Apple iPhone 4S 16GB - AT&T - Black

I recently upgraded my 16GB version to 64GB for less than 200 bucks.  I wanted to upgrade to the newer models, but I'm not going to waste my money on something that can play the same music for more money.
 
Anyways,  the sound from the Iphone 4s is excellent to my ears.  It's gets better with different audio apps in its stock form.  You don't need to hack it, to unlock it's full audio potential.  Just buy some apps and call it a day.
So my first app that I enjoyed for a while, was the Denon audio app.  You can make your own eq curves.  Sounds really good without an amp.  
Second app is BBE Pro.  This app will bring out the bass along with sound stage, when hooked up to an amp.  Love this app with my bass heavy mp3's.  
Third app is Kaisertone.  This app will give you a 30 band EQ and a few DSP's.  This is my favorite to play Flac files with.  
Once is a blue moon I'll use Neutron.
 
Now I listen to my music a few ways. 
1. Through the 30pin connector, into my FIIO E12A.
2. Through the audio out, into my FIIO E12A.
 
The first method you get what you get with FIIO L9 or L11 connector.  With the L11, you have to choice to use your own cables and charge/sync at the same time.  But I can't barely tell any SQ differences between cables.
 
The second method you get get to hear a difference in your cables you use.  Friends and myself can hear SQ differences when swapping cables.  I like this for when I want a mechanical EQ just to tweak my sound faster depending what I listen too.
 
 
 
 

I use the 30pin line out dock on my iPhone 4s as a portable source. As a portable source the iPhone 4s makes an excellent choice for lots of reasons that I'm not going to explain in this review. Here are the highlights that do it for me. I'm going to make the case that the iPhone 4s make a great dedicated lower cost portable source. The best function the 4s has going for it is web connectivity. I want to listen to the 'Ex Machina' Soundtrack By Portishead’s Geoff Barrow And Ben Salisbury right now. I can do that with a smart phone! I want access to the millions of tunes in the Tidal music catalog I can do that to. I can load WAV files onto the 4s granted the iPhone won't do 192khz / 24bit or DSD... well la dee freaking da, I don't care. I can't consistently tell the difference between 16bit and 8bit tracks. Try going to audiocheck.net, select the tab blind audio test and take the '16-bit v/s 8-bit Blind Listening Test' for yourself.
 
Soundexpert.org has the sound quality measurements on 4/4s, I realize that the measurements and numbers are far beyond anything the human ear can quantify, I know my ears can't. 
 
I do think that using the line out dock is the way go. Bypassing the on-board amp circuit and using a dedicated external amp offers superior sound quality but you already know that. 
 
The iPhone 4s will soon be three generations out of style and the price will reflect this. I think this is a steal that offers a very high price to performance ratio.