John Phillips wrote:

In article , Tat Chan wrote:



Excuse me for jumping in, but going back to Jim's finding that,
"although measured to deliver 50W into 8 Ohm loads, this fell to 36W
into 4 Ohm loads", wouldn't this mean the amp was improperly specced or
designed? I am under the impression that most amps would deliver more
power (not necessarily double) into a 4 Ohm load than an 8 Ohm load.


I guess it depends on your standards and how you look at things.

as long as my amp can drive my speakers, I'm happy ...

well, that would be one criteria anyway.



An "18 Watt/8 Ohm" amplifier which also drives 36 Watts into 4 Ohms
would achieve the usual modern standard [1].


yes, that sounds right. I got thrown off by the "50W into 8 Ohms" figure


Thus the Kraken could
be considered to be perfectly well designed to provide 18 Watts
into a nominally 6 Ohm loudspeaker (i.e. one with an impedance of 4
Ohms minimum).

so a speaker with a nominal impedance of 6 Ohm has as its minumum
impedance, 4 Ohms? I thought it could go below that at certain frequencies.



It just wouldn't get the "50 Watt" label. However, that may be fine.
If the loudspeaker had a sensitivity of, say, = 93 dB at 1 metre for
a nominal 8 Ohm Watt then you could still get unclipped peak levels of
around 105 dB from an "18 Watt" amplifier - which would be fine for a
very reasonable range of music.


yes, the Kraken would be fine for driving very efficient speakers at a
"reasonable" listening level.



[1] Some amplifiers exceed this. The older Krells, for example, continue
doubling output power down to to 2 Ohms or even lower.

So the newer Krells might not do this? Cost cutting reasons, or they
don't make them like they used to?