jimjazzdad wrote:But I can't help playing devil's advocate
There's nothing fundamentally 'wrong' with the concept of a passive controller -- it just comes down to the implementation and installation, same as it does with an active controller. It's all swings and roundabouts...
Danish mastering engineer Holger Lagerfeldt has a pretty good video out about why he loves his passive monitor controller
Looks well-designed... but some of his claims and graphs are a little misleading IMHO. The problems he highlighted in the active controllers either come down to poor implementation (like the mains hum artefacts), or are irrelevant and grossly misleading (like the D-A noise floor at -123dBu, which is bordering on technical perfection). And some of the shouty purists might get sniffy about the idea of all that sharp-edged digital control floating around next to the precious analogue!
I think if one manages to keep sensitive to cable length and has good amplifiers with high impedance inputs, the whole high frequency loss thing goes away.
Very low source output impedance is important too (and that can become a significant problem in a passive design at high volume attenuation), but yes, I agree that if the implementation and installation is done well it can work fine -- and I have been known to use a passive controller myself from time to time...
The use of switched attenuators make the biggest difference in performance terms IMHO -- although the Drawmer design uses a clever four-gang pot to improve stereo tracking compared to most standard designs.