Unimpressive sound from Tannoy B475 subwoofer?


I impulse bought two tannoy b475 18" pro subwoofers over the weekend for what seemed like a good price.

Unfortunately, I can't seem to manage to get decent sound out of them. Did I just make a mistake and buy subs that don't perform well, or is there possibly a problem with my setup?

They want 400w-800w. I've tried a crown 800 (bridged) and a jbl synthesis 400 (bridged) and neither made them sound all that hot. The sub signal is coming from a pioneer elite, which isn't the best setup, but seems to drive my mb quart vera sub fairly nicely. The tannoy sounds much worse.

One possible issue: the crown needs a + and - for input, but the sub output is RCA, so I cut the end off a RCA cable and got the +/- from that. Perhaps bad idea?
dddrrreee
The transformer looks like the right one.
An SMS-1 could be picked up used for around 400.00. It would help greatly.
I see a ~$400 velodyne sms-1 on amazon -- is that what you were referring to? Or do you mean JBL sms-1?

The tannoy has a tx2 system controller that came with it. Am ordering connectors to see if that makes any difference.
Argh. Sorry, missed the velo reference above somehow. Got it.

Thanks for all the suggestions!
Thanks Rwwear! Looks like I just missed the listing.

Unrelated to the original topic: I wish the audiogon software would send an email notification for subscribed threads.