mp3 background noise with 3.5mm adapter

[Guest kdavidyates]

I recently purchased the short OEM 3.5mm adapter for the Omnia, as in: http://us.st12.yimg.com/us.st.yimg.com/I/y..._2038_149790151

I immediately noticed three things. First, the sound quality is far, far better than with the bundled 3.5mm adapter (long cable, handsfree with analogue volume control). Treble is cleaner, less distortion on crash cymbals, and everything is altogether more crisp and focused. Second, music playback is noticeably louder. Third, there is loads of background noise that depends on what the phone is doing. I can hear hissing and all sorts of squeaks, crackles, pops, old dial-up modem sounds, etc. that change when I touch the screen, or use the optical mouse, or open a program.

I'm fairly sure that this isn't caused by the cable - for instance, if I turn the screen off with a power button press, then turn it back on, there's no hiss. If I do this in WMP, then there's no audible hiss on music playback to start with, but if I pause playback after a few seconds, the noise is back.

With WMP and touch player the noise settles down to a rhythmic crackling, with each crackle lasting just under a second, and separated by just under a second. It's like you can hear the processor decoding the mp3! The volume of the noise also does not depend on the playback volume, it is just there in the background at constant volume, and only audible at very low volumes or during very quiet passages in the music. This suggests the noise is not caused by distortion in the op-amps, but is instead some kind of interference from the processor.

Speculative hypothesis: the bundled handsfree has a built in attenuator, which explains why the volume is lower, and also why I can't hear the hissing through it. The pity is that the sound is so much better with the short OEM cable adapter that I don't think I can go back to using the long one! It seems the long cable cuts out a lot of what you want to hear as well as what you don't.

Anyone else experienced similar issues? If so, did you come across a fix? Like I said, I hear no noise at all with the bundled adapter, just with the short cable adapter as in the picture.

Cheers to all who read/respond.

Edited January 29, 2009 by kdavidyates

[Guest kdavidyates]

Anyone?

[Guest thetwiztidfreak]

Anyone?

Where did you get that smaller adapter? i hate having that long ass one in my pocket with headphones and my phone.

[Guest kdavidyates]

I'm in the UK and got mine at fommy.co.uk. The P/N is AAET503CBEBSTD so if you Google that you should be able to find it.

[Guest kdavidyates]

Ok found a partial solution to this issue if anyone's interested. I used soundtester.exe to adjust the HP(04) variable under Normal>Headset, which seems to relate to the sensitivity of the headset used. If using particularly sensitive phones with the short adapter (I use Super.fi 5 pro, which are pretty sensitive), lowering this value to -13.5 or -15db greatly reduces background hiss and noise.

Thx for reading.

D