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Test your soundcard for clipping, with this sample
Jan S.
post May 26 2003, 19:57
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For everybody fighting with occasional clipping (or perfectionists wanting to test everything) you should try the attached sample, udial.

Testing:
  • play the sample in your favourite player (decoded or not, having disabled all DSPs and EQs that can interfere)
  • if the output sounds weird at any time you should:
    • lower the output vol. in your soundcard config (should be the speaker icon in your system tray).
    • For some soundcards 48kHz is better (audigy 2 etc.).
    • lower the vol. till the sample doesn't sound weird at any time.
The output will sound really weird if your settings clip.
Your output can occasional clip without you knowing/hearing it. But for us perfectionists this will theoretically give a better quality output.

ATTENTION: Play this sample at a low volume anytime, even if you hear nothing special! It can be very harmful to equipment and/or your ears.
It's strongly recommended to use some very cheap (PC) speakers if you want to test this,
otherwise you might really ruin your tweeters (it has happened several times already).

Attached File(s)
Attached File  udial.zip ( 217.55K ) Number of downloads: 20624
 
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DickD
post May 28 2003, 16:28
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I have a Win NT4.0 machine with a 'Pro16V-A Pnp' soundcard at work which is rather limited. I already worked out that it can only work at 44.1, 32, 22.05, 16, 11.025, 8 kSa/s sampling rates.

With Microsoft Sound Mapper, sampling rates like 24 kHz sound like a 45 record played at 33 rpm as all the sound comes out slower. It purports to work at 48 kHz, but it's clearly downsampling to 44.1 kHz. "How well?" is the question.

Just to check how bad Microsoft Sound Mapper is, using FB2K I resampled to 48000 S/s, (even in Slow mode, 64-bit), and set the playback waveOut device to MSM. The sound broke up terribly after the first three tones, with a dirty sounding loud siren sound. This shows that there's practically no filtering going on in the downsampling, so as I suspected, I'm much better off using FB2K's Resampler to play 48 kHz content.

Listening on a plain WAV player or FB2K at 44.1kHz to the waveOut/'Audio Playback' device that doesn't support 48000 S/s, I hear the dialing tones plus a reasonably quiet and pure high pitched frequency-modulated varying tone over the four longer tone-dial tones. The frequency-varying tone sounds like an american cop show siren on helium, unrelated to the tone dialing frequencies. Musically, I guess it might have been about 9 semitones of variation from peak to trough, or a frequency ratio of 1.7.

Looking at the spectrogram in a WAV editor, it's 19-21 kHz frequency modulation and very intense, so I shouldn't be able to hear it all with the volumes my soundcard can reach, if any at all. So I guess my cheap soundcard isn't properly filtered and I'm getting beating between the 19 kHz and its image above the Nyquist limit, at 25.1 kHz, coming out at a 6.1 kHz difference frequency, with the 21kHz part of the sweep beating with a 23.1 kHz tone, causing a 2.1 kHz beat frequency.

Hmm, that doesn't sound quite right as it's more like 18.5 semitones - a ratio of 2.9 to 1. But alternating Add Location... tone://6100,0.3 and tone://6200,0.3 (both with volume set to about -45 dBFS by editing replaygain values) sounds plausibly about right for the extremes of the tone sweep at similar loudness, so I suspect that the brickwall filter is imperfect, but perhaps it's good enough to reduce aliased frequencies in the 23.1 to 25.1 kHz range to below -45 dB or so (very roughly).

I'm glad I don't have clipping in my signal chain, and I'd say for real music -45 dB intermodulation with aliases isn't going to be an audible problem (certainly not with the noise floor of this sound card and the noise of the computer fans), so I'm pretty darned happy with it.

Using the Equalizer to apply -20 dB to the 14 and 20 kHz bands, is enough to make it inaudible, even though I'm pretty convinced it's well below 10 kHz, so this backs up the idea.

By the way, to hear the effect of clipping on this sample in FB2K turn your Windows Volume down low and remove Advanced Limiter (or Soft Clipping Limiter if you use it) from your DSP list, then turn on ReplayGain but turn off clipping prevention. Alternatively, just listen to the musepack samples already posted (with clipping prevention turned on - perhaps those samples should have been manually edited in FB2K to set ReplayGain values to 0.00 dB).

