This room is rectangular, there is stair railing in the front on the left when looking at the front of the room and a HVAC soffit in the rear alcove on the left when looking at the back from the front of the room.
Overall length of sanctuary plus alcove = 51' 5" (612" + 5" = 617")
The total volume of the sanctuary, minus the front platform, plus the triangular prism formed by the vaulted ceiling, plus the rear alcove, minus the HVAC soffit in the alcove, is 13,550 cu. ft.
Sanctuary Measurements
The sanctuary is: 8' H x 28.66' W x 45.66' D Note that the Height is only to where the wall and ceiling come together.
The vaulted ceiling triangular prism is: 3.42' H x 28.66' W x 43.66' L
Sanctuary Height at wall/ceiling joint = 8' (96")
Vaulted Ceiling Height from floor to peak = 11' 5" (132" + 5" = 137")
Width of the sanctuary area with vaulted ceiling = 28' 8" (336" + 8" = 345")
Platform Height = 6" (.5 ft) Platform Width = 24' (288") Platform Depth = 13' (156")
Platform Front Extension = 6” H. x 18” D. x 9' L.
Sanctuary Rear Alcove Measurements:
The alcove is: 8' H. x 25' W. x 8' D.
Walls and ceiling are 1/2” plasterboard.
Alcove Height = 8' (96")
Alcove Width = 25' (300")
Alcove Depth = 8' (96")
Alcove Duct Soffit Height = 8' (96")
Alcove Duct Soffit Width = 2' (24")
Alcove Duct Soffit Depth = 2' 4.25" (24" + 4.25" = 28.25")
Alcove Duct Soffit is 1/2” Plasterboard.
Converting all the measurements to cubic feet:
Sanctuary: 8 x 28.66 x 43.66 = 10010.3648 cubic feet.
Sanctuary vaulted ceiling is a triangular prism, where its height is 3.42 feet, base is 28.66 feet, and depth is 43.66 feet, area of a triangle is 1/2*b*h, and its depth is d, giving (1/2*b*h)*d = 2139.71548 cubic feet
Platform: .5 x 24 x 13 = 156 cubic feet. Platform Ext. .5 x 1.5 x 9 = 6.75 cubic feet. Removing the volume of the Platform from the Sanctuary gives 9854.3648 cubic feet.
Alcove: 8 x 25 x 8 = 1600 cubic feet. HVAC duct soffit: 8 x 2 x 2.3542 = 37.6672 cubic feet
Removing the volume of the soffit the alcove is 1562.3328 cubic feet.
SUM TOTAL: Sanctuary minus Platform, plus Sanctuary vaulted ceiling, Alcove minus HVAC soffit is 13,549.6631 cubic feet, rounded to 13,550 cubic feet.
Open Stairwell:
To the left of the platform you can see railing. The railing protects an open stairwell.
The stairway opening from the platform to where the landing borders the outside wall is 52-1/2" W x 109-1/2" L x 41" H.
There are 5 hardwood steps 43-1/4" wide with a rise of 7" and a tread depth of 11.25" each. The wall on on the left side is 1/2” plasterboard, the wall on the right side is wood.
The hardwood landing is 50-1/4" x 56-3/4" There is a 42” x 80" metal exit door in the outside concrete wall.
From the landing to the lower level floor the right side of the stairwell is concrete block. There is a 23"x32" window in the concrete wall where stairs go from landing to alcove at bottom. The left side is 1/2" plasterboard.
The stairwell opening over the stairs going from the front stair rail, platform level to the landing threshold is 54-1/2" W x 102-1/2" L x 41" H.
Height from the lower level floor to the platform level of front railing is 10'. There are 10 hardwood steps, 8" rise, 11.25" tread depth each from the landing to lower level floor.
The alcove at the bottom is 6' x 8' with a 24" x 80" hollow core wood door going into lower level on the left. The right wall and the rear wall are concrete block. The alcove ceiling is 1/2” plasterboard.
** The volume of the stairwell was not calculated as I'm not sure how to accurately measure it. I couldn't find any information doing a web search.
Building Materials and Makeup:
1. The inside walls are 1/2" plasterboard except where noted.
2. The building wall frames are 2x4, 16" on center with fiberglass insulation.
3. The sanctuary platform is 2x6 support with 1/2" particle board covered with pad and carpet.
4. There is no insulation between the platform supports.
5. In a closet wall in the lower level, there is a open area underneath the platform where the stairs go down to the stairway landing. It is 79” L. x 45” W. The open area starts under the platform 2' from edge of stairs and tapers down to the landing.
6. The ceiling/roof structure is constructed with scissored trusses, believed to be 2' on center. Fiberglass insulation with blown cellulose over the top.
