Stewart Pinkerton wrote in message news:2Oxic.21007$_L6.1353991@attbi_s53...
On 24 Apr 2004 15:24:40 GMT, (Thomas A)
wrote:

However, if I would do the challenge, I would seek up two amps with
different HP filtering in the bass range (if such exist among car
amps; there is nothing in the rules what I can see about the built in
normal HP filtering of amps to avoid DC). Play the music to the film
"Fifth Element" and use speakers with e.g. 10 x 15 inch woofers in a
closed box system in a sealed small room. Play the song where there is
a sweep going down to 5 Hz at loud volumes and try to "feel" the
difference in the body. 1.5-3 dB difference in the 7-15 Hz region may
be percieved differently. Challenge rules, see

http://groups.google.com/groups?q=%2...cox.net&rnum=6

Unfortunately, you failed to notice that in test condition no. 5,
Richard is allowed to EQ the amps to have the same frequency response,
negating this kind of cheap shot.

He states:

"The sole purpose of my
amplifier challenge is to determine if the differences in amplifiers
are audible."

A previous post of mine disapperad, but there are resports of tactile
differences of vibrations in the 7-15 Hz region in non-manipulated
amps driven within spec using a before/after test. This was found for
e.g. Halcro dm68 from the normal input (-1 dB at approx 15 Hz)
published in Swedish MoLT 2002, issue 3, using music from the "Fifth
element" contaning information down to 5 Hz (14/14 correct in blind
tests). The flat DC-coupled input did not reveal any differences.

So I tend to agree with another poster, the test is quite meaningless.
If you want to buy an amp, you should not have to correct its
frequency response due to its flaws. Better to buy an amp with no
flaws.

Thomas