# Definitive Technology BP Tower: Is this an amp or crossover issue?



## kain889 (Feb 15, 2014)

Hello all,

First of all this is my first post so bear with me. I have a Definitive Technology BP2002 that has an issue with either the crossover or amp. When the bridges are removed and speaker wire is connected to the high, middle and low posts independently, the "low" (powered sub) has no output but the tweeters and mids are fine. But if I plug in a sub cable into the LFE the sub works as it should. So there is an issue with the low speaker post somewhere. It appears the "low" posts go directly into the amp and then into the sub and skips the crossover. The high and mid posts skip the amp and go into the crossover board. How can the amp work through LFE and not the posts? 









I have taken it to a speaker shop and they have visually inspect it and found nothing. They want to order schematics of the boards before they can do anything and could take at least few weeks. I can mail it into definitive and they said it can take also take a few weeks. Ebay has some BP2002 crossover boards for $25 but I don't know if that would fix it. Any ideas?

Thanks!

I have uploaded a picture of the crossover board. It looks to me like there is discoloration on one of the coils.


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## ajinfla (May 10, 2009)

kain889 said:


> How can the amp work through LFE and not the posts?


The hi level (posts) input is usually less sensitive than the low level (RCA). Have you tried increasing the volume (of your receiver/amp driving the input) significantly? If still no sound, you may have something amiss is the hi>low step down, possibly a faulty zener diode or series of resistors. It's most likely on the amp itself.
Yes, a schematic helps there.
Where do those red/white wires on left go to?

cheers


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## kain889 (Feb 15, 2014)

Thanks for the reply.

I have other powered BP towers for my current mains and they work perfect with my receiver setup. The low response is zero. The red/black from the crossover goes up into the insulation so I cant tell but it doesn't look like it goes to the sub. The sub has its own connections that come directly from the amp. I'm thinking it the amp too. hoping it was the $25 crossover


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## ajinfla (May 10, 2009)

kain889 said:


> The low response is zero.


Once more, that is with the receiver/speaker wires connected to the "Low" binding posts, receiver turned up at least half way, yes?



kain889 said:


> I'm thinking it the amp too.


The amp itself is fine. If yes above, the issue is with the connection between the "Low" posts and the amp. In between, will be a hi>low step down, to get the receiver output down to "line" level, so the amp can process. Most likely a network of resistors, yes, on the amp board somewhere, where the "Low" wires terminate.

You could replace the jumpers between "Mid" and "High", feed either with your speaker wires, then feed the RCA input of your choice with the RCA sub out from receiver (which you may be doing now). Will work just fine.

cheers


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## kain889 (Feb 15, 2014)

Correct, with the speaker wire only connected to the low posts there is zero response regardless of sub volume, level settings or receiver volume. My other towers work perfect in current settings. The sub works great when connected to the LFE input so the amp itself is fine in that regard. The direct connections between the posts and the amp are also good, so it must on the board itself.

I use my powered towers in "Full/Large" setting so they get the entire frequency range and use the bridges to connect the posts. I actually bi-amp my mains with mid/lows bridged and highs on its own amp. The only RCA output I have is LFE for the sub. I will eventually sell my speakers so I would like them to work as designed.

Thanks for your help. I will just have to wait and have it repaired. The speakers are about a decade old. Would you recommend my local speaker repair shop or just send the boards to the manufacturer? Sounds like the turn around time is the same. The speakers are about a decade old.


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