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JBL VRX932 w/ double 18\" subs
sound_doc
Posts: 2
I have recently taken a position as the tech director at a large church. They appear to be running 3 VRX932's per side flown over 2 double 18\" subs placed under the stage. They are running the tops in passive crossover mode with a dbx 260 controling the crossover for the subs, ins and outs, and system eq. I have taken a quick look at their 260 settings and whomever installed the rig seems to have set the factory JBL preset for such a configuration. My questions are:
1) The double 18's seem to be producing plenty of low end and the room has a bit of a 60Hz roll as it is. Would it be a good idea for me to raise the crossover point of the tops to get some of the low end out of there? If so to what? I was thinking 100 or even 125Hz. The factory preset has them crossed at 81.1Hz which seems like ALOT of low end up top for a room with no balcony and double 18 subs installed.
2) By nature of the speaker hang the tops are about 3 feet in front of the subs. Should I add in a touch of delay to compensate. If so about how much? I was thinking 3 or 4 milliseconds. Once again the factory preset is reccomending zero delay.
I can certainly make the adjustments, listen to the rig, and decide if there is improvement, but I thought I would ask for opinions first. Any help would be greatly appreciated.
Thanxx
1) The double 18's seem to be producing plenty of low end and the room has a bit of a 60Hz roll as it is. Would it be a good idea for me to raise the crossover point of the tops to get some of the low end out of there? If so to what? I was thinking 100 or even 125Hz. The factory preset has them crossed at 81.1Hz which seems like ALOT of low end up top for a room with no balcony and double 18 subs installed.
2) By nature of the speaker hang the tops are about 3 feet in front of the subs. Should I add in a touch of delay to compensate. If so about how much? I was thinking 3 or 4 milliseconds. Once again the factory preset is reccomending zero delay.
I can certainly make the adjustments, listen to the rig, and decide if there is improvement, but I thought I would ask for opinions first. Any help would be greatly appreciated.
Thanxx
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Comments
2) JBL can't possibly know the delay settings, because they can't know the placement of speakers in relation to each other. They are not \"recommending\" zero, they are making \"no\" recommendation. If you know the height of the mains and the angle of the swing, then you can use that trig you swore you'd never use to compare the distance to the floor at the point of attack and the distance from the subs to that same point. Then delay the cabs that are the closest that number of feet with that output's delay. That will get you close, then if you like you can tune it in by ear.
Be sure to report back your results.
DRA