These commonly requested test signals can prove invaluable, so we have provided them on this web page for your convenience. Download them to your own computer, or to the computer at the sound booth in your church. Burn them onto a CD or save them onto your USB jump drive or your iPod so that you'll always have ready access to them.
For example, if you're wanting to teach yourself or your tech team what the channel EQ is capable of on your console at church, feed the pink noise into a console channel and listen to what happens to the sound when you make adjustments to the EQ settings on that channel. If you have a sweepable EQ, set the boost/cut knob for maximum boost or cut, and sweep the frequency. (Be careful to pull the master fader down before you make that adjustment so you don't hurt your speakers or someone's ears!)
Note: The "TEF" version of the pink noise may or may not be useful to you. It's actually a unique pink noise signal created specifically for use with the TEF analyzer. If you have a TEF, you already have this signal. If you don't, it may not help. But it's here anyway.
Or if you really want some entertainment, feed some of those really low frequency sine waves over your loudspeaker system and then walk around the room listening for the room modes and nodes. Even better, put a subwoofer or a floor monitor in a corner of the auditorium and try it again. I think you'll be surprised at what you hear.
If your loudspeaker system has some particularly sensitive feedback frequencies, the swept sine waves can be a real help in finding them. For example, if you'll set up your console so that the usual feedback culprits (mic inputs) are just on the verge of feedback, and then play one of the fast moving swept sine wave files (especially the one second sweep from 30Hz to 4kHz) over the loudspeaker system, you will likely hear the most problematic feedback frequencies ring out prominently.
Another fun one was contributed by fellow CSC member, Dale Shirk. It's a short (13 ms?) flat spectrum chirp that repeats every few seconds. It contains enough power to be quite audible, and is excellent for finding those surfaces that may be a problem, such as rear walls and balcony fronts. Just walk around and listen. With a little practice you can tell some things about the frequency content of the reflection. This signal is a killer for bad boxy rooms.
Each file is recorded as a mono WAV file at a 44.1 kHz sampling rate. The files are short to keep their size to a minimum, but you can have them play as long as you need by simply adjusting your playback device to repeat the file. This handful of test signals is a good place to start. If you think of other test signals that you want us to add, please just send us an email to let us know. You can reach us by writing to csbc@taipalemedia.com.
Swept Sine Wave - 20Hz-20kHz (20 sec)
Swept Sine Wave - 50Hz-500Hz (10 sec)
Swept Sine Wave - 30Hz-4kHz x2 (1 sec)
Reverse Swept Sine Wave - 15kHz-30Hz (6 sec)
Dale Shirk's Impulse Chirp (repeats for 60 sec)
Sine Waves at One-Third Octave Center Frequencies (30 seconds each, approx. 2.6 MB per file)
