Buying a sub - split or not to split the preout

[dalys1234]

i have been looking at the Fusion CS-AT1100 Active 10" Tube Enclosure which is an active sub.
I recently bought and installed myself a 2 pre-out head deck, 4 channel amp hooked up to 4 speakers. i am not quite happy with the sound so am looking at subs.
i was thinking about an active sub because it is easy to install and i can get one for a good price.
BUT if i buy a sub (active or not) i will have to split one of the pre outs for the 4 speakers so i can use the second pre-out for the sub.
OR i could just use 2 speakers in the front running through the 4 channel amp (which i think would be a waste of the amp) but means i would not have to split the preout

Thanks

[seankane]

Make sure to check on your amp for an input switch. Some 4 channel amps have a 4/2 input. In 4 mode both sets of RCA plugs are required. In 2 mode only one set will run the whole amp. Not all amps have this but some do, and its worth a check. In 2 mode depending on your amp the front channel RCA's run the whole amp. If your amp has this capability that would free up a set of RCA plugs for the sub.

Someone out there correct me if I am wrong but splitting the signal through "Y" adapters would seem to cut your signal voltage down to your amps, but I could be wrong.

[oldguyz]

Originally Posted by seankane

Make sure to check on your amp for an input switch. Some 4 channel amps have a 4/2 input. In 4 mode both sets of RCA plugs are required. In 2 mode only one set will run the whole amp. Not all amps have this but some do, and its worth a check. In 2 mode depending on your amp the front channel RCA's run the whole amp. If your amp has this capability that would free up a set of RCA plugs for the sub.

Thanks, seankane! You were right on for me. I sent an email to the manufacturer and their answer didn't help me. I posted on the manufacturer's forum and got no help. I searched many online forums and could not find an answer. Then I was planning on splitting the preouts to solve my problem and that is when I came across your response. I originally installed a 4 channel amp for my front and rears. Decided to add a couple of subs so I got a mono amp which has RCAs in and out. It supposedly passes the full signal through the outs to chain other amps but when I did that, my rears only got bass, not matter what position I set the switches to. I could only get good sound when I switched my 4 channel amp to 2 channel mode, but then I couldn't blast it because it would go in to protection mode. After reading your response, I then knew that the 2 channel switch was on the input side of the amp, not the output as I previously thought. Thank you. I went out and disconnected the RCAs coming from the sub amp to the 4 channel amp and everything is fine now. Appreciate it.

[metalshredder]

What is the model number of your amp? I could look it up and tell you better what might work. Also what head unit do you have?