Hi Chris and all,
I agree with you, Chris, on the sound quality of Rhapsody; I've not heard any compression artifacts on the admittedly limited number of selections I have on my portable player.
What is often overlooked in many forum discussions about data rates and audible artifacts is the complexity of the musical programming.
As someone who spent days on a professional listening panel auditioning various compression schemes at various data rates in a experimentally extremely well-controlled listening environment, I can state that for most musical content, it was surprising how many of the test selections passed the listening tests at very low data rates. At 192 kbps and higher, it was only with concentrated headphone listening (the phones were high-end electrostatics) and repeated A/B/X comparisons that some instruments sounded flawed: mainly harpsichord, and castinets.
These tests, by the way, were repeated by similar panels of "golden ears" in the U.K. (BBC music producers) and the Australian Broadcasting services and the results were the same.
ON the other hand, there was one test selction, an a cappella version of "Tom's Diner," by Suzanne Vega, that proved to be one of the most critical test signals. At any data rate below 320 kbps, Vega's voice took on a slightly metallic quality that was quite audible and offensive.
Using data rates above 320 kbps, all of the test selections including complex orchestral works by Ravel, with plenty of percussion, were artifact-free.
For those interested, the A/B/X comparisons required the listener to compare uncompressed digital files to various codecs (unnamed) at random and see if we could detect any audible differences. You always had the choice of listening to the headphones or high-end tri-amped professional monitors. Some compression artifacts that were easily detectable with headphone comparisons totally passed with loudspeaker listening.
While I've been amazed at how much excellent music remains untainted by data rates as low as 192 kbps, I never forget the Suzanne Vega example.
Regards,
Alan
