Axiom Home Page Forums General Discussion Technical Questions Amps and Power, for Micah

Fred, as we discussed a couple years ago, I don't care for that Crown calculator. If it's used without the correction for the room effect the result comes up about four times too high, and there's no hint of this on the calculator page itself. On the discussion page it doesn't appear until an "Other Considerations" section near the end. Even then, instead of suggesting that the figure from the calculator be divided by four(and a smaller amp be bought), the suggestion is made that it be used for added headroom.

On another point, if a correction for the room contribution(either the one suggested by Crown or another)is applied, then the in-room figure for speaker sensitivity(e.g., 95 dB for the M80s)shouldn't also be used, since this would be counting the room effect twice.

When a peak of as much as 20dB is mentioned, this is almost always referred to the average, rather than the minimum, level. For example, listening at a comfortably loud 80dB average, on some material a peak as high as 100dB might take place. The total dynamic range(quietest part, but not silence, to the loudest part)on a few of my classical CDs is as much as 60dB, which would mean listening over a range from about 40dB(nearly inaudible)to about 100dB. On the other hand, one of the pop recordings used in a speaker stress test described in my AES Journal was so uniformly loud that the total dynamic range was essentially 0dB.

Okay, enough of this miserable typing with the board in this condition.