Members Don Davis Posted July 9, 2012 Members Share Posted July 9, 2012 Now for the hooking up two 712's, I am certain that it's got "input" and "thru" jacks. Wouldn't this be how you would loop from one cab to the next? Where you intending to run one 712 per channel or bridging the amp? If you looped the two 712's in stereo then you where running both 712's off of one channel if I'm reading your question right. Link to comment Share on other sites More sharing options...
Members Tomm Williams Posted July 10, 2012 Members Share Posted July 10, 2012 If the limitation was it feeding back, more/bigger speakers or more power will NOT give you more GBF . THIS +1. and what was feeding back? monitors, mains, FX in the monitors maybe? I would identify this issue before spending any more $$$$$$$ on adding stuff that may not help much at all. Link to comment Share on other sites More sharing options...
Members Tomis17 Posted July 10, 2012 Author Members Share Posted July 10, 2012 Despite all the :":freak::facepalm:" I understand I may have done something wrong in my setup and/or my tuning that was why I asked. If I thought I did everything correctly I would not be asking. I have learned much from you "pros" out there in the past so I was hoping you'd continue sharing your knowledge with me. I'm no expert so next time you start giving me the "":freak::facepalm:" keep in mind that I am just an amateur seeking for answers. That said, lesson learned -> I need to tune my system better before assuming I need more headroom. Thanks for all your help. Link to comment Share on other sites More sharing options...
Members Tomis17 Posted July 10, 2012 Author Members Share Posted July 10, 2012 First, you can't defeat the laws of physics. Doubling the distance reduces sound levels by 6dB...that's a lot. So what sounded fine at 20 feet is defnitely going to be noticeably reduced at 40 feet. Add the factor of a packed room, and you lose all the advantages of any room reverb.Next, I don't understand how you draw the conclusion that feedback somehow indicates a lack of headroom. Headroom is unused power. Has nothing at all to do with why you get feedback and is definitely not synonymous with gain before feedback. Lastly, did you get clip lights on any part of the system? If your amps are sized well to the speakers, and you didn't get clip lights briefly flashing, you were absolutely not "out of gas". Get your set up so it doesn't feed back, and you'll have more success. It's very unusual to have feedback from FOH (rather than stage monitors) in a packed room, so you may have really been pounding eardrums to death. Get some knowledgeable and unbiased input from those at the show about the performance levels before you try to go louder. CraigV thanks for your input. Clip lights occasionally came on when I turn the gain on the amps to past 3 o'clock. At or below that the clip lights never came on. Link to comment Share on other sites More sharing options...
Members Tomm Williams Posted July 10, 2012 Members Share Posted July 10, 2012 What else can you identify that may have contributed to the less than ideal GBF? Link to comment Share on other sites More sharing options...
Members dboomer Posted July 10, 2012 Members Share Posted July 10, 2012 First, you can't defeat the laws of physics. Doubling the distance reduces sound levels by 6dB...that's a lot. So what sounded fine at 20 feet is defnitely going to be noticeably reduced at 40 feet. If he's talking about a 40 x 60 foot room he'll pass critical distance at about 5 maybe 10 feet from a speaker. Inverse square stops operating beyond critical distance, so likely the SPL at 40 feet will be nearly identical to that at 10 feet. Link to comment Share on other sites More sharing options...
Members jlb Posted July 10, 2012 Members Share Posted July 10, 2012 AH came up with some excellent tuning's for this setup. This thread may help you. http://acapella.harmony-central.com/showthread.php?2788949-SRX-712M-Biamp-DSP-tunings&highlight=srx+712+tuning Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted July 10, 2012 CMS Author Share Posted July 10, 2012 If he's talking about a 40 x 60 foot room he'll pass critical distance at about 5 maybe 10 feet from a speaker. Inverse square stops operating beyond critical distance, so likely the SPL at 40 feet will be nearly identical to that at 10 feet. But the OP did hear a noticeable drop in volume as he walked from the speakers, so there must be an explanation. Here's my guesstimate of what happened (and Don I welcome your opinion of it); Critical distance of course assumes room reflection. The OP said there were 300 people attending. While not necessarily overcrowded, that's a very full room at 8 square feet per person. He stated the mid-high speakers were on poles on the subs, so the subs were well below head level. Either at floor level or waist-high. With a packed room, and likely a lot of people close to the stage area, LF energy is absorbed evenly and there will be greatly reduced room reflection, so critical distance could very well have been much further out from the speakers. So he did hear a reduced LF level as he walked out. I'd be interested to know if the feedback was HF, mids or LF, or all over the map. Link to comment Share on other sites More sharing options...
