Re: Unity on Soundcraft Si Expression 3
Patrick,
To give you a comparison: let's say an analog mixer can output a maximum of +24dBu in signal level. If your meter's "0" or Unity point equates to +4dBu (professional Line Level signal, nominally), then when your signal reaches the "0"/Unity mark, you have about 20dB of headroom left before the output of your mixer will distort.
For the Expression Series, the manual states that the Mix Output is capable of a maximum output of 21.5dBu. If you wish to correlate this to your dBFS metering, then you would subtract the amount necessary to get you back to +4dBu, which leaves you with about 18dB of headroom, or "-18dBFS".
So, for this mixer, I would say that -18 would be a good "0" mark to shoot for. It's a compromise between enough headroom and Signal-to-Noise Ratio (but it's always been a compromise...the terms are just changing a bit).
