Level Matching - TAD ET-703a Instruction Manual

The key to configuring a multi-way system is
to select speakers of appropriate sound quality
and output sound pressure level, and to correctly
divide and adjust the frequency bands and levels
of each speaker.
• The output sound pressure level of the ET-703a
is 107 dB/W, which is a high efficiency level, so
select speakers with relatively high levels for
the midrange and woofers (e.g., speakers with
an output sound pressure level of 95 dB/W or
higher).
For example, if the woofer is at 97 dB/W,
the theoretical level can be matched by
attenuating the woofer by 107-97=10(dB) using
a level control.
• If a passive filter is used for attenuation, a
voltage divider such as L-Pad is required.
The larger the attenuation, the more heat is
generated by the resistor, so use a resistor with
a high power rating.
10

LEVEL MATCHING

Example of L-Pad attenuator with 8 Ω impedance