400hz 1khz ring +echo

[buggyboy]

Hi,

I'm looking to dampen our sanctuary to increase gain before feedback. right now we have a lot of ring in the 400 - 1000hz range. i've used eq to cut it as much as possible with my rane 15 band GEQ, but it still isn't enough. so now i'm thinking it's time to put up some acoustic panels of some sort.

there is also a bit of echo...not a full echo, but a long reverb hang time. i suspect that i due to the overflow area which is separated by only a partition wall. the overflow itself is a empty boomy box. drywall and tile.

any thoughts?

thanks,
David

[Gracetech]

It might be sound coming off of the back and sides of the cabinet causing the issue. It's hard to give advice on this sort of thing without hearing it in person. Do you have some pictures, dimensions, and wall/floor/ceiling material of your room. It's possible from enough information that we can steer you better.

crt

[cmchamp]

I'm with Chad on this one, the issues are more than likely the combination of polar pattern of the loudspeakers in question, polar pattern of open microphones, and the number of open microphones.

[buggyboy]

Thanks,
I'll get any measurements you need, just let me know what you want.
the speaker is a bose 802.
only 1 open mic usually, with a cardioid pattern.

the mic is center stage at the edge.
the speaker is stage left at the edge, tilted a bit inward to cover the crowd.

yes, a terrible placement. I'm going to try moving it out a bit for now. i have another thread dealing with using different speakers to move the sound production away from the stage.

thanks

[cmchamp]

Here are the octave and 1/3rd octave plots for these

[waynehoskins]

Wow, it doesn't even begin to have any directivity until 1K! Between that and shooting sideways from one corner of the stage to fill the entire audience chamber, I can definitely see the potential for this problem.

[tdangelo]

Originally Posted by waynehoskins

Wow, it doesn't even begin to have any directivity until 1K! Between that and shooting sideways from one corner of the stage to fill the entire audience chamber, I can definitely see the potential for this problem.

Directivity until 1kHz? Hah! Wayne, you are old enough to remember the saying, "No Highs, No Lows, Bose!"



- Tom D'Angelo
NYC

[buggyboy]

For some reason the board doesn't allow me to download those files. the same thing happens with pictures hosted on the board.
i found the plots here,
http://docs.google.com/viewer?a=v&q=cache:euCwMlgTK9IJro.bose.com/pdf/pro/polar_plots/panaray_802/pp_panaray_802_octave.pdf+pp_panaray_802_octave.pd f%E2%80%8E&hl=en&gl=us&pid=bl&srcid=ADGEESi2O2LRCQ ay7DHIMW26KTEgh6h_IrKR_0ea9V7B5qtD6rGSIa9R4zLwzb3Z UCsTV5S7eREJuEM3pp72CLXg44rNmROyUzE_TajCXR8-ND4p82fR09uux1NX0cGHgsPmMd14s9kb&sig=AHIEtbRiUkg12 X9k4sUgzxHiruF_B3DAmw

but i don't know what they mean with the 0 to 90 degree markings.
i'll note that i think mine are series 2 instead of series 3.

I'll be gathering the room dimensions and the height of the speaker and taking some pictures...any other measurements you'd find helpful?

[buggyboy]

Alright friends, tonight i am armed with dimensions and photos.

the measurements are all on this picture...

http://imgur.com/ZUygW.png

Some Photos ...

looking southwest in overflow
http://www.picstation.net/show-image...dc7f993a76664a

looking south in overflow
http://www.picstation.net/show-image...149088e38a4f44

looking northwest in overflow
http://www.picstation.net/show-image...13bea8c73b9494

looking northeast from southwest corner of sanctuary
http://www.picstation.net/show-image...ef3f4cef5b5315

looking southwest from corner of stage
http://www.picstation.net/show-image...79cafbf0fbb1cc

[buggyboy]

from opposite corner of stage
http://www.picstation.net/show-image...4cf1fd4c2b44c9

from the bose speaker location
http://www.picstation.net/show-image...6cf73716842914

looking east from pews
http://www.picstation.net/show-image...076d595d709a47

from rear of sanctuary
http://www.picstation.net/show-image...ba40b9dc5a520c

from bose location showing alternate podium placement
http://www.picstation.net/show-image...18dbe96b420de4

from pulpit showing alternate placement
http://www.picstation.net/show-image...4d4baa818d20e3

from left rear, high, showing alternate podium
http://www.picstation.net/show-image...0d06a6e44aa61a

I forgot to take some with the partition closed.

the materials in the room are mostly cement board, i was surprised to discover. the north (stage), east (overflow) and west walls are all cement board. the north and south walls in the overflow and the south wall of the sanctuary are drywall. the ceiling is hard to say, i believe it could be classed as cement board.

not the best for acoustics i know. but these were not built to be a church. the overflow and the sanctuary were once two separate school buildings that were moved and joined to become the church. so short of a new building, this is what i have to work with, even if the result is sub-optimal.

is moving the main speaker to roughly center a good idea?
what can i do about the ringing?

thanks very much for you willingness to help.
David

at this point i'm thinking about hanging the one of our bose speakers about in the middle of the space, angled down. then if front fill speakers are needed i can deal with those later. it's worth noting that the congregation almost never uses the front 4 or 5 pews. so i can get away without the fills for awhile anyway.

[Gracetech]

So in the pictures there are two speakers. Is one not working?

Unless the people are standing right next to the speaker with a mic i can't see why it would be feeding back unless it's really loud.

I assume we are talking about a handheld mic and not a lapel mic?

Does the 70v system in the overflow work?

What type of console do you have? What does the EQ look like? Are you using a Bose processor? What EQ are you using for the system and where in the signal chain is it?

I can see that you will have some flutter echo issues in your space which may be causing you grief. With sloopy speaker boxes like the Bose you are going to have sound going everywhere which generally makes people want to turn up the level. Is this whats happening?

crt

[buggyboy]

the other speaker isn't hooked up at the moment, it is functional, but disconnected.

in order to get the high enough volume in the rear pews (where people actually sit) the speaker is turn up quite loud. but the mic (cardioid, dynamic, stand mounted, aprox. 20 inches from the pastor's mouth) starts to feedback before the volume at the rear pews is sufficient.

the overflow as well as the other remotes are disconnected (not my fault) and installed long before my time. i'm not even certain what they are. i'll find out soon. they were functional until the lines were cut.

my mixer is a biamp 683b, the onboard eq is simple 3 band. i am using the bose controller, the rane 15 band GEQ is placed after the bose controller and before the amp.

I would say flutter echo would describe the sound in the room.

i don't know what you mean about, "sound going everywhere which generally makes people want to turn up the level."

thanks for your reply