Members mrcpro Posted July 4, 2011 Members Share Posted July 4, 2011 I'm DJing in this small parking lot quite a bit this summer but am having a heck of a time getting the low end right. There's a hole right where I want it most - the space in this video: [video=youtube;RxAxYbN0LFE]http://www.youtube.com/watch?v=RxAxYbN0LFE But it's overwhelming everywhere else. We received a complaint from an apartment complex two blocks away that the tenants were being shaken out of their beds last Saturday. And get this: the speakers are pointed in the opposite direction from these apartments, and the sound also had to travel through the buildings on both sides of the street to get there. I'm using my new home built B&C 21" subs. I think they were about 6-7 feet away from the back wall. I know that probably the best thing to do would be to put them against the wall but I really need them in front of me for a barricade. This place gets pretty wild and I need some protection back there. Would it be better to move them in closer to the wall or further out? This space is a downtown parking lot during the day, and we all have to hustle our butts to convert it into a bar before 9pm - so there's not a lot of time for experimentation. Thanks to all who have suggestions and Happy 4th! Link to comment Share on other sites More sharing options...
Members Coaster Posted July 4, 2011 Members Share Posted July 4, 2011 one location around here fixed this exact problem with a cardioid array built out of srx 728's and some dsp. i believe they used 12 728 to build the array. the time i was there prior to this i had the cops there with 4 mtl-1x in just a few minutes. Link to comment Share on other sites More sharing options...
Members dboomer Posted July 4, 2011 Members Share Posted July 4, 2011 Almost doesn't matter which way you point them as the lowest frequencies tend to be non directional. The sound may be coupling through the ground and carrying to the neighbors that way. Sound travels much farther through solids than through air (remember putting your head to a railroad track). You might try "floating" them on something spongy. They will have more low output (at least at some frequencies) if you butt them up to the wall. Closer to the wall will cause cancellations at some frequencies (1/4 wave). Link to comment Share on other sites More sharing options...
Members RoadRanger Posted July 4, 2011 Members Share Posted July 4, 2011 I think they were about 6-7 feet away from the back wall.Round trip time = 6.5 feet times 0.91 ms/foot times 2 = 11.8 ms. Half wave (cancellation) frequency = 1000/(11.8 x 2) = 42 Hz. Link to comment Share on other sites More sharing options...
Members mrcpro Posted July 4, 2011 Author Members Share Posted July 4, 2011 Round trip time = 6.5 feet times 0.91 ms/foot times 2 = 11.8 ms. Half wave (cancellation) frequency = 1000/(11.8 x 2) = 42 Hz. So I think what you're saying is that I had them placed at the worst possible distance? Makes sense... Link to comment Share on other sites More sharing options...
Members RoadRanger Posted July 4, 2011 Members Share Posted July 4, 2011 So I think what you're saying is that I had them placed at the worst possible distance? Makes sense...Any distance near a hard surface is bad - in this case you'd also get a peak at 2x that frequency and another cancellation at 3x (126Hz = goodbye kick drum), etc. Link to comment Share on other sites More sharing options...
Members dennis a Posted July 4, 2011 Members Share Posted July 4, 2011 I'm using my new home built B&C 21" subs. I think they were about 6-7 feet away from the back wall. I know that probably the best thing to do would be to put them against the wall but I really need them in front of me for a barricade. This place gets pretty wild and I need some protection back there. How many subs do you have and how are they placed...how far are they from each other? I feel their relationship to each other is a larger issue than their relationship to the back wall. You have cancellations that you may not be able to remove but you may be able to relocate them. Coasters cardioid suggestion may help with the apartments but will have little effect on the local cancellation(s). Link to comment Share on other sites More sharing options...
Members mrcpro Posted July 4, 2011 Author Members Share Posted July 4, 2011 It's just two 21" subs coupled together in front of me. What I'd like to do is turn them down and get better low end in the dance space. The deck above where I shot part of that video - the low end is literally rattling everything in sight. You can't even keep your drinks on the tables. Link to comment Share on other sites More sharing options...
Members dennis a Posted July 4, 2011 Members Share Posted July 4, 2011 It's just two 21" subs coupled together in front of me. What I'd like to do is turn them down and get better low end in the dance space. The deck above where I shot part of that video - the low end is literally rattling everything in sight. You can't even keep your drinks on the tables. I can't tell much from the video...any chance you could post an overhead diagram including boundaries, sub location, and dimensions? please include the dance floor and cancellation Link to comment Share on other sites More sharing options...
Members RoadRanger Posted July 4, 2011 Members Share Posted July 4, 2011 There's an old saying about it not being how big it is but knowing how to use it I think? Link to comment Share on other sites More sharing options...
Members dennis a Posted July 4, 2011 Members Share Posted July 4, 2011 There's an old saying about it not being how big it is but knowing how to use it I think? I didn't know that referred to sound equipment Link to comment Share on other sites More sharing options...