Incidentally, a possible safety idea when posting potentially equipment-damaging files (e.g. sounds too quiet so you turn it up and fry your tweeters with the ultrasound) is to post the files in a password-protected zip file with a password such as 'warned' so the user has to acknowledge they've been warned before playing the sound and can't just play it with FB2K's archive reader either.

People should also be careful that perceived loudness is reasonably high before hiding messages such as text in the spectrogram's 18-22 kHz region, as some people were discussing after the Aphex Twin pictures in music thread. (This will also protect people's pets from hearing damage to a degree)

Do many speakers or headphones come with a fuse, circuit breaker or limiter to protect them from currents in excess of their design rating? (I've seen that lucpes' Infinity RSII speakers do).

Incidentally, the same effect of gradual reduction of sensitivity is true of vision. Red light is normally reckoned to be no more than about 670 nm, I can see a 790 nm infraredlaser (I used safety precautions and did this in a laser lab), but only if it's focussed to a small very intense spot (major dazzle on an IR viewer, way brighter than sunlight would be) will it be visible as a dull red glow on a piece of card in a reasonably dark lab. Also, the reason weak red light plus weak blue on a computer looks like indigo/violet is that the red cone response versus wavelength has a second peak, but at lower sensitivity beyond the green and towards the tail of the blue at short wavelengths.
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Posts in this topic
- Jan S.   Test your soundcard for clipping   May 26 2003, 19:57
- - grbmusic   I'll try it and then I tell about it!...   May 26 2003, 20:03
- - grbmusic   It's a kind of joke??? With foobar is imposibl...   May 26 2003, 20:19
- - atici   I listened to it OK with all my DSP plugins off, i...   May 26 2003, 20:25
- - Jan S.   QUOTE (grbmusic @ May 26 2003 - 09:19 PM)It...   May 26 2003, 20:26
- - Jan S.   QUOTE (atici @ May 26 2003 - 09:25 PM)it soun...   May 26 2003, 20:28
- - grbmusic   QUOTE (Jan S. @ May 26 2003 - 04:26 PM)what y...   May 26 2003, 20:44
- - boojum   I am not sure about the distortion. I do get the ...   May 26 2003, 20:54
- - Pio2001   19.5 kHz ! At full power in headphones, I hea...   May 26 2003, 21:47
- - Thikasabrik   Well... it looks as if it isn't clipping for m...   May 26 2003, 22:44
- - ben   Yeah, I just clipped my ears with the 19.5khz tone...   May 26 2003, 23:08
- - outscape   QUOTE (Pio2001 @ May 26 2003 - 03:47 PM)19.5 ...   May 27 2003, 03:25
- - Rizban76   I suppose my sound card is really screwed up. I ca...   May 27 2003, 04:27
- - fewtch   MonkeysAudio is so annoying. No separate WinAMP p...   May 27 2003, 04:45
- - Mr. Mulder   If you give me an email address I cand send you ...   May 27 2003, 07:29
- - anza   When I have foobars resampler on and set to 48kHz ...   May 27 2003, 07:58
- - LPTB   QUOTE I tried with DirectSound and I got nearly sa...   May 27 2003, 08:08
- - KikeG   Ugh! I hear too annoying ultra-high pitched to...   May 27 2003, 08:13
- - Mac   Ugh, you should put a warning when you post sample...   May 27 2003, 08:30
- - freakngoat   That is the craziest sample ever. How does it work...   May 27 2003, 08:45
- - Halcyon   What a useful sample! My results for Audigy 2...   May 27 2003, 09:29
