Wiring PA Cab, need help.

SlayerSlaughter

SlayerSlaughter

New member
I'm currently starting a new project. I got 2 Audio Dynamic Cabs with 2 15" Kapton Voice Coil Subs and 4 4" Silk Fiber Dome Tweeters. I'm going to be using a 600 watt at 4 ohms GTDaudio BM-9200 Head. The cabs say its 1400 watt total power, but not sure the ohms.

How would I wire the subs and tweeters together so I can plug in the 1/4" jack to the back from the pa head? Any ideas or suggestions?
 
Re: Wiring PA Cab, need help.

More info needed. Is this a pair of single 15 cabs, or a pair of 2-15 cabs? Four tweeters per side, or two?

Are the tweeters built into the cabs, or is this all separate pieces?

You're going to need crossovers somewhere - you just can't wire those tweeters to an amp a put full-range into them. If these are assembled, two-way cabs, then the crossovers are probably inside.

We'll need to find out the impedance somehow.

Pics would help.
 
Re: Wiring PA Cab, need help.

4 tweeters per side and 2 15s per side. Top row is tweeters, than a 15" horn, than the 2 subs, one above one below.

All I know is they are audio dynamics 911 special.

I have some pics let me try and upload.

Everything comes out of the cab, nothing is built in.

Already opened them up, everything was a mess, and all I saw was 2 5watt fuses on each side, one for positive one for negative in each cab.
 
Re: Wiring PA Cab, need help.

Got some pics, don't remember if this is how I add images. But here.


This is what they look like.
2011-01-15_14-46-49_734.jpg


2011-01-15_17-35-16_499.jpg
 
Re: Wiring PA Cab, need help.

So to my understanding, I can easily wire the subs up, but once I bring in the tweeters I have to add a crossover? I'm new to wiring up pa cabs and speakers, any good places to read up?
 
Re: Wiring PA Cab, need help.

You need a three-way crossover in each cab. This will divide up the full-range from the amp into three frequency bands: lows to the 15s, mids to the horn, and highs to the tweeters. If they are in there, the crossovers will look like little PC boards with capacitors, coils, and maybe some power resistors on them.

Crossovers are used to prevent frequencies for which a driver is not designed from getting to that driver. Putting highs into a 15 is not going to cause damage, but it's not very efficient, since 15s don't reproduce highs well, if at all. Putting lows into a midrange horn is bad, because they will over-power the driver and blow it. Same thing with putting mids or lows into a tweeter - you'll blow it. Midrange drivers and tweeter are designed for their frequencies only, and will not tolerate lower frequencies. They need to be small to reproduce highs, but by being small, their power-handling capability is low.

The crossover is the traffic cop that makes sure each driver gets only what it needs.

If you don't have the crossovers that came with the cabinets, you are in deep doo-doo. Crossover design is very specailized to a particular cabinet and set of drivers. There are plenty of folks who could design a new one, but you'd need specs on every driver in the cab.
 
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Re: Wiring PA Cab, need help.

Like Rich said.

The X-overs (if there) would be connected to the input jacks on back. It would likely be one big piece with the jack and a bunch of electronic doo-dads attached. From there you'd have three sets of wires going to the woofer, horn and tweeter. That would be a passive X-over arraignment.

Now if the back of your speaker has three jacks labeled something like low, mid and high and no X-over network you need a separate X-over box. That would be an active box (it would plug into an AC line) and it would need to be a three way design. An active X-over box will set you back a few hundred bucks. Plus you need three amps to drive the cabs. One for the low, one for the mid and one for the high.

To confuse you even more some speakers might have a passive X-over but also let you use an separate active X-over instead. Look for an input labeled full range. That would be the passive input...one amp does the whole of the work. In addition you would also see and low, mid and high input...each input getting fed from a separate amp.
 
Re: Wiring PA Cab, need help.

Clear pics of the rear jack panel and any electronics inside the cabs will be helpful.
 
Re: Wiring PA Cab, need help.

You'll need two passive 3 way X-overs. They should cross at about 500hz and 3000-4000hz. Check Carvin or Peavey and the like. I imagine it will set you back 100-200 dollars plus the time to make them fit. Just like speakers X-overs can only handle so many watts. You should be able to get a model that handles 500-800 watts with no problem. Plenty of power to do your dirty work!

But before you even think of that make sure your drivers work! Find a low powered amp and run some easy listening music with the bass rolled off. Test each tweeter with a VERY low volume signal. Turn things up until you hear sound. Just above a whisper is fine. Then do the horns and the woofers.
 
Re: Wiring PA Cab, need help.

If I remember it said it runs at 34hz-19khz? Does this make a difference? That's the only option, to spend hundreds? Damn. The speakers were free though.


Any ideas on somehow making this work??? Somehow?
 
Re: Wiring PA Cab, need help.

Your only option to get the speakers working is to spend some cash. A set of passive X-overs would be the cheapest and probably best solution. The behringer X-over will do you no good without more power amps. The 34-19 spec you gave is just the frequency range of your cabinets. A X-over divides those frequencies up and sends the lows to the woofer, the mids to the horn and the highs to the tweeter.

What are you trying to do with these speakers? If they don't need to handle bass guitar or kick drum I would recommend scraping the idea of salvaging your current units and putting any more bucks into some used or new cabs. Speakers tend to last a LONG time unless abused. I've got a pair of EV cabs that have seen HEAVY use for over a decade an still work like new.
 
Re: Wiring PA Cab, need help.

SlayerSlaughter said:
Will something like this work if I wired everything to the correct 1/4?


http://mobile.musiciansfriend.com/product/reviews?base_pid=182464&page=1&sc=date&so=desc#
Click to expand...

No. That's an ACTIVE crossover for bi-amped or tri-amped systems. In those systems, the crossover comes before the power amps. So, you'd need three power amps, one each for lows, mids, and highs. There are a whole bunch of advatages to this which I won't get into here.

You need a pair of passive three-way crossovers.

Edit: Something like this:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-652

or this:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-654

BTW, Parts Express is highly recommended. Call their tech support folks for pro audio, they might be able to guide you through getting these cabs back together.

Also, +1 on testing all the drivers first. No sense buying crossovers for a bunch of blown speakers. A little MP3 player with a stripped-back headphone cable should be enough to hear if they work, and doesn't risk blowing anything.

And this: Are there drivers on the backs of those fiber glass midrange horns? In the pictures, it kind of looks like there's daylight shining in through the horns. Missing mid drivers would be a bad thing.
 
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Re: Wiring PA Cab, need help.

I know the subs and the tweeters work, I tested them, but than I noticed the horn didn't have anything in it. So now what? This is horrid lol like I said thankfully they were free.
 
Re: Wiring PA Cab, need help.

Oh, I do have a dual power amp, and a pa head. Would that work now if I got that behringer? Or should I find a crossover? And now since we know the horns aren't going to work, is there a way to bypass them or something? Or do I invest in those also?
 
Re: Wiring PA Cab, need help.

If the drivers are missing from the horns, I think it's time to give up. Without the horns, they'll have a huge hole in the midrange right where the vocal ought tt would cross to be. That's assuming you can find a weird 2-way crossover that will cross the 15s into the tweeters (around 3-4kHz).

By the time you buy crossovers and midrange drivers, you're will on your way to a legitimate pair of PA cabs. Those cabs kinda look like bargain-basement disco speakers to me, and I wouldn't pour a lot of money into them.
 
Re: Wiring PA Cab, need help.

So any suggestions on a good pair of pa cabs for a nice price? This sucks, I guess ill break down the speakers and see if I can sell them, or contact the dude and see if he has the parts.
 
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