I thought Audioholics said that Power Current is a non-issue these days?
The BP7001SC has a minimum impedance of 3.3 ohms (Sound & Vision Mag).
But @ 90dB, I don't think I was able to tell any differences between the Acurus 200X3, Emotiva MPS2, or the Denon PMA2000IVR.
It depends on many factors. It may be the case for you but not necessarily for others. Consider the following example:
Speaker A
Sensitivity: 87 dB @2.83V 1 meter
Nominal impedance: 4 ohms
Speaker B
Sensitivity: 90 dB @2.83V 1 meter
Nominal impedance: 8 ohms
Speaker A is therefore 6 dB less sensitive than speaker B.
Now let's day Person A owns speaker A and Person B owns speaker B and that Person A typically likes his music twice as loud and Person B. Remember, to perceive twice as loud, SPL may have to be as much as 10 dB higher, let's say 9 dB just for ease of demonstration.
So now Person A will need an amp that could provide this extra 15 dB (3 for being 4ohm and 3 for the lower sensitivity, and 9 to make it sound twice as loud) of SPL.
Let's further assume in this same room, Person B typically needs 10W to get the SPL he likes.
Since for every 3 dB of SPL increase you need to double the power, so to get Person A that extra 15 dB, he needs to have 32 times the power that Person B needs, that's 320W. On top of this, even for non classical music you need to have 2 to 3 dB of headroom so suddenly Person A would need a 500 WPC amp.
I know I am being extreme, in order to show how quickly the power requirement goes up depending on the characteristics of a specific speaker and its owner's personal preference. In reality, even a 15 WPC tube amp can do well in a smaller room, powering not too hard to drive speakers, for individuals who know how to protect their hearing, and play their music at moderate SPL (say, around 70 dB instead of 80 or higher).
