On Thu, 09 Mar 2006 15:45:28 +0200, Fella wrote:

OK, then. No, it isn't.


Gasp! You've turned human, you have actualy answered a rhetorical
question without resorting to stupid name calling. Ok, thanks, and
congrats! Now, let's expand that same question:

What are *all* the different electrical measurements that need to be
made to the signals and to the sound coming out of the speakers to
understand what a *human being* hears, perceives and interprets from his
hifi system. One of them is DB levels, ok. Then what? What else?


Not sure what you mean in terms of measuring the sounds coming out of
a speaker - you don't know if they are right unless you know what went
in, and this is how things are specified. You put a known set of
signals in, and measure what comes out. If they are the same - or
close enough - then you can be sure that whatever you put in will
result in the same coming out.

As for what you measure, well, you have

Power - the ability to reproduce the right level for a convincing
performance

Level (your DBs, perhaps) - you wouldn't want to reproduce a smoky
nightclub trio at 110dB, nor would you reproduce a symphony orchestra
at 30dB. Set it appropriately to the music.

Frequency response - to guarantee that tone balance doesn't get
changed, and also that the relative loudness of various instruments is
right

Distortion - to make sure that you don't get a whole lot of other
stuff out when you play your music. Some manifestations of distortion
are more objectionable than others.

Do you have the perfect microphone that is able to emulate exactly what
I as human being hear?

Emulation of human hearing is the last thing you would want from a
microphone. What constitutes perfect depends on the situation, but
generally you would want a flat frequency response, both on and off
the forward axis. The ear doesn't even come close to this.

Do you have a perfect account of the processes going on in my brain
during the musical interpretation of external sounds being heard by my
ears? Do you have a perfect computer model of that?

No, and neither is it particularly important. If you can reproduce the
same external sound field with a reproduction as would have occurred
with a live performance, then your brain/ear combination can get on
with its work interpreting both the same way. That is the goal of Hi
Fi.

d

Pearce Consulting
http://www.pearce.uk.com