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Gear / Technical Help => Ask The Tapers => Topic started by: splumer on August 05, 2014, 10:38:08 AM

Title: Static issue... Exceeding Max SPL?
Post by: splumer on August 05, 2014, 10:38:08 AM
Back in June I recorded the Panic show in Cleveland, and in my main rig I got some static during the louder parts. Since the show was kind of loud I thought maybe I exceeded the SPL's of my mics. My secondary rig sounded fine, so later I checked the tech specs, and now I'm not so sure exceeding the SPL was the issue. Here's the info:

Main rig: Beyerdynamic MCE86II shotgun mics > Art Phantom II (for power) @ 48v > Marantz PMD660
Secondary: Shure BG4.1 > Tascam DR-05

The max SPL for the Beyers is 128dB at 1khz, for the Shures it's 127dB. I attached a sample. I've never had this issue before, even with loud indoor shows. Here's a link to a recent recording:
https://archive.org/details/rre2014-04-11

A sample of the Panic show is attached. Ideas?

Title: Re: Static issue... Exceeding Max SPL?
Post by: bombdiggity on August 05, 2014, 06:01:40 PM
Sometimes you can clip in the pre before it gets to the recorder or at the pre stage in the recorder?  I don't know your gear but know the second of those can be an issue with the R-44 (which has a tiny secondary set of meters that in theory should alert one to that prospect). 
Title: Re: Static issue... Exceeding Max SPL?
Post by: GLouie on August 06, 2014, 03:08:07 AM
I don't specifically know your gear, but your sample definitely shows clipping during the static (see attached screenshot). It's not perfectly flat during the clipping as is usually the case when a mic preamp is overdriven, so it's hard to know where this occurred. You say it's never happened before under similar circumstances; is the ART giving full phantom voltage/current? Do you always run the PMD660 mic attenuator on or off? All settings like recording level were like usual?

I thought the PMD660 had P48 available? Why the ART?
Title: Re: Static issue... Exceeding Max SPL?
Post by: splumer on August 08, 2014, 08:56:43 AM
Sorry I didn't respond sooner. The 660 has phantom available, and I've used it before, but after two shows getting cut short due to batteries dying, I decided on a phantom power unit to run the mics. Yes, they're not very demanding power-wise, but at a show they draw enough to kill the 660's batteries after about 90 minutes.

Mic attenuation was off, everything was as usual except that I had the Art at 48v instead of 12v. That wasn't a conscious decision, it was an accident. The level meters on the 660 were fine the whole time, and the levels were actually fairly low in post.

BTW, Jon, I think I drove by your store in Nag's Head when we were in the OBX back in June. If I had known it was you I would have stopped in! I may order some mics...
Title: Re: Static issue... Exceeding Max SPL?
Post by: GLouie on August 08, 2014, 09:50:02 PM
Hmm, so it WAS a different setup! You might do some tests with that ART set to 48v instead of 12.

And I never believe meters unless I've checked the gain stages. Meters won't tell you if a previous stage is clipping.
Title: Re: Static issue... Exceeding Max SPL?
Post by: splumer on August 08, 2014, 10:53:20 PM
Hmm, so it WAS a different setup! You might do some tests with that ART set to 48v instead of 12.

And I never believe meters unless I've checked the gain stages. Meters won't tell you if a previous stage is clipping.

Well... sort of different. Can a different voltage make a difference?
Title: Re: Static issue... Exceeding Max SPL?
Post by: GLouie on August 09, 2014, 11:32:41 AM
If that P48 setting was the only difference, it would appear that could be the problem. It's a little odd, but if you wanted to investigate, I'd start there.