----- Original Message ----
From: Paul Jacobson <>
To:
Sent: Sunday, 27 May, 2007 12:22:24 PM
Subject: Re: [Nature Recordists] Re: 16 Bit & 24 Bit recordings
I'd intended to delete the last message but inadvertently hit send
instead.
apologies.
Paul
On 27/05/2007, at 9:01 PM, Paul Jacobson wrote:
>
> On 27/05/2007, at 7:25 PM, Phil Tyler wrote:
>
>> Giving you 8 bits, theoretically, more resolution of
>> low level sounds with 24 bits.
>>
>> Phil
>
> I suspect it's far more than 8 bits as that would imply 2^8 =3D 256
> additional "steps", whereas the actual difference is between 2^16 =3D
> 65,536 and 2^24 =3D 16,777,216.
>
> The page I posted a link to earlier in the week has this rather
> pertinent example:
>
> http://www.24bitfaq.org/#Q0_1_1
>
> "To elaborate further, each bit gives us the ability to represent
> about 6dB of dynamic range. A passage that is 6dB louder than another
> passage is said to be twice as loud as the other passage.
If something is twice as loud that would be 3db, if the voltage increases b=
y twice that is 6db. Each bit of the digital system is measuring a halving =
(or doubling) of the voltage which is in 6db steps. There in lies some of t=
he problems, as each halving of the voltage nears the ends of even the 16 b=
it range we are trying to measure really, really small voltage changes. In =
some of the first CD players on the market they were unable to resolve some=
of these very small changes due to the 'noise' in the circuits created by =
all the RF from the components. There was one particular model made by Phil=
lips which over time degraded quite badly until it reached a point it could=
not distinguish signal from noise. This was cured by re-soldering all the =
solder through connections on the earth plane of the pcb, even better was t=
o actually put a wire through the hole and not rely on the solder alone. Ev=
en today many of the 'domestic' CD players are probably unable to fully res=
olve all 16
bits due to 'noise' in the circuits. So I do tend to take with a pinch-of-=
salt the claims by some manufacturers that their device is 24 bit as the en=
gineering needed to ensure you can resolve those minute voltage changes ove=
r the circuit noise is not something that is easily acheived for =A3300 / $=
Message: 600.
Subject: I would imagine no make that hope that the Sound Devices attain near t=
he maximum.
Phil
>In the 4- bit example, we theoretically have 24dB of dynamic range that ca=
n be
> used. But what if recording doesn=A2t take advantage of all that
> dynamic range? What if the recording never peaks beyond 6dB of its
> maximum possible limit? In this case, the recording would only take
> advantage of 3 of what we call the least significant (or left-most)
> bits, meaning 18dB of dynamic range. 16-bit recordings are capable of
> a theoretical maximum limit of 96dB of dynamic range. This means that
> a single wave could have up to 65536 discrete values that can be used
> to represent it. But if the same wave recorded at 16-bit peaks at
> 48dB below its maximum possible limit, then there would only be 256
> discrete values that can be used to represent it, taking advantage of
> only 8 of the least significant bits. The 8 most significant bits
> would contain no information whatsoever, and would remain unused. In
> the case of 24-bit recording, you=A2d have a maximum of 16,777,216
> values to choose from, and in the case of a wave peaking at 48dB
> below its maximum possible limit, the wave would still have 65536
> possible discrete amplitude values that could be used to represent
> it."
>
>
>
>
> "While a picture is worth a thousand words, a
> sound is worth a thousand pictures." R. Murray Schafer via Bernie
> Krause
>
> Yahoo! Groups Links
>
>
>
"While a picture is worth a thousand words, a
sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause
Yahoo! Groups Links
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