woofer - need buying advice

[flavor8]

Hello,

I have a pair of Peavey PA speakers; they are tall cabinets, each with 4 12" speakers and a horn on top. I just got a new (2nd hand) amp, and while testing it managed to blow one of the woofers (actually "blow" is possibly exaggeration; it now makes a buzz on loud bass notes).

So, I'm shopping for a pair of 12" woofers. (The ones I am replacing have model # 12810PA).

Questions:

1) I don't need to replace the other three pairs of speakers, right?
2) The amp is 125W per channel; the woofer started malfunctioning when I had the volume at 5 on the amp (which was pretty damned loud, let me tell you; half the block could hear them ). So, what wattage should I be shooting for?
3) Subwoofer, or woofer? These guys do not have subwoofers in them, and the bass side of things use some enhancement. But is that going to throw off the frequency balance of the whole stack??

Is it safe buying stuff on ebay? E.g., what's wrong with any of these?
http://cgi.ebay.com/Power-Sub-Woofers-12-700W-Pro700_W0QQitemZ5880370969QQcategoryZ3291QQrdZ1QQcmdZViewItem
http://cgi.ebay.com/Heavy-Duty-Sub-Woofers-12-1000W-New-Pro8012_W0QQitemZ5880370139QQcategoryZ3274QQrdZ1QQcmdZViewItem
http://cgi.ebay.com/2-Set-NEW-12-Raw-Woofers-Speakers-for-PA-DJ-Speaker_W0QQitemZ7398553092QQcategoryZ47095QQrdZ1QQcmdZViewItem

As you can tell, I don't know too much about speakers, so any advice here would be much appreciated.

Thanks!

 

[markw]

Speaker systems are made up of three inter-related parts. The speakers themselves, the enclosure (which is designed for a specific speaker), and the crossover. While you might be able to "fit" any old 12" speaker in there, it most likely won't perform as well as the other speakers in there since this box was designed specifically for these speakers.

These are PA speakers, not home speakers designed for home use. They are not designed to plumb the lowest depths of the audio spectrum. T hey are designed to project a specific, limited, frequency range as loud as possible. By trying to "force" them to produce more and deeper bass then they are designed for by feeding them lots of power below their designed lower limit might cause problems, as you may have discovered.

I'd advise you to not bother trying to put a subwoofer in there. Owing to the differences in enclosure requirements it will most likely not preform correctly and, since subs don't generally handle the upper ranges to well, you may lose part of whatever upper bass the original speaker puts out and a goodly portion of the lower midrange

Personally, I would suggest you contact Peavey and try to get an exact replacement, or info on how to select a matching one. That way, you'll have back just what you had before.

And, no, you should not need to replace any other speakers aside from the one that's making the funny noise.

good luck.

 

[flavor8]

Alright, thanks for the advice.

Two new pieces of information:
a) I called Peavey, and they gave me the modern model # (these are relatively old speakers). The woofer is rated at 60W; they didn't have a record of the cabinets; also, they don't know the frequency range.

b) I checked out the other speakers in the box -- they're ALL the same speaker 12810PA, except for the horn. In other words, there are 4x60W speakers, connected in series from the crossover, and then a seperate circuit from the crossover to the horn. (4x60W == 240W output?? Or 60W output??)

I don't think your guess that the cabinets are (in this case) engineered for perfect audio output is correct; they seem primarily to be engineered for durability and ruggedness (metalled corners, carrying handles, etc etc).

So, given all this, what can I do in the way of "hacking" this to produce a better output? Is replacing the crossover a worthwhile exercise?

What if I change out the crossover, so that I have 3 circuits:
1 --> horn for the highs
1 --> 3x60W in series for the mid->low
1 --> ??? for the low

There would be room to add a couple of tweeters while I'm at it, if this would make things more balanced overall. If so, should I buy everything (subwoofers/tweeters) @60W, or would a higher wattage work just as well? And how do I find the crossover that I'd need for this configuration?

Does this sound sane? Or would you just buy Peavey's replacement speakers?

Thanks!

 

[MacManNM]

Alright, thanks for the advice.

Two new pieces of information:
a) I called Peavey, and they gave me the modern model # (these are relatively old speakers). The woofer is rated at 60W; they didn't have a record of the cabinets; also, they don't know the frequency range.

b) I checked out the other speakers in the box -- they're ALL the same speaker 12810PA, except for the horn. In other words, there are 4x60W speakers, connected in series from the crossover, and then a seperate circuit from the crossover to the horn. (4x60W == 240W output?? Or 60W output??)

I don't think your guess that the cabinets are (in this case) engineered for perfect audio output is correct; they seem primarily to be engineered for durability and ruggedness (metalled corners, carrying handles, etc etc).

So, given all this, what can I do in the way of "hacking" this to produce a better output? Is replacing the crossover a worthwhile exercise?

What if I change out the crossover, so that I have 3 circuits:
1 --> horn for the highs
1 --> 3x60W in series for the mid->low
1 --> ??? for the low

There would be room to add a couple of tweeters while I'm at it, if this would make things more balanced overall. If so, should I buy everything (subwoofers/tweeters) @60W, or would a higher wattage work just as well? And how do I find the crossover that I'd need for this configuration?

Does this sound sane? Or would you just buy Peavey's replacement speakers?

Thanks!

They are 60W. If you like the speakers then put the same woofer back in them. If you dont like them, sell them on e-bay or something. It's not worth changing them all around.