I am looking for some closed-ear headphones that are not too expensive (under $50 or so preferably) that provide good noise isolation mainly. To give a reference point, I've been borrowing my friend's Beats Studio for a while. I know people aren't very fond because they're very overpriced, and I have no intention of buying them. However, I need to give them back soon and unfortunately they're the best comparison I have in terms of over-ear headphones I have experience listening to.
I'm not particularly looking for something with strong bass, but I have no problem with bass-heavy headphones since I mainly listen to music with elements of trance, dubstep, etc.
I came across two suggestions that stuck out to me from the headphone buying guide thread that specifically mention noise isolation:
1) Monoprice 8323 ($23)
2) Philips Citiscape Downtown ($33)
The next category ($75-$150) has a few as well that mention having good isolation, although I would prefer not to spend that amount.
1) Shure SRH440 ($100)
2) Audio Technica M50 (~$150)
Does anyone know if the ones I mentioned or others have noise isolation similar to what I'm used to with the Beats Studio? I acknowledge the flaws they have, such as requiring batteries in order to even function at all, the slight buzzing sound of the noise cancelling when they're on but nothing is playing, etc. Which is why I'm open to other suggestions, I would just place a higher priority on noise isolation than sound quality I suppose.
I read multiple reviews on some of the ones I linked to as well as the Beats, and comments about noise isolation seem to be across the map. For every comment I seem to find saying one of the headphones has "great noise isolation", the next one says that the noise isolation is no good.