This Does Not Commute
Sydney Morning Herald
Monday January 29, 2001
WITHOUT headphones, portable CD players are next to useless. Sure, you can connect them to a hi-fi or powered speaker system, but then they're no longer portable. The problem is that building loudspeakers into a CD portable is not easy. First, you need speakers that are large enough to reproduce the entire music spectrum, yet tiny enough to fit into a CD portable. Then there's the matter of squeezing in an amplifier powerful enough to drive those speakers. Finally, there's the difficulty of ensuring sufficient power to run the amplifier and spin the disc.
Panasonic seems to have solved all these difficulties with its new SL-PH270 portable. Borrowing from technology used in its telephones and portable DVD players, it has managed to make a CD portable that can be used without headphones. The two speakers built into the lid are powered by a stereo amplifier rated at 90 milliwatts per channel. The efficiency of the amplifier module is so high that a single set of alkaline batteries gives 20 hours of playback when using the speakers. If you use headphones, battery life increases to 24 hours.
One reason for this is the use of audio-compression technology in Panasonic's anti-shock memory. In a conventional CD portable, a lot of battery power is consumed by spinning the CD at the correct speed. In the SL-PH270, with its anti-shock circuitry, the disc motor operates in short bursts, during which time audio signals are retrieved from the disc at high speed, compressed, then stored in a solid-state memory chip. Instead of playing back directly from CD, the music plays back from an integrated circuit. This effectively halves the demand on battery power. The disadvantage is that compressing the music to fit on an IC degrades the quality of the audio signal.
There are other drawbacks to putting speakers into a CD portable. Size and weight are obvious ones the SL-PH270 is by far the biggest CD portable in Panasonic's range, and the second-heaviest. Also, the SL-PH270 can erase the information on a credit card's magnetic strip because of the magnetic field surrounding the speakers.
So what about the sound? Unfortunately it is quite tinny, with a complete lack of deep bass and no treble to speak of. The little that's left sounds brash, strident and quite metallic. There's not much you can do to correct this, since the player's X-BASS and RAIL tone circuits operate only through the headphone socket. While it's possible to improve sound quality by turning off the anti-shock circuitry when listening via headphones or the line output, you can't do this when listening to the speakers switching on the speakers also forces on the anti-shock memory. Distortion is moderate at very low playback levels, but increases dramatically as output is increased.
Panasonic's SL-PH270 is a great idea, but until the sound quality of the speakers is improved and the speaker magnets are shielded, it's unlikely to be a hit with commuters.
Iinfo file
Panasonic SL-PH270 Portable CD Player
Price: $359
Panasonic (Australia) Pty Ltd
1 Garigal Road, Belrose, NSW 2085
13 26 00
paccc@panasonic.com.au
www.panasonic.com.au
© 2001 Sydney Morning Herald