Darryl Miyaguchi wrote in message ...

For what it's worth, I have performed enough ABX testing to convince
myself that it's possible for me to detect volume differences 0.5 dB
using music, so I doubt very highly that a group test would fail to
show that 1.75 dB differences on a variety of different music are not
audible using a DBT.

I think it's generally acknowledged that such differences are audible.
Mirabel seems to be arguing that, given what he claims is a 1.75 dB
difference, every member of Greenhill's panel should have scored at
or near perfection, and the fact that they didn't bespeaks some flaw
in Greenhill's methodology.

I'm not yet convinced that there really was a 1.75 dB difference here,
however. What Greenhill says about the 24-gauge cable is:

"Its 1.8-ohm resistance resulted in a 1.76-dB insertion loss with an
8-ohm resistive load."

How does this translate to the specific test in question, which used a
recording of a male a cappella chorus (where the fundamental tones, at
least, range from 60 to less than 1000 Hz)?

Greenhill only level-matched a single pink noise test, and the only
times he discusses levels in the article appear to be in reference to
pink noise tests. E.g.:

"A 1- to 2-dB decrease in sound level was measured for the 24-gauge
wire during the pink noise listening tests."

I freely admit that I'm out of my element here, but I don't think we
can automatically assume that there was a similar difference in SPL
when listening to the choral music.

Hopefully, someone with some technical expertise can shed some further
light on this.

bob