PA system/speaker wire problem?
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Posted on Oct 28, 2008 09:10 am
cptasker
Member Since: Oct 28, 2008
Hi guys, I was wondering if anyone might be able to point me in the right direction....
I have a mcgregor sd15 pa system, one of these: www.mtraudio.com/mcg_disco_review.htm
with 600 + 600 watt speakers. (also mcgregor)
The person I got it from said it worked fine the 1st few times, then after some dust gathering and a couple of house moves its been passed on to me and I finally got around to hooking it up today.
At first switch on, one speaker is completely dead bar some crackling and humming, the other speaker is really low with no bass. I switched the speaker cables over and the problems reversed, so am I right in thinking its a speaker wire problem?
The connectors are neutrik nl2fc connectors on both ends (4 in total) and I unscrewed them but they look fine, except for some slight play in the connectors. The cable itself is ELV professional hi flex 2 x 1.5
This was a package, quite expensive too by the looks of it so I'm not sure what to do next! The monitor through the headphones is fine so maybe the connections at the speakers have taken a knock or does it sound like an issue with the left and right channels on the box itself?
Sorry for the essay but I know how frustrating a 2 word question with no info is!
Cheers
CP
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Oct 28, 2008 09:16 am OK, so you switched cables and the problem reversed, so, let me ask you this, did you just switch the speaker end of the cable? If so, the problem could be in the amp itself, or the jacks of the amp. If you switched the entire cable, meaning both ends, then, just replace the cable.
...and welcome to HRC...
Oct 28, 2008 09:23 am Why thank you! Noce to be here :-)
Well, now you mention it, I just switched off the system and switched the cables at the actual system inputs... I'll try it now switching both ends... sit tight! hehe
Oct 28, 2008 09:28 am I'll be sitting for the next 6 hours, I ain't goin' nowhere :-)
Oct 28, 2008 09:37 am Hmm... not looking so good!
At first I had:
left (crackle no sound)
right (low sound)
I swapped inputs left for right into the back of the system box and had:
left (low sound)
right (crackle no sound)
I then completely swapped wires and got:
left (crackle no sound)
right (low sound)
So maybe its a fault on the system itself? as swapping the wires completely didn't change the problem.. booo!
Oct 28, 2008 09:40 am Duh.. there really is a fine line between stupid and clever... Ive just realised that by swapping the inputs on the back of the system I was merely transferring the problem from one side of the room to the other.. as the speakers stayed in the same place....
Oct 28, 2008 09:42 am looks to me like the left side of your system may have an issue, but first, get some contact cleaner and Q-tips and clean out the jacks real good. It can make a WORLD of difference sometimes...
Oct 28, 2008 10:06 am No joy I'm afraid.. looks like its gonna have to be a proper repair job as I have no idea past wire/fuses! Thanks for your help, much appreciated.
Oct 28, 2008 10:10 am it wouldn't hurt to unscrew the panel and take a look at the back of the jacks and see if it's a simple loose wire or something of that nature before committing to a repair bill.
Oct 28, 2008 10:12 am Clean the pots too.
Oct 28, 2008 10:22 am You're right! I will try that later when i get in from work and let you know what I find... what/where are the pots! lol x
Oct 28, 2008 10:25 am pots are the mechanical mechanism under the "knobs"...if those get dirty, they can make all kinds of noise, and if it's been hanging out in smokey clubs and crap, they are dirty. Get a pressurized spray can of contact cleaner, pull the knob off exposing the pot, spray it, turn it from extreme left to extreme right...rinse and repeat.
Oct 28, 2008 10:31 am Is this system a self powered system? Meaning that the mixer also has the amp in it?
If it is, there is not a test that I can recommend. If it is not. If there is a separate amp that you are plugging into. Try swapping out the cables going to the amp. You might have a problem with them, instead of the speaker cables.
Try to narrow down what is making the noise. Is it the amp, or is it the mixer. I know you said that the headphone is clean. You still can have a mixer issue despite the fact.
Oct 28, 2008 10:33 am
oi!
Oct 28, 2008 10:52 am Good point dB.
There is a separate amp with this. Are you using RCA cables to the amp? Or are you using mic cable?
The difference between balanced and unbalanced is very important. An unbalanced cable can give you all kinds of problems.
