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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Subwoofer Forum => Topic started by: Nick Wixom on October 10, 2017, 10:28:31 PM

Title: Mixing subs to achieve a cardiod sub array
Post by: Nick Wixom on October 10, 2017, 10:28:31 PM

I have at my disposal 4 EV tx2181 subs, 4 EV tx2152 tops and a pair of powered ev ekx-18 subs. The last time a used this rig I left the EKX subs at home and just stacked two of each cabs on the outside of the stage. Looked nice, but had a ton of sub on stage to deal with.

The other day I got to finally use the cardiod sub feature on the ekx subs for a small gig. I was blown away by how effective it was and how much it reduced my stage volume.

I'm wondering if I could run the EKX subs in cardiod mode next to my Tour-X subs and achieve similar results. I don't have prediction software to test this and I don't have space at my shop to test it either. The venue that I most commonly use these in does not allow for a center array of subs.

Any one that understands sub arrays and the physics of that stuff able to tell me if this would be a wasted pursuit? I'm currently using my M32 as my processor for my mains, so extensive processing is unavailable.

Title: Re: Mixing subs to achieve a cardiod sub array
Post by: Jeremy Young on October 11, 2017, 07:55:37 PM

Hi Nick,

It's "generally" not a good idea to mix subs of different models.  Differences in the phase response and frequency response inherent to the two subwoofer designs will likely cause more issues than benefits unless you have a lot of time/tools to measure and align them (over my head for sure, but others on here could explain if you had a good measurement rig and the space to do the measurements, which it doesn't sound like you do). 

If you're wanting to use your TX2181 subs in a cardioid configuration, all you need is at least two channels of amplifier, some digital delay for one of them, and a polarity reversal (special cable at it's crudest, off the board or amp would be better for experimentation).  I don't have an M32 but i suspect it would have delay on it's aux outputs, so you could run your subs on a pair of aux sends (one with the appropriate processing applied).  EV has a good guide for determining just what that processing needs to be online here: www.electrovoice.com/downloadfile.php?id=8913 (http://www.electrovoice.com/downloadfile.php?id=8913)

There is no way to utilize the processing inside your powered EV cabs to make your other cabs act the same way that I'm aware of, if that's what you were asking.  Hope that helps!