Sound System Analysis for Trinity United Methodist Church

SALT Logo The following is a report prepared by Ken Ellis after an evening at Trinity United Methodist Church listening to a Praise Band practice and evaluating the sound system.  These comments come from a background of 12 years experience with the Sound And Light Team (SALT), running sound for various church services, Praise Bands, and concerts.  Please feel free to accept or reject any of the recommendations I have made.


House Speakers:
Currently, Trinity's house speaker system consists of an array of 14 ceiling speakers (in 4 zones) and two front of house speakers (hung to the left and right of the stage).  The left house speaker seems to be wired in parallel with the 3 ceiling speakers in the front left zone.  There are two sets of 12AWG wire feeding these speakers, but each of them appears to power all 4 speakers.  The right house speaker seems to be wired similarly.  The 4 zones each are connected to one side of a stereo amplifier providing about 185W RMS per zone.

The tonal quality of the sound from the ceiling speakers is significantly different from the tonal quality of the left and right house speakers.  The ceiling speakers have noticeably more treble.

When using the 14 ceiling speakers, the source of the sound comes from many places.  When the system is used for voice (speaking), this does not seem to be a significant problem (except that it seems like someone in the clouds is talking to you), however, when it is used for music, the multitude of sound sources combine to "muddy" the sound.  Clarity is lost.  Intelligibility of the words suffers.

I believe that clarity, intelligibility (ability to clearly understand each word), punch (bass response), edge (high frequency response), and directionality (direction you hear the sound coming from) can all be enhanced by using ONLY the left and right house speakers (and not the ceiling speakers) for Church services and concert type programs.  However, to do this, some changes would be required.

We tried turning off the ceiling speakers in the two rear zones and increasing the volume on the two front zones.  This seemed to give a better sound:  less mud, better clarity, and a little better snap and punch.

I suggest re-wiring the front two zones, disconnecting the left and right house speakers from the ceiling speakers and providing a new 8AWG wire run from each of the house speakers back to the amplifier room.  The house speakers appear to be rated at 300W RMS.  Therefore, I suggest getting a new 1200W RMS amplifier to power the left and right mains.  That is, 600W to the left and 600W to the right.  This will provide enough power to cover peaks without distortion (currently these speakers are under-powered and the amplifier distorts easily).

To run the main speakers, I suggest using ONLY the main left output of the mixer (there is no value added in paralleling the left and right outputs and it can sometimes cause signal cancellation), connecting it through the 31 band graphic equalizer (located near the mixer) and then to the left AND right inputs of the new 1200W amplifier.

Once the change mentioned above has been made, it is CRITICAL that you get someone who has KNOWS how to set the 31 band house equalizer to set it BEFORE you make any judgment on how the system sounds.  I know you will not be pleased with the sound unless this is done correctly!  The room has acoustic tile ceiling, acoustic padding on the walls, and a carpeted floor.  These all need to be dealt with in the equalizer setting. The natural sound of this room is rather "dull" because all the acoustic treatment soaks up the high frequencies. The most difficult part about equalizing the left and right main speakers will be to get "snap" and "sizzle" the whole way to the back of the room without making the sound too "sharp" in the front of the room.

I suggest leaving the 4 ceiling speaker zones intact and connected two of the existing amplifiers providing 185W per zone (with no graphic equalizer).  To run the ceiling speakers, I suggest connecting the front left zone to the subgroup 1 output of the mixer, front right to subgroup 2, rear left to subgroup 3, and rear right to subgroup 4.

For a Church service, I would use only the left and right house speakers.  That is, leave subgroups 1-4 OFF.  If you have occasion use the sliding partitions to divide the room into two or four smaller rooms, you could run sound in any combination of these rooms using the appropriate combination of the subgroups.  It would even be possible to run multiple programs in different rooms simultaneously (as long as they were not loud enough to pass through the sliding partition.

You could experiment and see if the sermon could be heard better through the ceiling speakers than through the mains.  However, I feel certain that any musical program would be better through just the left and right main house speakers.

