vandersteen Model 5 x-over for 2WQ functions

I have tried to do my homework but have a few questions about the Model 5 crossover for the 2wQ subwoofer.

1. I am interested in getting a Model 5 x-over for my 2wqs to run with my 3a sigs. As I understand it, it comes with either balanced ends or RCA ends ($200 difference) depending on whether my preamp/amp setup uses xlr or rca. (Mine uses RCA) Is this correct?

2. An RCA ending transmits 6db less than an XLR. If you use xlr to rca adapters, you still lose that 6 db. Is that correct?

3. Since the formula for the capacitance needed for an exact 80Hz crossover in a 50K impedence machine includes both crossover Hz and impedence, by varying the impedence setting on the Model 5 crossover, you can vary the exact crossover point since the impedence on the amp is fixed. Is that correct?

Thanks. Information available about this crossover is a bit sketchy.
My system currently mirrors the one you are planning: Vandy 3A Sig's with a pair of 2Wq subs and the Model 5 crossovers (with RCA input jacks). In response to your questions (as best I can answer them):

1. The Model 5 crossover can be purchased with either the XLR or RCA input jacks. Unless you will have a LONG run from your preamp to the crossover (say, 10 feet or more) and an equipment setup that generates quite a bit of interference, there is no particular advantage to the XLR model, and you might as well save the $200.

2. Essentially you are correct -- using the adaptor will negate the signal gain achieved by the balanced inputs. If you plan to use an adaptor, you should simply buy the crossover with the RCA inputs.

3. I think your analysis of the electrical characteristics is correct, but let me add an additional point. By varying the settings on the "DIP" switches on the two crossover boxes, you can vary the impedance, thereby changing the bass response of the subwoofer(s). My Bryston 4B-ST has a nominal input impedance of 50k ohms, but my Vandy dealer recommended that I try the impedance settings both one step above and one step below the one designated for 50k ohms to see which I preferred. Initially, I preferred the impedance setting one step lower than 50k ohms, but after listening to my system for some time, and adjusting the "Q" setting and the sensitivity setting for the 2Wq subs, I finally decided that the 50k ohm setting sounded best in my room. Therefore, I suggest you follow the same procedure while "tweaking" the quality of the sound.

Best regards, and enjoy the new sub(s).
1. Correct. In your case, you should use the RCA version.

2. The 6db lost is only meaningful if your power amp is truly balanced and has both RCA and XLR inputs. If your amp only has RCA input, there is no other way to connect it so you will never have the 6db gain.

3. I don't know if the switches of the Model 5 crossover changes its impedance or not but you set those switches on and off to vary the crossover point for a particular input impedance of your power amp.
I should have mentioned in my first post that you will need to obtain the list of settings for the "DIP" switches when the Model 5 crossover is used with the 3A Sig's / 2Wq combo. The settings that normally come with the Model 5 crossover are intended for just the Model 5, and these are different than the settings for the 3A Sig's. You can obtain the settings for the "DIP" switches directly from Vandersteen, and some Vandy dealers may also have them handy. I can also provide you with the list of settings if the other sources don't pan out.
Thanks so much for the replies. It sure helps to know what you are buying.