Performance
When we did our first MP3 player evaluation a few issues back, we discovered that achieving meaningful test results from one of these units is a bit like getting blood from a turnip. I’ve run our standard battery of test signals through several MP3 encoders with varying degrees of success. Even when the conversion process leaves my test signals relatively unscathed, the resulting measurements from the playback device look pretty bad when compared to even a mediocre CD player. This is primarily due to the fact the MP3 data compression scheme is based on human perception, which is rather easily fooled.
Combining a perception-based audio compression scheme with something that moves and changes like the Internet is bound to produce new products at an astounding rate. With all other music delivery systems, you buy a piece of software that is specifically designed to work with a single type of playback device. With MP3, the file format is about the only sure thing; the list of potential encoders and playback devices is quite long and grows on a daily basis. Even if we did publish specs, the numbers would only be valid if you used the same encoding software that we used to convert the test signals. This whole thing is a mess from a measurement standpoint.

Given these considerations, we determined that the most reasonable approach was to subject all MP3 players to an A/B test. For this test I used our reference studio monitor system for playback and compared the MP3.8 to a high-quality home CD player. Three of the more-demanding tracks from the most recent IASCA competition CD were converted to MP3 through one of the many available encoders and transferred to the MMC. While I’ll never claim to have the world’s best set of ears, I did perform exactly this type of A/B test three or four times a day for a number of years in the CD and cassette manufacturing industry. This boy ain’t easily fooled.

Overall, sound quality from the MP3.8 was quite good. Tonally and dynamically, it’s very close to the original CD. The only area in which I could discern a real difference was in the noise floor. During instances of very low level, such as the beginning of a soft classical track, the MP3.8 exhibited a touch of noise that wasn’t present in the original recording. I can’t imagine that this small amount of noise is going to be noticeable with the music that most people listen to. Even with low-level program material, you’d never be able to hear the noise in a moving vehicle.

User Evaluation
User interface for the MP3.8 system is required in two places: in your car and on your computer. The in-car part is easy; the MMC changer interfaces through most RFX series head units and behaves exactly like a CD changer. The changer is exceptionally small and could be installed practically anywhere.

The computer interface side of things was the part of this system that worried me from the outset. When anything works well, I don’t like to mess with it, therefore, I hate installing new software on my computer. As it turns out, my fears were completely unwarranted. This is perhaps the most unobtrusive software installation that I’ve ever performed. The only additions appear to be a single device driver for the downloader and a small application that provides a MMC status window that’s about the size of a desktop icon. For handling the MP3 files, Rockford wisely went with something that’s already available and working on any Win95/98 system — Windows Explorer. The downloader appears in Explorer as a removable hard drive and behaves accordingly. Point, click, drag, and drop — I love it.