Once upon a time I remember seeing a few PA setups that featured one or two subs facing away from the audience(setups of 10 or more). The bands were running IEMs, so I assume it was entirely for FOH sound. Is there an advantage to this setup, I'm having trouble finding anything about this particular setup.
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Reversed Sub woofers
- Thread starter DrewMcDrew
- Start date
Sometimes they reverse a couple and kick them 180° out of phase to reduce rumble on and below the stage.
It's called "cardioid sub arrays". It works by reversing one of the subs, lowering it about 3db, adding a couple of milliseconds of delay, and reversing phase.
Here's a cut sheet from EV about it.
The purpose is to cancel out sub frequencies behind FOH. Keeps stage rumble down. So your not on a boomy stage, and running monitors so high to overcome the bass bleed.
Here's a cut sheet from EV about it.
The purpose is to cancel out sub frequencies behind FOH. Keeps stage rumble down. So your not on a boomy stage, and running monitors so high to overcome the bass bleed.
Hi.
Attached is another paper on the subject by Rog Mogale.
Creating a cardioid is a bit more demanding than just reversing+delaying some speakers, but after reading those two papers, You will understand how it works.
You'll also understand why the cardioid bass bins aren't very widely used.
Regards
Sam
Attached is another paper on the subject by Rog Mogale.
Creating a cardioid is a bit more demanding than just reversing+delaying some speakers, but after reading those two papers, You will understand how it works.
You'll also understand why the cardioid bass bins aren't very widely used.
Regards
Sam
I have, when we had time to set it up and align it. On big shows, you really need an afternoon to dial it in properly. Lately, some processor makers and even a few sub makers have made it a lot easier and faster with processor settings and even processed amplifiers and subs built with three drivers, one in a reversed configuration to achieve the physical part of the cardioid configuration. And there's several variations on the them now.
But however it's done, it takes a lot of processing, a lot of real estate in some configurations, and a lot more subs to achieve the level you want after you've applied the processing. In some cases, you are using lobes to achieve putting the low end where you want, more often, you are using nulls to lessen the level, as on the stage where the coupling of a big left/right sub array can really be ferocious on the stage. And in my experience, some of the "punch" and "impact" is lost, an anomaly noted by many folks. However, is situations like an outdoor orchestra setting, where reproduction for several thousand folks is needed, but you can't have a big lobe happening in the middle of all of those string mics, it's great to be able to do.
In my particular case, I've not been blessed with a very understanding boss, not to mention clients as we're allowed only a few hours to deploy the rig, wire up 40+ orchestra mics, do a quick and dirty line check and go with downbeat. They don't want to cover the expense of the extra day, the extra gear, and the real estate in front of the stage to deploy a properly set up cardioid sub system. So I have only, ehh, 5 or 6 shows with cardioid subs under my belt. If you look up "Cardioid subs" on the Net, you'll find tons of info about it. One notable system is the system that was out with Carrie Underwood last year. The system engineers deployed a rather extensive cardioid sub array that was quiet on the stage and allowed for nearly-perfect and even coverage of low end for her show. There were a few articles written about that system in the various pro audio magazines. There's many examples of the cardioid arrangement out there.
And now that I'm playing again, I care nothing whatsoever about dealing with that sort of thing anymore....
Hi.
You're welcome.
I have not yet made the tests I was planning to do since a DIY cardioid bass array doesn't even quite work on paper in the way I hoped to.
Because of mainly this:
If done correctly in a 3-way system using other than purpose designed cardioid cabs, You'll lose about 1/4 to 1/3 of the front projecting SPL after the frequency response hump that the cardioid by design produces is leveled.
You can't do that leveling easily with simple EQ's either, at least not with the ones readily available for us budget oriented
.
What exactly is the problem You need to solve, or do you just have a general interest on the subject?
Regards
Sam
You're welcome.
I have not yet made the tests I was planning to do since a DIY cardioid bass array doesn't even quite work on paper in the way I hoped to.
Because of mainly this:
If done correctly in a 3-way system using other than purpose designed cardioid cabs, You'll lose about 1/4 to 1/3 of the front projecting SPL after the frequency response hump that the cardioid by design produces is leveled.
You can't do that leveling easily with simple EQ's either, at least not with the ones readily available for us budget oriented
.What exactly is the problem You need to solve, or do you just have a general interest on the subject?
Regards
Sam
The D&B J subs work very well and with a lot less of them than, say, the EAW SB1000 and its variants. However, they are huge and heavy. And how about that price tag...
and the D&B amplifiers required to properly deploy them!! But they do make it a lot easier to calculate and deploy.
And they are probably totally inappropriate to mention in this conversation...
and the D&B amplifiers required to properly deploy them!! But they do make it a lot easier to calculate and deploy.And they are probably totally inappropriate to mention in this conversation...
