Note: This post is part 3 of a 3 part series and is an excerpt from an article by Vance Breshears in the August 2011 issue of Technologies for Worship Magazine. The full article can be at http://bluetoad.com/publication/?m=1284&l=1

In our previous post we talked about stage layout as a part of the live sound isolation process.  Remember, to improve isolation, it is important to start at the end and work backwards.  As a listener, what is the experience that you hear from the sound systems in a live venue?  What do you hear on a live recorded track?  The listening experience definitely includes factors such as the nature of the speaker system and room acoustics.  But if both those factors are optimized, then how can the experience be improved?  And when it comes to a recording, what are some typical issues that can be easily resolved?  One problem comes when you hear more of any particular instrument or vocal sound than you want.

Today in this last post we will discuss microphone technique.

Microphone technique

When it comes to microphone selection and placement, there are generally two options:  close-mic’ing and area-mic’ing.  Close-mic’ing would be using a clip-on microphone on a string, brass or woodwind instrument while area-mic’ing would be using a microphone further away on a mic stand.

Now close-mic’ing is not the “fix-all” ideal approach in every application, especially concert applications and live recordings.  But most churches that combine full rhythm sections and praise teams with an orchestra can find a much greater gain before feedback by close-mic’ing all acoustic instruments. 

This is where we can see the application of the inverse square law.  For example, instead of mic’ing two or three violins with one overhead or area-mic, an individual clip-on mic for each instrument can increase the gain before feedback by far more than the 6dB you find in the inverse square law.  This same idea can work for almost the entire orchestra.  The downside to this approach is the cost.  If you have already started adding up the mic count for a large group, it can quickly get out of control.  Along with the number microphones you need a substantial mix console to handle the input count. 

Keeping that in mind there may be some compromises that need to be made, it might work to pick a few of the first chair players from each section and close-mic them while area-mic’ing the others.  None of these ideas are ironclad.  Try different things and see what you get. 

Other beneficial techniques might include the use of an instrument preamp, direct box input, or even pickups instead of a microphone, and by using cardiod microphones instead of omnidirectional microphones whenever you can.  And, of course, if you have them available, experiment with the use of gates in the dynamics section of your digital console.  The simple use of gates in your mix can make a tremendous difference in cleaning up the sound quality.

Summary

For both live and recording mixes, in order to improve isolation between instruments, it is helpful to think in terms of the three methods for improving the situation: physical isolation, stage layout and microphone selection and technique.  Look at any options you might have with each of these and you’re sure to find some alternatives to ways to make improvements.

Note: This post is an excerpt from an article by Vance Breshears in the August 2011 issue of Technologies for Worship Magazine. The full article can be at http://bluetoad.com/publication/?m=1284&l=1

In our last post we talked about physical isolation as a part of the live sound isolation process.  Remember, to improve isolation, it is important to start at the end and work backwards.  As a listener, what is the experience that you hear from the sound systems in a live venue?  What do you hear on a live recorded track?  The listening experience definitely includes factors such as the nature of the speaker system and room acoustics.  But if both those factors are optimized, then how can the experience be improved?  And when it comes to a recording, what are some typical issues that can be easily resolved?  One problem comes when you hear more of any particular instrument or vocal sound than you want.

Today we will discuss stage layout.

Stage Layout

There are number of isolation issues that can be solved by a change to the stage layout.  Again with acoustic drums, their location and orientation in keeping them isolated from other mics can dramatically help.  Now it is not always easy to accomplish this.  Small stages can really limit the flexibility for changing the layout.  But unique ideas can be developed if you are creative in looking for options for the physical location of the drums and other instruments.

Other instruments can create significant volume issues as well.  Guitar amps are at the top of this list.  One option to look into is moving the amps off stage and out of the performance space and using a microphone at the amplifier.  Another option could be to build isolation boxes that are lined with absorption material to contain the acoustic energy from the amp.  Both these two options can work extremely well since it allows the player to run his/her amp at their preferred level to achieve the desired tone. 

It is not optimal to have a loud acoustic instrument next to a sensitive instrument microphone.  For example, an acoustic drum kit directly adjacent to an acoustic guitar with a condenser microphone will most certainly have problems.  There will be a lot of drum sound in that microphone making it difficult to get a good mix.  If the goal is to get a specific sound out of that guitar, it may be wise to just move their location further away from the drums to a more controlled area of the stage

Another issue is monitor speakers.  These speakers can produce excessive sound energy on the stage that will be picked up by the various instrument and vocal microphones as well as excessive sound energy out into the house adding to the background noise level.  The preferred solution is to move monitors closer to the musicians (raised up on a box), orient monitors facing towards an absorptive surface, and if possible, to turn them down.  Of course, one of the preferred ways to reduce stage monitor noise is to transition to in-ears, personal monitors, headphones.  While not always practical or readily accepted by all musicians, these devices will provide some of the best sound isolation and eliminate monitor specific issues.

Summary

For both live and recording mixes, in order to improve isolation between instruments, it is helpful to think in terms of the three methods for improving the situation: physical isolation, stage layout and microphone selection and technique.  Look at any options you might have with each of these and you’re sure to find some alternatives to ways to make improvements.

