If you did a A/B blind test comparison of 100 salk people with half of them using separate amps and the other half using the powered monitors majority of the people wouldn't be able to pick out 50 of the powered monitors and some would even choose and prefer the sound of passive then the actives.
I can't speak for Salk customers but if you are claiming that you can't tell the difference between a passive and active speaker of the same model you are mistaken.
The Paradigm Active 40 I own has an identical passive version. Look at the specs for the passive version:
Studio 40 v2 Specifications
Design
3 driver, 2-1/2-way bookshelf / stand-mounted
Crossover
3rd order electro/acoustic at 1.5kHz, 2nd order electro/acoustic at 400Hz
Frequency Response On-Axis
±2dB from 59 Hz - 22 kHz
Frequency Response 30° Off-Axis
±2dB from 59 Hz - 20 kHz
High Frequency Driver
25mm (1 in) PAL™ pure-aluminum dome, diecast heatsink chassis, ferro-fluid cooled
Mid/Bass Frequency Driver
170mm (6-3/4 in), MLP™ mica-polymer cone, AVS™ diecast heatsink chassis, 38mm voice-coil
Low Frequency Driver
170mm (6-3/4 in), filled polypropylene cone, AVS™ diecast heatsink chassis, 38mm voice-coil
Low Frequency Extension
34Hz (DIN)
Sensitivity Room / Anechoic
91 dB / 88 dB
Impedance
Compatible with 8 ohms
Suitable Amplifier Power Range
15 - 180 watts
Maximum Input Power
140 watts
Weight
70 lbs. (32 kg)
Dimensions HxWxD
21.5" × 8.75" × 12"
(54.6cm × 22.2cm × 30.5cm)
and now compare with the active version:
Active 40 v2 Specifications
Design
2-driver, 2 way with built in electronic crossover and amplifiers
Crossover
3rd order electro/acoustic at 1.5kHz, 2nd order electro/acoustic at 400Hz (lower bass driver)
Amplifier
High current, discrete output, Powersaver auto on/off, thermal protection
Amplifier Features
Bi-amplified: 325w/125w RMS for bass/midrange drivers, 150w/50w RMS for high frequency drivers
Frequency Response On-Axis
±1dB 36Hz-22kHz
Frequency Response 30° Off-Axis
±1dB 36Hz-20kHz
High Frequency Driver
25mm PAL™ pure-aluminum dome, diecast heatsink chassis, ferro-fluid damped/cooled
Mid/Bass Frequency Driver
170mm, MLP™ mica-polymer cone, AVS™ diecast heatsink chassis, 38mm voice-coil
Low Frequency Driver
170mm, mineral-filled polypropylene cone, AVS™ diecast heatsink chassis, 38mm voice-coil
Low Frequency Extension
32Hz (DIN)
Weight
70 lbs. (32 kg)
Dimensions HxWxD
21.5" × 8.25" × 13.25"
(54.6cm × 21.0cm × 33.7cm)
Anyone and everyone can hear the difference between them regardless of the amp you use on the passive version in a blind listening test.