The question of whether or not you need a sub-woofer was raised by someone.  I don't think that a sub-woofer would be a good place to put your money at this time.  I think that the left and right house speakers will have adequate bass.  However, if you ever do decide you need a sub woofer, one or two of them could be placed at the extreme left and/or right of the stage, on the stage.  When re-wiring the left and right main speakers, you could run extra wires back to the amplifier room for future sub-woofer(s).

If you had a lot of money available to put into a sound system, you could probably get a SLIGHTLY better sound in this room if you installed a NEW central cluster array.  However, the array would have to consist of at least 5 and maybe 6 separate speakers, they would have to be carefully selected for coverage angle and carefully installed to point in exactly the right directions to cover the whole room evenly and minimize any reflection off walls.  The new central cluster would have to be located further out into the room compared to the location of the old central cluster (which is no longer used because of excessive feedback).  Personally, I think the ceiling in this room is a little low to use a central cluster.  Also, I don't think central clusters work well with acoustic tile ceilings.  I would not spend God's money on a central cluster at this time.  First, I would try the suggestions I made above about using just the existing left and right main speakers.


Monitors:
Currently, Trinity has two monitor speakers hung by chains above the stage.  Unfortunately, both of these speakers are damaged.  One produces basically no high frequency sound at all.  The other has a very distorted sound.  Besides the fact that they are faulty, they do not provide enough coverage for the stage.  They are aimed too far back and there is a quiet spot at the center of the stage.  You could take them down and get an estimate on getting them repaired.

However, my suggestion would be to purchase 3 new monitor speakers for the Praise Band musicians.  These should be "slant" monitors, preferably with an angle of 45 degrees.  Cerwin Vega makes some nice slant monitors that are economical, light weight, rugged, and sound good.  You need monitors with a fairly wide coverage angle.  Use one in front of the guitar players, one behind the drummer and percussionist, and one in front of the keyboard and bass players.  Do NOT use more than 3 stage monitors because you only have one monitor amp with 185W for the stage monitors.  Continue to use your two existing slant monitors for the singers powered by the other side of the monitor amp at 185W.

If money is available, you should have a 31 band graphic equalizer on each of the two monitor sends from the mixer.  I prefer the Peavey Q-431FM 31-band equalizer with feedback finder lights.  This equalizer has a light above each of the 31 sliders.  If feedback occurs, the light above the slider that controls that frequency illuminates.  This tells you which slider to move to eliminate the feedback.


Mixer:
When we started Praise Band practice, there was a very loud "hum" in the monitor speakers.  We had all the inputs muted, so that was not likely the source.  We tried unplugging the feed from the mixer to the monitor amps and that cleared the hum.  I suggested we put a ground-lift on the mixer power supply.  However, when we looked, we found the mixer power supply already had a ground-lift.  About then, the problem spontaneously came clear.  After thinking about it a while longer, I realized that the mixer power supply was a metal box and was sitting loose in the bottom of a metal rack.  We discovered that when the mixer power supply rubbed up against the metal rack, it became grounded and produced the hum.  This power supply should be relocated to a place where this problem cannot reoccur.

As stated above, I suggest re-wiring the mixer so that the main left output goes through a 31 band equalizer and then to both sides of a new 1200W amplifier to drive the main left and right house speakers.  The main right output could be connected to both the left and right inputs of the cassette deck used for record.  Subgroups 1 and 2 should directly feed the two sides of the existing amplifier powering the front left and right ceiling speaker zones.  Subgroups 3 and 4 should directly feed the two sides of the existing amplifier powering the rear left and right ceiling speaker zones.  Monitor send 1 should continue to go to the amplifier powering the front (singer) monitor speakers.  Monitor send 2 should continue to go to the amplifier powering the rear (band) monitor speakers.  Effects send 3 should continue to go to the MIDI Verb.

