Members TheDoctorMo Posted July 29, 2011 Members Share Posted July 29, 2011 I've played one gig with my new PRX-XLF sub. It was a decent-sized room for a class reunion. It had plenty of thump even though we didn't get a proper sound check, like I would have preferred. Tomorrow, we are playing in a much-smaller bar. So, I'm planning on only using the XLF and not my other HPR151i sub. I was wondering, however, how the XLF sub works when there is only one channel being used. The manual states that it sums a stereo signal into a mono signal. However, if I plug into the left channel only, am I getting only half of the power? The manual doesn't mention this. Even if I'm running a mono output from my mixer into the sub, should I use an XLR splitter to send the signal into both channels of the sub? Thanksmike Link to comment Share on other sites More sharing options...
Members imnotded Posted July 29, 2011 Members Share Posted July 29, 2011 You are only getting half the signal, but you are most likely not running anything through the sub that requires a stereo signal anyway. Just plug the XLR into the left input. Link to comment Share on other sites More sharing options...
Members TheDoctorMo Posted July 29, 2011 Author Members Share Posted July 29, 2011 Does that also mean I'm getting half the power, too? Link to comment Share on other sites More sharing options...
Members sibyrnes Posted July 29, 2011 Members Share Posted July 29, 2011 Even if I'm running a mono output from my mixer into the sub, should I use an XLR splitter to send the signal into both channels of the sub? No. If you are running stereo then you should use both inputs to sum the stereo channels into the sub. If you are running mono, it doesn't matter. Either way you can still get full power out of your subs. Link to comment Share on other sites More sharing options...
Members Mutha Goose Posted July 29, 2011 Members Share Posted July 29, 2011 I run with 2 XLFs. Each one only gets 1 input. I still get full volume, or output SPL if you will, out of each box (if I am understading your question correctly). Link to comment Share on other sites More sharing options...
Members jwlussow Posted July 29, 2011 Members Share Posted July 29, 2011 One side of the amp will not mean half the power (non-bridged mode). Amps are rated per channel so, for example, 800 watts per channel will be delivered to each output. If you are asking if 800 watts per channel is the same as 1600 watts...and using only one side means 800 watts or half the power, it really isn't that simple. Just use one side and you will be fine. Link to comment Share on other sites More sharing options...
Members TheDoctorMo Posted July 29, 2011 Author Members Share Posted July 29, 2011 Thanks, everyone. That's what I was hoping to hear. I bought an XLR splitter, so I plan on running from the mixer to the sub. From that, the output of the sub to the XLR splitter, and then into each top. Link to comment Share on other sites More sharing options...
Members tombo007 Posted July 29, 2011 Members Share Posted July 29, 2011 Dasiy chain the tops. Mixer, to sub xlr input, sub xlr output with xover engaged, to one high box XLR input, xlr output to other high box xlr input. Link to comment Share on other sites More sharing options...
Members TheDoctorMo Posted July 29, 2011 Author Members Share Posted July 29, 2011 I will if I have a long enough XLR cable to connect the tops. I'm running low on long XLR cables for this weekend. mike Link to comment Share on other sites More sharing options...
Members mrcpro Posted July 29, 2011 Members Share Posted July 29, 2011 Your splitter idea should work too. But I'm going to join this discussion from a slightly different angle. If you liked your sound last week, I'd set up the same way tomorrow. It's only one extra cab. You just never know. I don't know how many times I wish I had brought that other sub when I've cut down to just one. Link to comment Share on other sites More sharing options...
Members Zeromus-X Posted July 29, 2011 Members Share Posted July 29, 2011 Just to throw this out there, the first gig we used the XLF, we were thinking it wasn't a whole lot of bass relative to what we were expecting, but we ran in mono with daisy-chained tops. The second show we ran in full stereo, plugged into both sides of the XLF, and the difference was noticeable. There were a lot of factors that changed -- it was a completely different venue for example -- but we swear there's a difference between plugging into the left-only and chaining the tops, and plugging in both inputs and running the rig stereo, even with everything panned center. Link to comment Share on other sites More sharing options...
