Re:PC4K Threshold - Not accurate?
2013/12/02 07:08:14
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This was a great thread! I actually performed the same tests earlier this year with X2a. Too bad I didn't know or read this thread first! I submitted my own bug report to Cakewalk.
To this day, the PC4K Bus Comp is still screwy when compared to other, emulated/replicated SSL 4000 bus comp's out there. Particularly, Cytomic's the Glue was my go-to comparison, similarly to the OP and his tests. And to an astounding coincidence, I also compared results to the Sonitus Comp, which could be considered a more laboratory-type comp, IMO.
Overall, the PC4K and Cytomic's the Glue are not the same, even though they are modeled after the same, hardware console. [Insert head scratching here]. When comping a test 1kHz, 0dB sine wave, a threshold value of -12dB (at 2:1 ratio) on the PC4K nets an output amplitude of -6.9dB. On the other hand, the Glue's threshold and ratio set a the same values net an output amplitude of -10.2dB.
If we can expect the following equation shown below to be true, then the PC4K is indeed the mathematically correct compressor, even if it's 1dB off. The Glue, on the other hand, is way off, at 4dB.
Input dB - (-Threshold dB)
------------------------- + (-Threshold dB) = Output dB
Ratio
However, in my opinion, the Glue is more "musical," and it's not the placebo effect either. Overall, the release times of the Glue seem more in-tune to rythym, especially in sidechaining. When the PC4K is sidechained, it seems sloppier and not easily adjustable to the beat. In contrast, the Glue is tighter, more precise and flows better rythmically. For me, this gives the easy win to Cytomic's the Glue. After all, we want a compressor to sound good in our music!
So who's right, who's wrong? In terms of emulation/modeling, it's probably a toss up. But does it really matter? While it's cool to emulate a monster-sized studio console, it remains a novel idea and more of a marketing gimmic perhaps.
But all in all, putting threshold and output differences aside, the Cakewalk PC4K Bus Comp is a little sloppy. It could be better.