INVITATION: Can you hear high THD?

Alright guys and gals, a new test for you to try out for 2020!

You know that measurements of audio gear typically will include harmonic distortion tests. We see numbers like 1% THD, 0.1% THD+N, etc... all the time. Typically also included with graphs in DAC, amp, preamp, phono cartridge results.

But what does this mean when it comes to listening and with real music?

Here's an opportunity to try for yourself and let me know what you hear - preferably using the best sound system you have! As usual, the results will be collected, analyzed, and published once the data gather is done by the end of April 2020. Plenty of time to listen and let me know what you hear.

Remember that I have used rather high amounts of distortion in some of these samples... Theoretically, this should be nowhere as difficult as "can you hear 16-bit vs. 24-bit?" or "24/96 vs. 16/44.1" tests.

Enjoy

Test: Is high Harmonic Distortion in music audible?

 

Downloaded the file and will report back within the requested time frame for feedback.

 

I can see the differences between samples (THD+N = 0.0002585%, THD+N = 0.0006592%, THD+N = 0.0007055%, THD+N = 0.0120781%), but I'm not sure I can here them due to the speakers/ears limitations. The intermodulation distortion is too weak to be heard with normal equipment/ears. Your challenge is very sneaky. I think this is the test of the liars who boast.

 

It is when your amplifier is clipping. Amplifier distortion rises sharply when it begins to clip, the slope of the curve is nearly vertical and the effects are highly audible when listening to music.
Also distortion is additive. Distortion in the recording (often intended by the artist) + distortion in the source + distortion in the preamplification + distortion in the amplification + distortion in the loudspeaker + distortion in a room (phase / reflections) when added together can sound intolerable.

 

i heard very slight edginess in some of the tracks- nothing objectionable.
additive distortion from the recording to room "chain" especially when pushed hard with complex music- can be very objectionable.

 

Hmmm...

Not sure what you're seeing here Bob. Wanna PM me? Curious what you're using to get those number!?

It's definitely not meant to be sneaky!

 

If we're getting into the thresholds of human audibility here....some people are going to be surprised.

 

Maybe, we'll see. What I can say is that there is at least one person who has gotten the sequence of lowest --> highest distortion level correct already in the test!

Like I said, the THD levels I applied are actually quite high - ridiculously high in fact - for things like DACs.

 

This is cool! I'll take the test tonight (if I still remember when I get home).

 

You understand that a deaf person could also get it right, correct? Only 6 possible answers.

 

Only 6 possible answers? Better go back to calculating your combinations and permutations.

As for deaf person, sure, if lucky enough, a deaf person can tell the difference between a $100,000 system and a $200 system as well.

 

As discussed in PM. Your analysis is incorrect.

 

Just a bump of this topic - 2 weeks left to get results in - closing end of April.

Thanks in advance for those giving this a try!

 

Results up now...

BLIND TEST RESULTS Part I: "Is high Harmonic Distortion in music audible?" Procedures & Settings

BLIND TEST RESULTS Part II: "Is high Harmonic Distortion in music audible?" Respondent Results

Will have a part III with some subjective impressions later.

Bottom line:
67 total listeners responded. Most people felt they heard a difference, but ~20% could not hear a difference even at up to 3% THD added to the music.

Of those who heard a difference, there was a meaningful trend towards preferring low distortion. High distortion was described by many as sounding worse. In terms of magnitude, the bias against higher distortion was somewhere between 0.02%/-75dB and 0.3%/-50dB. Other nuances reported in the posts, but it is good to see that among audiophiles, higher fidelity did matter and sounded "better" .

Thanks to everyone who participated!

 

Hi Archimago, seeing this very interesting thread a bit late!

Now that the ‘test’ is over, could you tell us a bit more about the characteristic of the distortion?

For instance, was it dominant 2nd, 3rd, or an even amount of both? Also, what was the phase of the harmonic with relation to the fundamental? Also, what proportion of higher order harmonics were present.

Many thanks!

EDIT: My bad, saw the details on your methodology page. Thanks again for putting this together!

 

Dunno about THD but the things I used to hear with THC...