Members dboomer Posted July 10, 2012 Members Share Posted July 10, 2012 The OP said ... No offense to the OP .. but ... it seems he doesn't understand cause and effect. He appears to be trying to relate a bunch of things that probably don't go together. The low level drop he though he heard is more likely the result of room mode cancellations. It's easy in a room this size to have 20-30 dB swing in spl over a 4-5 foot distance. A room full of people would still put you in my 5-10 foot guess (of course I don't know much about the room) Link to comment Share on other sites More sharing options...
Members drumstix Posted July 10, 2012 Members Share Posted July 10, 2012 Just to bring it up, may not be any of the issues here. Could it be possible that you are hearing a low end void dead center of the stage? Sort of the power alley effect? Assuming the subs are under the tops side of stage. Link to comment Share on other sites More sharing options...
Members Axisplayer Posted July 10, 2012 Members Share Posted July 10, 2012 Sometimes it can be the room itself and we never get that sort of information, just the dimensions. I work one club that has a Western decor. The designer built the main room with a dance area near the stage, and then you pass through a set of three arches that sort of divides the one room into two areas...dancing and eating. They are high enough you don't really see them unless you look up. It just looks like a couple of columns in the room about 4" square. The room is only about 2000 square feet. I can bring in my QRX212 tops over a pair of LS1208 subs and 5K watts, crank it up, and in the area where the band is, it is uncomfortably loud. I don't like being in there. You literally can step under the arch, less than a 2' step, and the sound is now lacking a little high end, and the entire level drops at least 10-12 db immediately. There is no fix. You either use stacks in both areas (not practical in this room) or you live with it. If you turn it up enough to hear well in the back, the front room and dance floor empties out. If you turn it to a good level on the dance floor, the band sounds like a radio in the back. I try to ride the fence. It isn't easy since mix position is in the "dead" area just as you walk through the first arch, and along one wall. You cannot mix this room and get it workable in both areas unless you have mixed this room a few times and figured it out. Wonder what this room actually looks like instead of just dimensions and the distance he walked from stage..... Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted July 10, 2012 CMS Author Share Posted July 10, 2012 No offense to the OP .. but ... it seems he doesn't understand cause and effect. He appears to be trying to relate a bunch of things that probably don't go together. The low level drop he though he heard is more likely the result of room mode cancellations. It's easy in a room this size to have 20-30 dB swing in spl over a 4-5 foot distance. A room full of people would still put you in my 5-10 foot guess (of course I don't know much about the room) I'm giving the OP benefit of the doubt that he walked around most of the venue and didn't just beeline out and back. I'd be very surprised to experience a mode that encompassed the entire dance floor in a room that size, but it's certainly possible. Well, that and you don't like to admit you could be wrong. :poke: Link to comment Share on other sites More sharing options...
Members agedhorse Posted July 10, 2012 Members Share Posted July 10, 2012 Almost guaranteed that it's a combination of improper set-up and tuning along with room acoustics. Start with proper set-up and tuning (when you mention that when you eq to remove feedback things get muddy indicates you are trying WAY too hard to correct something that can not be corrected that way or are way overcorrecting or have completely run into room acoustic gain limits) and then move onto the room issues. Link to comment Share on other sites More sharing options...
Members RoadRanger Posted July 10, 2012 Members Share Posted July 10, 2012 Yes, the 712's were pole mounted over the subs. The speakers were well above people's heads tilted downward.Just to clarify was it the bottom, top or just the horns of the speaker "well above people's heads"? AKA how high were the bottoms of those cabs above the dance floor? I'm also curious why they were tilted down? Was it one of the super live high ceiling "gymnasium" type rooms that are hard to not sound like mud in? Link to comment Share on other sites More sharing options...
Members TimmyP Posted July 13, 2012 Members Share Posted July 13, 2012 With those amps (and itechs) it's easy to set them up such that the output is not what clips first. Makes the system run out of gas pretty quickly. Link to comment Share on other sites More sharing options...
Members bbrunskill Posted July 15, 2012 Members Share Posted July 15, 2012 You should be able to hit well over 100dB with that rig. Sounds to me like your gain structure is not right somewhere. Where was it lacking the most - highs or lows? I have a pair of SRX718 at the church I work part time at, and they work really well when coupled together. Definitely louder, and to my ears there is a little more low extension too. So try that, if having them centered won't work, stack them off to one side, it will still work, and as the bass is coming from a single point, it should still be fairly even throughout the room. If it's your highs that are running out of gas, you might need to upgrade to a pair of 722. They have a 4in compression driver which will give you a fair bit more oomph. 2x 12 rather than one will help too. Keep the 712's for gigs where you need more monitors. Link to comment Share on other sites More sharing options...
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