# Live rig help.. Do I need a preamp, or...?



## synrgy (Mar 9, 2009)

I posted this on my usual production forum and got little response, so I thought I'd try here. My apologies if this belongs in a different sub-forum. Allow me to lean on my n00b-crutch if that's the case. 

So I've been playing in a band again for the last few months, for the first time in several years, and I'm trying a bunch of new things that I've been wanting to try for a long time, with mostly good result, but there's one snag: volume.

So skipping a ton of unimportant pieces of the chain, let's say the setup looks something like this:

Guitar-->Rig Kontrol 3 pedal-(usb-->rackmount pc)->PA system

The PA consists of 2 JBL Eon 280w powered 15", and 1 JBL Eon 500w powered 18" Sub. When I run my DJ set up (whatever units-->pioneer mixer-->PA) into it with the volume at about 2, it shakes the foundation of my house.

When I run the guitar setup through it, with the volume cranked to max, regardless of if I use the computers output (an m audio audiophile 192 sound card) or the Rig Kontrols outs, I can't even hear myself over just the one other guitar player (100w head 4X12 cab) let alone the rest of the band.

Logically, this makes no sense to me, as I figure the PA is supposed to be doing the work. Regardless, I need to solve the problem, and I'm figuring that *maybe* something like a preamp or a compressor/limiter/maximizer or something along those lines, placed between the computer and the PA would solve the problem?

I can sort of work around the problem by running an extra line out to a half stack (100 watt head/cab) and this is great for just the guitar tones, but I'm triggering a lot of MIDI sounds as well, and several of them have bass frequencies that could really damage a guitar stack, so I don't want to go that route.

Any insight anybody could offer me is greatly appreciated. I'd like to keep my costs relatively low, but believe in proper investments when the right case is made. If I have to buy some piece of kit, let's pretend my starting budget is roughly $3-$500, would prefer lower (of course) but could go higher if necessary.. Course it'd be even better if I didn't have to buy anything, that I'm just missing some stupid detail..

For the record, to get the PC to even be audible with the other guitar player, I had to run (in both Cubase or Ableton) my master levels completely maxed/clipped. Just to be audible. With a 1000 some odd watt system.


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## budda (Mar 10, 2009)

so you run the guitar's volume and the computer program's volume at 10, and you're barely audible correct?

Don't the powered speakers not have a volume knob or anything?

When you run your DJ rig, you are running everything into a mixer - which is probably boosting your signal - then that signal is being fed into the powered speakers.

sounds to me like you just need a power-amp before your speakers, as they wont give you a huge volume increase all on their own.


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## synrgy (Mar 10, 2009)

budda said:


> so you run the guitar's volume and the computer program's volume at 10, and you're barely audible correct?
> 
> Don't the powered speakers not have a volume knob or anything?
> 
> ...


 
the powered speakers are cranked in this situation, yes. (certainly not when in use with my dj set up)


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## WarriorOfMetal (Mar 20, 2009)

it sounds like a preamp couldn't hurt...but why not just get an actual guitar amp and be done with it?


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## stuh84 (Mar 20, 2009)

Sounds like two problems.

1) The PA you have is rated PMPO (Peak Mean Power Output), so that it tells you what the absolute peak it COULD hit would be, whereas the other guitarists amp is rated RMS, so the average power it puts out. I've seen gear rated at about 200 watt PMPO which were realistically only about 25 watt RMS. Edit: Ignore this, just checked the JBL website, however it still doesn't mention RMS, only continuous, which isn't quite the same thing.

2) The frequencies you are outputting are getting swallowed up. You could be doing all the right things, but if the general sound coming out doesn't have the right frequencies to cut through, it will get eaten alive by near enough anything. I find this problem with a lot of modelling gear, in that on its own it can sound loud, but the moment you stack a tube amp or anything else with certain frequencies, it just dissapears as its missing vital frequencies


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## Tukaar (Apr 3, 2009)

Try getting something of a smaller speaker. Using those 15's and 18's are prioritizing your bass frequencies, but not your mids. The guitar is a midrange instrument, they are what makes the instrument audible.


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## SargeantVomit (Apr 11, 2009)

You should be running from the soundcard to an on stage mixer before your mains and sub if you aren't. So yes you need a preamp. 

Are you also running the drums and/or vocals through your PA setup? Are they getting the volume they should too? 

1)Do NOT put a power amp in the chain before the speakers. That is ridiculous and will blow your mains onboard power and possibly the drivers.

2)You don't need 12's, that is also ridiculous.


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## synrgy (Apr 24, 2009)

Should have updated this WEEKS ago.

The problem was something really simple and stupid. Akham's razor strikes again, and I was just way overthinking things.

The PA cabs have a mic/line level button. I pressed it. Problem solved.  b2b 

In my defense, the button is not easily seen.


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