View Full Version : PRX718XLF Bass Speaker

10-12-2016, 11:46 AM
Hi There,

We have a PRX718XLF Bass Speaker for use with our DJ business. We are NOT using the pass thru option on the speaker. Our full range speakers are on a separate output.

I understand the speaker has an internal crossover, and it is set-up for a full range input. However our mixer has a subwoofer output with a user selection of the cut off frequency for the low pass filter. The control is marked from 40Hz to 200Hz on a sliding scale.
Is it OK to use this output for the PRX718XLF. If so, where should we set the mixer low pass filter (options are between 40Hz to 200Hz).

Thanks for your help.

(I have submitted this question with JBL Product Support, but have not receive a reply yet).

Ed Zeppeli
10-13-2016, 07:51 PM
Freq. response is 35 - 87 Hz. Try 80 if your mid/highs can go that low.

Does your mixer act as a high pass when using the sub out? If not, you might be better off using the built-in crossover from the sub instead of having the uppers trying to replicate that low bass that the sub is playing anyway.

It'll give you more headroom.

10-13-2016, 10:54 PM

I have PRX635 and 618S-XLF subs.

If you only have the subs I would set it up like this. On your PRX718 there is s push button(PASS THRU) where you can either use it in HI PASS or in FULL RANGE mode. What this means is if you have for ex. PRX735 you schould have it in HI PASS mode. If you are only using the subs then use it in FULL RANGE mode. The on board x-over will still work in either modes. The best is to have full signal coming to the woofer as possible.

When I am using my PRX with my dbx260 I run the Low band pass frequency in OUT mode and on the PRX618S in XOVER in OUT mode.

I have measured my PRX618S sub with the XOVER button either in IN or OUT mode, the freq response measured with ARTA acoustical program shows the same freq response, so this means that the internal x-over is the same in both cases.

Full signal to the subs works best and then adjust your GAIN knob to your liking.