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Re: HiMD Clipping Test results

Subject: Re: HiMD Clipping Test results
From: "stoatwizard" stoatwizard
Date: Thu Jul 13, 2006 11:38 pm (PDT)
Graham,

Looking at your results and the settings you had. I agree that on Hi
sens you have clipping - indeed you have a tiny bit on the Low sens
via the speakers too.

The clipping is probably because you have too much electrical input
level to the HiMD for the Mic-Hi sensitivity.

If you are achiving 0dBFS with the recording level set to 11 or below
you must lower the sensitivity of the HiMD or it will clip. That is
assuming the gain profile of all HiMDs are similar to the NH700 I
tested this on. At least the new RH1 seems to use the same chip. The
measurement results are shown on

http://www.wildlife-sound.org/equipment/himd/himdpklevels_meas.html

The rule of thumb is reasonably easy to remember in the field - if on
a HiMD you are getting near 0dBFS recording at a manual level setting
of < 12 then change down a gear in sensitivity, otherwise you will
suffer preamp clipping.

This is independent of PiP powering issues, which mean you have
to choose your mic carefully if you are using PiP. I tested a Sony
ECM 719 which should work with a Sony MD and indeed it does - PiP
settles at 1.5V, and my old Marantz ECM-8 settles at 1.2V. Both these
are reasonably in spec. The OKMII and Rapid capsules, and probably
Panasonic WM61 capsules would not run in spec with the Hi MD. But
this was not at issue in your case as the original recording looks
okay.










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