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Gear / Technical Help => Recording Gear => Topic started by: NOLAfishwater on February 01, 2013, 03:03:04 PM

Title: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: NOLAfishwater on February 01, 2013, 03:03:04 PM
I used the M10 as the microphone for my DSLR and it turned out all distorted. Weird b/c it was showing levels in the green all night. When I got home it seemed to distort on the kick drum and deep bass licks. the limiter was off and it was set to manual. Have the dial turned all the way back. I did have the output set to headphone instead of line out but I didn't think that would make difference on the input end. What could have caused this? It was a loud show.
Title: Re: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: Ozpeter on February 01, 2013, 06:30:38 PM
The mics themselves being overloaded.  All recorders have some limit to the loudness they can handle.
Title: Re: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: John Willett on February 02, 2013, 04:06:09 AM
I used the M10 as the microphone for my DSLR and it turned out all distorted. Weird b/c it was showing levels in the green all night. When I got home it seemed to distort on the kick drum and deep bass licks. the limiter was off and it was set to manual. Have the dial turned all the way back. I did have the output set to headphone instead of line out but I didn't think that would make difference on the input end. What could have caused this? It was a loud show.

Very likely because the level controls are *after* the first amplification stage.

If you overload this first stage of amplification before the sound gets to the level control there is nothing you can do.

It's unlikely to be the mics themselves.

This is a common problem with video cameras that do the same thing.
Title: Re: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: Ozpeter on February 02, 2013, 08:33:21 PM
Quote
It's unlikely to be the mics themselves.
I meant what you said, but I didn't say it very well (at all!)
Title: Re: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: kleiner Rainer on February 03, 2013, 06:08:26 AM
I used the M10 as the microphone for my DSLR and it turned out all distorted. Weird b/c it was showing levels in the green all night. When I got home it seemed to distort on the kick drum and deep bass licks. the limiter was off and it was set to manual. Have the dial turned all the way back. I did have the output set to headphone instead of line out but I didn't think that would make difference on the input end. What could have caused this? It was a loud show.

Very likely because the level controls are *after* the first amplification stage.

...

I suspect the mics are overloading. My own tests point to a preamp architecture where the gain setting is IN the preamp (variable feedback). The same preamp topology is built into the M10s "big brother" D50 so I suspect its a favourite with Sonys design team. From what I have seen in ECM capsule datasheets, the maximum SPL they can tolerate is between 115 and 125dB. If this is the case with the M10 mics, this is a SPL where hearing protection is required.
Another point to keep in mind is that bass drum kicks have a very high peak to average SPL, so if the mics are clipping, they cut off the peaks and the mic preamp is still within its linear range. BTW clipping off voice peaks is the usual way to improve peak to average power ratio in AM and SSB transceivers.

Since the same mic amp is also used for external mics, and does not overload easily, the evidence points to the mic capsules.

Greetings,

Rainer
Title: Re: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: NOLAfishwater on February 03, 2013, 12:15:14 PM
Do you think running the limiter would help? Seems like I had the gain turned all the way down. If this doesn't work I will have to get some kind solution together.
Title: Re: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: kleiner Rainer on February 03, 2013, 01:56:57 PM
Do you think running the limiter would help? Seems like I had the gain turned all the way down. If this doesn't work I will have to get some kind solution together.

No. If the mics are the culprit, no amount of limiting would help. You would need some sort of "sound attenuator", i.e. some kind of dense foam, but with a linear frequency response. Dunno if that exists. Maybe a "dead kitten" could provide some attenuation?

If you encounter this situation again, try more distance between the recorder and the sound source, or external mics that can cope with extreme sound pressure levels. The built-in mics are better for very low sound levels with their extremely low noise level.

Greetings,

Rainer
Title: Re: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: F.O.Bean on February 03, 2013, 09:36:25 PM
Do you think running the limiter would help? Seems like I had the gain turned all the way down. If this doesn't work I will have to get some kind solution together.

Says the man with more gear than almost anyone ;D
Title: Re: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: NOLAfishwater on February 04, 2013, 03:00:25 PM
Do you think running the limiter would help? Seems like I had the gain turned all the way down. If this doesn't work I will have to get some kind solution together.

No. If the mics are the culprit, no amount of limiting would help. You would need some sort of "sound attenuator", i.e. some kind of dense foam, but with a linear frequency response. Dunno if that exists. Maybe a "dead kitten" could provide some attenuation?

If you encounter this situation again, try more distance between the recorder and the sound source, or external mics that can cope with extreme sound pressure levels. The built-in mics are better for very low sound levels with their extremely low noise level.

Greetings,

Rainer

That was the problem. I was using an 11-16mm wide angle lens so I was at the lip of stage in a small club with tin walls/ceiling so its loud. was wanting to alleviate having to run a preamp/external mic setup.
Title: Re: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: cybergaloot on February 04, 2013, 04:28:33 PM
Welcome to the brick wall
Title: Re: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: kennyb on February 04, 2013, 04:50:18 PM
Mic sens switch was set to low, correct? Sounds like the only solution is external mics that can handle ~130dB, possibly with a -10dB or -20dB pad before the recorder.
Title: Re: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: fguidry on February 12, 2013, 01:27:10 PM
I used the M10 as the microphone for my DSLR and it turned out all distorted. Weird b/c it was showing levels in the green all night. When I got home it seemed to distort on the kick drum and deep bass licks. the limiter was off and it was set to manual. Have the dial turned all the way back. I did have the output set to headphone instead of line out but I didn't think that would make difference on the input end. What could have caused this? It was a loud show.

You're using the DSLR audio subsystem?

If so, why do you think the distortion occurred in the M10 portion of the chain rather than in the camera audio?

Fran
Title: Re: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: NOLAfishwater on February 12, 2013, 04:01:11 PM
b/c I was recording on both the Sony M10 and the Sony D7. both recordings were equally distorted.
Title: Re: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: willndmb on February 16, 2013, 08:07:22 AM
b/c I was recording on both the Sony M10 and the Sony D7. both recordings were equally distorted.
so the m10 was going line out to the dsrl??
And you also had a rig running with a d7
What was the chain for both sources??
Title: Re: Sony M10 Internal mics distorted even though showing in green (-12db) all night
Post by: NOLAfishwater on February 19, 2013, 09:53:33 AM
Sony M10>mini cable>Canon D7. both the sony and d7 were capturing the same audio.