I'm just copying the email I sent to SF, hopefully it's clear what I'm asking and shows through the audio samples I've attached. Anyone have any idea what migth be causing this....FWIW< the tapes are complete, it's the overloading issue I have now. But looking back I was having the same issue with the old battery setup. This time instead of overloading and locking, it's overloading until I adjust the gain down. So same root problem I think, but not as bad as before.
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Pieter - Wanted to raise another issue, unsure if it's related to the battery swap we just did. I recorded two bands last night. I've attached excel files with snapshots of the wav files to show what's going on. Let me know if you can't open files in Excel, if not I'll find another way. Sample 1 is where I have a problem, sample 2 is fine. Attaching both for a reference. Also, my settings and gain were consistent for both recordings so there shouldn't be any significant variances. When I first did the battery swap I noticed my levels on my deck would overload at some point during each show, usually in the 20-30 minute mark. I originally thought it was user error because I'd bought a new deck to use and was still fine tuning the gain settings.
I recorded two shows last night. The second one (Audio Sample 2) is perfectly fine. The first one (Audio Sample 1) is where I see an issue. Looking back on three recordings I made when I first made the swap a few weeks back I had the same issues, but as I'd said I relegated it to user error.
The gain setting on the 350 preamp and on the Edirol R44 were set at +18db total (+12db on the 350, +6db on the R44), which I thought was a little hot knowing the unit and its sensitivity to high dB sound pressure, but I was going off the levels I was seeing on the deck at that setting. You'll notice the W channel is quite low relative to the X Channel. I had the gain settings on all channels set exactly the same per your recommendation. At the 26 minute mark, you'll see all 4 channels overload, at which time I dropped the gain setting on the 350 down to the lowest setting and the levels seemed to normalize to what I'd expect to see for a B Format recording i.e. W & X being comparable in gain, Y&Z being a little less, which is what I think the ideal gain across all 4 channels should be. After I brought the gain down everything was fine and the recording was fine.
Audio Sample 2 was fine across 4 channels from a W,X,Y,Z perspective. What I would expect to see for a B Format recording where the gain setting is constant across all 4 channels.
When I first start the unit I notice the W channel is significantly lower in total gain than the others until the unit seems to warm up and then I experience the overloads at which point I cut the gain back on he 350 and all levels stabilize. I think this is the key, W&Y should be comparable in total gain in an ideal setting.
Any idea what's happening here? Is there a chance the 350 preamp needs to "warm up" for a period of time? I also noticed this before I swapped out my Sound Devices 744 for an Edirol R44, which is why I was overcompensating the gain on W, as I'd mentioned in a prior email.
Curious what your take is on this, and if you've experienced it before. It's almost as if the 350 needs time to get warmed up prior to having all the channels stabilize. Please see the attached files for reference. Sample 1 is the defective file. Sample 2 is perfect.
Also, I checked with the sound engineer and asked him if he had adjusted the gain significant at any point during the set and he said he did not, he has a cap on the total gain and never adjusts it.
Thanks for your feedback. I have two more recordings to make this weekend and will report back but would like to get your take on this and know if you've seen it before.
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Here are the files, any thoughts from the TS?
