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Author Topic: Cardioid Sub Array, Subwoofer Steering, HOW TO DO IT?  (Read 68065 times)

Mac Kerr

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Re: Cardioid Sub Array, Subwoofer Steering, WHY TO DO IT?
« Reply #20 on: March 28, 2010, 12:13:27 pm »

Adam Schaible wrote on Sat, 27 March 2010 23:10

Sorry to dig this up... but curious about what you folks think.

With 8 subs, is this about as good as it gets?


That would depend on what you were trying to accomplish. It seems like a complicated array that makes a big lobe in the center. If that is what you are going for it may be great.

Some explanation about what is going on in the arrays, and what the purpose is might make the question clearer.

Mac
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Adam Schaible

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Re: Cardioid Sub Array, Subwoofer Steering, WHY TO DO IT?
« Reply #21 on: March 28, 2010, 12:24:44 pm »

I'm trying to get the most coverage out of 8 subs.  I spent a few hours working different patterns and didn't find anything that came close to as much forward coverage with 8 subs, and this had the advantage of rearward rejection.  
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Timo Beckman

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Re: Cardioid Sub Array, Subwoofer Steering, HOW TO DO IT?
« Reply #22 on: March 28, 2010, 12:26:51 pm »

I have build that set up 1 time only this one works very well if the stage is on the long side of the venue . If you have 8 subs i would go for a "normal" sub line and not for the some what V shape you have now .

(You might take a look at some predictions i map did

https://sites.google.com/site/timobeckmangeluid/een-evenement-en-nu (sorry the text is in dutch)


If you have enough amps and processor power you might go for a arc . Just make a straight sub line . The 2 middle ones stay at 0 ms delay (not taking the delay needed to allign them with the main lft/rght in account) Then delay the next sub with maybe 1 or 2 ms and go on 'till you get to the last one .

The other possibility is to displace the subs into a arc (so not doing it with delay but really bending the line of subs into a oval form . Damn this is hard to explain in english . Looks a little like this
 

http://cid-5933da57cf499561.skydrive.live.com/play.aspx/.res/5933da57cf499561!533/5933DA57CF499561!540?ct=photos

Edit: link repairs
« Last Edit: August 21, 2012, 11:03:03 pm by Langston Holland »
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Ivan Beaver

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Re: Cardioid Sub Array, Subwoofer Steering, WHY TO DO IT?
« Reply #23 on: March 28, 2010, 04:12:44 pm »

Adam Schaible wrote on Sun, 28 March 2010 12:24

I'm trying to get the most coverage out of 8 subs.  I spent a few hours working different patterns and didn't find anything that came close to as much forward coverage with 8 subs, and this had the advantage of rearward rejection.  

What exactly are you trying to do?  Use 8 subs or get a particular coverage pattern.

Remember that when you use an endfire array approach you will not get the same SPL out front as if you just used the same number of subs facing forward.

To get the same SPL, you will need more subs in an endfire or "cardoid" array.

It is all a tradeoff.  Which one is more important is up to you.
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For every complicated question-there is a simple- easy to understand WRONG answer.

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Bob McCarthy

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Re: Cardioid Sub Array, Subwoofer Steering, HOW TO DO IT?
« Reply #24 on: April 15, 2010, 10:47:12 pm »

Harry's pic is great.

Here is a pic I did recently that shows how the phase response drives the end fire array into the cardioid shape - interesting terminology point by Harry also - I agree that cardioid is an effect/result, not a configuration. Many ways to skin that cat.
This plot (and a second to follow that pairs with it) are excerpted from a more extensive blog post on the end fire.

Enjoy
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Bob McCarthy

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Re: Cardioid Sub Array, Subwoofer Steering, HOW TO DO IT?
« Reply #25 on: April 15, 2010, 10:48:24 pm »

second pic as promised
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Greg Longtin

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Re: Cardioid Sub Array, Subwoofer Steering, WHY TO DO IT?
« Reply #26 on: April 16, 2010, 08:35:26 am »

Ivan,

Ivan Beaver wrote on Sun, 28 March 2010 15:12

Remember that when you use an endfire array approach you will not get the same SPL out front as if you just used the same number of subs facing forward.

