Vandersteen 2WQ Subs and ARC Power amp

I do hear a thump.  And if I disconnect the main speakers and just listen to the subs, I do have very low level output.  This is beyond subtle though, all the way to nearly dead.  Unless I just need to get used to these....

Another piece of info, there seems to be little difference in output level with or without the crossovers.

4 ohm

The crossovers are X-2B, fixed values no batteries.

This is a long story, so bear with me.  The subs came with WX-2 variable crossovers, with batteries and switches as you suggest.  But, they were single-ended with RCA plugs.  That is a non-starter with my REF 150, which is balanced input only.  So, I got "clever" and tried to skip a step.  I located a dealer who assured me that his pair of 150K fixed value crossovers (marked "X-2 BAL", no switches or batteries) would work well.  I purchased those, and here I am.

So to summarize, I have very faint bass from both subs when I have the main speakers disconnected, with high-bass content recordings and moderate volume settings on the preamp -- nowhere near the volume of the mids and highs from the mains. The forum contributors say the Vandy's are "subtle" but I have to believe thay should be louder. It is very, very faint. Strangely, when I tried without the crossovers, I got the same result.

I tried connecting them using the method suggested by REL for ARC tube amps, red to 8 ohm tap, black to 4 ohm tap (on an ARC tube amp, the 4 ohm tap is ground, I verified this with an ohmmeter). But that didn't improve things. I also tried connected the subs black leads to physical ground, same result.

I tried switching the phase, I tried different speaker cables, nada.

Are these things 100 lb weaklings? I just get very little sound out of them. When I place my ear next to them withe the mains on, I cannot hear or feel bass. I can't even tell they are powered on.  

Some folks have suggested calling Vandersteen, OK, but he's a busy guy and I figure he will just suggest going through the process specified in the manual, using the variable WX-2B's (which, at the moment, I don't have). The first dealer I called yesterday wanted to sell me the top of the line crossovers (X-5??) which are about $ 1400 and can be adjusted. The second dealer I called (the one that sold me the fixed value crossover X-2 BAL) thinks I have the right one now.

The amp has a 300 Kohm input impedance, balanced, and the second dealer assures me the 150K values he sold me are the right ones. He says I could go down to 100K but wouldn't expect a dramatic difference.  
I think my next step will be to do an internet search for some WX-2B variable crossovers and go at this problem that way. If any one has a pair of these they want to loan or sell, let me know.

I did exchange emails with Mr. V yesterday, and along with John R of audio connection the suggestion is to purchase some X5 crossovers so I can adjust the impedance matching and dial in the bass using the procedure that John outlines above (thanks John).  Guess you can add my name to the list of guys who has been initially fooled by these subs.  I will check back again once I have (hopefully) made some progress.

Mr V, BTW, was very skeptical about using the subs without the crossovers.  I did that only at low levels to verify that the subs were working.

After another few days of listening, I am on board with these.  The system just sounds better, some voodoo stuff working here.  Mids are clearer, imaging much sharper, and when there is bass content, it's there, although understated.  Much different from any sub I have heard.  When I get my adjustable crossovers I will have more to report, but my system is sounding really great, better than it's ever been.  

Got my crossovers today, set them to 100K as a start, Q is at 2.  Still evaluating, but all I can say right now is the Rockports are really singing.

I went through the voltmeter based calibration that audioconnection suggested, (thank you) it was spot on with the new crossovers set at 100K.  Man, the system sounds good now.  I have the subs on a wood floor, without the spikes.  Should the spikes be used?    I don't usually like to rave, the sound can always be better, but this is a huge upgrade.

Thanks for the advice on the spikes.  I will install them after I experiment with optimal placement.  I do have some shoes for the floor.  Nice looking systems at Poverty Bay, BTW.  What are the amps in the main system?