Flown Subs, Ground Bounce, and People in 1/2 space

Re: Flown Subs, Ground Bounce, and People in 1/2 space

Phil Lewandowski said:
I should try and mess around with MAPP again and see what happens as you then lower that sub to say 10-20ft off the ground.
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It will block all your sight lines, is what it will do.

If flown sub arrays really had a huge detriment, they wouldn't be the holy grail of the big leagues.
 
Re: Flown Subs, Ground Bounce, and People in 1/2 space

Better yet, model a flown end-fire type array.
icon_cool.gif
This got some traction in a thread about under-deck sub array on Carrie Underwood's "push play" tour. I think you'll find the discussion relevant.

Bruce Reiter has links to pic of a flown version here: http://www.soundforums.net/live/threads/783-Carrie-Underwood-Sub-Woofer-Array?p=6596#post6596

There was additional discussion on the PSW forums.

Have fun, good luck.

Tim Mc
 
Re: Flown Subs, Ground Bounce, and People in 1/2 space

Bennett Prescott said:
It will block all your sight lines, is what it will do.

If flown sub arrays really had a huge detriment, they wouldn't be the holy grail of the big leagues.
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I'm am thinking about like in a small club environment when they fly subs 12-20ft off the ground. I am just curious what happens as you lower the subs, just so I can picture what is happening as the sub is moved closer and further away from the ground.

If you have a second I would be very curious of maybe 3 frequencies, 35, 60, 100hz ish; with a sub about 15ft off the ground, to see what happens as you lower the sub.


Thanks Much,
Phil
 
Re: Flown Subs, Ground Bounce, and People in 1/2 space

Phil Lewandowski said:
I'm am thinking about like in a small club environment when they fly subs 12-20ft off the ground. I am just curious what happens as you lower the subs, just so I can picture what is happening as the sub is moved closer and further away from the ground.

If you have a second I would be very curious of maybe 3 frequencies, 35, 60, 100hz ish; with a sub about 15ft off the ground, to see what happens as you lower the sub.
Thanks Much,
Phil
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If you are simply curious, why not download the free MAPP program from Meyers.
If you want to find out what will happen in the real world (MAPP is only two dimensional) stop the subs chain motors at various distances off the ground and do measurements in various places.

I flew the old house PA in First Avenue (Minneapolis nightclub) using bass speakers that went (IIRC) from about 12 to 20 feet off the deck. Ceiling height is probably just under 30 feet. Let me assure you, the LF was more even than the mid or HF with that installation, though after several different mid/high aiming sessions, we did get fairly even coverage throughout the room. First Avenue was particularly difficult for even coverage, with a wide main room, a mezzanine, and side balconies extending almost 180 degrees left and right.

There was no lack of 60 or 100 Hz with the flown PA, when seated, standing or falling down drunk. 40 Hz was about all that PA could do in the bottom, but if it was in the mix, it was pretty even throughout the room.

As Bennett notes, trim height is usually determined by sight lines, but room modes and nodes have more influence than trim height regarding even coverage of low frequencies.
 
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Re: Flown Subs, Ground Bounce, and People in 1/2 space

I think that people often seem to approach the effects of the floor the subs and the effects of the floor on the listeners as two separate events when they are actually addressing he same thing as the floor is a shared boundary.

To really mess up those that argue about losing level with flown subs, consider flying the subs very near the ceiling. Now the 'loading' boundary for the sub and the boundary affecting the listeners are two different boundaries and the effects can superimpose, resulting an in increase versus gorund stacked subs. However, a common issue with flown subs indoors is not paying attention to the relationship to the ceiling and surrounding surfaces, resulting in cancellation toward the listeners at relevant frequencies.
 
Re: Flown Subs, Ground Bounce, and People in 1/2 space

Brad Weber said:
I think that people often seem to approach the effects of the floor the subs and the effects of the floor on the listeners as two separate events when they are actually addressing he same thing as the floor is a shared boundary.

To really mess up those that argue about losing level with flown subs, consider flying the subs very near the ceiling. Now the 'loading' boundary for the sub and the boundary affecting the listeners are two different boundaries and the effects can superimpose, resulting an in increase versus gorund stacked subs. However, a common issue with flown subs indoors is not paying attention to the relationship to the ceiling and surrounding surfaces, resulting in cancellation toward the listeners at relevant frequencies.
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Ahh, yes, the ceiling causing a cancellation. That really could be an issue with smaller clubs, because there are times that the crowd almost gets 180 degrees below the flown subs/array and therefore would be recieving the largest time difference from the reflection off the ceiling.
 
Re: Flown Subs, Ground Bounce, and People in 1/2 space

Phil Lewandowski said:
Ahh, yes, the ceiling causing a cancellation. That really could be an issue with smaller clubs, because there are times that the crowd almost gets 180 degrees below the flown subs/array and therefore would be recieving the largest time difference from the reflection off the ceiling.
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In most small venues there is limited opportunity to work with steered bass arrays due to size & placement issues; hell, sometimes you have to hunt for a place to put a single sub! But there is a point at which you & Cap'n Kirk will ask Scotty to fight the laws of physics and you will not prevail. Every building has boundary surfaces and their physical relationship to one another is beyond your control. Sometimes you just have to let it go, do the gig and go home.

