Help needed with faulty speaker!

[harrygrey382]

Hi, my audio knowledge is limited so please be patient...
I've just built cabinets for my KEF CR160f's (fullrange that pre dates UniQ I think).
They were working fine when I tested them. I then took them out to paint the cabs, and when I resinstalled one was dead.
After minor investigations it looks like the little unit on the side of the driver has blown. I don't know what this thing is, it has a capacitor on top (well, a little blue cylinder that says ALCAP), and below this is a plastic case with something pink inside. The +ve wire goes through this unit.
When I bypass all this and go straight to the driver sound comes out perfectly. I could keep it like this but I assume it's there for a reason.
So, if you're still with me I have two questions. Firstly, what is the faulty unit and secondly how do i fix it?
Any help seriously appreciated.

[lndm]

Could it be an inductor (coil) and a capacitor? AKA as a notch filter, designed to flatten a peak in the response. Not critical but desirable all the same.

[harrygrey382]

yeah that was the sort of thing i was thinking. Does that mean it'll sound fine most of the time but somewhere along the frequency range it'll sound nasty? Are they cheap to replace?

[lndm]

There may have been a resistor too. Without them, things might be okay. Do you have access to an equaliser? maybe a friend with one in the car? Kick up 6kHz and see if you like what you hear, this may illustrate the desire for notch filters.

You'll want to find out the values. They won't break the bank to replace but this is an opportunity to upgrade the parts so, you'll spend as much as you can or want too.

[richie00boy]

It sounds like the drive unit has a built in tweeter. By bypassing the crossover as you are, you might have blown the tweeter.

Can you take some pictures of the crossover module and/or trace out the schematic?

[harrygrey382]

Richie, I've tried to do some research on these drivers but looks like there aren't many around. The middle cone/tweeter is called a 'wizzer'. Bring any light?
The photo shows the blown unit, and the terminals on the left are what i short cutted to.
The sound coming out was still fine, could I really have blown a tweeter?

[richie00boy]

LOL a pic showing the cone (and hence drive units contained therein) would have been more useful

If it has a separate tweeter and you have bypassed its crossover and fed music there is a fair chance the tweeter has been blown. Tweeters cannot handle any bass whatsoever.

But if it has a simple whizzer cone then it's a fullrange unit so the network could either be a bass-enhancing network or a notch filter or some other similar device. So it won't have blown anything if you bypass it.