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[Rich Stevens]

That puts us back to the "flying" idea...

[Rich Stevens]

[Brad Weber]

Mike Sessler wrote on Sun, 17 June 2007 17:49

You may get better coverage, but your gain before feedback will almost surely go down. Like others have said, you need to get the speakers in front of the stage. Start with that and work up from there...

I have to disagree.  Getting the speaker coverage in front of the mics is best but just getting the speakers to where they are aimed at the seating rather than hitting everything but the ceiling indirectly will likely improve the gain before feedback go down, especially for the vocal mics that are shown stage left.

If you mix mono you don't want such extreme overlap from the speakers.  The center aisle helps as that's where the worst interactions would be, but it looks like you could almost get away with one 90 degree horizontal speaker if it is located on or at the short parapet wall.  It appear that it would greatly shoot over the mics.

My concern with a center cluster is that with your constraints it starts becoming the voice from above.  You may be able to get the coverage and even intelligibility, but it may be very disconcerting as far as localization.

Rich, keep in mind that while you can grossly show the nominal speaker coverage with angles such as you have done, the coverage a) is three dimensional, the coverage is based on the actual distance from the listener, which will be a combination of both the horizontal and vertical distances (e.g. the coverage in plan for a 90 degree speaker that is 5' in front of the seating and 25' overhead is that from a speaker 25.5' away from the front row, not one 5' away, and for your 23.5' depth, a speaker 34.3' away for the back row),  b) is not nice clean angles like that, it is usually more ovoid, c) is defined by the -6dB points, it's not as though the sound stops there and different speakers respond differently outside that angle (some may actually go back up in level at certain angles), and d) the coverage is very frequency dependent, it is usually much larger than the nominal angle at lower frequencies and can vary at other frequencies, some speakers even flip the horizontal and vertical pattern at some frequencies.  So the angles such as you show do give a general idea and are very helpful, but don't show an accurate picture.

[Rich Stevens]

Brad Weber wrote on Sun, 17 June 2007 17:46

...it looks like you could almost get away with one 90 degree horizontal speaker if it is located on or at the short parapet wall.  It appear that it would greatly shoot over the mics.

Do you mean just the stage left speaker, where it's shown on the wall?

Brad Weber wrote on Sun, 17 June 2007 17:46

My concern with a center cluster is that with your constraints it starts becoming the voice from above.  You may be able to get the coverage and even intelligibility, but it may be very disconcerting as far as localization.

Ding! NOAH....

Brad Weber wrote on Sun, 17 June 2007 17:46

Rich, keep in mind that while you can grossly show the nominal speaker coverage with angles such as you have done....

Well, no matter what I do, I try to make sure it's gross.  Seriously, I know all that, but working in 2-D, I had to draw a line somewhere, so why not the "nominal" angles?  I actually did a bit of trig and corrected the angles (at least partially) on the overhead cluster drawing.  I didn't bother on the top-of-wall version since the angles were much shallower and I was in a hurry.

[Ira White]

Ivan Beaver wrote on Sat, 16 June 2007 18:48

I am still failing to see what differance an eq will make in a room with reflective surfaces vs one that is dead? The only way you can eq a room is with a wrecking ball or bulldozer.

Sorry I was late getting back on that question. I thought that was familiar terminology. EQing the room simply implies that you are having to tune the speakers for all the generated room characteristics, not just the speaker response. In a well designed studio control room for example (a controlled environment which could be compared to a "dead" live sound environment), you don't have to EQ for the room or top-notch studio monitors properly designed and configured for the space.

Conversely, a reflective room is going to be demanding when it comes to tuning out the predominant frequencies that are reflected and enhanced around the room, no matter how accurate the speakers might be. Is this not obvious or am I missing something in your question?

