Midrange Speaker Test (500 Hz Warble Tone)
The 500 Hz warble tone evaluates the midrange speaker response. The 500 Hz warble tone qualifies as a warble tone because of the different audio characteristics present as opposed to the sine tone. The 500 Hz warble tone produces a warble sound. At midrange frequencies, use a warble tone instead of a sine tone because the location of a warble tone source, such as a speaker, is easier to identify. A normal sine tone can set up a standing wave within a vehicle. A standing wave may cause difficulty in determining the source location.