i just installed a second amp to power 2 more subs in my ride. using the line out on the first amp(mono amp) i pluged them to the line in on the 2nd amp(2 channels)on the front input then the front input out to the rear input in. (using the line outputs from the hu only one set available). the front and rear speakers are hooked to the speaker outputs on the head unit. everything worked great with the mono amp by its self now when i fade to the front channel the output to the amps fade out and my front channel is not as loud as it was so i have to fade it to the front channel and at the same time loose some of my amp output in order to balance front and rear component speakers.
vr 300w mono amp--10" sony explode
jenson 400w 4channel bridged 2 channel-2 8" RF subs
2-5 1/2 pioneers
2-6 1/2" sony explodes
sony HU
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juscrusing
where are you getting your signal for the original mono amp? you said you only have one set of preouts to work with, which you are using for your second amp.
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Life moves pretty fast; if you don't stop and look around once in a while; you could miss it.
A y-connector between the out of the first amplifier and the front/rear of the second amplifier may be better than a loop within the same amplifier.
On the fade issue. Set the fade once for your interior speakers. Don't touch it again. This is where your fade is set. Same with all the bass boost and other tone controls.
NOW set the gain on your amplifiers. This should solve your problem.
Any time you make changes that effect the resulting maximum output voltage of your head unit pre-outs you need to readjust the gain!
See this page: https://www.bcae1.com/gaincon2.htm
Read it carefully. Hint. Gain is not a volume control.
If the system still isn't loud enough or balanced enough you do not have a system setup / tweaking issue. You will rather have an overall system design and planning issue.
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New Project: 2003 Pathfinder
i will try some y connectors and see if it solves the problem i kinda had a feeling this might have something to do with it
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juscrusing