Dear Worship Leader & Sound Person – TAME YOUR VOLUME!
Yesterday, we talked about the dangers of being too loud in your worship venues. If you haven’t already, I urge you to go back and read the article. Understanding the problems loud and uncontrolled music creates is one thing – knowing how to keep it in check is another.
Before we go any further – make sure your church is equipped with a very important piece of equipment: a Sound Pressure Level (SPL) meter. These can be picked up at Radio Shack – but make sure the one you buy is capable of giving you C-weighted measurements. Without this tool – everything is left to speculation and personal taste. With a good SPL meter, you can properly keep sound levels in check. It also helps to be able to honestly tell someone who says “hey, the music was too loud today” that the music was the same level it was last week. (There is an exception to that…and we will cover it later.)
The chart to our right tells the story (according to OSHA) of how long the human ear can stand to hear certain levels of continued dB exposure. Keep in mind (for reference) that 30 dB is the range of a quiet home. 45-50 dB is the range for the average household (unless you have my kids). It is also worthy to note that a 10 dB shift in any current dB volume is perceived by the human ear to be double the amount of the current volume. In other words – a venue at 82 dB that has a sudden spike to 92 db would be perceived to have gotten twice as loud. That figure should become very important to you as you start tweaking your sound.
Let’s keep the chart above in mind as we look at a scenario and how we use our SPL meter. In order to find out how loud we need to keep our mains – we need to find out what is going on on the stage. Turn the house speakers down completely. Listen to only monitors and any existing sound (electric guitar amp, drums, etc) coming from the stage. Let’s say that your SPL reads “102 dB”. In order to properly mix the house to keep that noise from spiking through, you must keep the house approximately 10 dB higher. This means your total mix will be about 112 db. Based on OSHA’s chart, the maximum time the human ear can be exposed to those levels is a little less than 30 minutes. Yes, perhaps your worship music set will be less than 30 minutes – but weekly exposure to these levels will prove to have ill effects on the hearing of your congregation.
So what needs to change? First – we should set a goal. Most venues that I know of (including all three of our own stateside venues) run at 95 dB peak SPL. This means that your sound should not break past 95 dB. Keeping this measurement in mind, we can ascertain that the sound from the stage (without the mains) needs to be no more than 85 dB. This means we’re going to have to significantly cut back on volume. Try isolating each instrument and seeing what the dB level is. Drums too loud? Get a sound barrier like a plexi-glass shield. Guitar amp too loud? Enforce a mandatory volume reduction and then “encourage them” to not go above that level.
“They also make amp shields that are very much like the drum shields. Also we have an “Amp Box” at the LifePoint FBC Campus which does a great job keeping the the stage volume down.”
Keeping your venue beneath the 95 dB ceiling is now a little easier – but it isn’t the end of the story. Tomorrow, we will taking a look at other factors that have a bearing on the volume at your venue. Stay tuned!