Below are the detailed graphs of the desk's frequency response accompanying the Cadac Live 1 article, which appeared in SOS January 2013 (/sos/jan13/articles/cadac-live1.htm).
My THD measurements were better than the published specs, achieving 0.001 percent THD via the mic input with 10dB of gain, rising to 0.003 percent via the line input, with the gain adjusted to provide unity through the desk (ie. +16.5dB). With +21dBu at the outputs THD rose to 0.007 percent — all far better than the 0.02 percent given in the specs.
Checking the signal-to-noise ratio, I measured -90dB at the direct outputs, which is exactly the same as the specification. At the main outputs I obtained figures of -98dB with the master output muted, -95dB unmuted but with the master fader closed, and -91dB with the master fader at unity. With all mono and stereo input channels routed to the stereo bus, the SNR was -80dB with their faders closed, and it rose fractionally to -79dB with all faders up and preamp gains at zero. These are excellent results, and imply an unweighted dynamic range of well over 100dB in practice with all channels contributing, with the output stage alone matching the published figure of 119dB.
The equivalent input noise is given as less than 127dB, and I barely achieved 126dB A-weighted (123dB flat), which is adequate but not sensational. The CMRR figure was also disappointing, as I couldn't get close to the claimed 86dB — performance varied wildly, with different channels ranging from 53 to 74dB (at 1kHz).
Crosstalk is quoted as being between -80 and -90 dB at 10kHz, but I could only achieve this by measuring crosstalk between the direct outputs of adjacent channels. Crosstalk to adjacent aux outputs measured -75dB, and through mix buses it was fundamentally limited by the off-attenuation of the pan-pots, which is only about 65dB. In other words, if you pan a signal hard left it will also appear on the right output at around -65dB. This isn't a problem in practice — it will still sound panned hard left — but it does compromise the measurements!
Finally, the phase response is given as being less than five degrees at 20Hz. This figure would be much higher if the console employed input and output transformers. I measured a phase shift of about 0.1 degrees at 20Hz, with a smoothly increasing phase shift above 20kHz, reaching just one degree at 30kHz.
The frequency response through the console is nicely controlled, with -3dB points around 5Hz and 80kHz. The low frequency response is curtailed slightly when the preamp is running at maximum gain, bring the -3dB point up to 15Hz — but I doubt anyone will notice that!
