Bubba Kron wrote |
Since its just subtractive, most the time it means it wont hit the op-amp?
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You seem to be significantly misunderstanding how these things work.
Sure, passive filters don't use op-amps... and yes, passive filters can only cut...
BUT
An active filter doesn't suddenly 'switch' to passive just because you're not boosting on any given band. -The op-amp is always in the path, and sums the signal with a filtered band either "IN-phase" (for boost) or "OUT-of-phase" (for cut). -But it's ALWAYS in the path, and it's always summing, whether you're boosting, cutting or set flat.
Not only that, but the filter section isn't passive. It uses several op-amps per band, frequently arranged in a state-variable or wien-bridge arrangement. These are resonantly-tuned and the frequency, gain and resonance can be tuned to change the center frequency, boost range and 'bandwidth'.
The CP-10 is always using its op-amps. There is no boost/cut structural difference... only the band 'in/out' switches change things, by disconnecting the second path from the summing stage for each band, but the signal still goes through five sequential summing stages, even if all five filters are disconnected.
Now... to submit a thought to your direct question: yes, different filters will sound different. If a bandwidth control goes sharper or narrower, it will obviously be capable of a different range of sounds.
Even given the same center frequency, the same depth of cut and the same empirical 'bandwidth' (which is a tricky notion, because many filters use constant-Q/variable-bandwidth, while others use constant-bandwidth/variable-Q designs, which behave differently to increased cut or boost... but we'll ignore that for now) they can give measurably and audibly different results.
One thing is the actual Q of a filter, and two units which produce almost identical pass response curves can produce significantly different impulse responses as a result of differences in this area.
Don't be led into thinking that the only differences between EQs is the make-up stage. -That's marketing bullshit, and utterly muddies the water. -The REAL differences are in fundamental topology. -That's what people like Rupert Neve understand on a level which goes right down to the great man's DNA, I almost believe.
I've spent some time dabbling with EQ designs, and I've built a few. Some sounded better than others for different tasks, and some have sounded significantly different... even when they've only used 553x and TL07x op-amps.
It's the design. going right down to the foundation. -The op-amp is like the paint job. -Sure, they might make a lot of the paint job in the brochure, but if you tried to sell anything in this business based on getting people to understand its TRUE merits, there'd be a lot of glazed eyeballs at the end of every sales pitch.
Short answer. -yes, a GML will sound different. (And frequently noisier, from my experience.) But there is no 'better' unless you think it's better. -And it's got almost nothing to do with cutting or boosting, or how the op-amp is "hit"... It's to do with topology and fundamental design.
Keith