PHILIPS AH489

Commentary

A large 3-way speaker system with natural crossover design.

Natural crossover system is adopted.
In conventional speakers, the split vibration near the crossover point and the distinctive chirping of the tweeter were cut off with a filter. In this method, the filter of each unit has its own frequency characteristic, so the phase is disturbed and the connection between the units is not smooth, causing distortion.
In the natural crossover method, all filters in each unit are removed and the crossover network is limited to one condenser.

A 20 cm cone type woofer is installed in the low range.
The Woofer features a newly developed drive coupling and rim suspension.
This system was developed based on a fundamental review of the electrical design of the voice coil, the geometric method of the cone, and the surface treatment method. The effect of the filter is incorporated into the speaker unit itself, thereby eliminating the control of characteristics by external filters.
In addition to the elaborate design of the edge, damper and diaphragm, the best matching with the enclosure realizes a curve with a good fall.

A 5 cm dome type skoker is installed in the middle area.

A 2.5 cm soft dome type tweeter is installed in the high range.
The resonance peak is dumped by installing a precisely designed resonance absorption chamber on the back of the tweeter on the magnet.
In addition, unlike the sound-absorbing material used in the enclosure, it is made of a material that can cope with changes over time and damping effects.

The enclosure uses a bass reflex system.

Model Rating

Method	3-Way, 3-Speaker, Bass reflex system, Bookshelf Type
Units Used	For low band : 20 cm cone type For Middle Area : 5 cm Dome Type For high-pass : 2.5 cm dome type
Frequency characteristic	38 Hz to 20 kHz
Max Input	110W
Output sound pressure level	88dB/W/m
Crossover frequency	950 Hz, 5 kHz
External dimensions	Width 355x Height 560x Depth 248 mm
Weight	10.5kg