P.A. question...

mello_bedwetter · #1 08-27-2011, 11:30 PM

Tonight I went to see a local country band. I noticed they were using a rack mixer, a powered mixer, power amp(at least one), a total of 6 15" speakers(3 per side)as mains, and 4 stage monitors. I talked to the bass player during a break and he said they were using the Mackie powered mixer to run the monitors. They had 3 guitars, bass, and drums mic'ed along with running the vocals. I'm just not sure how they would have the PA hooked up with the equipment I mentioned. I guess my question is how do you hook up the powered mixer along with a power amp and rack or board mixer so that the powered mixer runs the stage monitors and then run 6 FOH speakers? Now they may have had 1-3 power amps, I'm not sure.
I have a Yamaha EMX512 powered mixer. My speakers are 2 15"(s)for mains and I have 2 12"(s) and 2 15"(s) I could use as stage monitors. I'm trying to figure out what I would need to utilize what I have and how to hook it all up. I'd like to have at least 2 15"(s) per side for FOH or maybe even 3 like the band had tonight.
That's about all the info I have. Sorry for the long-winded post...thanks for any help.

T-Bird · #2 08-28-2011, 03:23 AM

Hi.

They most likely used the direct outs from the rack mixer strips to feed the powered mixer channels. Or they had a splitter (doubtful).

A plenty of options to do it, here's a few.

The rack mixer runs the mains (amps + towers) and the powered mixer runs the monitors (max 2 monitor "groups" L & R).

The rack mixer runs the mains and the powered mixer runs the monitors, L & R + feeds one amp through either AUX sends or from the group sends = 4 monitor "groups"

The rack mixer runs the mains + 2 monitor groups and the powered mixer runs 2 monitor groups.

The rack mixer runs the mains and monitors, the powered mixer acts as an amp (with EQ and possibly FX as well) only, being fed through the AUX sends of the rack mixer.

While it looks good, having 3*15 cabs as mains means an inefficient, heavy system. Unless we're talking about line arrays.

Regards
Sam

mello_bedwetter · #3 08-28-2011, 08:10 AM

I'm going to go over these options a few more times. It's early and my brain isn't working just yet.
I understand what the band member said as for as the 4 stage monitors I think. The powered mixer has 2 channels(amps)...each side having 2 8 ohm speakers would give them 4 ohms per channel and 2 speakers making 4 monitors.
In my case with my Yamaha EMX512I'm trying to figure out how to use a power amp and mixer for additional speakers. I have a PDF manual for the Yamaha but I'm not positive in what the diagrams shows. It does show a power amp and speakers coming off the PM. I'll post the PDF of the Yamaha....
Well I was going to but can't figure out how...sorry.
http://www2.yamaha.co.jp/manual/pdf/...c_en_om_d0.pdf

mello_bedwetter · #4 08-29-2011, 03:53 PM

I wrote Yamaha and got a reply but I can't make much of it. Sounds like he left out some words. Here it is:
Run out of the front panel's monitor and main out L jacks to a power for additional monitors and mains. This will allow for 4 speakers on the EMX (Monitor/Mains) and 4 speakers on the power amp (Monitor/Mains).

I was hoping for a little better instructions.
Thanks.

**nutdog** · #5 08-29-2011, 04:00 PM

Do you want to get a rack mixer like they have or use the EMX as the mixer?

mello_bedwetter · #6 08-29-2011, 04:03 PM

Quote:

Originally Posted by nutdog

Do you want to get a rack mixer like they have or use the EMX as the mixer?

It doesn't really matter. I can go with either. I've got a friend that has a mixer I can use for now...I need to see if it's a rack or not.
The band I saw had a rack.

nashvillebill · #7 08-29-2011, 04:23 PM

I didn't quite follow all of this, but my powered mixer (Peavey XR1200D) is really flexible with several Send and Return jacks. I can use the mixer's internal power amps to power the Mains as a straight L/R stereo mix and use the Monitor Sends to power 2 external monitor amps separately. Or for a smaller gig I can use one of the power amp sections to power a mono Main mix and the other channel to power a mono Monitor mix by connecting the appropriate send/returns with a short patch cable.

Or for larger gigs: I run the Main L and R Out to a separate rack with a big 2-channel power amp, a 2-channel EQ and 2-channel feedback eliminator, feeding the two main speakers (big 3-ways). Then I run the mix for Monitor A Out into the mixer's Power Amp A in (actually the Graphic EQ in so I can EQ the monitors) using the mixers internal power amp to run one set of monitors. I do the same thing with the Monitor Mix B, going into the other side of the powered mixer's power amp, for a second pair of monitors.

