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Old 2010-11-29, 08:48
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diablo75 diablo75 is offline
Join Date: Nov 2009
Posts: 926
Wink I've found (and "fixed") a glitch with Thor

I've been doing some experiments to determine the cause of a very strange problem.

I have a project I've been working on that has a few of Thor's in it. They're pretty much unmodified from their default settings that come with the factory refills. When you play back the composition within Record, all sounds fine. But when you export the composition as a WAV file, you'd often hear a sharp, red-line clip that last for a fraction of a second at the moment in the song these Thor's emit their very first note in the song. From that point on for the rest of the song it sounds absolutely fine.

At first I thought, "Could it have something to do with input gain at the mixer, shooting a super hot signal down the channel for a split second before realizing it's too hot and lowering it" so I checked that and reworked the master output of the thor to compensate for the lost gain that was boosting the signal from thor. This didn't help.

So then I tried a little experiment.

This particular thor is controlled by a Sequencer, playing a bass line loop over and over. This doesn't start until until the 5th beat of the song, so up until that point it's totally unused and silent. The moment the first signal is sent to it from the sequencer, there's that POP sound (and when you look at the waveform of the WAV there is clearly an acute red-line event that coincides with this instruments opening note as no other instrument makes it's debut in the song at that time).

I thought... "Because this problem occurs when it's first used, but never again for the rest of the song... perhaps the Thor needs to be "Warmed up" before it can be trusted to not clip itself."

So what I did was pull one extra bar of the loop on the sequencers transport towards the beginning of the song, so that the Thor would actual begin to play one measure too early. I then automated the Mute button on the mixer so that the 1st, 2nd and 3rd beats are muted at the mixer, it unmutes on the 4th beat and remains unmuted for the rest of the song. I then used the razor tool to cut the extra measure of sequencer in half (at the third beat) so that I could delete the sequenced notes that occur at the 3rd and 4th beats that otherwise would have been heard as a result of the automated unmuting of the mixer channel.

This WORKED and has the effect of "warming up" Thor under a muted channel before it is heard for the first time. It's as if all it needed was to clear it's throat before it could sing clearly.

The strange part about all this is the fact that you don't hear this artifact when working within the software and hitting play to listen to what you've got; only after you export a song to a WAV file and open it up in something like Audacity. These were 24-bit WAV's too.

Anyway not sure what causes this; I'm just glad I figured out an easy way to work around it (I was afraid I was going to have to manually redraw the wave form in something like Wavelab 6 to cover the hiccup).

Last edited by diablo75; 2010-11-29 at 08:51.