Bose 501s - Manual (Page 5)

2. Proper Phasing of Your 501s
It is important that the connections to your speaker and receiver or amplifier be the same for both channels
so that both speakers are in phase. (Incorrect phasing will reduce the bass output of the speakers.) The
two terminals on the back of the 501 are marked 4 OHMS and COM. Start with your left 501, Place
it on the left side of the room. Connect this speaker to the left channel speaker output terminals of
your receiver or amplifier. (If there is a choice of impedances on the amplifier output, use the terminal
marked "4 OHMS." Connect the "COM" terminal of the left speaker to the "0"or "GROUND" terminal
of the left channel output. Connect the "4 OHM" terminal of the speaker to the "PLUS" or "4 OHM"
terminal of the left channel amplifier output. Connect the right speaker in exactly the same manner.
(Check your connections carefully by observing the rib marking on the zipcord wire, allowing you to
determine which wire is connected to which terminal), if stranded wire is used, be certain that the loose
strands are not accidentally touching the other terminal of the amplifier, causing possible damage or a short
circuit. Also make certain that all amplifier and speaker terminals are securely tightened.
3. Fusing Your 501s
Any loudspeaker is subject to damage if the amplifier powering it should fail. Using a fuse with each
speaker will minimize the possibility of serious damage to your speakers. Use a BUSS AGC-3 Fuse for
amplifiers rated less than 50 watts rms or a MDL-2 Fuse for amplifiers rated over 50 watts rms. The fuse
should be conneaed in series with either of the two wires in the cable to each speaker. A fuse holder,
such as a BUSS'3383*1 or a LITTELFUSE 356001, may be used for convenience.
IV. IN CASE OF DIFFICULTY
If you suspect a problem with one of your 501$, it's worth a few minutes of your time to determine whether the defect
is in the 501 or in some other portion of your high fidelity system.
If one speaker sounds defective, switch the left and right speaker cables where they are connected to your amplifier or
receiver. If the trouble moves to the other speaker, the defect is not in the speaker or the speaker wiring.
If the trouble appears in both speakers, connect your 501s to another amplifying source or high fidelity system that is
operating properly. If the trouble is not apparent, the difficulty is not with the speakers.
If the trouble persists in one or both speakers, contact your dealer. He will verify the defect, and will arrange
for service either at our Factory-Authorized Service Agency or by the BOSE Factory. If it becomes necessary for you
to return your unit to the faaory, he can obtain a Return Authorization Number which must appear on the outside
of the carton when the unit is returned to the Factory. BOSE Corporation will make every effort to remedy any
problem within the terms of the warranty at minimum inconvenience to you. (See Section Vll.)
V. TECHNICAL INFORMATION
Speaker Complement
Woofer; A 10-inch, long-excursion woofer with a specially designed high-temperature one-inch long voice coil, long-
throw foam surround and spider. Using a high-energy ceramic magnet, this woofer is capable of extremely high power
output at low frequencies. In addition, the cone and dust cap are designed for exceptionally smooth frequency response
throughout the middle-frequency range.
Tweeter: Two 3-1/2-inch, high-sensitivity tweeters, with large ceramic magnets to minimize power dissipation in each
speaker. Additionally, they are designed for very smooth and extended high-frequency response. These speakers are
carefully matched to the woofer and crossover network.