Testing audiophile claims and myths
Apr 23, 2015 at 12:46 PM Post #4,577 of 18,259
Our AP test sets here at Emotiva do an excellent job of testing transient performance - amongst a lot of other things.


If you're with Emotiva, why aren't you identified as a Member of the Trade? Better get that taken care of.

se


Now I understand why your profile name is KeithEmo. But Steve is right. Best to get designated a member of the trade.

Good to have someone with Emotiva on the forum :)
 
Apr 23, 2015 at 12:49 PM Post #4,578 of 18,259
   
This is incorrect as the impulse in both cases is a result of the low pass filter, and not the format itself. Furthermore, perfect impulse response (which neither system achieves) is meaningless as it requires infinite bandwidth which is totally unnecessary for human ears.
 
DSD does have other disadvantages such as greater distortion and noise and of course incompatibility with EQ, which is a total deal breaker, imo.

Output filter for DSD can be MUCH more shallow than foe PCM - which usually uses extremely steep/brickwall filtering, even at 700+kHz sampling rate - and this is the reason why comparably sized file DSD will always have the upper hand over pulse response o the PCM.
 
True, neither system achieves the perfect pulse response. But achieving approx 99% vs 84% for DXD (PCM 384/32) is a difference - not to mention the CD at some 15 or so % .  http://www.lindberg.no/english/collection/004.pdf
 
True, distortion is higher on DSD - but not to audible level. Both noise and distortion go down at higher sampling.
 
True, virtual EQ (DSP) is impossible with DSD. As much as I would like to say "under perfect conditions it does not matter" I am aware there are cases EQ via DSP is beneficial in real world. 
 
Apr 23, 2015 at 12:56 PM Post #4,579 of 18,259
True, virtual EQ (DSP) is impossible with DSD. As much as I would like to say "under perfect conditions it does not matter" I am aware there are cases EQ via DSP is beneficial in real world. 

 
You more or less need DSPs in order to get to as close to perfect conditions as we can get.  Digital crossovers, time alignment, etc for bi/tri amped speakers are extremely useful.
 
Apr 23, 2015 at 12:56 PM Post #4,580 of 18,259
  Output filter for DSD can be MUCH more shallow than foe PCM - which usually uses extremely steep/brickwall filtering, even at 700+kHz sampling rate - and this is the reason why comparably sized file DSD will always have the upper hand over pulse response o the PCM.

 
It is not an upper hand if it only affects inaudible/ultrasonic frequencies! Come on.. we've been over this many times.
 
Apr 23, 2015 at 12:58 PM Post #4,581 of 18,259
   
You more or less need DSPs in order to get to as close to perfect conditions as we can get.

 
I'd go so far as to say that DSP has the capability to make >1,000 times the sonic improvement compared to the difference between CD and other HD digital format you can name.
 
So yes... DSP matters, and a system which can't support it is dead in the water.
 
Apr 23, 2015 at 1:06 PM Post #4,582 of 18,259
  So yes... DSP matters, and a system which can't support it is dead in the water.

 
It certainly is for me. Even with headphones.  I play everything I can out of foobar since I can use TB Isone with it.  It leaves plain stereo in the dust.
 
Apr 23, 2015 at 1:11 PM Post #4,583 of 18,259
I like this debate, but more important is if the differences are audible and then how much. Or is it placebo. Or does "audiophile" gear maybe have some sort of tweaked DAC to actually REALLY sound different to let audiophiles hear the difference between those and "consumer grade", correctly adjusted DACs?

There is no such thing as "consumer grade", correctly adjusted DACs.
 
There is also no such thing as correctly adjusted pro level DAC. 
 
They can be both correctly adjusted - and still sound poor. 
 
I have said, many times over, that analog sections, inevitable in ANY - ADC or DAC - will play a major role in SQ. And two "boxes" (whatever) that are according to the electrical schematic and conventional measurements more or less indistinguishable can sound MUCH different - IF one box uses regular grade electronic components, the other parts known for better performance. It can be the same type of aparatus, with stock and "super" parts - and both will sound decidedly different.
 
Use microphone feed and listen trough both - and you will start to understand what I have been about all this time.
 
A SINGLE poor/regular grade capacitor in the entire chain can bring the performance considerably down - now go and get any service manual and start counting how many of those are in a single "box" - the entire chain is comprised of many such "boxes".
 
Compared to these losses in analog circuitry, is DSD vs PCM pretty pointless - and should be put right first.
 
A single quality capacitor from regular, not audio specialist manufacturer, can exceed the cost of ADC or DAC chipset. Not to mention those from specialized audiophile production. For this reason, these quality parts are usually never seen in commercially available equipment - listening trough the same analog crap, used by practically everyone, both in consumer and pro gear, should - and does - yield the same or very similar results - PCM or DSD. Neither of which being taxed to the max, as analog signal gets so mangled in commercially available equipment BEFORE it ever sees ADC - let alone DAC - that it does almost not matter at all. 
 
