[DSK]

You might find that you like having bass both in the subs and in the main speakers.  I ran my system for a while this way and didn't mind it.  The benefit to sending low bass to the subs (and not to the main speakers) is that distortion caused by main speakers can be eliminated.  However, if there's not much distortion from the main speakers, then it helps to spread the bass around the room, which can help to even out room modes that are activated. The detriment is that it can get a bit hard to phase align everything.

Bob, don't the HPF's cause phasing changes of their own?

[ctviggen]

In my particular system, I split the signal to go to both two subs (stereo) and to the main speakers.  I didn't use a high pass filter.  (At least in that iteration -- I'm still trying to redo the system to use a HPF.)  So, all I had to worry about was trying to get the phase between the subs and the bass driver of the speakers correct.  I spent some time adjusting phase of the subs, and it's a pain in the butt to do by yourself.  I need to have my wife help me. 

[gitarretyp]

Bob, don't the HPF's cause phasing changes of their own?

Yes, and here's a nice little java applet to calculate phase shift for first order networks. Adding a crossover will make phase alignment more difficult.

[randytsuch]

Yep.. I think I will go for Gary's solution at first..

It just seems to me that randytsuch (#5) misunderstood my post #2 as I at first wanted to split the stereo signal but needed to know if it affected the sound quality..

As a reply to Occam in #10
Are you using the SB for volume control?  Yep
What specific amp are you using? DIY icepower build into the speakers
What speakers? DIY, http://softica.dk/dk/webPages/passage/passage20_0.htm
What interconnects presently, or what would you prefer to use? Analog
Can you solder and make a small diy project, if you want to avoid the use of splitters? Yep. No problem. Just wanted a simple solution now for getting this up and running. I might try out another setup later.

Thanks for the input.

~sn1009

Yeah, I did misunderstand your question.  Sorry if I caused you ridicule

I thought you were trying to combine signals, to feed a mono signal to your sub.  Then I read it again, and figured you just wanted to split them.

Again, sorry about that

Randy