PA+ gain help... basic DJ setup but doing something wrong

DJ Gaffle

Let me start off by mentioning that I did read the startup section in the forum.

...but

I'm at a loss whether I should be at +4dbu or -10dbV on the back plate input of the DR PA+. With +4dbu, it seems as if I have to have my mixer's master volume almost at 10 and my QSC RMX2450 gain at nearly max to make my amp clip.

Here's my setup:

Rane TTM57 mixer (http://rane.com/jpg/ttm57slflat.jpg)
DriveRack PA+
QSC RMX2450 (bridged mono with parallel input)
2 QSC HPR121i powered speakers
1 Danley TH-115 sub

I started by using the DR's wizard and added my HPRs in stereo, RMX2450 with Custom sub in bridged mono. I could not auto EQ or auto LEVEL because I do not yet have a DR mic to do so. THe sub's crossover is HPassed @ 26.5Hz BW24 and LPassed @ 90Hz BW24 with 0db gain. The tops crossover is LPassed @ 95Hz BW24 with 0db gain. I have No subharmonics and No EQ configured.

Most of the reading here talks about 'unity' gain adjustments when setting the proper system gain levels with the DR to get things in harmony. I have a Mackie 1202VZ but I'm not using it nor do I want to unless my event calls for it. My gig setup is generally simple and my DJ mixer does not have a unity gain (only channel line levels faders with output meters and a master out). The specs (http://rane.com/ttm57sl.html#gpm1_13) for my mixer seems like it gives adequate output in Volts rms from master but why do I have to press in for -10dbV in order to get the DR's light indicators to really move?

I can get everything to sound good and not distort but I really want to be able to take advantage of the DR's limiter abilities. WHen I've set my gain level as best I could, the limiter (LOW) threshold lights on the front of the DR seemed liked they flicker constantly. Sorry if I sound clueless. :roll:

DJ Gaffle

... some of my :? frustration has been lifted with the instruction manual. I went and downloaded the DRPA Training guide and it explained LOTS that the near useless manual didn't.

Before reading this training guide, I could NOT figure out what the main display screen's (G, FB, C, P, L and LH/RH, LL/RL) meant. Now I know :roll:

I'm still confused about the INPUT/OUTPUT headroom meters on my DRPA+. It has signal starting at 30 with a value of 0 at the top; whereas the DRPA in the training guide has input DBu meters and threshold starting at -30 and +20 at the top (page# 73).

Could someone explain this? Setting my limiting on a older DRPA makes since based on this labeling as compared to the PA+'s labeling.

Gadget

It would appear that your mixer has a -0- output level on the XLR's and -3 on the balanced 1/4\" outs... The DRPP+ is +4 and -10 when using the different options on the back... This puts your mixer about in the middle output wise and in the +4 position I can see where you might have problems getting the amp to clip.

Now, the -10 position is considered \"consumer\" level... but you would have more input signal into the driverack...

So which input setting do you have the DRPA set at ? Sounds like you are getting sufficient level to trigger the limiter... the lights indicate the threshold (level you set the limiter to start working) is being achieved...remember that the DRPA doesn't have brick wall limiters ...so some overshoot is inevitable if you push the level past the threshold you set...

Make sure you DON'T have the limiter on the amp on, and make sure the HPF is OFF on the amp as well.. you also don't need the parallel inputs on when you are in the bridged mode...that would be for situations like dual mono subs or identical outputs in a dual channel setup like a single mono output from your mixer into channel 'A' that feeds channel b as well so you could drive 2 speakers with one input...

Remember when using the limiter to watch the threshold as you set it. Start with a high threshold and set your system to about the volume you wish to start the limiter, then lower the threshold to the point the limiter starts to show activity on the meter (+- activity) again, there will be overshoot so don't expect the DRPA to \"Protect\" your speakers...That is why we like to set the gain structure so that the MIXER clips as the amps do...

Dose the mixer clip and the DRPA NOT CLIP when you use the -10 option on the DRPA? if this is true then use the -10 option but remember to shut OFF the limiter when setting the gain structure.

G

DJ Gaffle

@+4dbu, I see that I am able to make my amp clip but I have to have my mixer's Master OUT at about 80% (which I usually don't turn it that high). In this scenario, my amps gain knob is at about 70%.

@-10dBV, I can make my amp clip with my mixer's master at 65% and the amps gain knob at about 60%.

I may stick with the +4dbu setting. I'm configuring this DRPA with the aforementioned mixer but my gigging unit is a Numark NS7. I think it has a hotter XLR output level than this mixer. I'll be using it Sunday night and will make the necessary adjustment then.

I'll be switching the parallel back to 'stereo' on the amp to and add the missing XLR cable that runs between the DRPA's LOW channel (right) -> RMX's Ch. 2 input.

This DJ mixer works with a digital DJ software called Serato Scratch Live. The software (which plays your digital music files) can be set with individual song gains to control that songs volume and an overall gain from 89db to about 98db which is like a master gain. It scans your entire song library and performs what are called 'overviews or analysis' on the song building the waveform and also adjusting the individual gain parameter of that song. An 70's song like \"Deacon Blues\" would have its gain higher than a modern-day song like \"Buy you a Drank\". The Master adjust I have is at 91db. Any song I play will never clip and all songs in my library will automatically adhere to that level. If I adjust the master software parameter to 96db, every song I play will most likely be clipping. The mixer's physical knob which you see in the picture is for adding control while DJ'ing as are the line up/down and cross faders. (sorry so long winded).

Thanx!