# Cardioid Subwoofer



## Stingebr (Sep 12, 2013)

Hello everyone:

Im thinking configure my 2 sealed single 12 inch subwoofer in cardioid pattern.To get more dB in front and eliminate all the back projection in the wall of the sub frequencies. iwill make this setup this weak to check if it really work for home theaters applications.

Some one have made this configuration?
Please let me now yours opinions and experiences.

Thanks


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## hjones4841 (Jan 21, 2009)

Maybe I don't understand your question, but I don't think that orientation in the enclosure will make much difference in how it reacts with the room. Of course, if one sub faces into a back wall and it is close to the wall, then that likely will cause some cancellations at some frequencies.


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## Stingebr (Sep 12, 2013)

I have made the configuration and it not what I expected. It get more punch in the center but in some places in the corner and back that it get total cancellation. I will display some pictures of the room acoustic for the sub in 80HZ.

This is my original subwoofer placement in my room:

PICTURE 2

This is the new placement test for the cardioid Subwoofer.
Cardioid subwoofer consist in one woofer in the front and one in the back. The woofer in the back need to invert polarity phase and adjust the time delay to create the cancellation in the back so i gain some dB in the front:

PICTURE 1

In cardioid subwoofer i get more punch in the center of my listening area, but i get some cancellations in the corners. In single stereo subwoofer i get a more distributed bass around the room. Both make cancelation in the back of the room but that is because of the comb filters. 
I will keep with the cardioid setup because is the one in which i get a more energy of bass in the center.


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## luegotelodigo (Mar 27, 2009)

How did you do the simulation?


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## Wayne A. Pflughaupt (Apr 13, 2006)

I’ve never seen the term “cardioid” used with subwoofers. It really isn’t correct as sub output is virtually omnidirectional, not directional as cardioid implies.

Which is Picture #1 and which is #2? They are not labeled. And you describe them both as “cardioid,” even though sub placement between the two is obviously different. :huh:

Regards, 
Wayne


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## luegotelodigo (Mar 27, 2009)

It's quite common in PA applications create cardioid patterns by the use of two omni subs.

A cardioid is the sum of a monopole and a dipole so if you space them about 1/4 Lambda, switch polarity of the back one and delay it the equivalent of another L/4 you should get a back cancellation and a front coherent sum (+6 dB), additional attenuation of the back one will help with the backwards cancellation.

Sorry to refloat such an old post but I found it googleing for home applications of cardioid subs and I didn't realize.


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