Blown Speaker question

Blown Speaker question

Postby ebick » Fri Oct 15, 2010 2:26 pm

OK< so I have this old PA and speakers that I don't use much anymore. Someone needed a PA and I dusted it off.....sorta....the speakers have been out in my garage in Florida for 10 years. :shock:

When using the system, there was definate crackling coming from both speakers. When I got them back home, I took them apart a bit to see if the woofers were cracked or damaged. Figured they were because:

the speakers have been out in my garage in Florida for 10 years.


To my surprise, they looked fine. There's a tweeter up top but I can't really see anything with that. So here are my questions:

1) Could dust and crap on the woofer cause this?
2) Is there anyway I can confirm that it's the woofer?
3) I haven't used these in 10 years + so I am not really inclined to spend a bunch of money to repair. Is a woofer basically a woofer? I mean I know that there are different quality ones, but are there other specs that I would need to check other than the size to make sure that a new one that I might be inclined to get would work?

Thanks in advance.
Ed

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Re: Blown Speaker question

Postby tigerstrat » Fri Oct 15, 2010 5:04 pm

1) No

2) Yes, connect the woofer (or the whole cab) to a known working amp and see if you still get the crackling. Conversely, try hooking up a known working speaker (of matching impedance) to the PA amp.

3) If replacing, you would want to replace with one of matching Impedance.
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Re: Blown Speaker question

Postby ebick » Fri Oct 15, 2010 5:46 pm

tigerstrat wrote:3) If replacing, you would want to replace with one of matching Impedance.


So, if I had another woofer with the same impedence, I could hook that in, even though it may not be the same size, just to check?

How do I check what the impedence is? I don't recall seeing anything on the woofer.
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Re: Blown Speaker question

Postby jdsmodulus » Fri Oct 15, 2010 7:47 pm

Volt/OHM meter will put you in the right direction. Simple.
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Re: Blown Speaker question

Postby JonnyBoy » Fri Oct 15, 2010 10:03 pm

Rick turner mentioned old speakers sitting upright for too long, gravity will pull the cone out of whack and you get noisy coil rub. it will crackle and make horrible noise if bad enough. Its time for a recone if thats the problem since the spider and frame aren't holding the speaker perfectly anymore. Try a shop vac with a brush attachment so it wont have to hard of suction to tug at the paper during cleaning.
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Re: Blown Speaker question

Postby tigerstrat » Fri Oct 15, 2010 11:33 pm

Contact cleaner on all your pots, jacks, and switches while you are at it.
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Re: Blown Speaker question

Postby hogan » Sat Oct 16, 2010 7:21 am

ebick wrote:
How do I check what the impedence is? I don't recall seeing anything on the woofer.


use a multimeter set to ohms and put a lead on each of the speaker contacts, +/-. It will read between 6 and 8 ohms on an 8 ohm speaker if it's not blown. Between 3 and 4 ohms on a 4 ohm speaker etc. The point being, that the ohms of a given speaker are seldom dead on to what they're rated to be. This is not cause for concern.
If the voice coil has dropped the speaker will still show proper ohmage but will sound like shit due to rub and will have to be reconed.
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Re: Blown Speaker question

Postby ebick » Sat Oct 16, 2010 8:12 am

Thanks to everyone for the assistance.

OK, so I looked again, with my glasses this time (FUCK! I'm gettin' old!) and I see an 8 Omega, which I assume means 8 Ohm. So.....if it is the woofer, any 15" 8 ohm speaker will work?
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Re: Blown Speaker question

Postby strumminsix » Sat Oct 16, 2010 11:49 am

ebick wrote:Thanks to everyone for the assistance.

OK, so I looked again, with my glasses this time (FUCK! I'm gettin' old!) and I see an 8 Omega, which I assume means 8 Ohm. So.....if it is the woofer, any 15" 8 ohm speaker will work?


Re: omega

Greek letter or word? The Greek letter is the symbol for ohms. And ohms are just ohms, not short for omega. In fact, Omega is also a brand name for speakers.
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Re: Blown Speaker question

Postby ebick » Sat Oct 16, 2010 11:54 am

Greek letter
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