Note: This is part 2 of a 3 part series.

Note: This post is an excerpt from an article by Vance Breshears in the August 2011 issue of Technologies for Worship Magazine. The full article can be at http://bluetoad.com/publication/?m=1284&l=1

Live Sound.  Those words alone can evoke nightmares of past mixes that one could only hope to forget.  Anyone who mixes sound knows that things can get out of control very quickly.  It is easy to throw up some microphones, get a mix going and get caught up in chasing levels while trying to sort through the sonic mess. 

There are a number of techniques that work together in creating a great mix, but we want to focus on one, sometimes overlooked issue of isolation between instruments.  The challenge can arise with either a live mix or when producing a recording or broadcast mix.  The problem of bleed from one instrument into an adjacent instrument’s microphone can limit the amount of control you can have and reduce your ability to clearly define the mix.  While it is a process that requires some imagination and hard work, the idea that a good stage layout, some well-placed absorption or isolation materials and proper microphone technique can radically change the way your mix glues itself together.

Identifying the Issues

To improve isolation, it is important to start at the end and work backwards.  As a listener, what is the experience that you hear from the sound systems in a live venue?  What do you hear on a live recorded track?  The listening experience definitely includes factors such as the nature of the speaker system and room acoustics.  But if both those factors are optimized, then how can the experience be improved?  And when it comes to a recording, what are some typical issues that can be easily resolved?  One problem comes when you hear more of any particular instrument or vocal sound than you want.

This article will address physical isolation, stage layout and microphone technique.

A Little Technical Background

Pardon the nerd-speak for a minute, but a technical principle may help in explaining why stage layout and microphone placement can help.  It is the principle of the inverse square law.  It might sound complicated to some, but it is a primary concept in the field of sound that can help in understanding the distance and sound level relationship between instruments, vocals and microphones.  The inverse square law states that for every doubling of distance there is a 6dB gain or loss in sound pressure.  This applies to everything “audio.”  For example if you stand 10 feet in front of a loudspeaker that is playing music at 90dBA, and you then move back another 10 feet, the sound pressure will be approximately 84dBA.  This same idea relates to how sound is picked up by a microphone.

Physical isolation

Loud instruments, most notably acoustic drums, are one of the biggest challenges to sound isolation.  Hearing the drums coming through choir microphones, for example, is often a common challenge. This is where a drum enclosure can help.  Now there is a long list of pros and cons for using a drum enclosure and both sides of the issue are hotly debated.  But for many venues there just aren’t any better options if you want to control an acoustic drum set on the stage.  Then again, there is always a hope that you can find a drummer who plays with control and doesn’t overpower the entire stage.

In switching music styles for a moment let’s look at the layout of an orchestra.  All horn instruments (and musicians) are hard to control, but trumpets and trombones can be especially problematic.  The main problem comes when you have other mics across the stage for strings and woodwinds.  In this type of application, stage baffles can be utilized to provide acoustic isolation.  These baffles are usually lined on the backside with some kind of absorption material.  They aid in isolating the horn sound from the other mics as well as into the audience and performance space.

When it comes to the architectural finishes on the stage, sound absorbing products including materials on the floor, walls and ceiling are all part of the equation.  Area rugs or carpeting on the floor, acoustic panels or drapes on the stage walls, absorption on the ceiling or absorptive clouds suspended from the ceiling can all help to control the sound in the stage area.  Of course, the use of absorptive materials needs to be weighed against other acoustic requirements and aesthetic considerations.  For example, if you have a choir on stage that you want to be able to hear in the main seating area, you’ll likely want reflective materials on the floor where they are standing and on the wall behind them.  These reflective surfaces will help them to hear each other as well as project the sound out into the room.  But between absorption and reflective surfaces, it’s all a balancing act.

Note: This is a 3 part series – Part 2 will be posted next week.

Innovation is one of AD-NY’s main areas of focus and applauds the hard work of Programming summer intern, Jack Holland in developing two proprietary tools the office utilizes on a regular basis.  “Jack’s contributions have been invaluable over the three summers he’s been here,” expresses AD CIO Paul Sawyer, “his technical genius has greatly improved our efficiencies and enhanced the productivity of almost every employee in the NY office”.  Jack’s ongoing efforts with our ADPMA program helps the firm track project milestones, deliverables and receivables as well as generates valuable performance data on projects. This information output becomes utilized for staff training and development in honing and fine-tuning service and deliverable quality.  Our BAKI application is another tool which harvests data from different software tools and integrates them into dynamic platforms that allow consultants to generate accurate reports – fast.  Jack starts his junior year at Colgate this fall. 

AD-NY extends hearty thanks and best wishes to summer intern Nick Shirley.  Nick, spent the summer lending a hand in the field and while in the office championed development of an innovative 3-D modeling tool for performing art spaces.  Nick’s help drastically shortens the time to process acoustic-related data and allows output to be presented in an attractive and user-friendly interface.  Now, AD clients have a quick way to see and hear how specific design choices affect the acoustic environment of spaces such as rehearsal room and concert halls.  Nick is entering his senior year at the University of Rochester.