[Brad Weber]

Rich Stevens wrote on Sun, 17 June 2007 19:56

Seriously, I know all that, but working in 2-D, I had to draw a line somewhere, so why not the "nominal" angles?  I actually did a bit of trig and corrected the angles (at least partially) on the overhead cluster drawing.  I didn't bother on the top-of-wall version since the angles were much shallower and I was in a hurry.

The main concept I was trying to get across is that a simple 2-D view of coverage can be very misleading.  For a simple example, think of a 90 degree horizontal coverage speaker located 5' in front of and 25' above a listener.  If viewed simply in a 2-D plan view the speaker appears to be just 5' away from the listener and thus the coverage from the speaker at that point would be 10' wide.  But that is not what is really happening.  Due to the height of the speaker it is actually 25.5' away from the listener, not 5', and the nominal coverage is 51' wide, not 10'.

So in a situation like would apparently exist for your central cluster where the speaker is high overhead but only a little in front, simply looking at it in terms of the nominal coverage is useful if the speaker is at ear height, but is not real accurate for the actual situation.  Add in the real coverage, the fact that it could differ greatly with frequency, etc. and what you actually get may not at all resemble what is shown by the nominal coverage in 2-D.

[Ivan Beaver]

Basically I hope you are not talking about applying an eq to the resultant reflection and the damage that it causes (either a bump or a dip) in the freq response at a single mic location.  

For what you "fix" at one location will more than likely cause a greater damage to all the other seats.  You have to do a detailed analysis including looking at the proper phase trace to determine if what you looking at on your software is either a minimum or non minimum phase event.  If it is non minimum you HAVE to simply ignore it-NO MATTER how bad it may look, as it is only existant at that mic position, other positions/seats will have a different response.

It is for this reason that you can't jsut simply go into a room and start whacking away at the eq hoping to fix the problem.  It might "look" better on your screen, but actually sound worse throughout the room.

[Ira White]

Ivan Beaver wrote on Tue, 19 June 2007 08:05

Basically I hope you are not talking about applying an eq to the resultant reflection and the damage that it causes (either a bump or a dip) in the freq response at a single mic location.

Not at all. Essentially, it was a general response about the potential need for better equalization in a problem room.
On the subject of graphic EQ, I was thinking in terms of any "resonances" created throughout the room primarily from multiple reflections in the low and low-mid range. This can be tackled at least to some degree with precision EQ. Most of the other adverse elements must be addressed in terms of speaker design and placement, room design, boundary treatments, and/or other aspects of tuning.

Thanks for bringing it up so the subject will be clearer.

[Scott Helmke (Scodiddly)]

Some good info above.  But I'd like to mention that you have the right idea - it really couldn't be any worse than the current setup, so why not try some cheap experiments?  If you can set aside  some off-hours time with the pastor and other folks and test the speaker(s) on top of the wall, on the ground at the sides, etc., you'll probably be able to get a lot of improvement for next to nothing in cost.

[Don Lanier]

I agree with Josh, Move that speaker out in front of the microphones and your sound will immediatly improve, take it down and put them on speaker stands down on the ground and then work at resetting all your mixer and eq settings. Since its been pulled back and back you now need to reset things. By yanking all the EQs down and turning everything down you system is running with no headroom, no gain and will sound like a cardboard box. Zero everything out and start fresh, one channel at a time and get the band and musicians/singers to help. This means a lengthy soundcheck !!!!

If you dont want these speakers on the ground(stands) buy wall mounts and put the speakers on wallmounts OUT IN FRONT OF EVERY MIC,
Or hire a professional to rig them, these speakers probably arent designed for flying but do have pole mounts for use with stands or wall mounts.

The picture I saw is your classic we dont want to see speakers so lets put them in up there and who cares(Because we dont understand) what the sound guy has to deal with. Youll be amazed how good the system sounds and how little feedback youll have when the Mics are behind the speaker. Trying to visualize 3D drawings and use Polar plots to fix this problem is a waste of time for a layman who is struggling to understand the basic principles of operation let alone propagation or dispersion angles etc....Simple, MOVE THE SPEAKERS.

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