Kenwood KL-4080 3-way speakers
My primary set of speakers. These vintage Kenwood KL-4080 speakers were in near mint shape when I bought them, and after replacing the capacitors in the passive crossovers, they sound good as new.
I picked up this pair of vintage Kenwood KL-4080 speakers earlier this year for an amazing $60 on Kijiji. They were made some time in the early 70s, and appear to be part of a family including the KL-5080 and KL-7080. The user manual says copyright 1970, so that's my best guess for date of manufacture. They happened to be in a near perfect condition—only some scuffs and minor damage to the wood veneer—but the speaker cones themselves were mint.
Rated for a maximum input of 50 watts, these 3-way speakers have the advanatageous option of tri-amping, so you may power the two tweeters, mid-range, and the woofer all separately with a dedicated crossover—a feature I understand is somewhat rare to see on speakers of this age. Alas, I only have a single receiver (not even capable of bi-amping!), so I'm stuck with the built in passive crossover system. It sounds just fine to me.
The back of each speaker also has a knob to adjust the sound between "normal", "clear" and "soft" settings. The "clear" setting noticibly enhances the high frequencies, while "soft" reduces the mid-range frequencies. I prefer a little more pronounced highs, so I leave them on "clear".
A few months after purchasing them, I decided to take on the job of replacing the capacitors in the passive crossover of each speaker in an attempt to improve the sound. I assumed the originals were most likely dried up as a result of being 30+ years old. I opened up the back to find that it was actually a very unintimidating job, even for myself who has very little soldering experience. Each speaker ended up needing two 22uf 50v capacitors and one 2.2uf 50v capacitor. They also needed to be bi-polar (or non-polar) which I found out is common for speaker crossovers. I found suitable replacements from a local electronics supply shop (costing $12 total) and went to work.
The work went quick and easy without any problems. I re-assembled the speakers and wired them up to give them a test. They sounded great. Before I did the repairs, I could hear a little bit of distortion in some of the higher frequencies, but now it's completely gone.
I've had them running with the new capacitors for several weeks now without any problems, so I guess it's safe to say they're gonna hold up. Success!