Author: Steve Temme and Brian Fallon
With the headphone market growing towards $10 billion worldwide, and products across the price spectrum from under a dollar up to thousands, there are many and diverse quality expectations and test requirements. Many audio engineers have moved across from the shrinking loudspeaker industry to the burgeoning headphone marketplace. Although many of the characteristics that make for a good in-room listening experience with a loudspeaker – good frequency response, low distortion, no Rub & Buzz or loose particles, etc. – also apply to headphones, and many of the same test principles apply, there are some significant differences and additional issues associated with headphone measurement that need to be taken into account. These include couplers and associated correction curves, acoustic seal, fixturing and additional tests such as L/R tracking. In this paper we outline the issues that are common to testing all types of headphones as well as those specific to particular types of headphones such as Bluetooth and USB headphone testing, noise-cancelling headphones, and Max SPL measurements to prevent hearing loss.