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Gear / Technical Help => Microphones & Setup => Topic started by: dwissl on October 05, 2006, 06:33:40 AM

Title: How much is 12MV in db?
Post by: dwissl on October 05, 2006, 06:33:40 AM

I have a SoundProfessionals SP-PSM-3, which has an open circuit
sensitivity of -35db. I read, that the BeyerDynamics MCE72 has an open
circuit sensitivity of 12MV. Could anybody here tell me, how much this
is in db? I'd like to know, which of the two is louder.

Thanks

Title: Re: How much is 12MV in db?
Post by: SparkE! on October 05, 2006, 11:32:50 AM

I think it depends on what the reference impedance is for your 12 mV and it depends on what the reference power or voltage level is for your SoundProfessionals.  Neither of those specs tell the whole story, although there may be some reference values that are commonly assumed for mic specs.  I think Brian Skalinder has dissected mic specs before and he might know how to compare your numbers according to standard references.  Also, poorlyconditioned has been through the mic sensitivity math before and may know how to compare your numbers.

Do you know if your -35 dB is a voltage spec or a power spec?  If it's a voltage spec (and I suspect that it is) and both mics are assumed to be driving the same reference impedance, then you'd just take 20 log (.012) = -38.4 dB, so your -35 dB mics would be louder.

Title: Re: How much is 12MV in db?
Post by: Church-Audio on October 05, 2006, 11:44:48 AM

Quote from: dwissl on October 05, 2006, 06:33:40 AM

I have a SoundProfessionals SP-PSM-3, which has an open circuit
sensitivity of -35db. I read, that the BeyerDynamics MCE72 has an open
circuit sensitivity of 12MV. Could anybody here tell me, how much this
is in db? I'd like to know, which of the two is louder.

Thanks

Here is a good calculator I use for taking the guess work out of these measurements you have to know the impedance of the load in witch the 12mv is referenced to. http://my.athenet.net/~multiplx/cgi-bin/dbconv.main.cgi