[theBjrd]

I know that Audio-Technica, AKG, Ultrasone and Shure headphones are the best and most recommended for <$100, but I know that iPhones have trouble driving them.  I'm looking for some fairly balanced, over-ear headphones that my iPhone won't have much trouble driving for around under $100.  Any recommendations?  
Also, don't hesitate to tell me that I'm mistaken and iPhones CAN drive some ATH M40s.  I'm a bit inexperienced and still getting used to the world of headphones and Head-fi.  

  Thanks!

 

[cel4145]

The M40S should sound fine with your iPhone. That's not to say you won't get better SQ with a headphone amp. But that's because better headphones are designed to perform even more beyond how an iPhone can power them. Doesn't necessarily mean that they sound bad without a separate headphone amp. Just they have more potential. 
 
Beware of high impedance/low sensitivity headphones. Those really do need an amp.

 

[takato14]

I'd suggest an AKG K240 Studio.
 
The K240 is very slightly harder to drive than say, an M50, but they still sound great out of my iPhone. It's a laid-back, effortless presentation, with tight airy bass, smooth mids and absolutely beautiful highs. They're the most comfortable headphone I've ever used and the isolation is actually quite good even though they're semi-open/vented. The K240s also have more room to get better with an amp than most headphones if you ever do get one.
 
One thing I can say though is that they are light and fall off your head pretty easily. They are definitely not a jogging headphone or anything like that. The cable is also 10 feet long and AKG doesn't offer shorter cables (which I think is absolutely dumb). Another thing is that they're pretty big, and while I adore the AKG styling I've had some people give me odd looks. lol.
 
I got my pair at Guitar Center for $100. One of my best purchases.

 

[Elektrospeed]

M-50's sound good out of the iPhone, been there done that. If you're lucky, you can get them <$100.

Perhaps you could also consider Sennheiser HD 239's. If you don't like how they sound, they can be easily and safely modded (search HD 238 modding). BTW, 239's are only a cosmetic update over 238's, so you can perhaps get cheaper 238's.

 

[takato14]

Quote:

M-50's sound good out of the iPhone, been there done that. If you're lucky, you can get them <$100.

Perhaps you could also consider Sennheiser HD 239's. If you don't like how they sound, they can be easily and safely modded (search HD 238 modding). BTW, 239's are only a cosmetic update over 238's, so you can perhaps get cheaper 238's.

I would greatly suggest the K240 over the M50. I have both and the K240 is much better.
 
The M50 has very "rude" treble, meaning it jumps out at you and slaps you across the face. It's not harsh but it's very in-your-face and I personally don't like it at all. The mids are absolutely atrocious. They're recessed so you don't notice them most of the time but when they do rear their ugly head you hear how peaky and grainy they are. The bass isn't particularly impressive either. They're good and exhibit some control but not much, and there isn't much slam or depth to it either.
 
The only thing they have over the M50 is better isolation. But as far as sound is concerned, go for the K240s instead.