Chopped waveforms

[SofaKing]

I just finished tracking a four-piece band and ran into a problem I could use some help with.

On one of the overhead drum tracks, most of the upper half of the waveform is suppressed. It has too much distortion to be useful as-is. All of the other drum tracks are ok. When I look at the drum overhead waveforms, here's what I see: chopped wave

It doesn't look clipped to me. The above-the-line part of the sound waves just aren’t reaching anything close to full amplitude. For these two tracks I used the same mics, the same cables, and the same preamps.

OK, I should have caught this problem upfront. I'll learn from that. But I'm not absolutely certain there was a problem capturing the inbound signal for this track in the first place. Is there any hope for this track or am I hosed? Any ideas on what could have caused this?

I was using an 002R connected to an iBook G4 (10.4.9 and PTLE 7.1) and a La Cie external hard drive. I've done all of the General Troubleshooting stuff except reinstall. The drummer has the mike and cable so I can't check that easily.

[Naagzh]

Wow, wierd. First, does the track actually sound BAD? You mentioned distortion... are you inferring this from its appearance or can you actually hear the distortion. If you can hear ugliness, how does it sound? Clicky? Dirty? Fuzzy? Whiny?

I ask because it's conceivable that PT has mis-drawn the waveform, and there's nothing wrong sonically.

[SofaKing]

Yes, the track sounds bad. It's more of a fuzzy distortion. As if the signal was too hot for the preamp or the converters, though I'm pretty certain there wasn't any clipping on input.

[Repo]

Its not chopped you have a DC offset http://en.wikipedia.org/wiki/DC_offset. Best advise is rerecord the track or somhow figure out ho your going to get a stereo feel out of the other overhead. i.e EQ differently or something. Thank sucks.

[SofaKing]

Thanks, Repo. There's another good article on the subject at Harmony Central. It suggests that that the DC offset may result from an inaccurate A/D converter. But I can't replicate the problem on my system.

The DC offset plug-in doesn't help, nor does a hi-pass filter. Re-tracking isn't an option so I'll have to deal with what I've got. If anyone knows of anything I can do to prevent this from happening down the road, I'm all ears. Thanks.