(Nousaine) wrote in message news:1KlWa.36390$uu5.4253@sccrnsc04...
(Thomas A) wrote:

....some snip.....

some more snip...

Where the "best scorers"
allowed to repeat the experiments in the main experiment?

This did not appear to be part of the protocol for any but subject analysis was
common.

My experience with blindtests is that results do vary among subjects.
I made a test where the CD players where not level-matched (something
just below 0.5 dB difference). Two persons, including myself, could
verify a difference in blindtest in my home setup (bass-rich music, no
test signals used), whereas two other persons were unable to do it.
Thus a retest with the best-scorers in a test is something which might
be desirable.

Many
questions but they may be relevant when making a meta-analysis.

In addition, have any of the experiments used test signals in the LF
range (around 15-20 Hz) and high-capable subwoofers (120 dB SPL @ 20
Hz)?

No. But there are no commercially available subwoofers that will do 120+ dB at
2 meters in a real room. I've tested dozens and dozens and the only ones with
this capability are custom.

Agree that commercial subs with +120 dB in room is hard to find.


I've just curious since the tests from the Swedish
Audio-Technical Society frequently identifies amplfiers than roll of
in the low end using blind tests.

The typical half power point for my stock of a dozen power amplifiers is 6 Hz.
I've not seen the SATS data though.

Have you ever tested yourself? You have a quite bass-capable system if
I remember correctly. You would need music with very deep and
high-quality bass, or test-tones, and perhaps a setup as described in
the link (a reference amp). The reference amp used by SATS have during
many years has been NAD 208. Other amps rated good is e.g. Rotel
RB1090. I am not sure at the moment which ones that were rated
"not-so-good", but I can look it up. The method they use is a
"before-and-after" test.

http://www.sonicdesign.se/amptest.htm


It might not be said to be an
audible difference since the difference is percieved as a difference
in vibrations in the body. I think I mentioned this before. Also for
testing CD players, have anybody used a sin2 pulse in evaluating
audible differences?

Not that I know of.

Ok. Maybe somebody (Arny?) could present scope pictures of sin2 pulses
of various DACs and CD players? In addition present them as audio
files on the pcabx site? It would be interesting to see whether those
players or DACs with distorted pulses (they do exist...) could be
revealed in a DBT. Especially players with one-bit and true multi-bit.