Management Summary
We appear to have a recording problem on 2.0.5
Using any of the three hosts: WASAPI loopback, WDS or MME, I get consistent
occasional clicking in recordings which are not present in the source material.
This is a regression as using 2.0.4 with the same input material yields a clean
recording with no clicking.
Testing on:
Windows-7 Toshiba Satellite laptop 494/881 GB free space
6 Gb RAM 2.5 GHz CPU 64-bit
Long version
I have been using recent 2.0.5s as production engines recently to give them a more
thorough workout.  This came to my attention recording from YouTube recently
using WASAPI loopback.  I transferred a recording to CD and played it on my hi-fi
to be surprised with a lot of clicks and thumps that I did not hear when recording.
I went back to the Audacity project (assuming these to be on the original YT recording)
and marked up the approximate locations intending to edit them out.  Once I had done
that I noticed that the clicks/thumps seemed to appear at reasonably regular intervals
starting out at around every ten seconds, changing to every five seconds mid-song and
then back to mainly around ten seconds.
I looked at another recording I had made from YT that day and when zoomed in and
using the Spectrogram view I noticed that many of the faults were double faults and
that they seemed fairly consistently to be 900-950 samples apart.  Viewing zoomed in
in waveform view showed clear discontinuities in the waveform.
I then went back to a recording I had made on Thursday evening from BBC FM radio
inputting through my Edirol UA-1EX USB soundcard only to find on detailed listening
that I had similar clicks/thumps there albeit not as frequently.
At this juncture I went off to the FAQ in the manual that deals with such stuff:
and made sure I took the advice there, in particular I upped the recording audio buffer from
its default 100 to 200 milliseconds, killed all extraneous processes, rebooted the PC.
Re-recording still yielded the problem.
I also tested a nice clean source of iTunes playing a ripped CD (256 VBR) and this
yielded the same clicky/thumpy results.
Subsequent testing on 2.0.4 with all the same source material yielded the nice clean
recordings that I have come to expect with Audacity.
I do have the original marked-up project (4.5 minute song) that I can supply as a 32-bit
WAV along with an export of the labels if that might help with any debugging.
Sorry to be the bearer of potentially bad news at this late stage in the cycle, but I'm
sure we really don't want any more (non-blue) egg on our faces ...
Peter Sampson
Tel: +44 (0)1625 524 780
Mob: +44 (0)7732 278 299