7. The left wall of the sanctuary has (8) 16” x 48" windows.
8. The right wall has (5) 16" x 48" windows, (1) 46" x 40" double pane (1-1/2” between panes) plexiglass window with blinds that is common with an office, and a set of double hollow core wood doors 59" wide x 80" height.
The alcove has (2) hollow core wood doors, one on each side that access closet space. Both doors are 39-1/2" x 80".
The door on the right of the alcove accesses a closet that has (2) 16"x48" outside
windows in the back wall of the closet. Right closet dimensions: 20" D x 88" W x 96” H
Left closet dimensions: 19-1/2" D x 89” W x 96” H
The worship band is on the far right the platform. The two guitar players are along the right wall, the drummer is in the right corner. The bass player is to the left of the drummer. The bass player has his amp leaning against the front wall angled upward. The singers are lined up across the front wall to the left of the bass player. Four of the singers have microphones, two do not. The worship leader plays a keyboard and is located in front of the bass player around the center of the platform, between the front wall and the front edge of the platform.
All the outside windows are double pane glass. Sanctuary/Office window is double pane plexiglass with a 1-1/2” gap between panes.
The two projector speakers hanging from the ceiling are 300 watt, 72 pounds weight each.
General Concerns:
This is not for studio construction, however the services are recorded every Sunday. We need to know what type of treatment, i.e. absorbers, diffusers, etc. we will need to tame this room. There are a lot of reflections, etc. It is a noisy room and a few people have approached me stating that the worship music is loud. While taking pictures and measurements of the open stairwell, I could hear that this area is a problem. While talking to the pastor I could hear the sound ringing off the concrete wall and echoing slightly in the alcove at the bottom.
Sunday I utilized my Radio Shack Sound Level Meter and stood out front of the sound booth so I could hear the room without the additional audio bias caused by the sanctuary alcove. Working with the audio engineer we were able to get a decent sound between 85-95 db. This would indicate to me that we should be able to tighten up the sound further with proper placement of absorbers and diffusors.
The budget for this is low, $300-500. The excellent carpenter who is helping me build my John Sayers designed studio also attends this church so we would be able to build anything needed.
Room Treatment Questions:
1. The sound booth is located in the center of the alcove at the rear of the sanctuary. The sound is being affected by the alcove and the audio engineer isn't getting a true representation of the sanctuary sound. It may not be possible to move the booth. Short of that, what would be a good solution for treating the alcove so the engineer can hear a more accurate representation of the sanctuary sound?
2. What will be a good solution for the sanctuary walls to tame reflections?
3. What type of treatment should we have for the vaulted ceiling?
4. What is a good possible solution for the stairwell and alcove at the bottom?
5. Should we fill in or line the empty open space underneath the platform where it meets the stairs? (Item 5. Building Materials and Makeup)
6. Should the projector speakers hanging from the ceiling be relocated or aimed differently? Standing on a ladder they now appear to be angled and pointing downward at the rear corners.
7. Any other thoughts, ideas, etc would be greatly appreciated.
Help With a Untreated Rectangular Church Sanctuary
Originally posted at johnlsayers.com, topic 17552.
Hi "uno", and welcome to the forum! :)
This isn't really a studio construction situation, but it's right up my street, for sure, so maybe I can help a bit with this. I've been running live sound in churches for more years than I care to remember, and I teach a brief "Sound and Acoustics" seminar for churches like yours all over the country, aimed at pastors, musicians, church leaders and sound volunteers, which covers these very issues. This is something that I'm fairly familiar with, and the issues you have are actually quite common in houses of worship.