To get the same SPL, you will need more subs in an endfire or "cardoid" array.



To clarify, I assume you are saying that SPL will drop if all cabinets are not in phase?

IOW, if all cabinets are in phase and delayed according to their spacing, front output should be very similar to a 'regular' stack...

Greg
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Ivan Beaver

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Re: Cardioid Sub Array, Subwoofer Steering, WHY TO DO IT?
« Reply #27 on: April 16, 2010, 07:22:44 pm »

Greg Longtin wrote on Fri, 16 April 2010 08:35

Ivan,

Ivan Beaver wrote on Sun, 28 March 2010 15:12

Remember that when you use an endfire array approach you will not get the same SPL out front as if you just used the same number of subs facing forward.

To get the same SPL, you will need more subs in an endfire or "cardoid" array.



To clarify, I assume you are saying that SPL will drop if all cabinets are not in phase?

IOW, if all cabinets are in phase and delayed according to their spacing, front output should be very similar to a 'regular' stack...

Greg

One might "think" that.  But when I did my outdoor measurements in a fairly large parking lot (no models or predictions-but actual measurements using real loudspeakers in a real space-WOW what a concept Rolling Eyes  Laughing ) using a 135' (if I remember correctly-not sure of the exact size-it was 2 years ago) dia circle, with every setup (I used from 2 to 4 cabinets and different models), I first took a measuremet (polar response in 10
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For every complicated question-there is a simple- easy to understand WRONG answer.

Can I have some more talent in the monitors--PLEASE?

Ivan Beaver
dB Audio & Video Inc.
Danley Sound Labs

HarryBrillJr.

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Re: Cardioid Sub Array, Subwoofer Steering, WHY TO DO IT?
« Reply #28 on: April 16, 2010, 11:50:34 pm »

Ivan Beaver wrote on Fri, 16 April 2010 18:22

Greg Longtin wrote on Fri, 16 April 2010 08:35

Ivan,

Ivan Beaver wrote on Sun, 28 March 2010 15:12

Remember that when you use an endfire array approach you will not get the same SPL out front as if you just used the same number of subs facing forward.

To get the same SPL, you will need more subs in an endfire or "cardoid" array.



To clarify, I assume you are saying that SPL will drop if all cabinets are not in phase?

IOW, if all cabinets are in phase and delayed according to their spacing, front output should be very similar to a 'regular' stack...

Greg

One might "think" that.  But when I did my outdoor measurements in a fairly large parking lot (no models or predictions-but actual measurements using real loudspeakers in a real space-WOW what a concept Rolling Eyes  Laughing ) using a 135' (if I remember correctly-not sure of the exact size-it was 2 years ago) dia circle, with every setup (I used from 2 to 4 cabinets and different models), I first took a measuremet (polar response in 10
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Harry Brill Jr.
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Ivan Beaver

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Re: Cardioid Sub Array, Subwoofer Steering, Why I stand behind my work.
« Reply #29 on: April 17, 2010, 09:29:52 am »

HarryBrillJr. wrote on Fri, 16 April 2010 23:50


I generally use the CENTER of the array as the ZERO distance point to make these comparisons but I don't think the difference would account for 3dB on axis.  Something else was going on.  My experience on axis has been different than yours.

And there in where the "problem" starts in any measurement situation.

This was a fairly large empty parking lot and I choose the particular size kinda as a "This should be large enough" type thing-ya know real scientific Laughing .  While the on axis 0 position was about 67' the closest boundary (which was a slopping hill with trees on it) was about 250' from the 0 point (that was on axis 0).  The side closest boundaries were probably 1500' or more away (and they were trees) and the rear closest boundary (again trees) was probably 500' away.  So I don't "think" any boundary reflection was an issue. There was a building (about 250
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For every complicated question-there is a simple- easy to understand WRONG answer.

Can I have some more talent in the monitors--PLEASE?

Ivan Beaver
dB Audio & Video Inc.
Danley Sound Labs
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