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[George S Dougherty]

The more I think about it, the more it occurs to me that volume and an untreated room is 90% of your clarity problem.  Different speakers may help since I know my tops with very narrow vertical dispersion do better than most in gym environments and other highly reverberant rooms.  They reduce the audible reflections from floor and ceiling, and a batch of people in the space help even more.  Treating the room will help as much, or more, and you may not need to replace speakers.  Ideally though, you'll still want to get those speakers up for all the benefits I explain in my other post.

In terms of volume, stage volume will muddy up your bottom end, especially if it starts loud.  The suggestions given here are excellent.  Hot rods or the plastic variant may help some as well if you need to bring down the drum volume.  Damping the drums and shortening up the ring is critical in a space like yours.  You can gate them at the mixer, but you'll still have the acoustic tone as well.  For your room, untreated, you probably want an almost dead sound to start with since the room will add all the liveness you need.  Drum volume is typically your starting point.  Guitar amps and everything else comes up to that level by nature.  A drum shield may help, but it won't do miracles unless you enclose it and treat the space inside to help protect your drummer's ears.

Acoustically, in a very reverberant room, the louder things get, the worse your clarity gets.  Inverse square law will drop your volume 6db for each doubling of distance.  When things are softer they'll drop into inaudiility more quickly.  If it starts louder, it stays louder longer as the sound bounces around the room.  

On top of that you have the natural phenomenon where our ears change the properties of our hearing when subjected to loud volumes.  This will impact perception of clarity as well.  Think of how the world sounds muffled and closed in after attending a loud concert, that's what you'll have all the time among your congregation, and softer speaking portions will suffer even worse because of it.

[Lee Buckalew]

In a highly reverberant room the inverse square law will follow within it's limitations, but only to the point of critical distance being reached.
Critical distance being the point at which the reverberant sound field is equal to the direct sound filed in dB/SPL.
Also, their is not one inverse square law, there are a few.
The one that keeps being referenced on PSW here is a -20Log calculation.  It specify's that a point source (it must be a true spherical radiator, capable of completely even 360 degree coverage over the entire wanted frequency range, of which there are none) in an open space (of which there are none in live sound, this would mean not even a floor) will have a reduction of 6dB/SPL per doubling of distance from the source.
Also, since this is for a single source, in the area where multiple sources (ie. more than one speaker) begin to overlap, the inverse square law also now has to contend with acoustical addition of multiple sources.
The inverse square law is much more of an effective guideline for live sound than a hard and fast calculation that will provide precise results.  You must understand how it works and what other factors affect your ability to rely on that calculation in order to effectively use it.

His,
Lee Buckalew
Pro Sound Advice, Inc.

[Adam Foster]

Thank you everyone for your input.

I will let you know that the drums are already in a cage with padded treated. All of the muscians are using the Aviom system for personal mixes. The only monitors I have are the pulpit, for lead singer and music, and the praise team monitor hung above the pulpit for jus the praise team.

As far as the line array the more I think about it the more I don't like the idea of them in that building. However I do need to get the speakers in the air in a cluster as some of you stated. I just don't know what type of speakers to turn to.  Any suggestions on speakers would be great.

Thank you everyone

Adam Foster

[Dick Rees]

Adam Foster wrote on Sat, 16 January 2010 16:48

Thank you everyone for your input. I will let you know that the drums are already in a cage with padded treated.

That doesn't keep the sound from going out the top and ricocheting around the room, especially with the A-frame.

Quote:

All of the muscians are using the Aviom system for personal mixes. The only monitors I have are the pulpit, for lead singer and music, and the praise team monitor hung above the pulpit for jus the praise team.

Yes, but how about amps???????

Quote:

As far as the line array the more I think about it the more I don't like the idea of them in that building. However I do need to get the speakers in the air in a cluster as some of you stated. I just don't know what type of speakers to turn to.  Any suggestions on speakers would be great. Thank you everyone Adam Foster

Still betting on the stage volume being excessive.  In ear monitors may make it even worse in that the players will be less aware of their amp volumes.  99 times out of 100 the problem will be the band level before the sound system itself IF you are running things properly, which I assume you are.  If you can't turn them down at the board, IT'S THEM.

Rule of thumb is that you need around 10dB of headroom over and above the ambient/stage sound to set up a proper mix.  It's easy to have the amps (and the reflected drum sound) hit between 90 and 100 dB at the front of the stage.  That's likely why you're up to the stated level to get a mix.

One thing that you CAN do:

Get the amps off stage in another room/space entirely.  Place them in shielded boxes and mic them into the PA from the remote location.  That will allow YOU to set their levels in the mix without having to deal with excessive stage volume.  As to the drummer.......counseling and an appeal to his/her sense of group spirit may be in order.

One last time:

If you can't turn the whole thing down with the mains faders, it's them, not you.

End of story.  

[Adam Foster]

The drums are in a fully enclosed cage. Only a little bit of low end travels through the cage. As far as the muscians being too loud, I don't think that is the case. We doe not have any amps on the stage. I have an active direct box that the guitar and bass use. I do agree however that our pulpit monitors could be too loud and reflecting back in the sanctuary. We are currenly in a new building project so treating the current sanctuary for acoustics will be useless at this point. I was hoping maybe I could get a more directional approach with the speakers and then be able to turn it down because the sound is pointed at them instead of hearing off the walls. Any suggestions?

[Dick Rees]

Edit:

Are you sure that the speaker type and deployment is the issue?

