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Mixing/Recording in a Gym, Fighting Poor Acoustic Treatment

Discussion in 'Studio Acoustics' started by bctour7, Jun 18, 2012.

  1. bctour7

    bctour7 Active Member

    Jun 18, 2012

    I'm looking for some help/validation with a few sound issues we've been having in our church.

    Some background - our sanctuary is a gym with a stage. So as far as size goes, the seating area is exactly the size as a basketball court. About 2-3 feet of clearance on each side of the court boundry lines, and I believe we seat around 600 people. The only acoustic treatment we have, is a bit of the 'cheapest option' fiberglass on the rear wall (does not even cover the entire wall) and the chairs/people that attend every Sunday. One of the biggest debates between our music director and me (tech dir.), is db. He wants it run louder -avg 95, but I'm much more conservative and protective of my own ears, so I tend to mix between 85-90. Any louder, and it does sound a bit more balanced because of really loud drums, but to my ear it just gets too much in such a small space, and the sound becomes unclear since the treatment isn't very good.

    He also wants more 'house sound.' He wants to hear the congregation singing in both the recorded mix (for the live stream) and wants me to put our house mics into the house sound. I'd love to be able to get this, but whenever I try anything, for the house sound I get feedback before I get any useable sound. And for the recording mix, I get a sound that sounds like mic-ing speakers in a gym. So I'm looking for some validation - that trying to get a good 'crowd noise' recording from an untreated gym is just not possible. Or, if anyone has any suggestions, I'd be happy to try and get something to work. I've thought about switching our house mics from overheads to a couple shotguns at the front of the stage, but I'm convinced that because of the size of the house and poor treatment, I'll still be getting more slapback from the rear wall than usable crowd sound.

    I'm also looking for general help with our recording mix. We use an M7, so I run the recording mix completly seperatly from the live mix. I have little recording experience, so the whole mix really doesn't sound that great, but I'm having the hardest time with the drums - I think it's just because of acoustic treatment/isolation, but I can't get a good presence out of the drums. They always sound far away from the mix. Here's the link to some recorded streams if anyone wants to take a listen.

    Bay_Area_CC @ Ustream.TV - . Free .TV shows, LIVE Video Chat Rooms.

    So, in summary:
    Smaller untreated spaces: Rule of thumb for dB?
    Mic-ing the house: Possible? Best way?
    Recording: Any suggestions from listening to our streams?

    Thanks in advance for any help!
  2. RemyRAD

    RemyRAD Guest

    Sep 26, 2005
    I am hearing way too much low-end boom. You need some high pass filtering for the recording. Putting microphones out for the congregation should be SM57's. Perhaps six in three pairs. This way you can keep the gain structure lower and pick up more of the congregation to be amplified. In these over acoustical environments, dynamic and not condenser microphones should be the norm. Condenser microphones pick up too much of everything you don't want. I had to teach this to the teachers of the Omega School of Recording in Rockville, Maryland, years ago. Dynamic microphones into reasonable preamps always sound good, provide isolation, reduce spurious pickup. That's why God created dynamic microphones. It's not a studio it's a gymnasium. Dynamic microphones are your friend. Condensers sound like the devil. After all, it was the Nazi's that made condenser microphones popular. What does that tell you? There's a time and a place for everything but sometimes the places dictate what to use.

    Firm believer in dynamics
    Mx. Remy Ann David
  3. bctour7

    bctour7 Active Member

    Jun 18, 2012
    I know I have undervalued high pass filters just because I didn't know much about them, so I'll be sure to read up more on that. I know the M7 has that all built in and easy to use, and I found this quick article that addresses the issue pretty well.

    (dead link removed)

    I don't know why using dynamic mics never even crossed my mind, but it makes perfect sense. I'll try and pick up a few extra 57s in the next couple of weeks to try it out. The only issue I could have however, is that the room is still used as a basketball court, so I can't get them very low. I'll follow up on this once I get a chance to try it out.