Members TheDoctorMo Posted July 29, 2011 Author Members Share Posted July 29, 2011 Your splitter idea should work too. But I'm going to join this discussion from a slightly different angle. If you liked your sound last week, I'd set up the same way tomorrow. It's only one extra cab. You just never know. I don't know how many times I wish I had brought that other sub when I've cut down to just one. The other sub will be in the truck. This place is kinda weird in that on one side, we have a thin wall that separates the band area from the bathrooms. The other side has a bunch of electronic dart boards and kitchen cabinets/counters. Cutting down on one sub would make it a bit less-cramped. My plan is to put the sub to the left, then both tops next to each other, but angled out just a bit. I'm not really sure how I'm going to do it, until I get there and have some time to think about it. Link to comment Share on other sites More sharing options...
Members TheDoctorMo Posted July 29, 2011 Author Members Share Posted July 29, 2011 Just to throw this out there, the first gig we used the XLF, we were thinking it wasn't a whole lot of bass relative to what we were expecting, but we ran in mono with daisy-chained tops. The second show we ran in full stereo, plugged into both sides of the XLF, and the difference was noticeable. There were a lot of factors that changed -- it was a completely different venue for example -- but we swear there's a difference between plugging into the left-only and chaining the tops, and plugging in both inputs and running the rig stereo, even with everything panned center. This will be easy enough for me to test. I can quickly run a stereo signal to the sub, then switch it out for a mono signal. Link to comment Share on other sites More sharing options...
Members heath_eld Posted July 29, 2011 Members Share Posted July 29, 2011 This will be easy enough for me to test. I can quickly run a stereo signal to the sub, then switch it out for a mono signal. Why wouldnt you do it like this anyway? Link to comment Share on other sites More sharing options...
Members TheDoctorMo Posted July 29, 2011 Author Members Share Posted July 29, 2011 We run in mono. Why bother with another, long XLR cable run when there is no need? Link to comment Share on other sites More sharing options...
Members jwlussow Posted July 30, 2011 Members Share Posted July 30, 2011 We run in mono. Why bother with another, long XLR cable run when there is no need? Why such long cords? Do you run from stage or out front? Maybe a small snake would be a good investment. Link to comment Share on other sites More sharing options...
Members TheDoctorMo Posted July 30, 2011 Author Members Share Posted July 30, 2011 I like to keep the stage tidy, so I will run the cables out of the way. We had a 8x4 snake, but it was more hassle than it was worth. Link to comment Share on other sites More sharing options...
Members TheDoctorMo Posted July 31, 2011 Author Members Share Posted July 31, 2011 Last night, we first ran only into one channel of the PRX-XLF sub. It had decent output considering the layout of the room and nearby obstacles. Then, using the XLR splitter, we sent a signal into both channels. There was a noticeable increase in output. Link to comment Share on other sites More sharing options...
Members Zeromus-X Posted July 31, 2011 Members Share Posted July 31, 2011 Thank you for confirming this. I presume you could get the same overall result by backing off the gains/attenuators on the tops and running more signal from the board, but it's just as easy for us to run the rig in stereo and not have to worry about that. Link to comment Share on other sites More sharing options...
Members Dookietwo Posted July 31, 2011 Members Share Posted July 31, 2011 Last night, we first ran only into one channel of the PRX-XLF sub. It had decent output considering the layout of the room and nearby obstacles.Then, using the XLR splitter, we sent a signal into both channels. There was a noticeable increase in output. A powered sub has a power amp built in. In general if it has 2 inputs these inputs are combined to mono. Combining 2 inputs ( if both inputs are in phase and have the same level ) to mono in general gives 6dbs more input level to the power amps. If the sub reaches full input at +6dbu and only *1* input is used you'll need to have your boards output meters at +6 dbu for the sub to give full volume.If your going into the sub with *2* inputs then your board only needs to be at 0dbu. The 2 signals combined in the amp to mono will equal +6 dbu and the sub will give full volume. Using both inputs causes the sub to reach full output sooner and with less input voltage Per Channel total.Using just 1 input means you need to have the input voltage higher before the sub reaches full power. In both cases the sub will only put out so much volume. Only the votage required on the input to drive it to that level changes. Dookietwo Link to comment Share on other sites More sharing options...
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