April 12, 2012, by Chris Huff
Ringing out a room is a process for eliminating problem frequencies, wherein those frequencies are prone to feedback in your room.
You might hear it called “tuning the system” or “tuning the room.”
The last phrase “tuning the room” is actually a wrong phrase to use. You aren’t tuning the room, you are tuning the house EQ to work in the room.
Additionally, tuning the system and ringing out the room are a little different. Ringing out the room focuses on feedback frequencies whereas tuning the system includes dealing with feedback frequencies, but is also aimed at sculpting the house EQ so your system sound is in line with your needs.
For example, a house EQ for a country music setup will be different than a house EQ setup for heavy metal music.
There are three methods for ringing out the room:
1. ($$$$) Hire a professional. An experienced audio professional can use a real-time audio spectrum analyzer and adjust the house EQ to obtain the desired sound. Not only can they deal with problem frequencies but they can also sculpt the house EQ to be better suited for your needs. Go this route if you can afford it. They can ring out the room but they can also tune your system.
2. ($$$) Use an automated solution. An automated room equalizer like the dbx DriveRackPA can be used to eliminate those problem frequencies for your system. It’s effective but not the best. Yes, I know dbx claims it a miracle in a rack component, but nothing beats your ears (or the ears of a pro). I’ve known people who have used these types of rack-based solutions for portable systems. In my experience of working on portable systems, I tweak the house EQ during the sound check based on what I hear.
3. (FREE) Ring out the system on your own. The cheapest option and one you can do. You won’t get the sound qualities that a professional would get using method 2, but if you’re dealing with feedback frequency problems, it’s a great place to start.
The eight steps to ringing out the system on your own:
1. Set up your board for a proper master volume level.
2. Set up a microphone on the stage for a person to use for speaking.
3. Have the person talk into the microphone and set up the proper gain structure for their channel.
4. Turn up the master fader until you begin to hear feedback as a slight ringing.
5. Identify the frequency by ear or use a spectrum analyzer. Only use a spec analyzer if you know how to properly use it.
6. Cut that frequency in the multi-band house EQ until it goes away.
7. Repeat steps 4 through 6 until many frequencies tend to feed back at the same time. Then….
8. Reduce the master volume back to the normal level. The person’s voice should still sound natural. If it doesn’t, tweak your house EQ changes appropriately by giving a little boost to those frequency bands you cut.
Going through this process, you’ll eliminate those problem frequencies while also gaining more headroom in your system before experiencing feedback.
Ready to learn and laugh? Chris Huff writes about the world of church audio at Behind The Mixer. He covers everything from audio fundamentals to dealing with musicians. He can even tell you the signs the sound guy is having a mental breakdown.