    You mentioned preamps as well, another thing I haven't had the chance to use very often. Do you have any suggestions for any that would fit a smaller budget? Espically if we're talking about 6 57s, would submixing into 1 pre amp be a major fail, or do we need 6 pre amps?

    Thanks for your quick response, this was all very helpful.

  4. RemyRAD

    RemyRAD Guest

    Sep 26, 2005
    While I like fine preamps myself, much of the newer equipment today far exceeds the equipment of just a few years ago. So I think that with what you are currently using (whatever that may be?) You should just try the 57's. Good preamps ain't cheap. For instance the API 3124 mixers provide for only four channels and cost around $2500. So that might not be an option. The newer Mackie consoles sound way better than their earliest permutations did. Others, likewise such as Yamaha, Midas, others, have a lot of bang for the buck to offer today. I didn't think your stuff sounded substandard by any means. Though one could hear the problems you are speaking of. And that's why I recommended dynamic microphones. Limited bandwidth and lower sensitivity can actually provide for better sound than equipment typically utilized in recording studio applications. Many folks want that condenser microphone sound but due to certain acoustical environments are far less practical and can actually produce a more substandard product. The guys at Omega didn't exactly believe me until I proved it to them. Of course in that instance, we were going into an all transistor vintage Neve which makes everything sound fabulous. That's not to say that newer mixers today aren't capable of that because I believe that they are. Newer designs are quieter, cleaner and offer a transparency that a lot of people like to hear. I personally prefer equipment that provides for a lot of colorful flavor. Either way, I still wouldn't think twice about utilizing dynamics in the situation in which you are working in. Perhaps the only place you would want a boutique preamp or a few boutique preamps might be on some lead vocals? Those might create a greater warmth and lushness that state-of-the-art preamps would leave people feeling cold, metallic, overly crispy around the edges. And the more that you use, the tighter you get them, the lower your game trim will be in order to thwart an excessive amount of hiss from cranking in too much gain. And I think you'll also find that utilizing dynamic microphones will pose less of a problem with excessive low-end boom without the need for excessive high pass filtering that could thin things out a bit too much.

    I know you're going to make this work.
    Mx. Remy Ann David
  5. dvdhawk

    dvdhawk Moderator Resource Member

    Dec 18, 2008
    Western Pennsylvania, USA
    You've been well-served with Remy's advice. Dynamic mics, high-pass filters, etc.

    Now a few random thoughts & questions that occur to me:

    I also hate omni-directional hanging condenser mics for this and most other applications. (but better for recording than for live sound reinforcement). As Remy said, they amplify everything I don't want.

    Compressors are also EXTREMELY useful doing church sound.

    I would engage the high-pass filter (or low-cut if it's easier for you to visualize) on every channel EXCEPT: kick drum, floor tom, bass guitar, piano / electronic keyboard / and any input dedicated to CD or music playback from the computer. With the possible exception of a super low bass/baritone singer - there's nothing in the super low frequencies you want getting into your vocals, guitars, etc. If it's not an instrument that specifically has useful bass frequencies, it's mostly noisy floor vibrations, rumble, and handling noise.

    Left/Right Speaker config, Center cluster, or combination of the two?
    Was there any thought when purchasing or positioning the speakers to avoid hitting the walls?
    Is the stage oriented on one of the short walls? or one of the long walls?
    Is it cut into the wall and elevated? or taking space out of the bball court?

    Is the fiberglass on the rear wall arranged as one contiguous area? Scattered is usually better.

    How big is your basketball court?
    Jr. High bball court is 74' x 42'
    High School court is 84' x 50'
    Collegiate & Pro court is 94' x 50'

    When measuring the dB level are you measuring from the front row? 50ft. away? 80 ft. away? or in basketball lingo, the base line? free-throw line? the top of the key? half-court? or full-court?

