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Re: Autonomous recorders (was "Saying Hello")

Subject: Re: Autonomous recorders (was "Saying Hello")
From: madl74
Date: Sun Sep 22, 2013 5:31 pm ((PDT))
> The specs say "-115dBV equivalent input noise", which I think might put i=
t in the "ok" bracket. I assume a lot of what you pay for them goes towards=
 robustness and programming flexibility.

Peter,

Apologies for technical mail.

"-115dBV equivalent input noise". Equivalent to what? You need the "what"
defined. I don't take specs at face value, so I put my "toy" Tascam DR-1
through its digital paces.

At 16 bits sampling, minus the parity bit and the biggest bit being 50%, I=

got dither noise on the smallest three bits. This is needed to average out=

the slight sampling noise if you record very low. That makes 11 bits clean=

which is 66dBs. That is well swamped by the natural noise in my recordings=

even when recording low.

At 24 bits sampling I only found a 20dB benefit which was 4 1/2 bits more
than the 16 bit digitiser, not the 8 bits or 48dBs I expected. I'll check
out another recorder. However, at the 15 1/2 equivalent (11 plus 4 1/2) bit=
s
available, this toy machine is as good as my low noise MKH mics, and SQN
mixer and the wind in the trees which the birds are singing from.

Summary. Don't believe all the sales hype. I worked out some figures.
Inevitable thermal noise (from vibrating electrons) drowns out the higher
(lower level) bits. A 24 bit - 22 active bits - digitiser goes down to
 -132dB which doesn't really exist, but you would feed that expensive
digitiser from a pro mixer which would drown out the noise anyway.

I've got a pro SQN mixer and I can't fault my DR-1 for noise, but I prefer=

mu DR-100, still in the "toy" category. It is easier to use, which is more=

important than theoretical specs.

David Brinicombe







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