EV ZX5 Horn Issue

[warrenstuart]

Hi All

 

One of the horns in my pair of EV ZX5s is having a tendancy to go low and dull compared with the other one and I just wondered if anyone has come across this before?

The actual driver is the EV ND2. When I first set up and do a test it sounds fine but then an hour or so into the gig I notice that one side has gone dull. The horn is actually working but at a low level.

Things I've done so far...

 

Swapped speakers over on amplifier channel outputs and the fault moves with the speaker swap so it's not the amp/mixer/playback device, it's definitely the speaker.

 

Switched the speakers from passive to bi-amp mode with the switch on the rear panel so that I can measure the DC resistance across pins 2+ & 2- that go to the horn and compare it with the good speaker and they read the same, approx 5.5 ohms. There is a passive limiter in series with the ND2 though so I'm not 100% sure if I'm measuring across the limiter or the ND2 or both??

 

I guess the next step may be to open up the speakers and swap the ND2 over between the cabinets and see if the problem moves with it but I don't have the time for that with the christmas gigs at the moment.

 

Any more advice gratefully received :-)

 

Warren.

[KevinE]

the limiter will be in series with the horn and possibly shunted partially by a resistor on the crossover. I would try swapping the limiter lamp over with the other one as they can go intermittent. While you have your hands inside, check the crossover for broken connections. Try wiggling any plug and socket in there while playing music, I'm sure I had a ZX4 with an intermittent plug. <_<

[warrenstuart]

Thanks Kevin, typically it hasn't done it for the last 3 gigs but will open it up and have a look next week :-)

[Cheeseweasel]

Worth checking that the horn is still bolted tightly to the front of the compression driver assembly and that the diaphragm is tightly bolted to the back. If these come slightly loose, level drops off rapidly and results in a low, dull sound.

[warrenstuart]

Thankyou cheeseweasel, I will check that also :)