ABX complex non-linear distortion test, about 5% on a music sample

[March Audio]

My result 9/10


foo_abx 2.0.6d report
foobar2000 v1.6.2
2020-12-14 08:07:41

File A: Quintet1.flac
SHA1: 78941da5875a6dc51169e29bbbb909399b75c377
File B: Quintet2.flac
SHA1: 2cea48c9ec2b493807e65e1d2b49deb19b543939

Output:
ASIO : MOTU Pro Audio
Crossfading: NO

08:07:41 : Test started.
08:09:10 : 01/01
08:09:25 : 02/02
08:09:40 : 03/03
08:10:03 : 04/04
08:10:42 : 05/05
08:10:58 : 06/06
08:11:34 : 06/07
08:12:26 : 07/08
08:14:47 : 08/09
08:15:05 : 09/10
08:15:05 : Test finished.

----------
Total: 9/10
p-value: 0.0107 (1.07%)

-- signature --
7fec2ca562c35ed808875f085546c109154b2e65

 

[March Audio]

@pma

Im doing a bunch of tests on audibility of low frequency distortion here:
https://www.audiosciencereview.com/...f-low-frequency-distortion-in-speakers.18291/

Real tests start here
https://www.audiosciencereview.com/...ency-distortion-in-speakers.18291/post-599826


Starting with simple tones (worst case scenario/most audible) and then will be moving to actual music.

 

[pma]

@March Audio
Thanks for passing the test and congrats!
I am following your tests in speakers.

 

[playmusic]

First attempt below.
Thank you for setting up this test!

foo_abx 2.0.6d report
foobar2000 v1.4.8
2020-12-14 18:36:03

File A: Quintet1.flac
SHA1: 78941da5875a6dc51169e29bbbb909399b75c377
File B: Quintet2.flac
SHA1: 2cea48c9ec2b493807e65e1d2b49deb19b543939

Output:
DS : Primärer Soundtreiber
Crossfading: NO

18:36:03 : Test started.
18:36:57 : 01/01
18:37:24 : 02/02
18:37:47 : 03/03
18:38:10 : 04/04
18:38:37 : 05/05
18:38:54 : 06/06
18:39:16 : 07/07
18:39:35 : 08/08
18:40:31 : 09/09
18:40:56 : 10/10
18:41:15 : 11/11
18:41:39 : 12/12
18:43:17 : 13/13
18:43:35 : 14/14
18:44:16 : 15/15
18:44:42 : 16/16
18:44:42 : Test finished.

----------
Total: 16/16
p-value: 0 (0%)

-- signature --
a34ad58cb8b4f55f1bc673b9a44e6bdb544782da

 

[preload]

I couldn't tell the two FLAC's apart, let alone make an AB selection, so you can count me in as a "fail."
I also don't think THD is as audible as some people think it is.

 

[Thomas_A]

Just realized it's only doing 2 trials. Editing a new test that will have more,updated link

I've tried a couple of times. Headphone directly into my Mac but are unable to find any differences. Anyone succeeded with your link yet?

 

[pfzar]

I've tried a couple of times. Headphone directly into my Mac but are unable to find any differences. Anyone succeeded with your link yet?

 

[Res-Head]

I am 20 years old and cannot hear any difference between the 2 files through my JDS Element, except the difference file which sounds noticeably worse. Which one is the original?

 

[pma]

Which one is the original?

This is up to the participants to guess ....

 

[MarsianC#]

I am 20 years old and cannot hear any difference

I guess we young people are not suited for critical listening. Lmao
I'll try a lowpass filter at 15 kHz (6dB/oct? more?) to simulate my ears in 20-30 years. Lmao²

 

[Propheticus]

Well, that was very hard. Half of the time I felt like I was taking the best guess. Had some background noise so had to turn up the volume on my open headphones. Didn't hear any artefact stand out or tell-tale distortion, it was more of a 'feeling' of fullness or pressure being there compared to the other file that did not have this filler.

foo_abx 2.0.6d report
foobar2000 v1.6.4
2021-02-10 17:00:24

File A: Quintet1.flac
SHA1: 78941da5875a6dc51169e29bbbb909399b75c377
File B: Quintet2.flac
SHA1: 2cea48c9ec2b493807e65e1d2b49deb19b543939

Output:
ASIO : USB DAC ASIO
Crossfading: NO

17:00:24 : Test started.
17:03:49 : 00/01
17:04:22 : 01/02
17:05:49 : 02/03
17:06:21 : 03/04
17:08:25 : 04/05
17:09:20 : 05/06
17:10:31 : 05/07
17:11:00 : 06/08
17:11:32 : 07/09
17:12:25 : 08/10
17:12:25 : Test finished.