Of course it is best if the speaker output is directed as much as possible onto the listeners with few if any reflections from the boundaries.  But I would not think that that would be 100% of the problem.

It may be that the mix position is situated in an area which is predominantly reflected/reverberative sound and trying to get a clear mix from that point results in excessive volume.

Moving the mix position to the center of the room would alleviate this, but we all know that's not happening in your average sanctuary.  Otherwise, fine tuning the system and mixing with EQ rather than volume is where I'd start.

[Brad Weber]

Adam Foster wrote on Sat, 16 January 2010 19:17

The drums are in a fully enclosed cage. Only a little bit of low end travels through the cage. As far as the muscians being too loud, I don't think that is the case. We doe not have any amps on the stage. I have an active direct box that the guitar and bass use. I do agree however that our pulpit monitors could be too loud and reflecting back in the sanctuary. We are currenly in a new building project so treating the current sanctuary for acoustics will be useless at this point. I was hoping maybe I could get a more directional approach with the speakers and then be able to turn it down because the sound is pointed at them instead of hearing off the walls. Any suggestions?

So it sounds like stage levels are minimized, which begs going back to the questions regarding the 96-108dB levels, as in why those levels and what those levels really represent.  As Tom noted, what weighting and response were used for the measurements?  Where were the measurements taken and with what?  Are those peak or average values?  The Pastor has apparently received so many complaints that it is too loud that they said something to you, so as Frank mentioned, how did you determine the problem was something other than simply the levels?  And as Dick noted, how did you determine that new speakers would resolve the complaints?  Has anyone considered simply turning it down or was that rejected out of hand?  You may not have a space or congregation that is amenable to such high levels and since you do not seem interested in addressing the space because you will be moving, simply reducing the levels may be a viable and effective alternative.

That also brings up the question why you apparently believe that an investment in new speakers is warranted but don't feel that an investment in acoustical treatment is?  Your idea of getting the sound aimed at the listeners and away from the walls is valid, however a line array is not really appropriate for that room.  It would likely not be that beneficial for a 60' deep by 45' wide listener area and might also create several new issues.  But beyond that, if it makes no sense to invest in the room acoustics then it may also make sense to do what you can without investing more in the sound system, instead optimizing what you already have and doing what you can to get by until you are in your new facility.  I don't know what you may have already done as far as optimizing speaker locations and aiming, tuning the system, etc., but it seems to make sense to exhaust those options first.  And if the complaints really are about it being too loud and not the other issues Fran noted, then simply turning it down rather than a line array or anything like that may be the best solution.

There may be information that hasn't been shared or issues that are not clearly understood, however I simply can't get past that the 96-108dB levels noted, that there have been complaints regarding the levels being excessive and that you don't feel that treating the room is justified as you will be moving into a new facility don't seem to lead to a new speaker system, and especially a line array, being an effective solution.  It may be, but it is not obvious based solely on what has been presented.

[Dick Rees]

Brad et al....

The more I think about it, the more I am concerned that the mix position is critical.  Certainly having the sound directed primarily onto the listeners is a salient feature.  But by the same token, having the mix position in the same area as the listeners is the key to a sympathetic mix.

Too often the mix position is considered to be an "obstruction" or intrusion into the seating/worship aesthetic.  Being in a recessed "closet", under a balcony, off to the side or up against a back wall will give a less than satisfactory aural image for the mix person.

Placing the mix person in the direct sound field and out of the reverberative field will be crucial.

DR

[Adam Foster]

Hello everyone.  I waited for this weekend to be over to give you guys a proper response in regards to measurements.

Our Sunday morning service ran at 93db on the front rown and 86db in the sound room. Our evening service which is a worship emphasis ran 97 on front row and 90 on the back row.  The measurement was measured with slow response and C weighting.

In regards to placement of mixing, that is something I really can't change unless I am going in a closet somewhere and I definitely will not be doing that. The sound room is in the back corner but in the open setting against the back wall. The mixing is set as close to the center as possible.

About speaker replacement, I am not really sure if we need to or not. My choice was wanting to have a center cluster to get the speakers away from the walls to try to increase clarity. Right now we do not have the right speaker enclosures to hang them in the center so we would have to get new speakers if we did that.

I do think the platform noise is at it's lowest that it's ever been since I took over the AV ministry. But during worship it is running about 96 on the platform.

I thought about asking if we could hang drapes on the sides of the windows which would not be that expensive and would look good. That would probably help acoustics a little.

I know that the best solution would be hire a professional an acoustically treat the whole room, but it doesn't seems feasible to spend $8,000 at this point when that building is getting ready to be renovated.

Again, I do appreciate everyone's input on this topic.

Thank you!

[Dick Rees]

Adam....

So the actual level is considerably lower than your original estimate......at least on the measurement day.  I usually take measurements A weighted/slow and that would read a tad less than the C scale.  I think you'll find that 86 dBA/slow will be acceptable to most folks in the front row.

Your mix position is not the best, but still not the worst if you're out in the open and not in a recessed space.  You can certainly try some treatment on the walls behind and to either side of you.  But as long as you're going into a renovation, why not just consider working the accoustic treatment into the job?

I'd also look at some smaller speakers and make sure that the pattern is narrow enought to keep the sound off the walls and ceiling.  There are angle tilters available for stand mounted speakers.  If you want to fly the speakers, please use a certified/bonded/insured install outfit.  DIY is just not an option here.  Also, if you use such an outfit they'll be a resource for recommending speaker type/configuration and install them at the proper angle for best coverage.

Good luck.

[ProSoundWeb Community]