Lexicon CP-1 PLUS V2.0 Owner's Manual page 43

Troubleshooting
Problem
Center channel only plays
Muffled sound in L&R channels
Center channel sound muffled
Hum
Balance control doesn't work in Pro
Logic or Stereo Logic
Panorama Calibrate isn't working
Interference with AM, FM, TV or
Cable TV
Page 38
Possible Cause and Solution
Check to see if your HiFi VCR has dropped out of tracking —
readjust.
Your VCR Stereo/Mono/L-R switch may be in the wrong position —
set it to stereo.
When no center channel is used, the rear-panel phantom button must
be pushed IN.
The center channel amp may be connected to the subwoofer jack on
the CP-1 rear panel. Reconnect to Center Output jack.
Finding and eliminating audio hum in a complex installation can be
a very frustrating task. Often, the easiest way to identify the culprit
is to systematically eliminate devices from the audio chain. If Cable
TV is connected to any equipment in the system, start by unplugging
the Cable completely, preferably right at the wall jack. If this elimi-
nates, or greatly reduces the hum, it's worth a call to your Cable
company. A quick fix, assuming your cable is round 75 wire, is to
attach a 75-300 transformer to the end, then attach a 300-75
transformer to that, so that the end is back to a round 75 wire. There
are commercially-available antenna lead isolators which may pro-
vide additional insulation from electrical surges.
If there is no center channel in the system, the center channel output
is routed to both the left and right main outputs. This means the left
speaker reproduces not only the left channel information, but also the
center channel information. If you set the balance all the way over to
the right, the left channel information will be attenuated, but the
center channel will still be present at the left speaker. In other words,
it's supposed to work that way.
Panorama is an interaural crosstalk cancellation program that pro-
duces an anti-phase cancellation signal to the opposite speaker.
When the calibration mode is in LEFT ONLY, there is still cancella-
tion signal coming out of the right speaker. This is a psychoacoustic
phenomenon and LEFT ONLY means the calibration signal should
appear to come only from the left (usually to the left of the speaker.)
The CP-1 does generate minimal amounts of RF energy and is in
compliance with FCC rules. If some interfering noise is noted, move
AM loop and FM "T" type antennas away from the CP-1 and reorient
them as necessary. Use shielded cable for FM and antenna feeds.
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