Doing an install today, basic 5.1 in family room. Customer told me he had an existing sub he'd like to use. Ok, no problem. I get here and find a vandersteen 2wq sub and wx-2 external crossover. Slight confusion begins as I research online. The crossover has RCA in/out, sub has banana plug speaker inputs. The diagram shows premp>crossover>amp>sub>fronts.

This is a budget job, and I'm using a denon avr 791. He really wanted to use this sub, but imam a little baffled as to how the heck this is going to work. Maybe I'm just slightly retarded today, but this doesn't seem like it's going to work with what I've got here.

Can anyone clarify for me before I waste too much time on this?

And based on what you've written, your customer needs an external amp to drive the sub.

Doesn't this sub have high level inputs and outputs? if it does then L+R speaker out from denon to sub, from sub to speakers. Denon set to large speakers.

retract my statement after researching on the web.
[Link: vandersteen.com]

That crossover is suppose to go between the preamp and power amp. It causes a 6db per octave roll off at 80 hz. If it's the box with switches you use those to match the input impedance of the power amp. If it's just the barrels with RCA ends then it's a fixed value for one value. The way this worked was the crossover removed some bass from the mains and the power amp. The sub is driven by the power amp output and expects this loss of bass. It has a boost to compensate. If you feed the sub a full range signal it will over drive it. If the Denon has pre outs and main ins and you can find the input impedance of it power amp section you can make this work. Otherwise get a normal sub. The Vandersteen is a very sweet musical sub. It's not really a home theater sub.

What is a budget guy doing with a sub like this?

I agree. A very nice sounding - audiophile sub. Did this guy get it at a garage sale??? You might contact a Vandersteen dealer, like Resolution Audio in Seattle, and they might be able to help you out, or call Richard Vandersteen.

Thanks y'all. After doing even more research, then speaking with the customer, I was able to convince him to just get a sub that was more appropriate for what was being done here.

He had the sub and some other gear that he had purchased in the late 90's that was, at the time, pretty high end.

It is a very nice sounding sub. Richard Vandersteen could probably give you some info on how to make it work best in your situation. But it is probably easier to just get a new sub. Plus you get a sale. :)

FYI, they do make a "HT" version of that sub with the "normal" inputs.