Samsung Galaxy S4 i9505 Audio Distortion with Low Impedance IEMs

It has been discovered by numerous users of low impedance IEMs that there is an audio crackling noise from a certain volume onwards. This video demonstrate this problem clearly using a sine wave. Using a pair of Ultimate Ears 600 (Super.Fi 5) IEMs, using a 1kHz sine wave as a demonstration, when the volume is set to 13/15, the audio signature suddenly changes from a gentle 1kHz hum to this weird electrical noise. At volumes 12 and below, as well as 14 and above, this issue does not surface. With even lower impedance IEMs like the Sony XBA series, this problem may surface at volumes 7 and below, which is unacceptable.

In reality, most songs fluctuate between various amplitudes. While having this problem at only one volume level may seem to be a non-issue, this problem is basically amplitude-dependent and at the volume where you hear distortion using the sine wave, you will most likely encounter crackling 2-3 levels down and anything above that level.

What is troubling is that Samsung is refusing to acknowledge the problem so far and has instead placed the blame on 'third party incompatibility'.

Based on reports received, virtually all production GT-i9505 experiences this issue. Not much is known about whether the GT-i9500 is affected thus far. Previous Samsung flagships like the Galaxy Note series or the Galaxy S3 does not suffer from this issue.

For more information, please visit http://www.jensign.com/S4Distortion/ where Dr. Michel Gallant has conducted a thorough analysis of this problem.