    The Inverse Square Law [you lose 6dB for every doubling of distance] would suggest if you read 90dB 80 ft. away - it's closer to 108dB 10 feet from the sound source. Conversely, if you're reading 90dB in the front seats 10ft from the sound source, it's 84dB at 20ft, 78dB at 40ft, and 72dB at 80ft. Some would view this as an opportunity to sit a distance from the source that gives them the volume they're comfortable with, but churches rarely work that way. They always sit in the same place and then complain it's either too loud or too quiet instead - welcome to church sound.

    What's the worship style? Contemporary? Traditional? Blended?

    I think church is very comfortable averaging at 90dB ( back of the room ) for contemporary music with peaks occasionally a little higher. Traditional might be a little quieter. Of course this is very subjective and depends on the style of worship and congregation's expectations. If a certain age-group sees an electric guitar on stage it's already too loud before they even start playing it. No the other hand, if it's a southern gospel group with good vocal harmony and bass-heavy tracks, they can be as loud as the Who as Knebworth and nobody will ever complain.

    I have read on other forums dedicated to church sound, that some pastors want the sound to "hurt" - I would quit that job and find another church if it were me. But the point remains, the appropriate volume is subjective.

    I run the sermon significantly lower. I like it to be very easy to hear every word, but without sounding "amplified". If I've done my job correctly (with the sound system installation and the job of running sound) it sounds like the pastor (who is reality 100ft. away) is standing 5ft. in front of you having a conversation with you.

    If you're using a Yamaha M7 - you should be able to route the congregational mics to the omni-outs and provide a mix that includes overheads. You would need to be sure you route the overheads to the omni-output(s) and keep them out of the mains. If you're getting feedback, they're re-amplifying the room and being pumped back through the FOH speakers. If they are going only to the recording device, and not the speaker system, you could turn them up to absurd levels and never get feedback in the room.

    Not very well organized thoughts, but things you can consider and give us a liittle more info.
  6. bctour7

    bctour7 Active Member

    Jun 18, 2012
    Going to engage any high pass filters that aren't engaged, in line with your advice for this Sunday, so we'll see what I can get out of it. I also might get around to hanging the 57s, but that might have to wait a week or 2. My descriptions and photos are probably overkill, but I'm sure I can refer back to them in future posts soon enough.

    2012-02-23_17-25-15_918.jpg 2012-02-23_17-25-53_605.jpg 2012-06-07_17-01-50_189.jpg 2012-06-07_16-58-06_329.jpg

    Maybe these photos will help a bit to explain the venue.
    2 suspended arrays, each a stack of 4 cabinets.
    There is also a center speaker, but it's not really in line with the others. It was meant to be used as a completely separate system for basketball announcing, but I've been playing here and there with making it usable. Not sure what it is yet, but it's not a bad sounding speaker.

    The system was designed by a sound company, (MSI out of Baltimore) so I would imagine speaker placement should be adequate.

    Stage is cut in on a long wall in case that isn't clear from the photos. The speakers are placed right over the stairs that lead up to the stage. The gym is mostly for high school, but maybe it is collegiate sized based on the overall gym dimensions below. Should be able to see the wall treatment from the last photo.

    Ceiling Height (To tiles) - 25' Sanctuary Length - 104'
    Sanctuary Width - 63'
    Dimensions do not include the cut out stage.

    Measuring dB mostly from the enclosed booth and around the back wall. I'll calculate out a bit and do a better job of running around with the meter this week to see where it stands throughout the space.

    Contemporary worship for the most part.

    I'm with you on the sermon dB. That was one of the first things I was taught while doing church sound, so I subscribe to the same rule of thumb.

    I do run 2 separate mixes, so I can easily keep the overheads out of the mains, but the worship leader thinks getting some of that mix in the mains would encourage people to sing out. I'm not sure if this is done much, but I could see where it would be good. I certainly understand why I was getting feedback, in my first post, I was more looking for a solution to get more usable sound before the feedback kicks in. The 57s should do just that.

