. I will investigate.

 

 

jackhifiguy
Post removed 

I saw people making unfair comments here discrediting Stereophile in a similar fashion on ASR.  Stereophile supplements their extensive listening with measurements, while ASR occasionally adds de minimis listening test in the end of measurements.  Although I look at their measurements as one of the decision factors, I understand there are other psychoacoustic components not being measurable at least based on today's technology.  That is why identical measurements (available today) can not be equated with identical performance.  I found Stereophile reviews are as such much more trustworthy.  

There are so many technical factors. Crown International in the late 1970s, 80s made some of the best built and technically measured stereo equipment in the world. Dollar for dollar the best. .00025 intermodulation .0025 THD at full rated output in their preamps. Power amps .0025 IM and .025 THD at full rated output at any of the Amplifers from their 45WPC amp to their 500WPC Stereo reference. Did they sound good? You bet!  However, if you wanted to pay the money for a less powerful amp with worse specifications that sounded remarkably better you would buy a Mark Levinson Mono Block pair with their preamp. I owned a Crown PL 1 SL1 and enjoyed it for 40yrs. Still  sounds acceptable as long as the switch buttons work for power and function. So outstanding quality. After 15 years I sent it back to Crown. They replaced one small capacitor in the power protection circuit. It all tested like new. So, testing is great.  It gives you an idea on how accurately quality control throughout is designed into equipment. But it does nothing to tell you about sound. The system might spec great but be overly bright or too robust on the same speakers. So room matching, speaker matching preamp, power amp, source are all important factors just as important as technical measurements. My old Crown equipment was so much better technically than my new tube integrated but in no way sounds as good. No contest. 

I really do not see the point of these posts. ASR is not taken seriously by those who are really interested in music. It is best to ignore them and let them argue amongst themselves.

The one thing I haven't seen mentioned is that most, if not all measurements are static. A sine wave (or two in the case of IM distortion) is fed into the device and deviations from the input are noted, or a power output recorded, etc. 

However, music is complex and dynamic. There is no guarantee that a static measurement accurately represents the device's behavior when handling a complex signal. One of the best examples of this were high-feedback solid state amps from the 1970s that measured well but sounded shrill and harsh.  Things are better these days, but there is still no perfect correlation between static measurements and musical performance. 

Then, there is also the interaction between multiple components. An amp that works well with a speaker with a benign impedance curve may not sound near as good with a difficult load. 

That said, measurements are still important, particularly when designing and manufacturing products. For manufacturing, measurements are the only practical way to maintain consistent quality control as there is no way to listen to every unit as it comes down the production line. 

Finally, don't think I'm a pure subjectivist. We are humans, and subject to both conscious and unconscious bias that have little or nothing to do with sound but which still affect a person's perception.  Just because the subject is hi-fi doesn't mean those issues don't exist.