This is a very, very common problem, and the simple answer is exactly what you expected: move the booth. There are no other good options. I run into this all the time, and it is usually very hard to convince the pastors, deacons, elders and other church leaders about just how important it is for the engineer to be part of the congregation. They don't want to even consider having an ugly sound booth stuck out in the sanctuary, with cables all over the place, but if you explain the reasons to them, do a clean., low-profile design for a booth, and demonstrate the results, most will eventually come around. In trying to explain this, I often use the analogy of a painter: I ask the pastors and leaders if they would hire a painter to come in and redecorate the sanctuary, but then insist that he must work blind-folded, with all the lights turned off, and one hand tied behind his back. In essence, that's exactly what they are asking the sound engineer to do: If he cannot hear the same acoustic environment that the congregation is in, then he's "working blind", and he cannot do a good mix. It is that simple. He's working with an "acoustic blindfold" that does not allow him to hear what he is doing, so he cannot be expected to produce good sound in the sanctuary. And that is especially true when the room already has poor acoustics, like yours does. If the pastor will not let the soundman be where he needs to be, then the chances of ever having good sound in the sanctuary are about as good as those of the blindfolded painter doing an acceptable job. Your case is not the worst I've seen, though: That would have to be the one where the sound booth was actually in another room, with just a tiny little non-opening window into the sanctuary "so the sound man can see", and a mic in hanging from the ceiling in the sanctuary hooked headphones in the booth "so the sound man can hear what is going on in the room" :shock: :!: I kid you not... The best location for the soundman in the room, is on the center line (or as close as you can get to it, if there is a center aisle such as yours), and about two thirds to three quarters of the way back in the open depth of the room. Your sanctuary is about 45 feet long, but the alcove extends 8 feet into that, leaving 37 feet open. So the console should be at roughly 25 to 30 feet from the front wall, or at the very least a couple of feet in front of that overhang. There's no way he can do a decent job under the overhang: I'm telling you that from first-hand experience, and you already know it anyway. That is a different bass-heavy acoustic environment under the overhang, and there's no way that he can do a good job like that. And running back and forth to listen then adjust, listen then adjust, is out of the question. Also, that booth looks to be too tall: the ideal place for the sound engineer's ears is just a bit above the ears of the congregation when standing. He needs a clear view of the musicians above the heads of the people, but nothing more than that. If his head is too high in the room, then once again he is not hearing what the congregation is hearing. What I have done in similar situations, with some success, is to convince the pastor to let me set things up the way they should be, temporarily, for one or two services, just to show the improvement in sound quality that can be achieved by a good engineer standing in the correct location. If it works out OK, and the difference is noticeable for the congregation and leaders, then you stand a much better chance of making that change permanent. If the pastor won't even let you do that for one service (it does happen, unfortunately), then I always make it clear to the pastor that the sound will never be good in his church, no matter what equipment or treatment he puts in. If the soundman cannot hear exactly what the congregation is hearing, at all times, then he cannot make the necessary adjustments . There's an interesting statistic that I mention in my seminars: Churches lose about 17% of their congregations due to bad sound, and for no other reason. Asking the pastor if he'd like to be able to stop 17% of his congregation from walking out and never coming back.... :)1. The sound booth is located in the center of the alcove at the rear of the sanctuary. The sound is being affected by the alcove and the audio engineer isn't getting a true representation of the sanctuary sound. It may not be possible to move the booth. Short of that, what would be a good solution for treating the alcove so the engineer can hear a more accurate representation of the sanctuary sound?
You'll probably need a combination of diffusion and absorption. Diffusion could be something like angled panels on the walls, polycilindrical shapes, things like that. They can be made easily from plywood, and covered with cloth to make them less attractive. And they need to be large.2. What will be a good solution for the sanctuary walls to tame reflections?
That's the normal way that people describe it, even though the real issue might not be that it is loud. If you are running the mix at around 90 dB, that isn't too loud for contemporary worship. I run at around 95 to 97, peaking at around 100, and I've never had a complaint that it is too loud, not even from the elderly folks. Normally what happens is that people hear something that annoys them with the sound, and since 90% of them aren't musicians or sound engineers, the only way they know how to describe the issue is "loud". The real problem might be reverberation, or resonance, or equalization, or coverage, or more likely a combination of the above. But the only way that non-technical people can describe the problem that they are hearing, is "loud". I have found that if you question them carefully, and get them to describe in greater detail, offering them words like "muddy", "strident", "tinny", "shrill", "thumpy", "echoey", and things like that, they actually can give you much better idea of what the real problem is. At one church where I taught the seminar, even though everyone said that the Sunday services were "loud", the real issue was that the volunteer soundman did not have the music balanced with the vocals: People just could not hear the singers! So it was the relative levels between the two that made it seem too loud. To prove the point, I ran sound for them for one service, and I actually ran it louder than they normally did, but with the vocals up front and the music more in the background: afterwards, several people thanked me for "turning down the volume"... :) So it's a matter of perception: talk to them, find out where they normally sit, and see if you can get them to give a more useful description of what really bugs them about the sound, instead of just "loud". Also ask them about speech intelligibility (but not with that word!). In other words, ask if they can hear the sermon clearly, and understand what the pastor is saying without difficulty, or if they have to strain to follow what he is saying. Do they sometimes mis-hear words that sound similar? etc.There are a lot of reflections, etc. It is a noisy room and a few people have approached me stating that the worship music is loud.
That sounds like one of your first candidates for treatment. Since that isn't a place where people will be listening, I'd just kill the walls with absorption: Maybe hang some thick panels of 703 on the side walls, going all the way down the stairs, and also on that door at the first landing. You say that's a metal door, so damping the surface of that couldn't hurt. Also replace that thin mat on the first landing with a thick, deep throw rug.4. What is a good possible solution for the stairwell and alcove at the bottom? ... While taking pictures and measurements of the open stairwell, I could hear that this area is a problem. While talking to the pastor I could hear the sound ringing off the concrete wall and echoing slightly in the alcove at the bottom.
