Speaker Knackered?

[King Tut]

Not strictly backline but . . . . I got a pair of Peavey PA speakers that I've loaded with Kappa 15 pro's. One of them is putting sound out of the tweeter but not the woofer. I've put a multimeter across the terminals - can't find any voltage but there seems to amps there (sorry I'm not much of electricity buff!). However - whichever way I put the probes on the terminals - the amps are popping the needle against the stop.

I'm assuming that as I'm reading 'something' at the speaker terminals, then it must be the speaker that's gone kaputt? Would that be the considered opinion of the experts out there?

And I'm assuming that if the speaker is shot, there's nothing I can do about it except replace it?

Any thoughts?

Cheers!

[LawrenceH]

[quote name='King Tut' post='962611' date='Sep 20 2010, 07:30 PM']Not strictly backline but . . . . I got a pair of Peavey PA speakers that I've loaded with Kappa 15 pro's. One of them is putting sound out of the tweeter but not the woofer. I've put a multimeter across the terminals - can't find any voltage but there seems to amps there (sorry I'm not much of electricity buff!). However - whichever way I put the probes on the terminals - the amps are popping the needle against the stop.

I'm assuming that as I'm reading 'something' at the speaker terminals, then it must be the speaker that's gone kaputt? Would that be the considered opinion of the experts out there?

And I'm assuming that if the speaker is shot, there's nothing I can do about it except replace it?

Any thoughts?

Cheers![/quote]

You need to check for resistance across the speaker terminals, not voltage! Should read about 5 or 6 ohms. If nothing, then most likely the speaker is toast, unless you can see a break where the wires join the terminals which might be repairable.
If it's fried, you could probably get a recone, depends how much the kappas are versus the cost of reconing.

EDIT: Oh, and do it when the speaker's not plugged into an amp.

Edited September 20, 2010 by LawrenceH

[King Tut]

[quote name='LawrenceH' post='962708' date='Sep 20 2010, 08:44 PM']You need to check for resistance across the speaker terminals, not voltage! Should read about 5 or 6 ohms. If nothing, then most likely the speaker is toast, unless you can see a break where the wires join the terminals which might be repairable.
If it's fried, you could probably get a recone, depends how much the kappas are versus the cost of reconing.

EDIT: Oh, and do it when the speaker's not plugged into an amp.[/quote]

OK Laurence thanks - I checked for resistance and there's nothing. That's the second blooming driver that's gone in this pair - not sure if it's the same actual one - could something be wrong with the crossover or have I just hammered them too much?

The speakers are pretty much redundant to be honest so guess it'll make a nice big paperweight!!

Now - what to do with the other driver? Are these speakers good for bass cabs?

[LawrenceH]

[quote name='King Tut' post='962715' date='Sep 20 2010, 08:50 PM']OK Laurence thanks - I checked for resistance and there's nothing. That's the second blooming driver that's gone in this pair - not sure if it's the same actual one - could something be wrong with the crossover or have I just hammered them too much?

The speakers are pretty much redundant to be honest so guess it'll make a nice big paperweight!!

Now - what to do with the other driver? Are these speakers good for bass cabs?[/quote]

If you're getting repeated problems with blowing drivers you may be pushing them with too much bass. I re-read your original post and see that you say you put the Kappas in there yourself. If the reflex tuning is suited to a speaker with different specs then you may well have a complete mismatch which first means the bass response will be screwed (perhaps forcing you to turn up too much and burn out the voice coil) and second means that probably the speaker isn't being protected from overexcursion at the correct frequencies when you do drive it hard. You can't just mix and match speakers and cabs without tweaking the cabs to suit the drivers, by changing the size/length of the reflex ports.

I think the kappa pros are probably quite good for bass cabs - get something like WinISD and have a play around, or have a look online for reflex cab designs built around them. Eminence may publish some designs themselves.

Apologies if this is a grandma-sucking-eggs type post!

[King Tut]

[quote name='LawrenceH' post='963328' date='Sep 21 2010, 02:12 PM']If you're getting repeated problems with blowing drivers you may be pushing them with too much bass. I re-read your original post and see that you say you put the Kappas in there yourself. If the reflex tuning is suited to a speaker with different specs then you may well have a complete mismatch which first means the bass response will be screwed (perhaps forcing you to turn up too much and burn out the voice coil) and second means that probably the speaker isn't being protected from overexcursion at the correct frequencies when you do drive it hard. You can't just mix and match speakers and cabs without tweaking the cabs to suit the drivers, by changing the size/length of the reflex ports.

I think the kappa pros are probably quite good for bass cabs - get something like WinISD and have a play around, or have a look online for reflex cab designs built around them. Eminence may publish some designs themselves.

Apologies if this is a grandma-sucking-eggs type post![/quote]

Absolutely not Laurence, I realised that different cones suited different cabs well but not to the point that the cones could actually be damaged. I thought it just affected the sound!

Thanks :-)

[Alien]

[quote name='King Tut' post='962715' date='Sep 20 2010, 08:50 PM']OK Laurence thanks - I checked for resistance and there's nothing. That's the second blooming driver that's gone in this pair - not sure if it's the same actual one - could something be wrong with the crossover or have I just hammered them too much?

The speakers are pretty much redundant to be honest so guess it'll make a nice big paperweight!!

Now - what to do with the other driver? Are these speakers good for bass cabs?[/quote]

Just checked it out in WinISD Col, and it seems the Kappa Pro is more suited to midbass operation. It will tune down to about 50Hz, but it'll need a mahoosive box to do it, and it won't handle much more than 100 Watts or so.

No real suggestions as to what you can do with them though - maybe you could give ebay a go if they're surplus to requirements?

A

[King Tut]

[quote name='Alien' post='965015' date='Sep 22 2010, 09:39 PM']Just checked it out in WinISD Col, and it seems the Kappa Pro is more suited to midbass operation. It will tune down to about 50Hz, but it'll need a mahoosive box to do it, and it won't handle much more than 100 Watts or so.

No real suggestions as to what you can do with them though - maybe you could give ebay a go if they're surplus to requirements?

A[/quote]

Thanks Andy - I'm off work sick at the mo so will give you a ring - we can share some coffee or something stronger and discuss options - yippee!