What is confusing about the HK156 specs is this:
Power Requirement AC 230V, 50Hz–60Hz, 100W
Power Consumption (full power/idle) 540W / 250W rated
http://uk.harmankardon.com/harman-kardon-product-detail-uk/avr-156-.htmlpower required of 100W for Power consumption (full power) of 540W and idle power of 250W
! Incredible! (read: ridiculous!
- see idle power)
No AVR is more than or less than sufficient. It has to consider the speaker to be used, and the space of application.
Using a speaker of 90 dB and above, the combo will sound loud in the space indicated. And since the bass power is more likely to be outsourced to a powered SUB, the speakers will be in small position which will not need full bass frequencies making the 60W at 1KHz (probably 40W at 100Hz?) a little bit acceptable.
If the 25A HIGH INSTANTANEOUs CURRENT is to be believe - then HK 156 is capable of dynamic headroom up to 5kW (
I^2 xR - huh!) - or 1kW/ch. OK, I give up on this!
What is HK up to nowadays? Does HK156 uses digital amps?
Practically, HK 156 is enough for a 90dB speakers, set as 'small'. A 60W/ch is dynamically useful up to 6W (97dB resulting loudness per speaker). Since the nature of typical sounds is basically spiky, the measurement of 60W/ch (I hope this is averaged power) 2 channels driven is fair enough to apply in 5-spiky power requirements of sounds!