Cubase Processing Precision, 32 Bit or 64 Bit?

[KHS]

@jwatte

Second: -146 dB quantization noise is still quite imperceptible, because you need to be playing at full scale to get to that point. If your signal is less than full scale, the quantization noise will also lower itself – this is what the “floating point” is all about. I measured my near-field Genelecs to about 112 dB SPL before distorting out (if I remember correctly – this was long ago – I don’t run them that hot, ever, because I like my ears) so the quantization noise would be below 0 dB even at max – and ears mask signals, so you can’t even hear a +20 dB signal when the room is blasting at 110 dB, much less a -36 dB signal, which you can never hear, almost definitionally.

This is not entirely true. How hot you run your monitors is just a matter of how much you turn your volume knob and thus how much amplification you are doing. There is a difference between the dBFS used in the digital world and the SPL you get from your monitors.
To get the full benefits of the 144dB SNR from 24 bit, in theory all you need is to make sure the signal is hitting 0dBFS before AD conversion. Now this is only in theory as there are other factors that comes into the equation and practically even the best converters will not give you more than 120’ish dB SNR.