It sounds OK when first played but increasing amounts of bit-crush type distortion occur on the vocal every time it is replayed, (e.g. if you loop it), The distortion reaches maximum after about 5 plays.
The increasing distortion on this track also occurs if it is (re)played on other media players, (other than audacity), and on both Windows and Linux OSes, but I can’t hear it on other tracks, (yet).
I’ve never encountered this type of problem before, it may be specific to my computer so not audible to others, (e.g. a buffer not being cleared causing errors which accumulate with each replay).
Any suggestions on a cause & cure ?, (I’ve already reinstalled the audio driver, it didn‘t help).
Simply playing the file doesn’t change the audio data, of course. Looping shouldn’t change the data either,it should just repeat the same data.
What will boost the volume and potentially cause clipping/distortion is mixing. If you are copying the audio on top of itself (or on top of another file) You’ll have to normalize (or adjust the volume) so that the peaks don’t exceed 0dB.
It sounds fine here – through all the loops.
Have you turned off Windows Conferencing?
You only obliquely said you were on Windows, but Out Of The Box Windows now comes automatically set up for Windows Conferencing. As part of that service, you get auto gain control and echo cancellation – whether you want it or not.
Another possibility is degenerative feedback from recording Stereo Mix or What U Hear. That opens up multiple sound pathways and while it makes recording from the internet really nice, it can destroy home recording.
The distortion isn’t glaring, but it’s quite obvious by the forth loop on the vocal “my money”.
I’ve tried playing on it Windows and Linux (on the same computer) with Audacity and different media players:
the progressively worsening distortion is consistent with them all. So it seems like a fault with my computer,
but for the fact that I haven’t heard it on other recordings: I’ve just been working on other recordings of the same band for the last few hours and the fault has not reappeared, however I just downloaded the attachment on my first post and the phenomenon is still there
It’s not an echo, or tunnely or fading: the distortion is like the crackly digital artifacts on low bit depth recordings.
It does not seem to be present the first time the recording is played, it accumulates with repeated plays.
There appears to be no difference between the first time and last time.
Try playing this file:
Other than MP3 compression damage and dither noise, each repeat is identical. If you can hear any difference then it must be a playback problem on your equipment or a psychological phenomena.
Listen on a different machine. All the elves that listen hear no difference between the loops.
You can get distortions like this if, for one remote example, your sound card is adding DC or battery voltage to the speaker or headphone connection. Over time, the sound would distort as the diaphragm or cone couldn’t move any more. My old SoundBlaster card had hundreds of electrolytic capacitors. They are not known for grace over their lifetime.
The UCA-202 we recommend all the time has a headset connection and can be used to monitor the computer show – and to feed external computer speakers. I bet it works fine.
I can hear the increasing distortion on your test-loop too.
I had considered that I was just noticing a defect more once I had detected it, but if after listening to it for a minute I switch media player off then on again, then replay the track I don’t hear the distortion on the first play. If it were a psychoacoustic phenomenon I’d still hear it after the restart, as I could hear it clearly half a minute earlier.
It must be specific to my computer, thanks everyone for testing.
As the problem is independent of OS, media player, file format, and audio drivers, something fundamentally wrong with the audio in my computer. Looks like a bare metal reinstall is in order, (I may be gone some time).
Not necessarily voltage to the speaker/headphone connection, but yes that’s a good point Koz. Once the signal is back in the analogue domain, the signal must (usually) be between the positive and negative supply voltages (or between Vcc and ground for single rail circuits). If the signal drifts too far positive or negative then the peaks will start clipping. Sound cards will often reset themselves when there is no signal, so this could be an explanation of why you here rapid degrading of the sound over the first few seconds. In short, it could be a hardware failure of the sound card.
“There’s how many volts of battery on the speaker lead? That is so wrong.”
It’s remarkably difficult to manage battery in audio systems, particularly speaker and high power. Older sound cards can create significant problems as their parts degenerate.
Reinstalling isn’t going to do it in my opinion. I think you have hardware problems and need to try the music on a different computer, or, at minimum, a different Sound Card. Multiple elves have listened to the work on multiple different computers and operating systems. The common thing between all of us is we’re not using your computer.
, (nor does mucking about with bit depth).