[net.audio] Cats in A-B CD tests - and Dogs, too

rfg@hound.UUCP (R.GRANTGES) (04/29/85)

[!-)]

I used to think all this stuff about cats and A-B testing of CD's
was malarkey.
But then I recalled that I had a mobile sound absorber and colorer of
my own - an elderley, plump, Golden Retreiver (female), name of Penney.
Zounds! An uncontrolled variable I had overlooked in A-B tests.
I had carefully removed my digital watch from the room and observed all
the other important caveats for A-B tests (Incredibly precise level
matching, even the latest sine-qua-non from Murray Hill, the absolute
time synch (+-10 milliseconds, 3 sigma)the proper color scheme for the
grill cloth (black for equal absorption at all frequencies), etc.) I had
learned to disconnect the icebox and the furnace and the door bell and the
phone and the battery powered clock in the upstairs bathroom that keeps
going "click, click, click..." I even use #12 AWG cable certified by
Jersey Central Power and Light (because I mostly enjoy Bass from 60 hz down).
In short, I thought I had done everything to insure super scientific
results (I even reinstated my subscription to Consumers Reports magazine
(which someone out there is always calling Consumers Union)).Everything!

Well,  you can imagine my consternation!

And Pennney wouldn't stay put, either. She'd pick herself up and plop 
down at an apparently random (but perhaps cleverly calculated) position
at odd (but perhaps important) moments.

Oh, God!  What did I do to deserve this cruel twist of fate!
Why me!      etc.

So, last weekend I repeated all my tests so far, but this time I drugged the
dog and moved her from place to place, carefully noting all effects on the
experiment. I won't bore you with all of the careful measurements I made
or the tedious calculations. I know you are really just interested in the 
"bottom line."  Well, with only one small exception, I can report a uniform
result that is most gratifying:

It didn't make any difference at all. Probably because Penney's coefficient
of absorption and bass resonant frequency are the same as my well worn wall-
to-all rug.

The single exception was when Penney was lying on my head. In those
instances I was aware of some perturbation of the sound stage and an
increase in background noise level. Since it is relatively easy to avoid these
instances, I conclude that I can ignore Penney's presence in future
A-B tests at home.

Thank Goodness for that!


-- 

"It's the thought, if any, that counts!"  Dick Grantges  hound!rfg