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View Full Version : Mic input setting in menu -50dB



davideo.net
12-20-2008, 09:37 AM
So I'm looking at the manual (page 48) and it says the default menu setting for the mic gain is -50dBu. The menu states "be aware that sensitivity will be higher if you choose -60dBu so you will record more noise." Call me stupid, but I don't get it. If 0dB is very loud, why is -60dB louder than -50dB? :huh: Please explain...

Tom Harman
12-24-2008, 02:07 AM
Here is an explanation from Wikipedia. See if this helps.


Sensitivity indicates how well the microphone converts acoustic pressure to output voltage. A high sensitivity microphone creates more voltage and so will need less amplification at the mixer or recording device. This is a practical concern but is not directly an indication of the mic's quality, and in fact the term sensitivity is something of a misnomer, 'transduction gain' being perhaps more meaningful, (or just "output level") because true sensitivity will generally be set by the noise floor, and too much "sensitivity" in terms of output level will compromise the clipping level. There are two common measures. The (preferred) international standard is made in millivolts per pascal at 1 kHz. A higher value indicates greater sensitivity. The older American method is referred to a 1 V/Pa standard and measured in plain decibels, resulting in a negative value. Again, a higher value indicates greater sensitivity, so −60 dB is more sensitive than −70 dB.

davideo.net
12-24-2008, 08:30 PM
So the Panasonic manual and Wikipedia are each saying the opposite thing... :furious3:

Tom Harman
12-25-2008, 02:12 AM
I think it works this way:

You use a microphone with a -50 dB sensitivity and plug it into your camcorder set to receive -60 dB. Your camcorder will record that as 10 dB "louder" than it really is. Since these number are logarithmic, it will be much easier to create clipping.

I struggled with this for years until I actually listened to several microphones plugged in at the 2 settings and heard it for myself.

Hope this helps.

Kit_L
12-25-2008, 03:39 AM
Tom: extremely lucid explanation.

Tks; have a great New Year

KL

davideo.net
12-26-2008, 07:20 AM
Yeah, Tom - that was perfect. Thanks.