Rational Acoustics Measurement Mic curiosity...

[Tj Hopland]

Mounted to a wall? Is it maybe catching a reflection off the wall?

[Ryan Gallagher]

Mounted to a wall? Is it maybe catching a reflection off the wall?

all good theories. But it was responding fine/normal to many films prior to that sudden behavior.

[Marcel Birgelen]

Also, while echo or reverb is more diffuse than the original signal, it should not fill the entire spectrum, when the original signal didn't fill it either.

[Marco Giustini]

I'm confident that what we see on video is 100% an issue with the recording sound chain.

[Ryan Gallagher]

Just popping back in to say that problem measurement mic seemed to come good next time I tried it. I did set a much lower sensitivity on the octa-capture and re-calibrate, which "seems" to have been the culprit.

It was such a weird behavior to diagnose... cause it was doing it even when the input meters on the octa were no where near peaked, but maybe once it exceeded it's headroom once the problem stuck around?

Or it just needed a vacation too?

The mic i swapped it for at FOH is still working fine (also adjusted lower on sensitivity and re-cal'd). Used it today to rough in a much better center channel EQ in this neglected room. Will hit it again with the set of 6 mics and my TD and other projectionist for teaching purposes, but the dialog intelligibility problems seem miles better now.

One of integrated sub amps died last week too, so we aren't getting a dolby or otherwise tech out to re-turn the whole system till that RMA comes back. Improving the EQ as we get time until then!

[Hong Sung Hyeok]

I use the SMAART, OctaCapture, and the Beyerdynamic MM1 microphone.

What value did you set for the sensitivity knob on the OctaCapture?
Before measuring, always adjust the knob whenever I calibrate the microphone on the SMAART.
(When I run SMAART, the first thing it does is select OctaCapture input and the microphone, choose the calibration file, and then perform microphone calibration.)

In my case, when I connect the signal generator to the microphone and set it to 104 dB, I adjust the sensitivity knob until the microphone input level shown in SMAART changes to yellow.

I think the margin space considered before clipping is the yellow area.

[Ryan Gallagher]

We had all 6 of our mics out today. Same model RT420 with calibration files.

We calibrated with 94db (cause that seems to be the Smart v8 default), input sensitivity all the way down because the first mic we were trying to calibrate was giving the same clipping/transient problem at a more normal sensitivity (kissing the yellow).

One of the 6 never came good and persisted with the transient clipping problem, then later in the day another one that was behaving fine for a couple hours started to exhibit the same problem. Did all the usual troubleshooting things, it appears to be the mic itself cause it would follow the mic when swapping them around, except sometimes it will be fine (like my original FOH mic after a few days went by and I recalibrated it at minimum sensitivity).

Quite annoying time suck, might be in the software chain or octa-capture pre-amps/phantom, but I would have thought swapping mics would not solve that. Proceeded with 4 mics instead.