[net.audio] Steven Bellovin's posting

mohler@druxu.UUCP (MohlerDS) (04/25/85)

I have several suggestions regarding a re-test, any or all might make
for additional data or results.

1. In an A/B blind comparison efforts should be made to not allow
   one listener to influence another (for instannce head nodding etc.).
   What ever means is used to allert the listener that a switch
   Was occured should be non-verbal.
2. Several similar tests have employed not just music but test discs
   with white or pink noise on them. This does nothing for audibility
   using music, however it may yield a clue to audibility of any differences.
3. You might try to borrow as good a headphone as you can for the re-test,
   something like a Stax: pro, lambda, sigma, srx-3 or audio-technica
   ath-9, ath-7 might be appropriate.
4. Listeners should be allowed to sit in the "sweet spot", walk aound
   or use any means they care to employ to try to discerne differences.
5. Try be careful of absolute system phase: i.e. an even number or no
   inversions from the source to the transducer. Audio's equipment
   directory lists some information on individual components.
6. If you can gather them, you might try using players with 16 bit non
   and over-sampled, 14 bit non and over-sampled D-A converter - filter
   topologies.
7. Double wide cats should make up for any meowing with the damping
   increase that a double wide cat provides.

I hope some of these suggestions prove useful.

			David S. Mohler
			AT&T -ISL @ Denver
			!druxu!mohler