Universal 3-Way Crossover  (400-1299A) Specifications Faxback Doc. # 14371
Network

CROSSOVER FREQUENCIES

The Crossover Frequency is the frequency point midway between two adjacent
filter networks.  At the crossover frequency, equal voltages should go to
each speaker.  For this unit, the stated crossover frequencies are based
on an 8 ohm load.  (Actually, the crossover frequencies may vary due to
constantly changing speaker impedance -- an 8 ohm speaker may vary from 7
to 15 ohms or more at different frequencies.)  Using L-pads and volume
controls can cause changes in the crossover frequency, as can differences
in speaker efficiency levels and the signal distribution of program
material.

Your Crossover Network has four selectable crossover frequencies:  800,
1600, 5,000, and 7,000 Hz.  Each speaker element has two options.  The
dividing networks are carefully designed to provide smooth crossover
between speakers (with standard 6 dB/octave attenuation).  Here are the 8
possible combinations (numbers are in Hz, letters are labels of
terminals.)

      Woofer               Midrange              Tweeter

      800 (A)              800-5000 (C)          5000 (E)
      800 (A)              800-5000 (C)          7000 (F)
      800 (A)             1600-7000 (D)          5000 (E)
      800 (A)             1600-7000 (D)          7000 (F)
     1600 (B)              800-5000 (C)          5000 (E)
     1600 (B)              800-5000 (C)          7000 (F)
     1600 (B)             1600-7000 (D)          5000 (E)
     1600 (B)             1600-7000 (D)          7000 (F)

Experiment a little to find the proper crossover frequency for your
woofer, midrange and tweeter.

SPEAKER SELECTION

To assure proper crossover points, use only 8 ohm speakers.  Use speakers
with adequate frequency range -- otherwise, you may find large "holes"
(frequencies at which the level of the audio output drops) in your speaker
system's response.

How about some ideas for speakers?  Here are two for starters -- you take
it from here:

    An 8" woofer (Radio Shack Catalog Number 40-1006), soft dome midrange
    (40-1281) and a cone dynamic tweeter (Cat. No. 40-1270).  (Suggested
    crossover points:  800/7000).

    A 10" woofer (Cat. No. 40-1331), midrange/tweeter (40-1289) and a
    piezo super-horn (Cat. No. 40-1381).  (Suggested crossover points: 
    800/7000)

Of course, there are many other combinations that might be very pleasing.
Take the time to browse around your local Radio Shack and see the various
combinations you might work up.

SPEAKER POLARITY AND PHASING

Speakers have two terminals with their "polarity" marked.  One is the
"hot" side (marked with a + or red dot).  The other is the common side
(marked with a - or black dot).  When you connect speakers to your
crossover network, connect the common side of your speakers to the -
(negative or common) terminals on the Crossover Network and the hot side
of your speakers to the desired crossover frequency terminal.

You might want to experiment with changing the polarity of any one of the
speakers to see if this enhances the sound of your speaker system.  The
sound from the speakers can add to or cancel each other -- this is known
as phasing.  Incorrect phasing causes a deterioration in sound quality or
a "hole" (absence of sound) in the frequency response of your speaker
system.

CONNECTIONS

Before making connections, mount the Crossover Network so you can
determine correct lead length.  Your Crossover Network can be mounted with
sheet metal or wood screws to the inside of the speaker enclosure.  (Take
care to avoid creating air leaks in the enclosure when installing your
Crossover Network.)

When making connections carefully remove insulation from the ends of the
wires and solder the wires to the appropriate terminals.

Connect the - (minus or unmarked) terminal of each speaker to the -
terminal for that speaker.  Connect the other terminal of each speaker (+
or marked terminal) to the appropriate labeled terminal.

When the wiring leads, cut and strip the wire to the desired length.  Make
sure all wires are connected properly and well soldered.  Be sure no stray
strands of wires (or solder) touch between adjacent terminals.  The input
terminals of the Crossover Network should be connected to a binding post,
terminal strip or jack on the back of the speaker enclosure.  Then connect
wires from your amplifier/receiver to these points (or jack);  be sure to
match polarities between these terminals and your amp/receiver.

NOTE:  This Universal Crossover Network is designed to handle up to 100
       watts of audio power (maximum music power).

(ALL-03/24/95)