ellisos020 believes that since there is a sonic compromise when listening to xm (or other source) through an fm modulator in a car, then fm must not be capable of high quality sound. Now that's logical thinkin'! Because a 30 dollar fm modulator on sale at Wal Mart or Best Buy sounds bad, then the 30,000 dollar transmitter in use at the local NPR affiliate must not be capable of high quality sound. GEEZ! Talk about apples and oranges!
Perhaps I shouldn't get too upset. I've had an opportunity that most people haven't. Since I've worked in radio for nearly 30 years, I've been able on many occaions to directly compare the sound of a recording playing straight "through the board" from cd, lp, or dat with the signal having been processed, broadcast on fm (or am), and received through the "modulation monitor"...an extraordinarily high quality tuner locked onto the station's frequency, with both an audible output, and meters to measure modulation, frequency deviation, separation, channel balance, etc. Not only does fm sound REMARKABLY clean this way, often indistinguishable from the source recording (with audio processing switched out of the circuit), I think most people would be shocked at how good AM sounds!
Even with the audio processing switched in the circuit, if it's been set by an engineer who knows what he's doing, the major difference between the direct sound source and that having been broadcast on fm is a slight softening of transients caused by the peak limiter "limiting" large transient peaks to allow for higher average modulation, thus giving the station more "dial presence" (loudness), and (by raising average audio higher above the noise level, particularly in fringe areas), extending effective coverage.
OF COURSE FM IS A HIGH QUALITY MEDIUM! Prior to the addition of the potentially noisy Zenith system for fm stereo in the early 60s, fm was THE highest quality audio medium available to the public. Certainly FAR higher in quality than lp or tape recordings! The ultimate in high fidelity was a live band or orchestra playing live on an fm station! Frequency response extended to 20khz or beyond, with distortion and noise levels within striking distance of today's best digital sources!
The addition of stereo DID compromise ultimate fidelity potential, but far less than many believe! Get your hands on a TRULY high quality fm tuner! One of the "super tuners" from the 70s and early 80s would be an excellent investment (from companies such as Pioneer, Kenwood, Sansui, or Yamaha). These can be found on Ebay for well under a hundred bucks, often around 50! Or choose a new fm radio such as the new PAL from Tivoli Audio. Think fm isn't high fidelity? Plug in your headphones, and tune your "PAL" (Portable Audio Laboratory) to your favorite public radio playing classical, acoustic jazz, folk, or any other kind of acoustic music. The PAL is a remarkable value at 129.95! (
www.tivoli.com)