Speakers
This section describes some things to watch for when buying vintage speakers.
Make sure drivers are original and functional.
Replacing drivers in speakers is always a crap shoot. The crossover (circuit that splits the signal up to send different frequency ranges to different drivers) is tailored to the original drivers. Even replacing a tweeter with a better quality one doesn’t guarantee better performance. Speakers without original drivers have a much lower resale value. I will never buy speakers without original drivers. If you are going to look at a pair of speakers look at a few pictures of them online first so you know what the original drivers look like. It is usually easy to tell.
It is also important to make sure all drivers are functional. Blown tweeters add an extra expense, if they can be fixed. Put your ear to each driver and make sure it makes sound. Note sometimes a tweeter may not have sound if the speaker has level controls and they are dirty. Try playing around with these controls and see if the tweeter cuts back in at all. If you hear it cut in even just a bit the driver is good. Other times there are fuses that could be blown. They are usually on the back by the terminals.
Is refoaming needed?
Many speakers used foam surrounds. This means the ring that holds the woofer cone to the basket is made of foam. This foam has a finite lifetime and it eventually fails resulting in the cone not being held in place. This is a routine fix, but make sure you budget for it. Don’t pay full market value for speakers needing refoaming.
Be wary of speakers that have been refoamed already, as it hasn’t always been done properly. Often poorly fitting generic surrounds have been used, or the voice coil has not been centered properly. You should be able to push the cone in a bit (straight in, not to the side) and not hear it rub. It is hard to describe exactly how to do this, maybe I’ll make a video one day. If you can’t find a place you can push on a woofer cone without hearing it rub then this is not good. This is usually fixable though.
If the speaker cone its self is damaged, it will often be cost prohibitive to replace them. Small damage can be patched, but probably don’t buy speakers with cones that have been kicked in.