----------
Total: 8/10
p-value: 0.0547 (5.47%)

-- signature --
c1eaeffc3a19c6ead3a5d06ddbd5238ce65e4d05

 

[preload]

It just dawned on me - what volume are y'all listening at? If the volume is normal, the 5% THD products might actually be below the threshold of audibility at their respective frequencies. In other words, the 5% THD might only be audible when the test track is turned up. That might account for some of the differences in performance with this test.

 

[Propheticus]

Normally I'm on: 13, to pass this test: 20.
But the samples sounded soft. Possibly due to being classical music and no replaygain. For normal listening I would've upped to 15 or 16.
Not sure this tells you much without reference/scale. Max is 60, but volume control is perhaps not linear.

 

[preload]

Normally I'm on: 13, to pass this test: 20.
But the samples sounded soft. Possibly due to being classical music and no replaygain. For normal listening I would've upped to 15 or 16.
Not sure this tells you much without reference/scale. Max is 60, but volume control is perhaps not linear.

Audibility would be based on dB at a given freq at your ears. Hard to know what your digital volume settings correspond to.

 

[Blumlein 88]

The idea would be to set to a normal or slightly louder than normal level you'd normally listen to this. For most people you likely have a sound level of 70-80 db with some peaks higher.

 

[pma]

Well, that was very hard. Half of the time I felt like I was taking the best guess. Had some background noise so had to turn up the volume on my open headphones. Didn't hear any artefact stand out or tell-tale distortion, it was more of a 'feeling' of fullness or pressure being there compared to the other file that did not have this filler.

Thanks for participating! Your guess on an original file was correct. I think we may disclose it, regarding the long time this test has been available.

what volume are y'all listening at? I

Not very low and not very high, you need to prevent your ear self-distortion.

 

[preload]

The idea would be to set to a normal or slightly louder than normal level you'd normally listen to this. For most people you likely have a sound level of 70-80 db with some peaks higher.

Sure and it would be nice to control for that by establishing the listening level as part of the protocol. Otherwise you will get a lot of false null hypothesis (no diff) test results if people listen at a level where humans are known not to be able to hear anything at that frequency, whether it's a distortion product or not.

 

[jensgk]

foo_abx 2.0.6d report
foobar2000 v1.6.3
2021-04-02 01:14:13

File A: Quintet1.flac
SHA1: 78941da5875a6dc51169e29bbbb909399b75c377
Gain adjustment: +5.14 dB
File B: Quintet2.flac
SHA1: 2cea48c9ec2b493807e65e1d2b49deb19b543939
Gain adjustment: +4.25 dB

Used DSPs:
Skip Track, Resampler (dBpoweramp/SSRC)

Output:
WASAPI (shared) : Hovedtelefoner (USB-C to 3.5mm Headphone Jack Adapter)
Crossfading: NO

01:14:13 : Test started.
01:16:35 : 01/01
01:18:02 : 01/02
01:18:19 : 01/03
01:20:19 : 01/04
01:20:36 : 02/05
01:21:04 : 02/06
01:21:43 : 02/07
01:22:14 : 03/08
01:22:33 : 04/09
01:22:51 : 05/10
01:23:22 : 05/11
01:23:36 : 05/12
01:23:47 : 06/13
01:24:00 : 07/14
01:24:10 : 07/15
01:24:23 : 08/16
01:24:23 : Test finished.

----------
Total: 8/16
p-value: 0.5982 (59.82%)

-- signature --
9e475d8baa5dee06e8bd4fbaaaa4d4aeccfc71fb

 

[rkbates]

Too lazy to attach the pc to the sound system so I just listened to the files. Thought I could tell them apart, then changed my mind on which was which. Clearly guessing. Should be able to save some money on my next purchase. Thanks for posting the files.

 

[2M2B]

So nobody yet, quite as expected. If there is hardly anybody who can hear such high distortion on music, so why there is a challenge of the -120dB THD??

Because a Etymotic engineer on Head fi said the upper limit on when THD was a issue was around 2% with music. So that could be why many still find the ER4XR with 1.65% still clean but might sound wrong on pure sines waves?.