McIntosh Stereotech 3 Service Manual

Page 2

SPECIFICATIONS

CABINET SIZE SHIPPING WEIGHT

26 high TS wide I3-5/l6 Deep 58 lbs.

CONSTRUCTION SYSTEM WEIGHT

#5 pound density non-resonant particle board panels. 9 lbs.
Extra heavy 1 inch front panel. Heavy guage 8 mil
vinyl. Simulated walnut finish. CROSSOVER FREQUENCIES

SPEAKER SIZE 600HZ 8 thZ

Woofer 12 dia. frame size (9-l/2 dia. radiator) IMPEDANCE
Mid-range 5 dia. frame size (3-l/LIH dia. radiator)

Tweeter I-S/M dia. radiator 8Q Nominal

CONTROLS

Mid-range GOOHZ To 3500HZ ~ boost, normal, and cut
Tweeter 3500Hz To 20,000Hz - boost, normal, and cut

POWER HANDLING: Sine wave steady state

75-
POWER
LIMIT ,5_ ___________
IN I |
WATTS Io- -'-___I____l_
I I
I l I I I
I | I I I
o_ 14, I I l l
20 250 600 3k 4k 20k

FREQUENCY IN Hz

Avoid operating the speaker system with sustained sine wave signals at power levels
greater than the indicated limits. Permanent damage may result.

POWER HANDLING: Program Material

High energy peaks normal to orchestral music are easily and faithfully reproduced
by the speaker system. These peaks are of relatively short duration and do not
produce the heating effect caused by sustained tone operation. The Stereotech 3
speaker system will handle up to TOO watts of orchestral program material. Care
must also be taken to use a power amplifier that has an adequate power rating.
If a low power amplifier is used, the loudest passages may be clippedH by the
amplifier. This clipping will cause the speaker to sound distorted. The large
harmonic Content of a badly clipped signal can cause excessive heating and
resulting damage to the high frequency speaker elements.

OUTPUT LEVEL

At T meter in a non-reflecting environment, the system will nominally produce an 89dB sound
pressure level when driven with l watt referred to 80.

LISTENING QUALITY

Smooth response has been achieved by careful design under controlled laboratory conditions.
The performance of the speakers in your listening room may be influenced to some degree by
the room Size, shape, construction, and furnishing. The location of the speakers in the room
will also affect listening quality. The additional features of low distortion and wide dis-
persion will help to provide superior sound in a typical listening environment.

There are two controls at the rear of the system. They provide 2-3dB boost or cut in the
frequency ranges stated in the specifications. For example, a room with heavy furnishings,
drapes, books, and rugs will absorb some of the high frequencies. This may cause the speaker
system to sound Idull". The tweeter control would then be placed in the "+H position to compen-
sate. The controls may also be used to adjust for individual tastes in music.

CONNECTIONS

Use heavy guage wire (#IS AWG or larger) when connecting the speaker s stem to the
power amplifier. The system leads preferably should have less than 0. ohms resistance

and not more than 0.8 ohms resistance. (62 feet of 918 wire has 0.4 ohms resistance.

This corresponds to 3l feet of two conductor wire).

Be sure to observe polarity when connecting the speaker system and power amplifier
-,- - u-I -'n uro-er stereo perspective.