As I mentioned above, that's a decent sound level for modern praise and worship services, so I don't think level is the issue. My guess would be that there are other underlying issues, and one thing that I suspect is those speakers. They only appear in one photo, and it's clear that you have them set up as a center cluster, but they do not seem to be aimed correctly, and that's a big issue. From that photo, they seem to be aimed at the wall above the rear alcove! They should be pointing down at the congregation, not at the wall. I would definitely start by re-aiming those so they are pointing into the middle of the congregation, and also angled a bit to the left and right, to get good even coverage of the entire seating area. Off-axis sound is always unpleasant, muddy, lacking highs, and unclear. If you aim those speakers so that the acoustic axes are pointed roughly at the middle of the congregation on each side of the aisle, you'll improve clarity a lot, and you will also reduce the reverberation problem considerably. This is probably the single biggest thing you can do to improve that room, and it costs you nothing! People are actually good acoustic absorbers, so if they are in the "line of fire" of the speakers not only do they get much more clear, direct sound, but they also act as treatment for you, at no cost. Another "freebie"! I'll bet that just doing this alone will give you a very noticeable improvement in sound. This is another issue that I see all the time in churches: speakers placed poorly, and aimed poorly.Working with the audio engineer we were able to get a decent sound between 85-95 db. This would indicate to me that we should be able to tighten up the sound further with proper placement of absorbers and diffusors.
Here's what we ended up doing for a church here in Chile, when the pastor asked me to help solve the same type of issue you have: Each of those panels is plywood with typical drop ceiling "acoustic" tiles below covering a think layer of mineral wool, and a thick layer of mineral wool on top. Hung from chains, and with spacers to keep the separation. The acoustic tiles don't actually do much: they are there more for decoration than effect. The pastor happened to have a bunch on hand, free, so we tried them out that they worked. Those panels do three things; act as diffusers, act as reflectors, and act as absorbers. Made a huge difference to that hall, which was basically unusable when I arrived.3. What type of treatment should we have for the vaulted ceiling?
Just saw this, after I already mentioned it above. Aiming speakers at the opposite rear corner is fine ... for speakers on stands at head-height! But not so fine for ceiling-mounted clusters. You doubtless already know that speakers emit in a highly focused roughly cone-shaped pattern at high frequencies, gradually transitioning to a sphere at low frequencies. The best place to be is on-axis, where the power balance is correct for all frequencies. The worst place to be is directly behind the speaker, where there are no highs at all, or off to one side, but even being a few degrees off axis makes a difference. So aim the acoustic axis of each speaker at the roughly the middle of that congregation on that side of the room. That gets the largest number of people closest to the center of the cone, and also keeps direct sound off the walls of the room, which is also very important.6. Should the projector speakers hanging from the ceiling be relocated or aimed differently? Standing on a ladder they now appear to be angled and pointing downward at the rear corners.
This might not be the case with your church, but its worth mentioning as it is also something I run into all the time: stage monitors. Musicians always seem to suffer from the famous "more or me" syndrome: They are never happy with the sound of themselves coming out of the their floor wedge, and they always want it louder. That's fine for a stadium, where you really can run each monitor as loud as the musician wants, but in a small room like yours, it is not possible. Cleaning up the monitor mix and getting the musicians used to reasonable monitor levels is the Next Big Thing that I always have to do when consulting for churches (after getting the speakers aimed right and the sound system tuned and calibrated correctly). The problem is simply that any sound at all coming off the stage into the congregation is going to muddy up the mix, and add unwanted reverb that is out of sync and out of phase with the rest of the mix and the rest of the reverb. Ugly. There's a difference between what musicians want in their monitor mixes, and what they need. What they want is usually the entire mix at 100 dB, with themselves on top at 120 dB! What they need is just themselves, plus the praise and worship leader, and maybe the snare and lead instrument, and they need that at a level 3dB lower than FOH mains. They will hate it, and they will kick and scream, but that's the way to do it. A good way to set the level of the monitors is to play a CD though the FOH speakers at the normal level of a service (say 90 dB, in your case), then sit in the front row and get someone to gradually bring up the same music in the stage monitors, until you start to hear it. As soon as you can also hear the stage monitors from the front row, they are too loud. Back off 3dB on those. Yes, that's probably unrealistic in a highly reverberant room like yours, and the monitors will probably need to be a bit louder than that, but it gives you an idea of how to go about setting up the monitor mix: minimal content, as low as possible. It must be quiet enough to not interfere with the FOH sound. You could even get the, to consider switching to an in-ear monitoring system, but that's probably outside of their budget. Those systems are great, but not cheap. Anyway, hope all that helps in some small way! - Stuart -7. Any other thoughts, ideas, etc would be greatly appreciated.