I have a biketronics system. When it was installed the line levellers were set to the default position. The left speaker is louder than the right. Will I be able to match the outputs of the speakers by tweaking the right line leveller?

 

advised by many here not to adjust the line levelers, have you double checked everything else?

 

Check the output voltage coming from the head unit (speaker wires that plug into the the BT355) with a 1k test tone at your desired volume to make sure they are the same.If that checks out connect the Lineleveler and check the out put voltage (RCA) to make sure they are also the same within .1 volt or so of each channel.
The easiest way to Check this at the RCA connection is if you have an old rca cord laying around cut it in half and strip the wires back and test. The outter braided wire will be ground and the small either red or white wire will be positive.

If the voltage differs from channel to channel contact Mike at BT.

 

^^^^^And make sure to disconnect the speakers when testing with the test tone.