Thank you for choosing the Speco
IMP80D impedance matching volume control.
The IMP80D is a unique adjustable designed impedance matching stereo volume control. The impedance matching 2x, 4x, 8x or 16x
switch positions enable the IMP80D to connect up to 16 pairs of 8 ohm speakers or 8 pairs of 4-ohm speakers to a single 8 ohm stable
amplifier and operate them simultaneously without the fear of amplifier overload, eliminating the need for a speaker selector or other imped-
ance matching device.
(
Note:
When using a 4-ohm stable amplifier, you can connect up to
32 pairs of 8 ohm speakers or up to 16 pairs of 4 ohm speakers.)
Wiring and Installation
First determine the minimum operating impedance of the
amplifier to be used in your installation. This information should
be in your amplifier owner’s manual. Using the speaker chart at
left choose the proper position for the impedance matching
switch (see Fig. 1) and put the switch in the correct position.
Fig. 1
Model IMP80D
80 Watt Impedance Matching Volume Control
Recommended Switch Position 8 ohm Stable Amplifier.
Connecting 2 Pairs of 8 ohm Speakers
Connecting 3-4 Pairs of 8 ohm Speakers
Connecting 5-8 Pairs of 8 ohm Speakers
Connecting 9-16 Pairs of 8 ohm Speakers
2X Position
4X Position
8X Position
16X Position
Recommended Switch Position 4 ohm Stable Amplifier.
Connecting 2-4 Pairs of 8 ohm Speakers
Connecting 5-8 Pairs of 8 ohm Speakers
Connecting 9-16 Pairs of 8 ohm Speakers
Connecting 17-32 Pairs of 8 ohm Speakers
2X Position
4X Position
8X Position
16X Position
8 ohm Speaker Chart
Recommended Switch Position 8 ohm Stable Amplifier.
Connecting 2 Pairs of 4 ohm Speakers
Connecting 3-4 Pairs of 4 ohm Speakers
Connecting 5-8 Pairs of 4 ohm Speakers
4X Position
8X Position
16X Position
4 ohm Speaker Chart
Recommended Switch Position 4 ohm Stable Amplifier.
Connecting 2 Pairs of 4 ohm Speakers
Connecting 3-4 Pairs of 4 ohm Speakers
Connecting 5-8 Pairs of 4 ohm Speakers
Connecting 9-16 Pairs of 4 ohm Speakers
2X Position
4X Position
8X Position
16X Position
