Print

Print


I'm a little disturbed by some of the assumptions here...

When the disc was cut, the recording characteristic would have been applied 
by an analogue network. This network, having first-order poles and zeros, 
would have had a well-defined phase response. An analogue playback network 
will, perforce, substantially invert the phase-shift of the recording 
network. This is not necessarily the case with a digital EQ network. The 
criterion should not be, in this part of the chain, which approach "sounds 
better" but which more accurately inverts the recording chracteristic, in 
terms of both amplitude and phase response. If, having reproduced the disc 
accurately, you still don't like how it sound, then by all means tweak your 
service copy to taste.

And as for loss of dynamic range - I think we would be hard put to exceed 
90dB between the Johnson noise of the pickup cartridge (never mind disc 
noise) and the highest reproducible peak off the disc. The last time I 
looked, 24 bits gave a theoretical dynamic range of 144dB, and commercially 
available convertors are getting within spitting distance. The drop from one 
end of the spectrum to the other on RIAA is 40dB.


----- Original Message ----- 
From: "Fred Thal" <[log in to unmask]>fdshg7
To: <[log in to unmask]>
Sent: Wednesday, March 10, 2010 2:26 PM
Subject: Re: [ARSCLIST] Disc EQ in the digital domain


> Hello Eric,
>
>> Transfering FLAT will cost you about 6-7 bits of dynamic
>> range - an audible loss.  EQ in the digital domain will not
>> recover that lost dynamic range.
>
> Can you describe the mechanism by which the dynamic range is lost in
> this process? Or can you point me to any relevant literature that
> fully explains this?
>
> Thanks in advance.
>
> Fred Thal
> ATAE / Audio Transfer Laboratory
>