3-way hi-fi speaker diagnostic, please

[Don Moose]

Hey there, fellas -

My $20 Vintage HiFi is having an issue with one of its speakers. It's got 3-way sets of Jensens with a C12-RL as a woofer, a 6"-ish mid and a 2-3" tweet.

There are 2 rectangular metal cans with 4 terminals each with Western Electric stamped into one side and a mess of numbers. One line ends in 2MF, one says 550VDC and 0-55C. This weekend, the left-hand set got much, much weaker than the right.

I tried a different set of speakers, and they were balanced, so it's down to the drivers or crossover ... caps?

What is a sensible, oscilloscope-free way to narrow things further?

Thank you!

[Enzo]

Those caps are oil filled, and I'd bet they were OK. But certainly it takes no scope to swap drivers and caps between cabs to find the bad element. 2uf 550v caps - a little overkill on the voltage. That is not four terminals, that is two terminals and two mounting screws.

Is that the entirety of the crossover? Two caps? I'd be thinking offhand the woofer is dead, dragging down the other drivers. Does its cone move freely?

[Don Moose]

Not sure it's visible in the photos, but all the connections are soldered.
Looks like I'm breaking out the iron tomorrow night. I'll start with the woof.

Who do you go to for recones/recoils of these?
Or do I replace them?

.... hey, I have a contact at Klipsch, and the volume is similar to a Heresy. I wonder if I can get he baffle out without porking the grille.

[Enzo]

I have several places I use ror recones. My top dollar top-notch work place is a nice lady near Detroit. Otherwise I use a local Waldom center nearby.

[Don Moose]

I may privately ask for a referral to Madame Detroit in a bit ... unless you have a top-notch, mid-to-bottom-dollar resource?

It seems to be the midrange - that looked easiest to unsolder (at the speaker side of the cap), so I started there. Instant balance. Then, to confirm, I hooked it back up - still balanced.

I accidentally fixed it, or cooked the cap unsoldering and resoldering, or I have a good-looking but rather resistive solder joint at the cap.

I pulled the midrange driver off the baffle and, with the radio going, I can hear that it's doing _something_. I can't really feel any cone excursion, though. What I can't hear is whether it's doing it as strongly as the mid on the other side.

Without a cap meter, and reluctant to subject these parts to any more heat stress, can you suggest a definitive step? Short the cap so the driver gets full range - on both sides ?

[Enzo]

I doubt you cooked the cap, that cap came from the day of Weller 140 watt solder guns, not 8 watt tiny irons. Likely just a failed solder joint.