End Fire Subwoofers (Carrie Underwood Spinoff)

J

Jared Koopman

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Jun 13, 2012
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I realize this is an old topic but I was reading through old topics and Bennet's article and I had a couple of questions (purely educational as I have no experience with the big rigs like this).

1. Can you do an end-fire array with any type of sub or does it require a specific design to implement correctly?
2. If you put an end fire array under a stage, how does that affect verticle dispersion (if at all)?

Thanks,
Jared
 
Re: Carrie Underwood Sub Woofer Array

Jared Koopman said:
I realize this is an old topic but I was reading through old topics and Bennet's article and I had a couple of questions (purely educational as I have no experience with the big rigs like this).

1. Can you do an end-fire array with any type of sub or does it require a specific design to implement correctly?
2. If you put an end fire array under a stage, how does that affect verticle dispersion (if at all)?

Thanks,
Jared
Click to expand...
Yes any speaker can be used in an endfire or cardioid array. HOWEVER I am starting to "rethink" some of that statement. If you have a physically directional sub- the energy that is used for the "rear cancellation" is going to be less by nature. So less cancellation.

HOWEVER-because the energy going to the rear is less-that means less sound-in and of itself.

I need to find some time to do some testing with larger subs that have physical directionality in a "steered" array to get a better handle on this.

It may end up being a "wash", or some new and unaccounted for may arrise.

Measurements will tell.

For the second question-directional arrays work best when they are free field and away from all boundaries.

As soon as you start to introduce boundaries (strage deck-walls etc) things start to change. How much-depends on the particular situation-what the wall is make of etc.

So you will still get some directionality-but how much has a lot of "depends" attached to it.
 
Jared Koopman said:
I realize this is an old topic but I was reading through old topics and Bennet's article and I had a couple of questions (purely educational as I have no experience with the big rigs like this).

1. Can you do an end-fire array with any type of sub or does it require a specific design to implement correctly?
2. If you put an end fire array under a stage, how does that affect vertical dispersion (if at all)?

Thanks,
Jared
Click to expand...


You can do it with any type, yes. Some types of subs already have a lot of directionality and don't gain as much, such as the large horn subs.

Depends on stage height, sub height, etc. Short answer would be, not much.
 
Re: Carrie Underwood Sub Woofer Array

Ivan Beaver said:
For the second question-directional arrays work best when they are free field and away from all boundaries.

As soon as you start to introduce boundaries (strage deck-walls etc) things start to change. How much-depends on the particular situation-what the wall is make of etc.

So you will still get some directionality-but how much has a lot of "depends" attached to it.
Click to expand...

Having an empty rear area is needed, yes, otherwise the reflections from that rear surface will arrive too soon in time - IE, before the array as a whole can cancel them out. I'm assuming there is a minimum distance based on total array distance to get the time to line up right.

However, not sure about side surfaces being bad. Imagine a tube of subs, where it was not only a pair of parallel subs firing in, but two parallel rows. One pair firing at each other top/bottom, the other pair at each other side/side. As long as the rear was to free space, it would essentially be a big bass cannon, would it not?

If the space under the stage was rigid and had no air leaks, other than plenty of space out the rear - it should work fine. However, how many stages just happen to be constructed like this? ;)
 
Re: Carrie Underwood Sub Woofer Array

How much space are you talking about? And by space do you mean complete open space or just an "Exit" port? Perhaps the purpose of my question is could an end fire array be used in a church or theater where there is the desire to keep visual impact to a minimum, yet still have the sonic impact.
 
Re: Carrie Underwood Sub Woofer Array

Jared,

I have used end-fire arrays next to stages plenty of times, outdoors, and been very happy. In my experience, however, putting them under the stage still couples lots of energy to the stage and can cause more problems than its worth. By definition if your array is enough of a laser beam that it can keep energy off the stage 3' overhead, it's not going to be covering your audience very well.
 
Re: Carrie Underwood Sub Woofer Array

Bennett Prescott said:
Jared,

I have used end-fire arrays next to stages plenty of times, outdoors, and been very happy. In my experience, however, putting them under the stage still couples lots of energy to the stage and can cause more problems than its worth. By definition if your array is enough of a laser beam that it can keep energy off the stage 3' overhead, it's not going to be covering your audience very well.
Click to expand...

That is what I suspected but I was just curious. Thanks for the explanation.
 
Re: Carrie Underwood Sub Woofer Array

Bennett Prescott said:
Jared,

I have used end-fire arrays next to stages plenty of times, outdoors, and been very happy. In my experience, however, putting them under the stage still couples lots of energy to the stage and can cause more problems than its worth. By definition if your array is enough of a laser beam that it can keep energy off the stage 3' overhead, it's not going to be covering your audience very well.
Click to expand...

That is very true, and an often overlooked area in MANY aspects of loudspeaker system design.

Very often people get "all hung up" on one particular aspect-and COMPLETELY miss the big part of the picture.

In other words, they "fix" one thing/area (be it with DSP eq/filters-loudspeaker layout (physical) and such) and yet make it worse for the major part of the audience.

But if all they are concerned with is ONE area-then fine-but remember who is paying the bills.

I like Jamie Andersons approach-Communism. Nobody gets it really good-but everybody get the same thing. So at least it is more consistent.

You HAVE to look at the BIG picture (unless it is a one person listening room), which some sound people think a concert is :(.
 
Re: Carrie Underwood Sub Woofer Array

Ivan Beaver said:
That is very true, and an often overlooked area in MANY aspects of loudspeaker system design.

Very often people get "all hung up" on one particular aspect-and COMPLETELY miss the big part of the picture.

In other words, they "fix" one thing/area (be it with DSP eq/filters-loudspeaker layout (physical) and such) and yet make it worse for the major part of the audience.

But if all they are concerned with is ONE area-then fine-but remember who is paying the bills.

I like Jamie Andersons approach-Communism. Nobody gets it really good-but everybody get the same thing. So at least it is more consistent.

You HAVE to look at the BIG picture (unless it is a one person listening room), which some sound people think a concert is :(.
Click to expand...

That will get you lynched in Kansas, probably Georgia, too. Be careful, Ivan.
 


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