Have fun, good luck.

Tim Mc
 
Re: Flown Subs, Ground Bounce, and People in 1/2 space

Tim McCulloch said:
In most small venues there is limited opportunity to work with steered bass arrays due to size & placement issues; hell, sometimes you have to hunt for a place to put a single sub! But there is a point at which you & Cap'n Kirk will ask Scotty to fight the laws of physics and you will not prevail. Every building has boundary surfaces and their physical relationship to one another is beyond your control. Sometimes you just have to let it go, do the gig and go home.

Have fun, good luck.

Tim Mc
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Exactly, that is what you gotta do epecially in the "audio trenches" audio work. This stuff ends up really interesting me to at least be able to understand the theory and how things work in an ideal situation, and then what starts to happen as you start to move into a non-ideal situtation so then I can at least have an idea of what could be happening.


Take Care,
Phil
 
Re: Flown Subs, Ground Bounce, and People in 1/2 space

Tim McCulloch said:
In most small venues there is limited opportunity to work with steered bass arrays due to size & placement issues; hell, sometimes you have to hunt for a place to put a single sub! But there is a point at which you & Cap'n Kirk will ask Scotty to fight the laws of physics and you will not prevail. Every building has boundary surfaces and their physical relationship to one another is beyond your control. Sometimes you just have to let it go, do the gig and go home.
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All absolutely true.

But... if you think about this stuff, and develop some idea about how it use it when it is possible... then once in a long while, when the need arises and the laws of physics are in your favor, you have the opportunity to look like a real true genius.
 
Re: Flown Subs, Ground Bounce, and People in 1/2 space

Scott Helmke said:
All absolutely true.

But... if you think about this stuff, and develop some idea about how it use it when it is possible... then once in a long while, when the need arises and the laws of physics are in your favor, you have the opportunity to look like a real true genius.
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No disagreement, Scott. Small rooms can defeat one's knowledge, though, and knowing when to move on can make a difficult and frustrating day into a decent day at work.

I watched and listened as the PM for a legacy rap artist spent 2 hours trying to "ring out" some really nasty room reflections that were making their way into the artist's mic. He tried a number of techniques (several that I'd not seen monitor guys try before) and never got the significant changes he was trying for. In the end the result was marginally better, but for most folks a coin toss would have decided what was improved. I give him props and credit, he worked very hard to give his boss a good gig... but eventually what he accomplished for himself was frustration. At least he could get back on the bus knowing he'd tried everything he could to deliver.

Have fun, good luck.

Tim Mc
 
Re: Flown Subs, Ground Bounce, and People in 1/2 space

I was recently on a show where the sound company had spent three days setting up for an outdoor show including center clustered subs. The star came out for sound check and after the first song said turn them off. No discussion, no possible changes, just do it and now. He wS footing the production bill so that is what happened.

On the other hand, with someone not as totalitarian, a couple of options would have been nice. I have been able to scale down some of the cardiod sub stuff from Bennett's article to a couple of different ways I can set up two boxes.
 
Re: Flown Subs, Ground Bounce, and People in 1/2 space

The lower room "Hell" at the Masquarade in Atlanta Ga is a lovely example of "wall bounce" in addition to any ground and ceiling reflections. The late 1800's built room has very thick solid stone walls and a concrete floor. 6 EAW SB1000 subs deliver ground pounding bass reflections off of those walls that arrive nicely at FOH almost 180 degrees out of phase. If you ever mix there be shure to do a walk around or you will kill the people on the dance floor and still feel like there is nothing happening below 100 hertz. It gets a little better when the crowd fills up and some of that bothersome direct sound is absorbed.
 
Re: Flown Subs, Ground Bounce, and People in 1/2 space

Tim McCulloch said:
Better yet, model a flown end-fire type array.
icon_cool.gif
This got some traction in a thread about under-deck sub array on Carrie Underwood's "push play" tour. I think you'll find the discussion relevant.

Bruce Reiter has links to pic of a flown version here: http://www.soundforums.net/live/threads/783-Carrie-Underwood-Sub-Woofer-Array?p=6596#post6596
Click to expand...

If this is an end-fire setup then the subs are actually firing forward, parallel to the ground and above the people's heads? I wonder whether there is a way to direct the LF a bit downwards (from a flown center sub cluster) to get more level on the floor?
 
Re: Flown Subs, Ground Bounce, and People in 1/2 space

eytan gidron said:
If this is an end-fire setup then the subs are actually firing forward, parallel to the ground and above the people's heads? I wonder whether there is a way to direct the LF a bit downwards (from a flown center sub cluster) to get more level on the floor?
Click to expand...

There is a JBL Tech Note on flown sub arrays that can be steered up and down as well as forward. This paper is about 10 years old.

Mac
 
Re: Flown Subs, Ground Bounce, and People in 1/2 space

Thanks Mac,

I've had this for some time, but I haven't read it yet. I have a long flight tommorow morning (to the Frankfurt fair), it's a good opportunity to do it.

Eytan
 
Re: Flown Subs, Ground Bounce, and People in 1/2 space

Yes you are correct. Kinda like what a line array is doing, shooting above people's heads. By the way Bennett, thanks for your "Subwoofer Techniques" articles, they are simple and clear.

Eytan
 
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