Need help diagnosing\replacing hf horn in PA cabinets

[kahlerwillits]

Hey TB!

The other day I bought a pair of Crate ps15h speakers of CL for a great deal ($50 plus a pair of stands). The only issue is that the horns don't seem to work. I bought them anyways because I believe this is a common problem and a simple fix.... but after scouring the internet for a couple hours and opening up the cab and looking at everything.... I realized I have no idea what I am doing.

I know it could be faulty wiring, but these cabs seemed pretty well kept and I know it is common for cheaper speakers to have their hf drivers fail. I have included pics of the parts I looked at.

What I want to know is what replacement parts I need and I how I go about replacing it. I am not trying to put much money into these at all but when it is all said and done, I want a pair for fully functional PA speakers.

Thanks in advance

 

[Zooberwerx]

Keep in mind that it could be the crossover(s). I'm not much of a diagnostician when it comes to enclosures but I'm hoping those who are chime in!

Riis

 

[4Mal]

Did you put a meter on the horn driver ? Knowing if the diaphragm is melted (likely) would be a good start...

 

[T-Bird]

Hi.

High power compression drivers can be checked for continuity with a regular multimeter.
Use 1,5V one if You're concerned about the warnings not to do it.

If the diaphragms (VC's) check OK, the cross-over is the most likely suspect.
Most cross-overs have protection bulbs in them, if those have done their job, replace with exactly the same kind.

If the VC's are toast, call Crate for a replacement.

Substituting a HF device without modifying the cross-over is IMO/IME even more of a crap-shoot than it is with low frequency drivers, so I do not recommend using a generic Eminence driver for example.

Regards
Sam

 

[kahlerwillits]

Ok, So I got my hands on a multimeter... but I will admit I have no idea what I am supposed to do with it.

Sorry for the lack of knowledge on this type of things. PA speakers are not my forte.

Thanks for the info!

 

[T-Bird]

Hi.

Ok, So I got my hands on a multimeter... but I will admit I have no idea what I am supposed to do with it.

Sorry for the lack of knowledge on this type of things. PA speakers are not my forte.

No need to apologise IMO, we all start from somewhere .

Thanks to the modern technology, the internet provides us with seemingly unlimited amount of information.
Pick one or a few from this list and enjoy:
https://www.google.fi/?gfe_rd=cr&ei=HvXEU7qiCPDJ8gfg3oCoAg&gws_rd=ssl#q=how+to+use+a+multimeter

Regards
Sam

 

[MrLenny1]

Easy fix with a multi meter.
Costs Approx. $20 to get new element.

 

[Geri O]

Set the meter to ohms, resistance, or the little omega sign. Or if there's a tone setting, use that.

If you have a tone when the meter leads are connected to the diaphragm leads, your diaphragm is good (although you need to inspect the windings for burns, melting, or other damage. Non tone, bad diaphragm.

Got ahead of myself. If there's no tone setting, only resistance, then set it to what I described in the first sentence. You'll need to set the range to auto (nearly every meter in the last 10 years or more has an auto setting) and the manual will tell you how to do that. You should measure around 12-13 ohms for a 16-ohm diaphragm and 5-6 ohms for an 8-ohm diaphragm. If you measure nothing or an extremely high resistance, it's bad.

If you put the diaphragm back in, or replace it with a new one, be sure to get some masking tape and a business card cut to a narrow (3/8" or so) width. Take a length of the masking tape, wrap it sticky-side out, and push the card down into the gap of the driver to clean out any crud that might be down in there. Use a magnifying glass to inspect the gap for said crud.

If you are going to deal with PA on about any level, you'll need to become somewhat familiar with the meter so you can trouble-shoot the issues that will pop up from time to time. This seems to be common with bass players...

 

[Steve Dallman]

I have a pair of similar vintage Crate two way PA speakers. The crossovers have light bulb protection for the tweeters. If the speakers are driven too hard, the bulbs will burn out and the tweeters won't work. Replacing the bulb is the fix. I don't know if yours has this protection, but mine do.