Bose 501s - Manual (Page 6)

Crossover Network
The crossover network exactly matches the frequency response of the woofer and tweeters throughout the audio range.
The crossover network effectively extends the high-frequency response of the tweeters. This network consists of two
high-grade film capacitors, two 5% resistors, and an inductor. Computer style wire-wrap connections are used throughout
the crossover network for maximum reliability.
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Power Handling Capability
Recommended Amplifier Power is as follows:
1 . Minimum rms power at 4 ohms — 20 watts
2. Maximum rms power at 4 ohms — 100 watts*
‘For reproducing speech and music, amplifiers exceeding 100 watts may be used if fusing recommendations
are foilowed. (Check Section III 8 3.)
Most sot owners will find amplifiers rated between 35 and 50 watts rms per channei most satisfactory. In fact, very loud
volume is possible with amplifiers rated at SO watts rms per channel. For source material with wide dynamic range, and
extremely loud volume, amplifiers rated over 70 watts rms per channel may be used.
Impedance Rating of the BOSE 501
The impedance of the 501 speaker system is 4 ohms. However, impedance ratings for high fidelity loudspeakers are not
based on universally recognized standards. Bose Corporation chooses a very conservative method for rating impedance.
The actual impedance of the 501 loudspeaker system over the audio frequency range is shown below. As can be seen from
the curve the impedance is always greater than 4 ohms, and over most of the audio range is over 8 ohms. Loudspeakers
with average impedance tower than that of the 501 have been rated by their manufacturers as having a nominal Impedance
of 8 ohms, indicating that their loudspeakers are suitable for use in multiple speaker installations. With high quality
receivers the impedance of the 501 is high enough to permit operating two 501 s in parallel.
20 40 too 200 400 1000
FREQUENCY IN Hz
2000 4000 10,000 20.000
VI. CARE AND MAINTENANCE
The 501 has a walnut vinyl veneer cabinet with a dark brown/random-black, textured grille cloth. The vinyl veneer may be
cleaned by wiping with a soft cloth wetted with water and detergent, or soap. The grille cloth requires no care, although it
may be carefully vacuumed if necessary.
The loudspeaker and crossover elements of the 501 are designed for long, maintenance-free life. Used properly, the 501
should provide you with many years of enjoyment.