clipping problems with MKE 300

[Jason OHara]

I am shooting with a Sony PD100A and a sennheiser MKE-300 and am experiencing clipping problems when recording in high volume situations (audio amplified through loud speakers or raucous carnaval parties here in Brazil) I have been troubleshooting the issue and have reason to believe it´s not simply an obvious case of blowing my levels.

The camera has 2 input volume controls:
1. a -3dB gain shift
2. a manual/auto volume input control

I have tried the gain shift in conjunction with a manual input shift to the lowest possible input level, but the problem persists. The effect of the manual input reduction is obvious when monitoring the audio, and is also apparent when reviewing the captured audio in my audio editor; the entire volume level is significantly reduced, never rising above -12dB, except for the sudden spikes where the clipping occurs? I wondered if the problem was being caused by a faulty connection, however, I can run the tape at length in low volume situations without any problem. At the same time, it cannot simply be a typical case of excessive volume causing the clipping, as the clipping instances are massive abnormal spikes in the audio level? I am confused and clueless, any insights are much appreciated. Thanks -J

[Peter Rhalter]

If the problem is "sudden spikes" then why not use the camera's AGC (auto gain control)? If the overall sound level is too high at "raucous carnaval parties" how about using an inline pad, maybe -10 or -20 or even -30dB, between the mic and the camera?

Best wishes,
Peter
______________________
http://www.parkfilms.com

[Steve House]

This is a classic example of where using an external mixer with a proper limiter comes into the picture. The problem is likely not so much a factor of setting the recording levels too high or too low, it's that the range between the average sound level and the peak sound levels is too wide. There won't be one magic level setting that's right for both ends of the spectrum. Pads won't do it either since they cut all levels equally and while you might be able to rduce the peaks below clipping, in the process you'll reduce the rest of the sound as well, thus increasing noise. A limiter would allow you to prevent the peaks from driving the camera into clipping while allowing an adequate level for the rest of the sound.

Of course, if the sound is so loud that it's driving the mic itself into clipping there's not much you can do except get a mic capable of handling a higher SPL. Senn rates the maximum SPL of the MKE300 at 116dB. Compare that to other Senn shotguns such as 125dB for the ME66 and 130dB for the MKH416, admittedly much more expenive mics (and of course that additional capacity is part of why they ARE much more expensive).