Jump to content

PA problem please help!!


Recommended Posts

  • Members

Ok if anyone can help it would be great!

 

we have used our pa a lot but mostly with just vocals and a bit of kick drum.we have a bigger set up and rigged it up last night to have everything going through it.

 

we have a Peavey XR 1220 powered desk going into 2 Peavey UL 15 tops.

 

From the sub out on the desk we go to a wharfedale power amp into 2 18" HK subs.

 

From the monitor out we go to a powered Mackie monitor.

 

wired it up and put some music through it and is sounded very good.

 

started to sound check the kit.

 

kick drum-slight almost delayed buzz after the thump

 

Snare drum-perfect

 

rack toms-terrible long harmonic buzz on every tom.(tried everything, could not get rid of it)

 

hi hat,cymbals-perfect

 

Bass guitar-buzzing

 

Vocals-perfect

 

All buzzing coming from tops,no buzzing from subs.

 

tried everything,changed mics,leads,eq,checked speakers.

 

Try the music again and now we notice a buzzing present on a track with a low keyboard intro.

 

we try the music and the drums through the mackie monitor-perfect.

 

I know it all points to the tops but we have checked them thoroughly and cant find anything wrong and as i said before we have had no problems with them before.

 

sorry to be so long winded about this but we are not sound guys and i have searched for an answer online, the only thing i can find is maybe a voice coil problem.would this not be a problem with the whole sound not just the lower frequencies?

 

cheers Mick.

Link to comment
Share on other sites

  • Members

It's sounds like your tops don't like the lower frequencies. Are you using any type of cross over or HPF(high pass filter) to keep the lows out of your top cabs? Your top has a claimed rating to 60 hz and I doubt it's really that low. If you are feeding it a full range signal that would explain why your kick and bass are "buzzing".

Link to comment
Share on other sites

  • Members

 

It's sounds like your tops don't like the lower frequencies. Are you using any type of cross over or HPF(high pass filter) to keep the lows out of your top cabs? Your top has a claimed rating to 60 hz and I doubt it's really that low. If you are feeding it a full range signal that would explain why your kick and bass are "buzzing".

 

 

Thanks for the reply,the desk has a built in cross over,the manual claims that its all sorted out automatically.

Link to comment
Share on other sites

  • Members

I don't think that is true from reading it. They included a warning not to select sub mode without subs because it would cut the low bass from the main speakers, and another place they mention that some boards don't cut lows from mains when using internal xovers so it seems that lows are removed from tops.

 

The console puts out 300 RMS per channel at 8 ohms. The tops are 8 ohm cabinets with a 98 db efficiency. Thats about 123 db max. I am guessing he is pushing the console into clipping which you hear on tops and not so much on subs. Even if he still hears it at low volume, I would suspect the damage has already been done to the speaker previously and this was the result. That is not a lot of power for drums, bass, etc to be plugged into it. Really easy to have clipped it and done damage to the speakers.

Link to comment
Share on other sites

  • Members

This is from the desk description-

 

The power amps deliver 600 watts to each side in all modes, and those modes with subwoofer option have a built-in fourth-order crossover that sends all frequencies below 100 Hz to the sub.

 

It also says that the desk has high pass filters.

Link to comment
Share on other sites

  • Members

I believe that powered mixer was one of the last things dBoomer was involved with at Peavey, and I'm certain that using the sub out option invokes a true crossover, and kudos to Peavey for making the "sub out" a truly useful option (unlike most powered mixers, which continue to send the lows to the main outputs).

Link to comment
Share on other sites

  • Members

We had a similar buzzing from our tops the other weekend. It was actually a physical buzzing from where the cab mated with the pole. And - like the OP described - often it kicked in after the source frequency died away...almost like a reverb. Subs were unaffected.

Link to comment
Share on other sites

  • Members

 

We had a similar buzzing from our tops the other weekend. It was actually a physical buzzing from where the cab mated with the pole. And - like the OP described - often it kicked in after the source frequency died away...almost like a reverb. Subs were unaffected.

 

 

thanks for the reply,we removed the tops and put them on the floor but they still buzzed.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...