- - Garf   QUOTE (Halcyon @ May 27 2003 - 10:29 AM)Final...   May 27 2003, 10:23
- - tigre   Great work! I knew before that my onboard VIA ...   May 27 2003, 10:59
- - Rasi   the squirling reminds me of a bird singing.... gue...   May 27 2003, 11:01
- - Gabriel   On this computer I get a birdy sound, depending on...   May 27 2003, 11:25
- - fragtal   Does somebody have .flac version of this sample or...   May 27 2003, 12:42
- - tigre   udial.flac   May 27 2003, 12:49
- - fragtal   QUOTE (tigre @ May 27 2003 - 01:49 PM)udial.f...   May 27 2003, 12:52
- - Halcyon   Garf, Why is this sample theoretical? Can you ela...   May 27 2003, 13:15
- - tigre   QUOTE (Halcyon @ May 27 2003 - 04:15 AM)Why i...   May 27 2003, 14:10
- - LPTB   Ok I did a test at work, with SoundMax integrated ...   May 27 2003, 15:15
- - JEN   Wow, that gave me a headache I can hear clicki...   May 27 2003, 15:16
- - Jan S.   QUOTE (JEN @ May 27 2003 - 04:16 PM)Wow, that...   May 27 2003, 15:42
- - fragtal   I have to pull down the master-volume (of the Crat...   May 27 2003, 16:13
- - JEN   OK, I tried it with resampling and here are the r...   May 27 2003, 16:16
- - ViPER1313   Would anyone be willing to take the sweep.wav samp...   May 27 2003, 16:27
- - Sachankara   Ehh... What are you supposed to hear? It sounds li...   May 27 2003, 17:11
- - grbmusic   Jan S. you should advice that take the test with t...   May 27 2003, 17:20
- - sony666   QUOTE (grbmusic @ May 27 2003 - 05:20 PM)Jan ...   May 27 2003, 17:41
- - LPTB   @grbmusic bummer man, sorry for your speakers... ...   May 27 2003, 18:01
- - JeanLuc   Two chains in my system, both fed by a TerraTec EW...   May 27 2003, 18:25
- - tigre   QUOTE (Sachankara @ May 27 2003 - 08:11 AM)Eh...   May 27 2003, 18:49
- - outscape   QUOTE (grbmusic @ May 27 2003 - 11:20 AM)Jan ...   May 27 2003, 18:52
- - LPTB   @tigre About the sample you provided, I can hear q...   May 27 2003, 18:53
- - tigre   Which one?   May 27 2003, 19:07
- - LPTB   The mpc sample you provided named correct.mpc.   May 27 2003, 19:28
- - Pio2001   QUOTE (fragtal @ May 27 2003 - 06:13 PM)I hea...   May 27 2003, 19:45
- - tigre   QUOTE (LPTB @ May 27 2003 - 10:28 AM)The mpc ...   May 27 2003, 19:52
- - LPTB   QUOTE If it's less than in the .mpc file it co...   May 27 2003, 20:02
- - grbmusic   QUOTE (LPTB @ May 27 2003 - 02:01 PM)I tried ...   May 27 2003, 23:37
- - grbmusic   QUOTE (outscape @ May 27 2003 - 02:52 PM)did ...   May 27 2003, 23:40
- - LoKi128   Well, tested with Winamp and my shitty on-board so...   May 28 2003, 01:15
- - KikeG   I tested again at home with my Audiophile, and hea...   May 28 2003, 09:25
- - Pio2001   THIS is a killer sample QUOTE (KikeG @ Ma...   May 28 2003, 11:59
- - lucpes   M-Audio Delta 410 card... dial tone + very high pi...   May 28 2003, 12:38
- - 2Bdecided   In fact, there isn't a hard cut off limit in h...   May 28 2003, 12:42
- - Moitah   When using Winamp's DirectSound plugin (v2.2.6...   May 28 2003, 14:18
- - JeanLuc   QUOTE (grbmusic @ May 27 2003 - 10:37 PM)QUOT...   May 28 2003, 15:16
- - jues   Soundcard: Delta 410. Christ that hurt - yeah, pu...   May 28 2003, 15:37
- - DickD   I have a Win NT4.0 machine with a 'Pro16V-A Pn...   May 28 2003, 16:28
- - Pio2001   This is a picture of the aliases that can appear w...   May 28 2003, 18:33
