Polk TSI tweeter issue - very faint output only ?crossover board problem

JBNZ

Hello,

I've been using the TSI 500 as lounge speakers for a few years with no issues. Recently it appeared that one of the tweeters died on one of the speakers. I really am not sure what caused it as they haven't been tampered with and are only ever played at relatively benign sound levels.

Anyway, I swapped the tweeters on the two speakers to see if it was a problem with the tweeter itself, however both tweeters worked on the working speaker and didn't work on the dud one. I'm thinking there must be some problem in the crossover controller but haven't managed to get far enough into the cabinet to investigate too much further. On close listening to the tweeter when its hooked up in the defective speaker, there is some faint tweeter output, it's just very very quiet.

My questions are:
- What is the most likely cause of this problem?
- Are there resistors of wiring on the cross-over board that can cause this problem?
- What is the best way of finding out the cause of the problem?
- How do I easily get the cross-point seeing as it's wired up still?

Unfortunately I live in NZ so I'm too far to send these to the factory. Any help / advice would be greatly appreciated.

F1nut

I'm not familiar with your speakers, so let's start with this. If they have two sets of binding posts check that the binding post nuts are screwed down tight.

JBNZ

Thanks for your reply,

I've done that and they are screwed down tightly. Any further advice on how I can attempt to investigate the problem further?

EDIT:
I retract me original comment that there seems to be weak output from the tweeter - it appears there is no output.

F1nut

In that case, you could have a loose connection, broken chassis wire or a bad component on the crossover. Swap crossovers to see if the problem follows.

JBNZ

Swapping them would involve a lot of desoldering and resoldering (and looks rather complicated), I'm not sure if I have the skills to do it without doing more damage to the components.

Are replacement cross over boards expensive?

[Deleted User]

No soldering will be necessary. The wires disconnect from each of the tweeters and drivers and the complete crossover pulls away from the rear of the enclosure with all the wires attached. There may be an internal sub-enclosure with the two lower drivers being separated from the upper section of the enclosure. If so, there will be a gummy material on the adjoining baffle that once you remove the wires can pass through. You might want to use masking tape on each bundle of wires with some kind of placement indicator to make rewiring the speaker easier.
There should be some damping material inside the cabinet, note how it is positioned before removing so you can replace it in the same position. As mentioned elsewhere Polk's CS guys can help with replacement crossovers, if necessary.

JBNZ

Good point, I'll try and do that this weekend.

BTW do you have any tips for disconnecting the wires from the drivers? I struggled for a bit when trying to separate them from the tweeter, is there a trick to it?

F1nut

They have little tabs in the middle that you have to depress.