Testing A Speaker Driver

[spinner 0]

I was going through my store room recently and came across an Eminence Kilomax 15" speaker in its original box.

 

I couldn't think what it was doing there and then I remembered.

 

It had been in one of the two bass bins I used for my daughter's 18th birthday party after which it

didn't work and had been in store for over 3 years!

 

Before it failed it had been fed a signal well within its capabilities from a Studiomaster 1600D amp.

 

The cone wasn't damaged and everything looked as it should.

 

So can anyone tell me what else I can test/should check to find out the problem?

Edited November 4, 2008 by spinner

[Bouncy Dancefloor 0]

check the tails that lead from the connections into the cone, they can sometimes become separated

 

 

[norty303 0]

Try connecting a 9v (PP3?) battery across the terminals and see if the cone moves. If it doesn't and the tinsel leads are still intact and connected then it's likely the voice coil has become damaged.

 

At this point i'd cut the cone out to see what went wrong if it was me...

 

Probably worth reconing considering the price of a new driver, although there are better out there for the money.....

[superstardeejay 0]

When I'm testing an unknown driver, the first step is a DC resistance check using a multimeter..it will be approximately the impedance give or take half an ohm or so.

 

Then gently push the cone in and out using spread fingers from both hands held flatly (so as not to poke through!!!) and make sure the cone doesnt scrape or rasp.

 

Then I'd hook it up to an amp and play some music through it starting quietly, any signs of distortion just turn off. If you think the speaker may have damaged an amp in the past, just connect it in series with a 24V lorry brake lamp acting as a limiter and you'll be safe.

 

 

 

 

[spinner 0]

When I'm testing an unknown driver, the first step is a DC resistance check using a multimeter..it will be approximately the impedance give or take half an ohm or so.

 

Then gently push the cone in and out using spread fingers from both hands held flatly (so as not to poke through!!!) and make sure the cone doesnt scrape or rasp.

 

Then I'd hook it up to an amp and play some music through it starting quietly, any signs of distortion just turn off. If you think the speaker may have damaged an amp in the past, just connect it in series with a 24V lorry brake lamp acting as a limiter and you'll be safe.

 

 

Thanks. I did number 3 originally and got nothing.

 

I'll try number one and two and see what happens.

[superstardeejay 0]

You should do it in the order I said or risk blowing up your amp if the coil's short (burnt out!).

 

 

[spinner 0]

You should do it in the order I said or risk blowing up your amp if the coil's short (burnt out!).

 

 

I will, when I can get round to it.

 

If the coil is burnt out what is likely to have caused it, bearing in mind the other one (long since sold) connected to the same amp, was unaffected?

[Andy Westcott 0]

As you've already connected it to an amp and got nothing, I'd say the motor is open-circuit somewhere - even a badly burned coil would probably react in some way, and it would take a whopping degree of overload to actually melt the coil and break the circuit. (My wife managed it once, but that's another story...)

 

Sounds more like a manufacturing fault to me rather than overloading - these higher powered drivers are pretty robust. Norty suggested looking at the flexible leads running from the coil to the connection terminals. As these are exposed, it represents a weak point.