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Re: Hello and a Sony PCM D100 question

Subject: Re: Hello and a Sony PCM D100 question
From: animalsounds
Date: Sat Jun 21, 2014 2:26 am ((PDT))
Mike, you wrote:=0D
 =0D
=0D
 > Your understanding of the limiter is the same as mine, the SN100 mode ho=
wever is not related to the limiter - looks like Sony sum those two ADCS to=
 bring the increased SNR.=0D
 =0D
=0D
 Yes, after re-reading the manual I see that the information on the SN100 m=
ode on page 70 of the manual is obviously wrong - it seems that they just c=
opied the text module from the LIMITER (page 69). That is much confusing an=
d one can get the impression that the folks at SONY themselves don't know w=
hat that option really does ;-) =0D
 =0D
=0D
 I therefore repeated the mic input noise measurement on my unit with the S=
/N100 option switched off and on. My (absolute) noise floor measurements ho=
wever are NOT affected by the S/N100 option. In both modes the unweighted n=
oise floor (bandwidth: 20 Hz - 20 kHz) is -125 dBu (or -127 dBA) at REC LEV=
EL 10 - the difference is less than 0.1 dB. =0D
 =0D
=0D
 But there is indeed a difference in the sensitivity. When the S/N 100 opti=
on is activated, the relative signal level (dBFS) is reduced by 1 dB, which=
 corresponds to an increased clipping level of -59 dBu compared to -60 dBu =
with the S/N option deactivated. =0D
 =0D
=0D
 In order to get absolute noise levels I use a -62.5 dBu, 1 kHz reference s=
ignal - so maybe that relatively high reference level somehow affected my m=
easurements (speculating that the S/N 100 would act like a limiter in some =
way).  =0D
 =0D
=0D
 Regards,=0D
 Raimund=0D
 =0D
=0D
 =0D
=0D
 =0D
=0D
 =0D
=0D
 =0D
=0D





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