..high end lamp cordSo the lamp cord of the '70s is the same as your Cat5 or Cat6 cable?
I don't think most studios care much about weight, and the higher end studios probably don't care about cost too much. Take a look at the JBL M2 . Producers want flat flat sound to avoid any coloration in the mix. JBL is using Class D amps and a DSP to achieve this. The speakers are still passive but need an active crossover to control them. The L300's, while expensive at the time, could only dream to be this accurate.