re: post 13
The first part involves verifying whether or not the amplifier meets the published specs of the manufacturer or not.
QSC says the PLX's are tested with both channels driven [stereo mode]http://www.qscaudio.com/products/amps/plx/plx.htm
Your test was done with one channel driven. You didn't follow your own
testing protocols, naughty naughty
The amplifier testing debate rages on, everyone debates on what is
a proper methodology. The problem is, there is too many variables.
Is the rms test method the best? This is akin to a continous test tone.
Is music a continous test tone? Usually not, perhaps on a rare piece of
music you might find a continous test tone. Maybe a 'special effect' found
on movies. Overal, the rms method is my favorite method because it will
torture the amplifier more than those easier tests that inflate the scores.
What if you do an rms test method plus a burst test to mimick music playback in general?
This is good too, I like this a lot.
Test duration? This is so important, yet overlooked by everyone. How
long was test performed for? Was the scores captured after
a 1 second test? 10 seconds? 1 minute? 1 hour? Manufacturers might follow
certain guidelines, but what is a good time period ? Perhaps a better
test is just to note how long the amplifier performed using a certain
ambient temperature as a reference. In other words, you
hook up the amp at a reasonable ambient temp, run the amp to full power,
then write down how long it operated before going into thermal protect
and/or blowing a fuse, or blowing itself up. hehehe
Test Duration Example;
* I tested my PLX at 2kw total.
* You tested the same amp at 4kw total.
* Lets throw in the the Crest 10001, I got 4kw - 5.5kw bridged depending
on if it was a 2 ohm or 4 ohm load.
A person looking at this data will assume the PLX is the same as the Crest.
But the test method and duration tell a bigger story. My PLX test is
both channels driven. Your PLX test is one channel driven, the Crest
is two channels driven. My PLX went into protect mode after 10 seconds,
your PLX had issues very quickly, but the Crest ran all day without going
into thermal protect.
PLX3402 is my favorite 'general purpose' high end amplifier. Excellent for midranges and
tweeters, works great for subwoofers, but expect less power. But if you were to use
an LMS-5400 caliber woofer [or equivalent, or beefier] and needed only one amplifier,
the PLX, PLX2 isn't good enough.