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[Scott Hofmann]

The whole problem of the ceiling, the beams, and the projector goes away if you mount column arrays to the side walls near the front of the room, basically where the speakers on stands are located. Here's another good one:
http://slsaudio.com/SLS%20Audio%20LS6593v2%20Ribbon%20Line%20Array%20Column.htm

[Mark McFarlane]

Your drawing is nice and geometrically pretty but, as was pointed out to me once and now have learned by experience, the 90 degrees may not be 90 degrees at all frequencies and at all distances. Best to get more information on the dispersion patterns to verify that they will be good for this particular room. You might already have taken this into account but, I thought I would bring it up.

Thanks Kent, I fully understand the frequency-dependent pattern issues.  The 90 degree pies are just provided as reference points.

[Mark McFarlane]

Mark,

Would it be feasible to adjust the projector, maybe just get it to hang lower with a new mount?  something like this:
any of the mounts form Omni mount
http://www.omnimount.com/products/ceiling_and_projector_mounts/projector_mounts/
and a pipe extension like this
http://www.omnimount.com/products/ceiling_and_projector_mounts/projector_mounts/accessories/npt_pipes/

That would maybe allow you to hang the projector lower and project under the speaker cabinet and still use the entire screen.

Nice idea, but I think to project under a 12" hung box and still hit the top of the screen the projector would need to hang close to 2 feet below the ceiling, putting it a little under 7' off the floor.  Probably not going to fly in this room, but a good idea.  If we can find some speakers that only hang 6 inches when tilted, then it may be a solution.

[Mark McFarlane]

The whole problem of the ceiling, the beams, and the projector goes away if you mount column arrays to the side walls near the front of the room, basically where the speakers on stands are located. Here's another good one:
http://slsaudio.com/SLS%20Audio%20LS6593v2%20Ribbon%20Line%20Array%20Column.htm

Thanks Scott.  Anything with decent pattern control would work where the current speakers are.  In fact, that has an advantage in that sometimes the room setup is rotated 90 degrees, and the wall locations would still cover the room fairly well.  My only real concern about those positions is the imaging, but it may be a decent compromise.

[Brad Weber]

Is the problem rotating the horn typically in a changing phase response in the crossover region, or just that the rotated pattern isn't measured by the manufacturer?

It is a phase reponse issue but due to the degree of interaction between the drivers changing.  Say you had a nominal 90 degree horizontal by 60 degree vertical horn in a typical two-way box with the horn over the woofer, in that case the interactions between the horn and woofer through crossover are related to the smaller vertical pattern.  But if you rotate the horn now you have a wider horn pattern interacting with the woofer and thus different interactions through crossover.  That can result in a different vertical pattern through crossover and in some cases some significant lobing and nulls.  Unfortunately, manufacturers rarely provide pattern information for speakers with the horn rotated.

[Scott Hofmann]

I think you will find that the SPL throughout the room will be so even that it will be hard to find the source! The Bose MA12 will require the Bose digital processor ($500). The SLS, TOA, or Community Entasys, etc. will need a DSP or active crossover.

[Brad Weber]

I think you will find that the SPL throughout the room will be so even that it will be hard to find the source!

But the intelligibility and gain before feedback may not be so great.  The problem I see with most column speakers is that they may have too great a horizontal pattern for being in the locations of the existing speakers.  You seem to end up potentially balancing too much level at the microphones versus too much energy hitting the rear wall.  And if the system is stereo you still have distance affects to address for coverage, for example the pulpit being in the pattern and closer than many listeners, while if mono you seem to have tremendous overlap in coverage in the center of the room.  Good coverage is not just lots of coverage but coverage where you want it and not where you don't.
 
Mark, matching tonality of any center fill may not be as much of an issues as it seems.  Because the left and right mains have less directionality at low frequencies you may want to roll off the low end of the center fills and let the mains carry that.  You may also want to EQ any center fills differently due to their relationship to the stage and pulpit microphone.  So it would be nice for them to have dedicated processing or EQ but actually matching response may not be as critical.

[Lee Buckalew]

Thanks Lee. 

Have you heard the IF2208's?  These seem to be the largest speakers they have ceiling mounts for...  Those 12's with 3" compression drivers look pretty nice, though, but I think we'd have to mount them on the back wall, behind the podium, which is problematic.  They are too big to hang in the middle of the room, in front of the projector.

The beams combined with the projector in this room really mess with options. Center mount speakers are in the way of the projector, and the beams lower the effective ceiling height to 8' if you want to hang on the beams.  Three ceiling mounted speakers might be the best solution, on each side of the beam.

Do you know if Yamaha's modeling software is free?

Mark,
Another great sounding option that sounds much more like something far larger is the Martin DD6.  Astounding bass response for the size, output capability more like an 8".  May be out of your budget.

Lee

[Mark McFarlane]

But the intelligibility and gain before feedback may not be so great.  The problem I see with most column speakers is that they may have too great a horizontal pattern for being in the locations of the existing speakers.  You seem to end up potentially balancing too much level at the microphones versus too much energy hitting the rear wall.  And if the system is stereo you still have distance affects to address for coverage, for example the pulpit being in the pattern and closer than many listeners, while if mono you seem to have tremendous overlap in coverage in the center of the room.  Good coverage is not just lots of coverage but coverage where you want it and not where you don't.
 
Mark, matching tonality of any center fill may not be as much of an issues as it seems.  Because the left and right mains have less directionality at low frequencies you may want to roll off the low end of the center fills and let the mains carry that.  You may also want to EQ any center fills differently due to their relationship to the stage and pulpit microphone.  So it would be nice for them to have dedicated processing or EQ but actually matching response may not be as critical.

THanks Brad, as always, a thoughtful and helpful response.

[Mark McFarlane]

Mark,
Another great sounding option that sounds much more like something far larger is the Martin DD6.  Astounding bass response for the size, output capability more like an 8".  May be out of your budget.

Lee

Lee, the Martin DD6 does look like good option.  The differential pattern (particularly the asymmetrical vertical SPL output they claim) is interesting and would probably work well if it works as advertised. But would require rotating the horn which some claim is less than ideal.  Good size, decent mounting options.  At around 1K/box it is pushing the budget, but I think I can deal with that.

I also just learned that we may need to be able to connect two different sources to this system, one an existing 'full console', the other an existing 8 channel 'simple mixer' that is used by many groups through the week for speech only or video presentations.  Another option is to keep the existing Tannoys hooked to the simple mixer, in which case we need to purchase a center fill speaker for the new system (since we can't repurpose the Tannoys if they stay connected to the current room system).  That is probably the simplest solution.

Considering the budget, could I be publicly executed using a Behringer DCX 2496 DSP with Martins?  3in*6out would theoretically give us the crossovers and parametric EQ needed  to voice a center channel and add a sub later.  Another option would be running in true mono and using a DRPA (2*6). This is assuming both DSPs allow a 'route any combination of inputs to any combination of outputs' without any stupid built in restrictions.  I have really researched either DSP.  Actually, aux-fed subs is probably not going to be adopted by the people that use this room, so a one-in DSP might be fine.

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