This may seem like a dumb question but...

[Flipx99 5,000+ posts]

shouldn't, think of the ipod like an amplifier, the headphones are your speakers and you're just plugging them into the outputs of the amplifier

2 things to consider here:

1) the resistance of the headphones

2) the sensitivity of the headphones...may make you turn it up more or not as much.

 

[hehe]

I would think the larger ones w. the "muffs" would be more efficient because you don't have to turn them up as loud to obscure the background noise.

I use some nice sony's for my little Ipod Shuffle and it seems to be working out well.

 

[IDSkoT 5,000+ posts]

2 things to consider here:
1) the resistance of the headphones

2) the sensitivity of the headphones...may make you turn it up more or not as much.

Well, of course volume is going to change it. But, the question makes us assume he meant at a single volume. It still remains, impedance is the only factor in the battery drain.

I have a questoin that is kinda not related...

Does anyone know if / how I can up the voltage on my iPod? I have a 3rd Gen iPod, and at full volume, I have to turn my HU to 50/62 (which is normally ear-bleeding loud) just to hear it...? And I don't feel like making / buying an amplifier for it. But I will make one if it comes down to that.