It has been over 2 weeks since I updated my iPhone 4 to iOS 6.0.1. My iPhone speaker has been working fine ever since the update. I know I had tried several things in between like shutting off all background apps, turning my phone off & on, plus changing some settings related to sound/volume & nothing worked until I did the update.
*So that should be your first step is to update to iOS 6.0.1.
The update did not fix my headphone or volume with external speakers (ie docking or auxiliary cable for car stereo) issue! I managed to resolve the issue after many attempts of searching the settings for something that seemed like it could be causing the issue & I found the Volume Limit had been set/modified by either the iOS 6 &/or 6.0.1 update or more likely from connecting my phone to my computer to charge it (this is when my issues first began). It has now been over a week & my headphones volume is still working. This is the second step to take;
*Go into your Settings<Music<Volume Limit setting & adjust it back up to full & you may want to for good measures turn the control off. When I went into mine I found it was set below 50%!
I hope this helps some of you!
Ever since the loss of Steve Jobs this company is really slipping! This crappy untested iOS would never have been released with Jobs at the helm! I am a software developer & this iOS has so many bugs in it!! My battery draining excessively fast issue has been resolved.