Need help setting up sub in a Pro-logic system (1 Viewer)

Ok, I hope I can explain myself clearly here:

I have an older pioneer vsx456 receiver and tower speakers with 12" woofers hooked up to it. I recently got a new sub. I want to hook up the sub so that the sub will play the frequencies in accordance to where I set the LPF on the sub AND so that the main speakers will still play all there normal frequencies. Does this make sense? Im trying to sort out the differences between using speaker level and line level connections. It seems that the line level connection is the way to go. So if I hook up my sub to the sub pre-out on my receiver what exactly will the receiver do? Does it have a LPF in it and what is it set at? The receiver's manual is no help here. Also, once I hook up my sub to the pre-out on the receiver, will the reveiver automatically stop sending my front speakers low signals and redirect them to the sub. Can anyone shed any light on this.

here is a quote from an article I just read:

"Your receiver or pre-amp will have at least rudimentary bass management features if it has a subwoofer output as yours does. Depending on your unit, you may be able to (1) send all bass frequencies below 80 Hz (or another cut-off you set) to the subwoofer, (2) send bass frequencies only to your main speakers (do not use the subwoofer at all), or (3) use both the subwoofer and your main speakers to produce bass frequencies below 80 Hz at the same time. Any receiver or pre-amp will allow you to use option 1 or 2 above. Be sure that if you do have your system set to route all bass to the subwoofer that the subwoofer is set up properly (connected to the proper output, powered on, set at the right volume level). Your receiver or pre-amp may or may not let you send bass signals to both a subwoofer and your left and right main speakers; check the manual that came with your equipment to find out about your particular model."
what I want is (3), is that possible?

If you're hearing the bass from your speakers now, and the receiver doesn't have any kind of speaker setting on it (large or small). Then I'd think that if you hook a sub up to it, it should start working from the get go without you doing anything. As long as you don't do anything to the receiver, it shouldn't do anything to the speaker outputs.

At least that's the way my Pro logic receiver worked, but I didn't have a sub pre-out on mine, so I had to play around with it quite a bit. Before I figured out what I was doing. And it seems that when I finally was happy with the settings, I got a new receiver.

If your sub has it's own LPF, I would hook it up in the TAPE OUT jacks. This way you won't affect your fronts and you can set your sub cut-off where ever you want.

Ahh yes, hooking it up to the tape out jacks will work, but only to a degree. You won't be able to adjust the volume of the sub with the receiver, as the tape out isn't affected by this. Which I found becomes a bit of a hassle.

thanks for the great idea of the tape out. I never would have thought of that. I'll give it a try!

Karl

Ok, the tape out jacks have two rca's (a right and left) and my sub cable only has one rca. Do I need to go buy a Y cable adapter for this??

Karl

Yes, a Y adapter would work. Or you can get another cable, assumming you have a l/r input on your sub.

But remember what I said in the post above, you're going to always have to adjust the volume of the sub via the volume knob on the sub. So if you listen to different volumes at different times of the day, it'll get annoying. I'd only do that as a last option. What happens if you plug yoru sub into the preout for the sub? The fact that the receiver has a sub preout means that it must have some kind of LPF in it.

I'll probably go with a Y-adapter since another sub cable will be like another $80(canadian). I actually already have one Y-adapter which is used for the input hook-ups on the sub. Now it looks like I'll have one sub cable with a y-adapter on both ends of it. Is this ok?

I have no idea what is wrong with my sub-out on the receiver. When I use it the sub volume is really really weak. Like about 10% of the normal volume so something must be wrong? My receiver is a pioneer vsx456 pro-logic unit and it about 5-6 years old.

karl