Do I need another amp for a sub-woofer?

[Alien Mantis]

GREAT pics and info on that Eclipse amp!

Good job.

That amp is SWEET. Plenty of settings on that sucker. You can make it do exactly what you want it to do.

Set the MONO off on both front and rear.
Set the BASS BOOST to 0 on both front and rear.

Use HPF on both front and rear.

Set the front crossover freq to around 150hz. ( as a close starting point )
Set the rear crossover freq to around 100hz. ( as a close starting point )

Adjust your gains according to your RCA output level on your source.
( Most are around 2-4volts. )

Use that beautiful LINE OUT to connect your Mono Sub amp!

Set your Mono Sub amp crossover LPF to whatever you set your REAR crossover setting to on your 4-channel Eclipse amp.

If it's 100hz, set the mono LPF at 100hz.
( if you choose to try 80hz, then set both at 80hz and see how it sounds )
Whatever you set the REAR and the MONO sub amp LPF at, leave the FRONT crossover set at around 150hz HPF.

TEST IT OUT on your favorite music. See how it all blends together.
Tweak it from there. Small adjustments. One setting at a time.
Tweak... listen carefully..... tweak.... listen carefully.

IF you follow these instructions, you will be close, and have a good baseline.
You might be totally happy with it using these settings.

Let me know how it turns out. Good luck.