The XR1200D is a few years old but it can sometimes be found fairly cheaply, it's a good mixer with built in digital reverb (its big and heavy, but it's mixer is quiet and the power amp is 300 watts per side into 4 ohms). It has a bigger brother, the XR1600D which has 16 input channels, and a smaller brother the XR800D I believe. The older version is the XR1200C which is not nearly as good. I think Peavey now makes a newer XR1200E but I don't know about it, by the way.

T-Bird · #8 08-29-2011, 04:29 PM

Hi.

The cabs/amp can be connected as instructed in the reply, but I fail to see why they want to use the main L out.

The only reason to me would be to keep one set of the "AUX" cabs FX free (if You have the FX version that is). Otherwise just jumping the channels (dual mono) on the "AUX" amp would allow You to use just the monitor feed for the amp.

OTOH, depending on how the mixer is set up, You probably can daisy-chain any number of power amps you might desire from either or both of the main outs (NOT speaker outs), and still connect 4 8Ohm cabs to the powered mixer.

Regards
Sam

mello_bedwetter · #9 08-29-2011, 04:34 PM

The guy told me the powered mixer was running the 4 stage monitors and I thought he said he had one channel of the powered mixer going to the rack mixer. I may be mistaken though. Bare with me please...I'm clueless. I've only been running 2 mains and 2 monitors for vocals only.
I do appreciate your replies.

**nutdog** · #10 08-29-2011, 05:41 PM

One band I'm in uses a similar setup. Everything plugs into a yamaha mixer. The main outs on the mixer go to a power amp which powers the two FOH speakers and a sub.

Aux send 1 and 2 go to the yamaha (it might be the same as yours but I'm not sure) powered mixer. He plugs 1 into channel one and 2 into channel 2. The the powered mixer powers the 4 monitors.

If you want to use your mixer, I believe there are L and R main outs on the front and a monitor out. Any of those will feed a power amp to power either the monitors or the mains. Which is what yamaha was telling you.

For instance, you could use your powered mixer to run the FOH speakers and run a cable from the monitor out to a power amp to power the monitor speakers. Or vice versa.

mello_bedwetter · #11 08-29-2011, 06:32 PM

Quote:

Originally Posted by nutdog

One band I'm in uses a similar setup. Everything plugs into a yamaha mixer. The main outs on the mixer go to a power amp which powers the two FOH speakers and a sub.

Aux send 1 and 2 go to the yamaha (it might be the same as yours but I'm not sure) powered mixer. He plugs 1 into channel one and 2 into channel 2. The the powered mixer powers the 4 monitors.

If you want to use your mixer, I believe there are L and R main outs on the front and a monitor out. Any of those will feed a power amp to power either the monitors or the mains. Which is what yamaha was telling you.

For instance, you could use your powered mixer to run the FOH speakers and run a cable from the monitor out to a power amp to power the monitor speakers. Or vice versa.

I noticed one of the posts mentions a feedback eliminator. Is that necessary?
Btw....I have a feeling the band was doing it the same way as your 1st explanation. I don't have my mixer here or I would take a look at it and follow along with your post.

**nutdog** · #12 08-29-2011, 07:14 PM

First, I'll say I'm not a live sound expert, but I just get stuck with PA duty.

This rig has a driverack that does the feedback elimination thing. A feedback eliminator is just an automatic EQ that senses feedback and reduces whatever frequencies it thinks are causing it.

It's kind of neat and can be nice for bands that don't have a soundman (or have a buddy that runs sound for beer). But I don't think it's necessary and it can suck from your sound if it's trying to compensate for feedback caused by setup problems.

If you keep stage volumes reasonable and keep your mics from aiming at monitors I don't see the need for them.

Edit: Most of the feedback problems in the band with the driverack come from the drum mics. The drummer has his own mixer and mics. He places his monitor beside him and it aims back at some of the mics. The first time he mic'd them the feedback was awful. They were mad at the driverack. I pointed out that the overhead mic was extremely hot and his monitor was pointing right at it. Saying things like this is what gets a bass player PA duty.

mello_bedwetter · #13 08-29-2011, 07:34 PM

All we've done so far with the P.A. is run 2 monitors and 2 mains for vocals only. That doesn't work very good because 2 of the guitar players can't control their volume...well they could if they would.
We're suppose to play at a couple different places, smaller/medium bars and I thought we'd be better off if we could run everything through the PA instead of just vocals.
Do any of you use the PA for just vocals? I'm just wondering how that works...as for as getting the right volume output and mix.
I don't mean to get off my main topic here...just curious. I'd still like to figure out what I need to run everything through the PA.

nashvillebill · #14 08-29-2011, 07:39 PM

I also mentioned using a feedback eliminator. On some gigs, it has not been necessary--in fact on small gigs I don't typically even bring it along, but some rooms seem to be especially juicy and I have also noticed, like nutdog said, an issue with the drummer's vocal mic. He'd swing it in on songs he sang backups, but then swing it out of the way on songs where he did not sing.