Members RoadRanger Posted July 4, 2011 Members Share Posted July 4, 2011 I didn't know that referred to sound equipmentYup - firearms too . Link to comment Share on other sites More sharing options...
Members mrcpro Posted July 4, 2011 Author Members Share Posted July 4, 2011 Yeah it does. Anyway the side wall is maybe 15' from the subs. Everything else is open space. The makeshift bar goes underneath the deck and extends out. The next building is hundreds of feet away. There's nothing in front except a railroad yard. Link to comment Share on other sites More sharing options...
Members RoadRanger Posted July 4, 2011 Members Share Posted July 4, 2011 Yeah it does. Anyway the side wall is maybe 15' from the subs. Everything else is open space. The makeshift bar goes underneath the deck and extends out. The next building is hundreds of feet away. There's nothing in front except a railroad yard.I suspect just one of them bad boys in the corner of the back wall and that side wall would scramble everybody's innards just fine . I'm sure you can find something else to use as a barricade . Link to comment Share on other sites More sharing options...
Members dennis a Posted July 4, 2011 Members Share Posted July 4, 2011 Yeah it does. Anyway the side wall is maybe 15' from the subs. Everything else is open space. The makeshift bar goes underneath the deck and extends out. The next building is hundreds of feet away. There's nothing in front except a railroad yard. Rather vague. I can enter info into a prediction program and determine the problem as well as the fix but I need a diagram from you Link to comment Share on other sites More sharing options...
Members Dookietwo Posted July 4, 2011 Members Share Posted July 4, 2011 Any chance your subs are 3.5 feet off the floor? This will kill 80 hz. Dookietwo Link to comment Share on other sites More sharing options...
Members mrcpro Posted July 4, 2011 Author Members Share Posted July 4, 2011 The subs are on the asphalt. I haven't elevated them. I just got a call from the manager. Yeah on the 4th. The owner is really upset about that noise complaint and even though we're in a commercial zone we may get shut down unless I get this figured out. Or I'll get replaced. I'm thinking seriously about RoadRanger's suggestion of corner loading one (or both if I dare) and using something else as a barrier. Then turning the sub amp way down. Link to comment Share on other sites More sharing options...
Members RoadRanger Posted July 4, 2011 Members Share Posted July 4, 2011 Any chance your subs are 3.5 feet off the floor? This will kill 80 hz.Only in the "up" direction - them poor pigeons won't have anything to shake their booties to for sure . Link to comment Share on other sites More sharing options...
Members RoadRanger Posted July 4, 2011 Members Share Posted July 4, 2011 BTW corner loading will steer the lows straight out of the corner (45 degrees to each of the walls). I'm not sure what is in that direction but if away from the "bass haters" that'd be a good thing Link to comment Share on other sites More sharing options...
Members agedhorse Posted July 4, 2011 Members Share Posted July 4, 2011 You sure the complaints are for real and not something that was generated by the event itself? Sound complaints are more politically acceptable. I have a very hard time believing that sub level 2 blocks away through 2 buildings is going to be anywhere near the ambient level in a commercial district, no less shaking folks out of bed. Especially 2 home made subs. I small a stinker here. Cardioid array isn't a practical solution here given the number of boxes. Link to comment Share on other sites More sharing options...
Members Dookietwo Posted July 4, 2011 Members Share Posted July 4, 2011 You sure the complaints are for real and not something that was generated by the event itself? Sound complaints are more politically acceptable. I have a very hard time believing that sub level 2 blocks away through 2 buildings is going to be anywhere near the ambient level in a commercial district, no less shaking folks out of bed. Especially 2 home made subs. I small a stinker here.Cardioid array isn't a practical solution here given the number of boxes. I agree. Make sure there is a real complaint. Next see the city rules for sound and get a spl meter and make sure your in the wrong. 1 person should not shut down an event for many. Only takes 1 blue hair to raise a complaint and give others who may not want your show to go on a reason. Sounds like someone doesn't like the idea of this going on and is looking for any reason to shut it down. You have rights as well. Dookietwo Link to comment Share on other sites More sharing options...
Members Dookietwo Posted July 4, 2011 Members Share Posted July 4, 2011 Only in the "up" direction - them poor pigeons won't have anything to shake their booties to for sure . Try it. You'll find its pretty omni. Dookietwo Link to comment Share on other sites More sharing options...
Members agedhorse Posted July 4, 2011 Members Share Posted July 4, 2011 If important people really don't want your show to happen, forcing the issue can really end poorly. You have to take this into consideration too. Link to comment Share on other sites More sharing options...
Members RoadRanger Posted July 4, 2011 Members Share Posted July 4, 2011 If important people really don't want your show to happen, forcing the issue can really end poorly. You have to take this into consideration too.Yes, always remember the Golden Rule: "He who owns the gold rules" Link to comment Share on other sites More sharing options...
Members agedhorse Posted July 5, 2011 Members Share Posted July 5, 2011 Yes, always remember the Golden Rule: "He who owns the gold rules" and he who fights with the ruler generally regrets that decision. Link to comment Share on other sites More sharing options...
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