Open vs. Closed vs. Portable in the $150 Headphones: Help!

Hi guys,

I'd really appreciate some input on my next headphone purchase. I'm looking to spend up to $150 or so.

I had a pair of MDR-700's that I used for DJ'ing in college, but after listening to my UE Super.fi 5 Pro's and my buddy's open-air Sennheisers, I need to upgrade.

I've been looking around online and I've narrowed it down (tentatively) to the following:

• AKG K240 mkii
• AKG K271 mkii
• Senn HD558
• Senn HD380
• AKG K450

All of these are around the $130 mark on Amazon right now.

If my choices suck, let me know what you'd suggest alternatively.

Honestly I've never listened to AKG's but my friends say they're the best and the online community seems to love them.

I can't decide whether I want open or closed. I like the idea of attenuating exterior noise, but it's not extremely important to me, especially at the cost of good sound. It seems that the K240's sound better because of their open design, what do you guys think about this? Do the K271's have better bass?

AKG headphones tend be analytic with tight, but low impact, bass. The main issue with them is that their bass is too low on impact, so they really come up short in that area. They are quite detailed, though. This is the type of thing where knowing the sound signature you want to get out of your headphones is key. 

I also can't decide whether I want collapsable (portable) cans or not (hence the K450's and HD380's). I will likely be taking my headphones with me when I travel (although I may just go with my UE's), but will at the very least take them around town with me to coffee shops and whatnot. Will the first three I've listed be too clunky or fragile to take around with me?

The AKGs are pretty clunky. I have the Superlux HD681, which is based on the AKG design, and it feels like I'm wearing a neckbrace everywhere when I leave it around my neck. I'd really suggest against trying to use a full-sized AKG as a portable. 

Will other people hear my music if I've got the 240's on? Will I hear everyone else in the cafe clear as day?

As a semi-open headphone, it's going to be in the middle. If you play your music on a relatively low volume, nobody should hear it, but semi-opens tend to leak more as the volume goes up. You won't hear everyone in the cafe clear as day, but it won't be as blocked out as compared to a full-sized headphone. 

Are the sound quality of the portable headphones appreciably worse than the full-size non-portable ones?
 

This is common at the same price point. There are some portables which sound very good for their price bracket, but in general concessions are made to make them portable. 

I listen to all kinds of music--rock, pop, hip-hop, jazz, and classical, along with tv shows on my macbook pro.

Last thing--most of these are at 55 Ohm impedance -- is this high enough that I will need a headphone amp when plugging them into my mbp and my ipod?

The AKGs may require amping, depending on the volume you listen at. They're not the most difficult headphones to drive in the world, but they're at that borderline where a cheap $20-30 amp would be able to make a small difference.

Sorry for all the questions--bit of a n00b. I'd really appreciate any feedback any of you guys would have, especially if you have personal experience with any of these headphones. 

Thanks!!!

Bryon

EDIT:

I think I'll have to add the Audio Technica A700 and AD700 to my list...but again, closed or open!? I don't know anything about how the ATH's sound compared to these other brands, either!

The AD700 has a wide soundstage, but one of the most anemic bass responses ever. Clear mids and highs, though. I personally did not like them much at all, but I like to have good bass extension in my headphones.