Other times when I'd get feedback (when not using the feedback eliminator):
-when a singer would step forward into the crowd
-when a singer would stick his/her hand over the mic or "cup" the mic with his/her hand
-when a singer would wave the mic around
-when I had to put a mic out front on a stand for an event person to make announcements

I would prefer NOT to use a feedback eliminator, but IMHO it's better to have a very slight degradation of the vox tone with the feedback buster engaged, than to have massive squeals of feedback blasting through the PA periodically.

nashvillebill · #15 08-29-2011, 07:46 PM

Typically for smaller to medium gigs (say up to 100 or 150 people) I would just run vocals through the PA and maybe some acoustic guitar. Over 150 folks or larger rooms I'd put some cymbals in the main FOH mix, maybe a smidge of lead guitar in both FOH and monitors (lead guitar was a little too quiet believe it or not). My last band I went over to the dark side and played rhythym guitar, and the bass player typically did not need PA support for his bass rig. Really big gigs I'd mic the drums as well.

Most bar gigs were in the 100 folks-or-less category, our favorite place was around 100 folks. It had a small house PA and we just ran vox through it. My guitar amp was plenty loud for classic rock/dance/country even on its low power (18 watt) setting.

**nutdog** · #16 08-29-2011, 09:06 PM

Quote:

Originally Posted by nashvillebill

Other times when I'd get feedback (when not using the feedback eliminator):
-when a singer would step forward into the crowd
-when a singer would stick his/her hand over the mic or "cup" the mic with his/her hand
-when a singer would wave the mic around
-when I had to put a mic out front on a stand for an event person to make announcements

You don't need a feedback eliminator, you need a singer eliminator

seanm · #17 08-29-2011, 09:16 PM

I have an EMX88s. It has main outs (L+R) and a mono monitor out on the front panel. On the EMX the power amps can run mains in stereo, or mains bridged to mono, or mono mains and mono monitors.

So the EMX really isn't setup to use the the internal amps to run monitors only without losing the monitor knobs or using only one of the power amps.

In your situation, I might try using the internal power amps to run the FOH speakers and an external amp to run the monitors. I have done this very successfully.

mello_bedwetter · #18 08-30-2011, 04:19 AM

Quote:

Originally Posted by seanm

I have an EMX88s. It has main outs (L+R) and a mono monitor out on the front panel. On the EMX the power amps can run mains in stereo, or mains bridged to mono, or mono mains and mono monitors.

So the EMX really isn't setup to use the the internal amps to run monitors only without losing the monitor knobs or using only one of the power amps.

In your situation, I might try using the internal power amps to run the FOH speakers and an external amp to run the monitors. I have done this very successfully.

So I could run 4 mains this way and 4 monitors with an external?
If I'm reading it right, the manual says when you use the main out or mono out, they are controlled by the powered mixer's bus. That's where I get screwed up. If both channels(main and mono) of the powered mixer are being used for the mains(main & mono bus, EQ), how do you use it for the power amp and monitors? Do you just set the EQ and main volume but then use the external power amp to adjust the volume on the monitors?
If you would, can you give me a step by step procedure on how I can do this with my EMX512? It sounds like I may only need to pick up and external amp and 2 more 15"(s). Thanks.

bmc · #19 08-30-2011, 04:48 AM

Here's an interesting PA set up a friend used years ago.

He would hook the FOH from the left channel output of the PA, and hook up monitors to the right channel output. He would then control the amount of monitor activity of each input (mics, guitars, etc) with the balance control in each channel. Effectively, the FOH gets run mono.

mello_bedwetter · #20 08-30-2011, 05:00 PM

Okay...I'm going to say a bad word here to some, but a friend of mine at the music store here in town has a "Behringer" EP2000 at the shop. Tomorrow night, if time allows, I'm going to stop by and he'll help me out as for as showing me what to do to hook the PA like I'm wanting, or at least show me how to do it in a way that will work. Don't worry, I'm not buying the Behringer...seems like too many have had bad experiences with their stuff. I guess that would be the type of power amp like looking for though? I'm not sure of the power rating off hand...I think 2000 peak, bridged. Something like 500 @ 4 ohms, not sure.
The gig in 2 weeks will most likely be done with just the vocals going through the PA. Thanks for all the help. I'm open to more too...even if it's about Behringer experiences. Thanks again.