PA System hook up

Adyx

Ok so the main questions about buying a PA are pretty much covered by Savman's excellent thread here. But while I grasp the basics of it, I'm still unsure of a couple of things so please bear with me.

My band currently uses a passive desk (Mackie CFX12 Mk 2) into two cheap Thomann active speakers. We are looking to upgrade to something along the lines Savman mentioned but I have a few questions.

1. What is the recommended way to hook up the 2 power amps to the 2 Hi/Mid speakers and 2 Subs given that our desk has left/right XLR outputs and a single XLR Sub out? The desk also has 2 TRS L/R outputs and 4 TRS Sub outputs. Should I include a crossover in my shopping list? Or is it simply 1 amp for the Hi/Mids and the other for the subs?

2. I have been given conflicting information regarding the TRS outputs (Which we don't currently use), is it safe to use regular instrument type leads to connect them to a power amp?

Sorry for the long post and if I come across like an idiot but we're getting more and more gigs and what we have really doesn't cut it.
Thanks for any help.

PaulBrewer

The missing part of your Jigsaw is a Crossover. The speakers you have probably have them built in.

In your new plan you'd go from desk output to crossover which would split the signal into bass (usually anything below 100 Hz), which goes to an amp then bass speaker (often called Sub) with the remaining frequencies going to your tops.

Adyx

PaulBrewer wrote: »

The missing part of your Jigsaw is a Crossover. The speakers you have probably have them built in.

In your new plan you'd go from desk output to crossover which would split the signal into bass (usually anything below 100 Hz), which goes to an amp then bass speaker (often called Sub) with the remaining frequencies going to your tops.

Thanks, that's what I was thinking. I guess I was hoping the sub output on the desk would do. Ah well, I might be able to borrow a crossover from work anyway.

Savman

Seeing as your Tops are already active, if you got active subs they would most likely have a built-in crossover. Problem solved.

In this case, run XLR cables from your Master L & R outputs on the desk into each sub, set the crossover switch to around 80-100Hz and run a short XLR cable to the tops. Once you buy the right Sub, it's easy.

PaulBrewer

Adyx wrote: »

T I guess I was hoping the sub output on the desk would do.

Ah ... a Sub out from the desk is from a crossover, just it's in the console. So no need for an external one.

Adyx

Savman wrote: »

Seeing as your Tops are already active, if you got active subs they would most likely have a built-in crossover. Problem solved.

In this case, run XLR cables from your Master L & R outputs on the desk into each sub, set the crossover switch to around 80-100Hz and run a short XLR cable to the tops. Once you buy the right Sub, it's easy.

Yes but the tops are cheap and nasty "The Box" ones and aren't really suitable for what we want them for.

PaulBrewer wrote: »

Ah ... a Sub out from the desk is from a crossover, just it's in the console. So no need for an external one.

There is only a single sub out on the desk though so could I use a y-splitter to input both channels or assuming there is an output on the subs, connect one sub to the other.

Like I said these might be really obvious questions but I'd rather look stupid and get it right then get it wrong and look stupid. Thanks again to both of ye.

PaulBrewer

Adyx wrote: »

Yes but the tops are cheap and nasty "The Box" ones and aren't really suitable for what we want them for.



There is only a single sub out on the desk though so could I use a y-splitter to input both channels or assuming there is an output on the subs, connect one sub to the other.

Like I said these might be really obvious questions but I'd rather look stupid and get it right then get it wrong and look stupid. Thanks again to both of ye.

The reason there's only one sub out is that bass cabs are often run in mono as bass frequencies carry little, if any, directional info (the 'stereoness') .

You can just loop the inputs to your bass amps, whether they're in the cabs or not.

Adyx

Thanks Paul and Savman. The help is much appreciated.

PaulBrewer

Adyx wrote: »

Thanks Paul and Savman. The help is much appreciated.