Halls with arched ceilings!

[richie1575]

I know there is no easy answer to this, but I have a Hall with an arched ceiling. The room is around 10m x 15m. The highest point of the ceiling is around 6m. It has curtains but hard floors, a typical church hall type building! (In fact it is!!)

I've been asked to put a PA system in for Voice and a little background music. They also want to use the room in landscape and portrait format.

I'm wondering about speaker location... possibly using 4 EVID 6.2's mounted on the side walls with a suitable switching arrangement. (or do I need to fly something?) The challenge is that they want to use a lapel radiomic and acheive a reasonable volume level without too much feedback. I'm hoping that an 1/8 octave graphic will suffice, but again, any ideas would be welcome!

 

Thanks in anticipation!

 

Richie

[Pete Alcock]

Hi Richie,

 

I put a system in a strangely similar Church hall room a couple of years ago. This was about 8m x 15m with domed (wooden structure) ceiling and hard floor. They wanted a bit more than background music though as the brief was for lively youth services.

 

I think what you're proposing with 3 or 4 speakers would work fine, although I would question the choice of EVIDs though. From the spec their dispersion is claimed to be 100 x 80 deg which is rather high and wide for this application. I'd try some small 8"+ horn cabinets such as as FBT Verve 8 or Jolly8 (or the more expensive RCF equivalent if you prefer). With a 60deg dispersion feedback would be less likely to be an issue.

 

You say the room needs to be used both ways round. This would be OK, but I would try to mount the speakers on the "long" walls, about 2-3m in from the end. This would put the presenter behind the speakers if the room is being used long-wise and would almost certainly allow the use of lavs. I agree, a clever switch box would take care of which two speakers are on depending how the room is set.

 

Regarding the graphic, I wouldn't bother as it'd only get fiddled with. You don't say what amp or mixer-amp you plan to use, but the desk eq should be sufficient to minimise feedback and get things sounding good. If you have any really bad room resonances you could use something like a DCX2496 to tame them, and lock it with a password.

 

This is the room I did. We couldn't fix anything to the ceiling and the walls were too low to mount the speakers. Accordingly I got a truss made and flew them (Verve 12s). The subs get wheeled out and plugged in when needed.

 

http://i2.photobucket.com/albums/y24/petealcock/ChapelHall1.jpg

 

Good luck with your project!

 

Pete.

[richie1575]

Many thanks for your reply Pete! I take what you say about the speaker dispersion issue! You're probably right about the graphic... I'm using a Soundcraft Gigrac 1000 as they've next to no money and I'm doing the job because I am a nice bloke! Will let you know how I go on! Thanks for the Pic, looks good!

 

ATB

 

Richie

[Rob_Beech]

I'd be tempted on the graphic if the budget was there, but either use one and lock it in a rack once it is set, or use a digital one and password protect it. You do get alot of flexibility with the DCX2496 which would work on switching speakers on and off as necessary aswell as giving you crossover control and some eq but a digital graphic like it's partner in crime the DEQ2496 increases flexibility quite a bit. You could also use user presets on either or both devices depending on what was being used. You may find that a fair bit of eq is needed on the system for the lapel mics but when they are not in use you can work with a flatter system. This of course all depends on who is there to operate this and switch presets if and when necessary.

[richie1575]

Thanks for that Rob, I have an old Thomann T-eq which was is reasonable that could be incorporated, I guess my plan would be to pre-set it and then screw a piece of plexiglass on the front of the rack to stop the prevent pretty patterns being made in the sliders!

 

On the speakers front, I have some EV ZX1's being offered at a favourable price, has anyone used them? I've played about with the ZX5 and it seems to be a reasonable enough box, the one other contender may be RCF's monitor 8. Like I said, I'm offered these for reasonable money, but is there anything else out there I'm missing?

 

Thanks for your support!

 

Richie