Need help with setup. Please

[djreverse]

I'm needing help hooking up my QSCPLX3602 to (2)JBL JRX100 18's, and a Crown XLS1500 to (2) JBL JRX100 15'S, all while linking through the DBX Driverack PX. I have read about the PX alot and I know it's made for powered speakers but my speakers aren't powered. The guy at Sound Ideas told me that it would be fine, that the PX version will run either passive or powered. I have all Neutrik Speakon NL4FC wires. I don't know if I'm supposed to switch the wires to -2 +2 on speaker ends, whether or not to daisy chain my amplifiers or anything. My 3602 has filters and input configuration that I don't know which position would work best in my position, I don't want to hurt anything. Can someone please guide me to do this? It would be tremendous help.

[The Dude]

I modified this pic from the DR manual for you. Hopefully it will help. Go through the wizard in the PX. Set up the system stereo 2-way. Since most of your stuff is Harman product, there should be parameters already in the unit. Where there are not, find something that is close to what you own. That will get you in the ballpark. Tweak from there. No daisy chaining and no wire switching necessary. No bridging. Run the amps in stereo mode.

[The Dude]

Another tip you won't find in any Drive Rack manual:

After you get the system tweaked to sound like you want it, set the limiters.

1) Unhook the speakers so you don't blow anything up.
2) Run music through the system up until you see the clip lights start to bounce on the amps.
3) Go to the limiting or compressor settings on the outputs of the Drive Rack.
4) If there is a limiter function use that. If not, set the output compressors to "hard knee" and use the compressors as hard limiters.
5) Adjust the limiter or compressor threshold so that the amps no longer clip.
6) Save setting.
7) You can now reattach the speakers.

This will ensure that your amps can never clip. You may need to further adjust the thresholds if you have more power than the speakers can handle.

[paleeman]

There's a HUGE difference between the PA and PX versions. The PX lacks the most important feature that you need, the crossover. So besides the limiter, eq, and some whatnots, that the PX offers, you still need a crossover. Although, you can use the amps filters to crossover, on the long run, you will have to get a crossover, or replace the PX with the PA model, to be able to use your system properly.
In normal mode (not bridge, not biamp) always use the Speakons 1+ and 1-.
Just my 2 cents. Good luck.

[The Dude]

WOW! I wasn't aware of that. I have experience with the Drive Rack series of processors, but to be honest, I've never used the PX. That is just stupid............NO CROSSOVER? Yes, I would definitely look into exchanging the PX for a PA+ or something with a crossover. You could make it work with filters, but not even close to as good as an actual crossover.

[paleeman]

Yes,it is absolutely dumb from dbx, to leave out the x-over from a device, that is essential for a 2 way system. Even if it is intended to be used with powered speakers, IMHO, you still need the cross. While subs will have a Low pass filter, very few powered 2 way speakers have High pass filters. And even if they have one, you should still be able to match the frequencies and the steepness of the filters, to make the system sound right. I think the PX is a waste of time, and time is money...