The equalizer controls on each mixer channel can be very useful, but the can also do a lot of damage to the sound.  From time to time, set all the mixer equalizer controls to "null" (center position).  Then only apply the equalizer settings that are NEEDED.  Listen to each channel one at a time and see if there is any tonal quality that is objectionable about that channel.  If so, try to eliminate the objectionable part.  For the most part, use the equalizer to "remove" sounds which are objectionable rather than to "add" things you want.  An exception to this would be to boost the high end of a keyboard or guitar.  Do not boost bass, cut the high end instead.

The only way to learn how to set an equalizer correctly is to practice, practice, practice!  It takes time for your ear to learn what frequency a sound is and translate that into the appropriate equalizer setting.

When building the monitor mixes, only include what is needed.  Front (singer) monitors need all the singers, keyboard, and the cassette used to play tracks.  Rear monitors need a little less of the singers, more keyboard, and some guitar.  Only add other things if there is a reason!


Keyboard:
Trinity's keyboard player just got a new "keyboard in a box", that is a MIDI sound module.  We tried to connect it to the second input on the direct box that was already being used for keyboard, but that did not work well.  We found we had to use a second direct box for the new "keyboard in a box".  But, we were able to feed both the keyboard and the new box into the existing keyboard monitor amp.

The sound operator should probably run the keyboard a little hotter in the monitor speakers.  It seems that most of the time, the keyboard is leading the tempo of the songs.  Everyone will probably stay together better if they can all hear the keyboard in the monitors.


Electric Guitars:
Initially, the guitar player's amps were VERY loud and were set behind the players facing front (traditional rock setup).  This caused excessive sound level on the stage and also made the guitars loud in the front of the house.  However, the guitars could not be heard well in the back of the house and they had no snap (high end) or bite (crispness).

Later in the evening, we got the guitar players to move their amps.  The guitar amps were placed in front of the guitar players and tilted at an angle so they faced right at the guitar players faces.  Now, they were able to greatly reduce the volume of the guitar amps and still hear themselves.  This greatly decreased the volume of the music on the stage - both by turning the amps down and by facing the amps the other direction.  Both guitar amps were miked and now the sound man was able to turn up the guitars in the house mix (without having too much guitar in the front of the room) and get a clearer sound and an even guitar level throughout the house.  I suggest you build some wooden brackets to tilt all the guitar amps at a 45 degree angle.

The rhythm guitar player sometimes uses a "fuzz" box when he plays.  I would suggest minimizing the use of this sound because it contributes to making the overall sound of the Praise Band "muddy".  I think you should strive for clarity in the sound of each instrument as well as each voice.  Fuzz has its place in Rock-N-Roll, but I am less certain of its place in Contemporary Christian Music - but then, that is just my opinion.

The lead guitar player did an excellent job of playing "accent notes" during times that the singers were between phrases or taking a breath.  This is a very good technique.  When the lead guitar player does this, the sound operator is able to put a lot more guitar music in the house mix without "stepping on the vocals".  Another thing that the lead guitar player did that was helpful was playing mostly high notes, not the mid range notes which are in the same tonal range as the vocals.


Bass Guitar:
The bass guitar appears to produce a rather significant "hum".  When we turn down the volume on the bass guitar or unplug it, the "hum" goes away.  I suggest trying the bass guitar and amp in another building to see if it is the florescent lights that are causing it to pick up "hum".  Maybe, try the bass guitar with another amp.  If a solution cannot be found, it would be a good idea to take the bass guitar to a repair shop to see if they can do anything about the hum.

The position of the bass amp is not very critical since bass sound is not very directional.  It is probably best to have the bass amp facing forward because we don't want to reflect the bass sound off the stage walls.  This could lead to noticeable peaks and valleys in the sound.  The direct mike cord connection on the back of the bass amp seems to work well.

The sound person should be careful to get the correct amount of bass guitar in the house mix.  Bass guitar is probably not needed on the monitor mixes.


