Since I started using my iPod Touch 5 after I lost my iphone 4S in Sep 2012, I felt that the audio from iPhone 5 headphone out isn’t as clear as that of iPhone 4S. In one particular video clip, the audible difference is very obvious. However, using lightning to 30-pin to LOD and amp, it sounded ok. Using a simple audio recording freeware, this difference can be “seen” and heard.
Equipment / software used:
Creative E-MU 0204
Ipod Touch 5
Lightning to 30-pin adapter
3.5mm to 2x 6.5mm Y-cable
(Kpop live performance. Area of interest: 0:50 to “la la la la”)
(Note: Content rights of this video belongs to KBS)
What I hear:
Using iPod Touch 5 headphone out, the “la la la” part suddenly become softer and muffled. It sounded similar on my mum’s iPhone 5 hp out.
Using iPod Touch Line-Out via lightning and LOD, the “la la la” sounds coherent to the rest of the song.
It sounded similar via hp out of my E-MU 0204, laptop (3 nos), iPhone 4S, iPod Touch 4, iPad 2.
How I record:
Line-out direct to EMU 0204 L/R Line in
HP out to EMU 0204 L/R Line-in
Both aren’t volume matched, I tried to record hp out such that on the “-12db” indicator on the E-MU 0204 is lit, but not the “clip” indicator.
What I seen:
What I hear and record (0:50 to “la la la la”)
Line out - http://www.mediafire.com/?862ngnnaf3jrn7f
Video converted to mp3 - http://www.mediafire.com/?2dlxrjopd5dbqbb
Audacity Project file - http://www.mediafire.com/?pnoa1v5n10q9020
(Note: You do not need hundred/thousand-dollars equipment to hear the differences)
Conclusion / Remarks:
From what I recorded, there is seems to be real difference between using iPod Touch 5 hp out and line-out via lightning. So, the difference which I perceive between my iPhone 4S and iPod Touch 5 hp out should be real.
What cannot be concluded:
Is this difference is a “fault” on both on my iPod and my mum’s iphone ? Or does it occur for all iPhone 5 and iPod Touch 5 ?
What causes this difference ? See update below.
Does it affects other files (ALAC, mp3, mp4, mov, etc) ?
It turns out to be a software issue. The video sounded correct when played on 3rd party app instead of Apple default video app. All along i thought it was a hardware issue because it sounded correct when using line-out via lightning.
According to goodvibes, it looks like there's compression on the headphone out.
It may either be a bug or something incorporated into the app by Apple. So, for those who watch video on iPod Touch 5 or iPhone 5, please take note.
Edited by kierai - 1/20/13 at 6:08am