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Help: power problem with Vandersteen 2Wq subs

I have a strange situation that I can't figure out, and thought maybe I'd get some help from other A-gon members. I have a pair of Vandersteen 2Wq subwoofers (great subs) which work fine. Earlier this week, I re-arranged my system a bit, and needed to plug the subs into a different power outlet than before. For some reason, they wouldn't operate when plugged into the new outlets. When first plugged in, both subs had the usual turn-on "thump", but then nothing happened, as if the sub's internal amp turned off. This happened with both subs.

After I re-arranged the subs' location, I plugged them into the Monster Power HTS2000 line conditioners that I use for all the rest of my audio/HT system. The sockets that I used on the HTS2000 work fine -- any other piece of equipment draws power with no problem. I then tried plugging the subs into an adjoining wall outlet (which may not be grounded -- not sure), but the subs still didn't work. I got the turn-on thump, and then nothing... So, I went through a series of diagnostic measures, and eliminated every cause I could think of -- I even checked the connections at the power amp just to be sure no wiring had gotten jiggled loose. I also checked the prongs on the plugs of the power cords to be sure that they were straight and making good contact inside the outlet sockets.

At this point, I moved both subs back to their original setup and plugged them back into their original wall outlet. This solved the problem, and they worked fine, just like before I re-arranged them. I'm thoroughly baffled. I looked through the troubleshooting section of the user's manual, and there is nothing that explains this anomaly.

I am going to call Vandersteen to get their input, but I was wondering if anyone who owns Vandy 2Wq subs has experienced a similar problem. The only thing I can think of that might cause this problem is some aspect of the circuit design for the internal amp that perhaps has to see a certain grounding arrangement to operate.

Any thoughts and comments are appreciated. I'd like to be able to re-configure my speaker setup, but can't do that given this odd problem.

Thanks -- Scott C
sdcampbell
sdcampbell OP
2,136 posts
 
Zorpman: Yeah, checked that too. The Vandy subs don't actually need a "turn on" audio current to fire up, like some subs that go into an idle mode when they aren't getting an audio signal. The interconnects that plug into the subs were "on".

The conundrum continues...
sdcampbell OP
2,136 posts
 
I decided to call Richard Vandersteen this afternoon, and he said that the problem I described is a new one to him -- never heard of anything similar. After some discussion, Richard said that the only explanation that seems plausible to him is a reversed ground in a wiring run in my house. He said that it is possible for a reversed ground to cause a phase cancellation between the transformer of my main amp and the internal amp in the subwoofer. His suggestion was get an electrician to trace the grounds in the house wiring, but in the meantime he realized my only option is to run the subwoofers on the original circuit where they worked fine. The other thing Richard suggested is to run ALL of my equipment off one circuit, rather than connecting the different pieces of gear to several different outlets. With everything on one KNOWN grounded circuit, everything will be protected. He also suggested plugging the subwoofer amps in first, then the other power amps, and then the rest of the gear, so as to get the main turn-on surges finished and stabilized before powering the other gear.

Obviously, I have some exploring to do with my house wiring. I've put in Hubbell grade outlets, etc., but the house is 50 years old and may not be be wired properly.

Thanks for any and all advice.
zorpman
87 posts
 
Get a cheap 3 LED outlet analyser in the electrical section. For @$8.00 USD it will tell you the status (reversed polarity, no ground, etc.) of every outlet you have.
sdcampbell OP
2,136 posts
 
Thanks to everyone for your input. I will pursue Zorpman's idea and get an outlet analyzer to find out what is going on with polarity and ground, and then consult an electrician.
swampwalker's avatar
swampwalker
5,138 posts
 
Scott- after you check the outlets with the analyzer, it may be as simple as reversing the connections from the wall wiring to some of the receptacles. Also with 50 year old wiring, unlikely that you have grounded outlets unless they were modified later.
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