    Thanks to both of you for taking the time for all that input. I should have been making better use of forums for the last year or so.
  7. moonbaby

    moonbaby Mmmmmm Moderator

    Feb 23, 2005
    MSI, as in Maryland Sound ?? If that's the case, I'll bet that this was a pretty nicely-done installation. Your complaints about the drums and dealing with a music director are very common. FWIW, I agree with the previous posts. One caveat would be that the onboard compressors in the M7 need to be set with fairly high thresholds to act more as limiters. This is to prevent aggravating any feedback issues, as heavier compression tends to do. This is where your gates will come in handy, but this will take you some trial-and-error with the various sources to nail. And don't get me started about amateur singers that think it's cool to swing their mics around in front of the floor wedges...:mad:
  8. dvdhawk

    dvdhawk Moderator Resource Member

    Dec 18, 2008
    Western Pennsylvania, USA
    I had to have a conversation with one of our youth pastors about not holding the mic like a gangster rapper. He was holding the mic by the windscreen and had most of the ball of the windscreen inside his hand while making some announcements to the regular congregation. I wish I could have dropped a nice phat beat under the distorted announcements that morning. So you have a brief chat with them next time they're on the schedule and tell them in 25 words or less that while that may look cool, it sounds awful. (all the youth pastors I know have the attention span of a hyperactive puppy, so you have to keep it short)

    bctour7, your photos and descriptions are not overkill at all. The more information the better, and the pictures are worth some large number of words upward of 999.

    As far as your worship leader's idea to mic the congregation to inspire more singing.... he makes a valid point, but doesn't understand that what he is asking you to do can't be done with typical hanging mics. As you've experienced with the hanging mics, by the time you get all the overly sensitive frequencies rolled off and notched out with an EQ - there's really nothing usable left. Typical omni-directional choir mics are hard enough to get any useful sound from when they're behind the speakers. If your congregational mics are in front of the speakers you'll need a mic with a clearly defined null in the cardioid or tighter pattern you can turn toward the speakers. (a few SM57's might just fill the bill) In an old traditional church, you may not get away with something as bulky and visually unappealing as a 57 - but in a contemporary setting like yours I doubt anyone will care about aesthetics if they get the job done.

    As far as the speaker placement - it looks a little wide to me - especially since you've said the center speaker isn't directly incorporated into the main system.
    A) From what I see in the pictures, I'd be concerned the horns of left and right arrays are hitting the side walls too soon.
    B) I'd be equally concerned there's a deadspot in the center of the first few rows that have little or no horn coverage - and clarity issues.

    I would want to test it to see if you need to use the center speaker to reinforce that little semi-circle of seats in the middle. Play some music and go sit in the second row on the center aisle and see how much highs and mids you're getting with just the main left and right speakers playing. Pay particular attention to the vocals (that's the most important thing in church) and hi-hats, acoustic guitars. It might be fine, it may be lacking - just make a mental note. Then go back 4 or 5 rows on the aisle and note any difference in clarity. Replay the same song as many times as necessary and take a sample from every section, you don't have to sit in every seat in the house (left right center / front middle back).
  9. kmetal

    kmetal Kyle P. Gushue Resource Member

    Jul 21, 2009
    Boston, Massachusetts
    Home Page:
    My band stopped using our racks' compressor/gate (dbx 166 xl), due to the squeaks it was introducing at our gigs. Bars, 100 people. It was so touchy, and we never got the presence we were looking for w/ out feedback, just wasn't needed for us. Fixed installations are a different animal, but we don't use the compressor in our portable live rig. Even chaining into/after a couple diff graphic eqs, just not worth it for the gigs. We could never get the 'fullness' before the squeaks started, it was just inherit effects of compressor/lackof-knowledge/small live rooms, the vlz's channels have worked just fine. we employed 166xl as a limiter, which made more sense in that kinda setting, but just found it unnecessary to lug around.
    For fixed installations an average club/bar a dbx driverack has done pretty well. I haven;t used it's RTA function, but the processing doesn't sound bad, and does alot decently. it has a delay for speakers. That thing has done some good work protecting amps/speakers, when people pin the master volume.

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