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XTi 4002 and JBL PRX 425s help


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#1 sc2bigjoe

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Posted 29 January 2013 - 02:49 PM

Hello!

I have purchased the XTi 4002 amplifier and I am running 2 JBL PRX 425s with it. I have a few questions with my new setup as this is the first time I have done anything like this before.

I have installed the presets from the website for the prx400 series and have set the preset on the display to PRX 425 Stereo. When I run audio through it though I have to turn the knobs up to about the 3 o'clock position before music starts bumping like I feel it should. I have to turn it up that loud as well also when running vocals/kick drum for practice sessions in a small room.

I feel like I should be getting more power, am I doing something wrong here? Using the band manager software I can see the input levels going into the XTi are pretty good and almost reaching the top (no clipping). However the output usually hovers right around the middle

Thanks everyone

#2 dakos

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Posted 30 January 2013 - 03:18 AM

Hello,
The Gain Knobs change the input sensitivity, so if you put the gain knobs on three o'clock position, you need more voltage on the input side of the amp to reach it's full power. Either turn the knobs further or push your mixer a bit higher.
Avi

#3 sc2bigjoe

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Posted 30 January 2013 - 02:07 PM

Hello, thank you for replying

My mixer is already outputing almost to clipping (not clipping though). I have a studiolive 16.4.2 and it should be able to output enough. Is it because I'm playing in a small practice space? We are playing metal and have  acoustic drums, mesa triple rectifier guitars and bass. Do you think I should have to turn up that high to be able to hear vox?

The band manager software I use already shows it's receiving inputs just how my mixer is outputing (almost all the way up) but even when I have the gain knobs up to 3 o'clock the output on the band manager software and the front of the xti 4002 don't even hit -20db

Thanks again

#4 dakos

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Posted 31 January 2013 - 12:12 AM

Then just crank the gain knobs all the way up and don't push your mixer further (never clip anything), as I explained the gain knobs don't change the maximum power of the amp and if you're at the max output of the mixer then you need to lower the input sensitivity, you can do it by cranking the gain knobs further until you get to the power level you need. The amp has no problem working like this all day long.

Please try to keep in mind that getting a good kick drum sound requires allot, probably a sub or two and a good amp to push it, with those speakers you're almost as close as it gets to having that sound but without the subs. Also about headroom!!! You're working in a non compressed live environment, playing a very demanding music type that requires allot of headroom, about 15dB, so engaging the on board limiter will help protect your speakers a bit better and give you a bit more confidence to push it further a bit.
Avi