driver sensitivity and cheap amps - a design question

[amo]

Unfortunately I do not have a deep understanding of how amplifiers work and wanted to clear up one assumption - would it be accurate to say that by using a VERY high sensetivity driver such as one of the PHLs and driving it by a fairly inexpensive "mid-fi" class AB amp, such as a US$120 plate amp, one could still get low distortion by not crossing over into the "B" side of the "AB" (assuming electronic crossovers). Further, can this very high sensetivity be achieved by using a large number of inexpensive drivers (such as Tang Bangs) wired similarly to a line array?

[thylantyr]

It's been proven that amplifier distortion
of 1% THD or less is inaudible.

You can drive high sensitivity drivers
with less power vs. drivers of
lower sensitivity.

I wouldn't worry about operating
a class AB amplifier in "A" mode because
majority class AB's are not really class A
to begin with, and if they are, the power
is very low and it would be inaudible.

The line source can increase sensitivity
and even moreso depending on
how you wired the drivers and if
the amplifier is up to the task of
driving low impedances.

If you have one high sensitivity tweeters
and one midrange, you can drive these
with ease with cheap amplifiers of low
power and still have great sonics, and
depending on which drivers you chose,
you have the ability to operate the same setup with more power for
even greater dynamics.

Due to the high sensitivity nature
of those types of drivers, you may
expose weaknesses by hearing noise
from the electronic equipment you use.

Use low noise amplifiers for the tweeters.

The low sensitivity tweeter/midrange
designs need more power to drive
them.

But, the most important part, regardless of sensitivity, is....

Do the drivers chosen sound good
to begin with ? /hehe

[amo]

Originally posted by thylantyr

The line source can increase sensitivity
and even moreso depending on
how you wired the drivers and if
the amplifier is up to the task of
driving low impedances.

So what would happen if you wired up lets say 10 drivers that are 8 ohms each, to be a total of 8 ohms. Surely it would not sound simply like the same driver only 30 dB more sensetive... Does this have to do with the damping power of the amp??? I know this is not the brightest qustion, but I am really curious.

[thylantyr]

Jim's line array doc.
http://www.audiodiycentral.com/resource/pdf/nflawp.pdf

[phreeky82]

well multiplying the number of drivers my a number N does not increase the sensitivity by 3*NdB. the sensitivity actually increases by 3dB every time you double the number of drivers. so having 10 drivers instead of 1 will get you around 9dB more sensitivity. at least that's the theory anyway, but i'm not sure exactly how well this'd work in practice. plus you'd have a hard time getting 10 8ohm drivers to give an 8ohm load in total.

my use of two drivers in one enclosure in my last project (well, my only REAL project to date), each of 87dB/w/m certainly did get an increase in sensitivity up to the 90dB/w/m range.