Testing a KEF 103/4

[Thomas Oder]

So I’m looking to buy a set of used KEF 103/4 speakers. I’ve read a lot about the foam on the bass drivers failing and causing the voice coil to rub and fail, and the ferro fluid drying out in the tweeters.

I can handle a basic refoam, and refilling the ferro fluid doesn’t seem too crazy; but, I would prefer to avoid replacing the cones and voice coils as that gets into more money than I’d like to sink into these.

This being said, is there any way to test for major damage without disassembling the speaker? I’m good with a multimeter and have a small mini amp I planned to bring.

 

[slimecity]

I guess ensure the top and bottom terminals are disconnected and meter the ohmage of both.

You can fit your hand thru the port, do that and do a feel test of at least the upper woofer to see if the surround and interior donut is intact.

Run audio into both terminals seperately and listen at the tweeter & midrange for audio, then do the same and listen and feel each woofer.

The real damage to the woofers occurs when the surrounds on the woofers "go", then people run them hard to make the bass louder. I had this happen on mine and the VC's were pretty much melted. Mercifully the tweeters & mids were fine, and I found perfect replacements for all 4 bass drivers.

Great speakers these, I like them better than my 104/2's.

 

[Thomas Oder]

I guess ensure the top and bottom terminals are disconnected and meter the ohmage of both.

You can fit your hand thru the port, do that and do a feel test of at least the upper woofer to see if the surround and interior donut is intact.

Run audio into both terminals seperately and listen at the tweeter & midrange for audio, then do the same and listen and feel each woofer.

The real damage to the woofers occurs when the surrounds on the woofers "go", then people run them hard to make the bass louder. I had this happen on mine and the VC's were pretty much melted. Mercifully the tweeters & mids were fine, and I found perfect replacements for all 4 bass drivers.

Great speakers these, I like them better than my 104/2's.

And in case I can’t test them, will the continuity of the bottom terminals tell me if the voice coils are bad?

 

[slimecity]

And in case I can’t test them, will the continuity of the bottom terminals tell me if the voice coils are bad?

It will be an indication - ie: if they are a dead short or open then you will know there is an issue there.

However they may read OK on the meter but could have been run for a while with decayed surrounds, meaning the VCs could have sustained some damage but read OK on the meter.

You really should run them up with audio as well - its something that every buyer should do with speakers - otherwise take on the risks of not having done so

 

[Thomas Oder]

Got the speakers, woofers and tweeters are blown, accepting offers on any and all parts, let me know if y’all want anything.