Apr 23, 2015 at 1:15 PM Post #4,584 of 18,259
  Back to DACs, though.... with an decent oversampling DAC, you will end up with a flat frequency response because the overall energy response is very accurate, and - at least with a sine wave - you will also end up with very low THD, yet you will end up with visible differences in transient or irregular waveforms due to ringing. (And which tests they will show up on, and which they won't, should be rather obvious once you understand how the tests work and what they're testing.) However, whether specific amounts and types of ringing are audible at all, and, if so, whether certain types "sound better", still seems to be a matter of debate, although the currently accepted "wisdom" is that post-ringing is more innocuous than pre-ringing with most content (which is why Dolby's latest encoder includes an option to upsample while "reducing pre-ringing at the expense of adding more post-ringing" as a way to "improve sound quality using post-processing"), and it also seems likely that certain individuals simply find one or the other more or less audibly annoying.

 
There shouldn't be a debate about whether certain types of pre-ringing due to digital filters are audible; it's perfectly within the realm of the industry to test if people can actually hear anything, be it comparing two music samples or listening to a null file. The current status seems to be that people can't hear any differences (pre-ringing or not) between hi-res formats and Redbook. Even with my now-gone setup of a Bifrost + V200 + HD800, I could down-sample things to 38k and not even hear anything in the null file, let alone in an ABX comparing the two music files. If someone tells me "well you need to hear how X-type cymbals sound", then I say, do the experiment on a decent sample of people and cement the legitimacy of hi-res formats. It never seems to get done. I mean, it really only takes one hi-res sound sample of an actual musical sound to do the trick.
 
Apr 23, 2015 at 1:18 PM Post #4,585 of 18,259
   
I agree. I could probably have put my question better as:
If one is really hearing differences among (pro-grade) ADCs/DACs, what are these differences, and are these differences expected given the specs? Moreover, are these differences still detectable in blind testing circumstances?
 
The answer I got, that I'm still not quite sold on, was pre-echo due to digital filtering. My doubt is due to my own testing of down-sampled (even sub-44.1) material where I can't hear such artifacts, and due to the theory about the frequency characteristics of pre-echo in cases of resampling to/from standard PCM formats. I of course could be convinced instantly if a hi-res sample could be provided that caused audible pre-ringing when down-sampled to Redbook.


From my experience not always we listen difference. And otherwise not what we listen has real difference.
 
I want said only what:
 
1. Fully correct double blind test demands deep knowledges of tested subject due many subtle details that can appear insignificant at first look.
 
2. Home double blind test we can consider as interesting experiment, but is not enought proof due not clear many the subtle details (goal 1).
 
3. Even professional carefully developed and performed test also is not true in last instance.
 
Apr 23, 2015 at 1:19 PM Post #4,586 of 18,259
   
You more or less need DSPs in order to get to as close to perfect conditions as we can get.  Digital crossovers, time alignment, etc for bi/tri amped speakers are extremely useful.

True.
 
That is why Quad ESL 2915 ( a full range electrostatic crossoverless design ) will always run rings around multi driver speakers requiring time alignment. 
 
DSP is a good, extremely useful,  but still - cure for the problem. Preventing the problem from occuring  is the better strategy.
 
Apr 23, 2015 at 1:26 PM Post #4,587 of 18,259
Quote:
 
From my experience not always we listen difference. And otherwise not what we listen has real difference.
 
I want said only what:
 
1. Fully correct double blind test demands deep knowledges of tested subject due many subtle details that can appear insignificant at first look.
 
2. Home double blind test we can consider as interesting experiment, but is not enought proof due not clear many the subtle details (goal 1).
 
3. Even professional carefully developed and performed test also is not true in last instance.

 
Agreed; a properly set up test isn't trivial. I do home testing solely for my own benefit and to save myself money ^_^ The actual rigorous testing on the broad (and specific) public, I leave to the industry. But in this case it seems trivial to do: grab a few pros who say they can hear differences, grab some normal folks who may or may not think they can, and blind test them properly on hearing pre-ringing. Then provide the sound sample for the broad world.
 
Apr 23, 2015 at 1:26 PM Post #4,588 of 18,259
I have said, many times over, that analog sections, inevitable in ANY - ADC or DAC - will play a major role in SQ. And two "boxes" (whatever) that are according to the electrical schematic and conventional measurements more or less indistinguishable can sound MUCH different - IF one box uses regular grade electronic components, the other parts known for better performance. It can be the same type of aparatus, with stock and "super" parts - and both will sound decidedly different.


First of all, the actual design implementation could be the biggest factor in which performs better, right? So better grade components doesn't guarantee better grade sound.

Second, this is a subjectivist argument. If you don't have ABX testing data to confirm that the differences exist, then you have no argument.
 
Apr 23, 2015 at 1:39 PM Post #4,589 of 18,259
  Quote:
 
Agreed; a properly set up test isn't trivial. I do home testing solely for my own benefit and to save myself money ^_^ The actual rigorous testing on the broad (and specific) public, I leave to the industry. But in this case it seems trivial to do: grab a few pros who say they can hear differences, grab some normal folks who may or may not think they can, and blind test them properly on hearing pre-ringing. Then provide the sound sample for the broad world.


Yes. For buying own apparatus home double blind test suitable tool. Currently impossible choose audio hardware by parameters. Many parameters not showed or don't measured.
 
Even if it will available, better way - go and listen.
 
Apr 23, 2015 at 1:52 PM Post #4,590 of 18,259
 
Yes. For buying own apparatus home double blind test suitable tool. Currently impossible choose audio hardware by parameters. Many parameters not showed or don't measured.
 
Even if it will available, better way - go and listen.

 
Better if it's at a local meet. Having to deal with audio equipment salesmen ranks on my list of things I enjoy right above "cleanup at Fukushima."
 

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