Drums:
The drums are too loud on stage, but cannot be heard well in the house.  You NEED drum mikes.  Minimally, you need 2 mikes.  I suggest buying new Shure SM57's (around $100 each).  One should be on a "desk" stand with a "goose" below the snare near the bass.  The other should be on a boom stand between the toms.  If you have more money and mixer channels, you could add additional drum mikes.  I think 4 mikes would be best.  Then you would have one on bass, one on snare, one on center toms, one on right tom.

If we mike the drums and get the guitar players and drummer to play quieter on stage, it should not be necessary to have a drum screen.


Congas:
The congas cannot be heard in the house.  You NEED one Shure SM57 on a straight stand with a "goose" above and between the congas.


Hand-held Mikes:
I was paying more attention to the technical details of the rehearsal than to the singers, so I'm not sure how well the singers were following the guidelines to follow:

When using a hand-held microphone, you should hold it even with your chin or just below your chin.  The mike should be facing almost straight up, just tilted a little bit towards you.  The audience should be able to clearly see your whole mouth.  Seeing your mouth is very important because even though we do not realize it, we are all "lip readers" to some degree.  People are able to understand your words much easier if they can see your lips.  Never hold the microphone in front of your mouth (like the rock singers do).  Speak and sing "across the top" of the mike, not "into" it.  Another reason to hold the mike at chin level is to reduce "P-popping" and breath noises.  This way, any bursts of air will pass across the top of the mike rather than into the front of the mike.

Hold the mike as close to your chin as possible.  Be CONSISTENT.  Hold the mike exactly the same way all the time, every time.  The mike should never be more than 4 inches from your mouth.  Don't torture the sound operator by holding the mike a foot or more from your mouth.  The sound operator cannot make you heard that way!  The only time to move the mike further away is if you are singing more loudly than you normally do.

Do not cover the top of a microphone with your hand.  That is likely to cause feedback.  When you are not using your mike, continue to hold it facing straight up.  Do not point it down and especially don't point it at a monitor speaker - you WILL get feedback.


Headset Mikes:
The keyboard player and the conga player were using headset mikes.  Headset mikes should be placed just below your lips.  Most headset mikes have a little red dot on the side of the mike that should face your mouth.  Be careful not to cough or talk to others when wearing a headset mike.  If you have to cough, move the mike out to the side, or take it off.  Do NOT hold the mike in your fist - that is likely to cause feedback.


Stage Volume:
One of the most significant problems of the Praise Band was stage volume.  Initially, everything was too loud especially bass, electric guitars and drums.  I was listening from the back of the house and asked the sound operator to turn off the house speakers so I could hear how much sound we were getting from the stage.  I thought he didn't hear me so I asked him again to turn off the house speakers.  He said "I did, the first time you asked me."  I was amazed at how much sound we were getting from the stage.  The whole house was loud just from the stage sound.

We then asked the musicians to bring down their volume and we repositioned the guitar amps in front of the guitar players.  This helped a lot to reduce the stage volume.  However, I am sure that over time the stage volume will creep up again.  Therefore, it is ESSENTIAL that the Praise Band leader as well as the sound operator keep an ear on the stage volume and keep reminding all of the musicians to play as quietly as possible while still being able to hear themselves.

Playing Contemporary Christian Music is not like a Rock Concert.  Volume is NOT everything.  In Contemporary Christian Music, getting the words heard and understood is far more important than getting the soul movin' to the beat.  Our purpose is to Praise and Worship God.


Sound Operator:
Being a sound system operator is a tough job.  I know - been there, done that.

Your sound system operator does a good job and seems very dedicated to his task.  He needs the cooperation and constructive feedback of the entire Praise Band.  But most of all, the Praise Band needs to trust the sound operator to do what is needed to make them sound best.  Each member of the band probably has ideas about what could be done to ensure that their music is heard.  But it is the sound system operator's job to blend all the music together, blend all the singers together, and most of all, ensure that the words can be heard and understood.  Although with Rock music, the message may be in the beat and in the music, with Contemporary Christian Music, the message is in the words.  The sound system operator should always put priority on hearing and understanding the words and then get as much of the music into the blend as possible - but without compromising the words.