- - fragtal   I just downloaded the correct.flac and I'm rea...   May 28 2003, 19:46
- - ViPER1313   Sounds fine to me on my SB-Live value w/ 48khz SSR...   May 28 2003, 20:24
- - atici   QUOTE (lucpes @ May 28 2003 - 06:38 AM)M-Audi...   May 28 2003, 20:39
- - Pio2001   QUOTE (ViPER1313 @ May 28 2003 - 10:24 PM)the...   May 28 2003, 20:50
- - kritip   QUOTE (Pio2001 @ May 28 2003 - 08:50 PM)QUOTE...   May 28 2003, 22:32
- - Stuv   Quite interesting sample this one. All ASIO, Wave ...   May 28 2003, 23:56
- - ViPER1313   QUOTE the sweep is more through and wont hurt your...   May 29 2003, 04:23
- - Halcyon   A quick note about Creative cards and audible arti...   May 29 2003, 09:09
- - KikeG   QUOTE (Pio2001 @ May 28 2003 - 08:50 PM)You s...   May 29 2003, 09:37
- - DickD   QUOTE (kritip @ May 28 2003 - 10:32 PM)I real...   May 29 2003, 13:27
- - mrosscook   I have an SB Live card and Harman-Kardon desktop s...   May 29 2003, 14:57
- - LPTB   KikeG, Halcyon You're both correct this is exa...   May 29 2003, 15:03
- - Pio2001   I remember people saying their SB live was incredi...   May 29 2003, 19:58
- - JonPike   Huh.. interesting. On XP here, can't rememb...   May 30 2003, 02:43
- - grbmusic   QUOTE (JeanLuc @ May 28 2003 - 11:16 AM)Sorry...   May 30 2003, 03:21
- - Halcyon   FYI. All of my test were done under WinXP Pro SP1,...   May 30 2003, 07:51
- - DickD   QUOTE (JonPike @ May 30 2003 - 02:43 AM)Hmmmm...   May 30 2003, 13:31
- - mrosscook   Pio, Since there may be issues with the OS for Cr...   May 30 2003, 14:08
- - lucpes   QUOTE (atici @ May 28 2003 - 07:39 PM)lucpes,...   May 30 2003, 14:18
- - Thikasabrik   Well, having tested more thoroughly at different s...   May 30 2003, 14:26
- - Pio2001   Below 44.1 kHz, if the resampling is done with ant...   May 30 2003, 19:01
- - Dave Hamaker   I extracted the sample to a wav file. I looked at...   May 31 2003, 00:30
- - Pio2001   The spectrum of the clipped sample has subharmonic...   May 31 2003, 01:37
- - Dave Hamaker   QUOTE (Pio2001 @ May 30 2003 - 04:37 PM)The s...   May 31 2003, 02:46
- - Pio2001   Here are the results of two bad processes performe...   May 31 2003, 09:29
- - Halcyon   QUOTE Switching to quality 2 (on a 1-4 scale) remo...   May 31 2003, 11:37
- - indybrett   Using Foobar through a Prodigy 7.1 soundcard. Jus...   May 31 2003, 19:29
- - Dave Hamaker   QUOTE (Pio2001 @ May 31 2003 - 12:29 AM)Here ...   May 31 2003, 21:50
- - JonPike   QUOTE (DickD @ May 30 2003 - 04:31 AM)QUOTE (...   Jun 1 2003, 01:48
- - JonPike   "foobar2000 player v0.666 released Changes: ...   Jun 1 2003, 01:57
- - Differenciam   Ack. My laptop made that sound quite painful.   Jun 1 2003, 02:30
- - Chun-Yu   QUOTE (indybrett @ May 31 2003 - 01:29 PM)Usi...   Jun 1 2003, 02:46
- - Halcyon   QUOTE (Chun-Yu @ Jun 1 2003 - 03:46 AM)Q...   Jun 1 2003, 10:09
- - DickD   QUOTE (JonPike @ Jun 1 2003 - 01:48 AM)OK......   Jun 2 2003, 14:36
- - JonPike   QUOTE (DickD @ Jun 2 2003 - 05:36 AM)The late...   Jun 3 2003, 02:42
- - DickD   This post has some factual assumptions that were i...   Jun 3 2003, 10:23
- - Garf   FB2K ditherer and noiseshaper should never cause c...   Jun 3 2003, 10:32
- - DickD   Thanks for the informative reply, Garf. I'll g...   Jun 3 2003, 11:34
- - Halcyon   I need help. I have tried everything that I can t...   Jun 3 2003, 13:53
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