Hi all

Right, last night saw me doing a 13th Birthday Party, which turned out to be a very good night in the end, but that wasnt the problem or the reason for this post.

Got everything setup, and fired up the music to do a sound check pre-gig.
I was using the Mackie 1501s and 450 tops......the left 450 was crackling and poping like nobodys business
Turned it all off.....checked all the leads.....and went for a second test......
Same thing again
What the hell is going on......used them the night before and they worked perfectly!!!

Went outside to make a phonecall or two, to see if anybody knew what might be causing the problem.......

The Duty Manager came over and said "Did I just hear you having some speaker problems?"
"yea, you could say that, just making a phonecall now to see if any DJ freinds know what the problem might be" I replied
He said "Well I think I might know, we have a hearing aid loop in the venue, and I didnt realise it was still switched on, that maybe the problem, as when we had BBC TV here for the Antiques roadshow then had similar problems with their P.A. kit, and one of the sound engineers asked if we had the hearing aid loop, and could I make sure its turned off."
"oh I see, well that might explain it" I replied.
"its off now, I would go and have another test" he said

Went back inside, and tried it.....same thing happening again :censored:
Really begining to painc now.......
Ok keep calm, lets turn them all off, leave it for a minute or two, then turn them back on just in case theirs some kind of memory effect going on and a turn off and on again will clear it and they will be ok......

Fired them up again a minute or so later.....and everythings now sorted!!!

Just wondering if anyone else had had this problem before coz its not somthing I have experienced before.

I was chatting to Gavin on MSN this morning about it, and its not somthing he has heard of before either.
But he did inform me of one thing which I have never been aware of before......
You should allways have the gains turned down on the speakers (or amps if passive) before powering on or powering off, or you can blow your speakers up!
Does everyone else know about this?
Is it just me that wasnt aware, coz I have never heard of that before!

Since 1986, having made a big mistake which cost money to rectify, I have never activated a system with the volume channels open. I always check - if that is what you mean.

Yep thats exactly what I mean Dan......

But out of all the amps I have ever had, I have never ever done this, I didnt realise it could cause damage, its very important though, only just paid out for this system wouldnt wanna break it

I get most of my knowledge from forums and DJ freinds, but thats not somthing I have heard mentioned before, so its deffinately somthing I will be taking note of in the future thats for sure!

Never heard of this happen with an induction loop.

Turning gear on: yes, make sure gains are down on your amp and mixer. Do the same when you turn it all off (the latter also makes sure it is done for when you turn it back on).

Always check!