In order to do his job well, the sound system operator has to receive complete cooperation from the Praise Band.  If he asks someone to play softer, move their amp to another location, or change a setting on their amp, they should cooperate.  If they don't understand why the sound operator has asked for the change, they should make the change anyway, but discuss it with the sound operator during a break or after practice.  If anyone has ideas which may help the sound system operator, discuss it with him in a cooperative way.  Keep in mind that it is the sound system operator's job to look at and hear the "big picture" and try to make the best compromises so that everyone and everything works well together.

Develop a good working relationship among the members of the Praise Band and the sound system operator.  Don't let problems fester, don't speak in anger.  Remember, we are all brothers and sisters in Christ.


Tape Deck:
You should have TWO cassette tape decks - one dedicated to recording and one dedicated to playback.  If you use the same cassette deck for both recording and playback, you run the risk of getting a very high frequency feedback loop which can destroy tweeters.  (I think that is what happened to the two monitor speakers hung above the stage.)


Effects:
Trinity's sound system has a MIDI Verb effects processor available which currently is not being used.  Generally, for a Praise Band, there is not a lot of need for an effects processor.  However, it could be useful for solos, especially someone singing to an accompaniment track.  Adding a little "chorus" to a solo can do a lot to smooth out a nervous voice and make the person sound more professional.

Generally speaking, an effects processor should be used on one or two microphones at a time or one instrument.  It should not be used on ALL the singers or the whole mix.


General:
The sound operator should have available a good assortment of adapters.  Radio Shack is a good place to get most of these.  The sound operator should also have available a good assortment of spare cords.  Radio Shack is NOT a good place to get these.  I have found that Radio Shack cords are not very reliable, especially the gray ones.  Go to a music store to buy cords.  Usually you get what you pay for.  Don't buy really cheap cords.  It is really frustrating to have a cord go bad in the middle of a performance  - been there, done that!  You should also have a few spare direct boxes, extension cords, multi-outlet strips, and ground lifts.

It was mentioned that there are 4 expensive choir mikes hanging in the ceiling that could be used for drum mikes.  I would NOT use them for drum mikes.  Expensive mikes get damaged too easily by being bumped around or dropped.  Buy some new Shure SM57's for drum mikes.  They can take the beating better.


The Spiritual Aspect:

Recommendations:
If you decide to do more work on your sound system than you can handle yourselves, then I would like to recommend that you consider contacting Jeff Lehmann of Aaron Studios in Hollywood, Florida.  Advent Lutheran Church in Boca Raton contracted Jeff to install a new sound and lighting system in conjunction with a Sanctuary remodeling a few years ago.  We were very pleased with Jeff's work, his knowledge, his honesty, his fairness, and his dedication to our satisfaction.
 
Aaron Studios Ent. Inc. - Jeff Lehmann
2632 Hollywood Blvd # 307
Hollywood, FL 33020
954-920-4020


I would also like to suggest that you look at a Sound And Light Training (SALT) Manual that I have written and placed on the Web at http://www.kodachrome.org/salt .  I especially recommend chapters: 3) Goals for Sound Systems , 4) Job of the Sound Team , 6) Mixer , 8) Equalizer , 10) Speaker , and 14) How the Performer can Help .

I would like to express my thanks to Trinity United Methodist Church, the members of their Praise Band, and their technical crew for the cooperation and courtesy they displayed to me while evaluating their sound system.  I thoroughly enjoyed the evening I spent with these fine Godly people.  I hope that my analysis proves to be of value to Trinity.

Please feel free to contact me if you have questions about anything in this report or would like me to perform any further analysis.
 

God Bless,
Ken Ellis
561-368-6852
SALT - Sound And Light Team
mailto:KenEllis@kodachrome.org
http://www.kodachrome.org/salt - SALT Web Pages
http://www.kodachrome.org/ellis - My Web Pages

Go to Sound And Light Training Manual (SALT) .