[KElyas]

I've heard this a few tims and am wondering if it's true and why so

 

[pclov3r]

I don't think so as long as you get cans that have some decent noise isolation. 
 
I think noise isolation is the important part here. 

 

[Sound Quest]

The 2 most important things for portable headphones is "noise isolation" and "low impedance".
 
If the headphone meets both of these criterias, then it won't matter if they aren't bass heavy as you'll still be able to hear your music loud and clear.

 

[GREQ]

Sorry, but I totally disagree with the previous two posts.
 
I've used all sorts of headphones outdoors, open and closed, and IMO a bass heavy presentation DOES help.
Sure, if you turn up your headphone to ear-bleeding volume, it doesn't matter. But if like me you listen at lower volumes and care for your hearing, the first thing you'll notice when you get out onto a busy street is that you can't hear the bass as clearly (if at all) especially if it's an open or semi-open design. 
Closed headphones are less problematic, but still benefit from a clear deep bass presentation if they don't have active noise cancelling. 

 

[pclov3r]

Quote:

Sorry, but I totally disagree with the previous two posts.
 
I've used all sorts of headphones outdoors, open and closed, and IMO a bass heavy presentation DOES help.
Sure, if you turn up your headphone to ear-bleeding volume, it doesn't matter. But if like me you listen at lower volumes and care for your hearing, the first thing you'll notice when you get out onto a busy street is that you can't hear the bass as clearly (if at all) especially if it's an open or semi-open design. 
Closed headphones are less problematic, but still benefit from a clear deep bass presentation if they don't have active noise cancelling. 

I don't think open and semi open headphones are meant for street use. 

 

[SmOgER]

There is definitely something in that statement.
Despite decent sound isolation, I tend to boost my bass futher with S600s when outdoors. But temp difference could be also a factor there, as in Lithuania we have outside quite often up to -15C during day in winter. I would imagine colder environment means less moving diaphragm which itself means better highs and worse bass. That's my theory. 

 
Btw, maybe just carbon nanotubes are more sensitive to temp differences?

 

[Elektrospeed]

If you see any of the isolation vs. frequency charts, you'll notice isolation usually increases the higher the frequency. This is because lower frequencies are more difficult to attenuate, either passively or actively. I think wavelenght has something to do with it, you'd have to use a really thick and dense mass to properly block lower freqs. 
 
For example in Car Audio, you use layers of "lead sheeting" or "high density vinyl" to block outside noise. Mass is what ultimately blocks lower freqs, and because roads are noisy environements you need as much isolation as you can get in order to obtain maximum SQ.
 
Back to headphones, you really don't have a lot of room to add mass / other isolation, and weight is a comfort factor, so it's really difficult to make a headphone that's both comfortable and great at isolating lower frequencies. So the designers usually decide not to get involved into an unwinnable fight with the lower freqs, and preffer to boost the lower end to compensate.
 
And that's also the reason why some "bass bias" is prefferable in car audio, very few people get involved into properly isolating their cars, and so most speakers tend to be bass heavy.
 
So yes, generally speaking, bass heavier headphones are usually a good idea for compensating outside noise
 
IMO, the best alternative is not full sized cans, but IEMs. It's like blocking the sun with your hand 5cms from your eyes, instead of using a 30'x30' blanket 5 meters above you, it's simply more practical (you know, the sun being sound, and shade the obtained isolation ha!).

 

[Tsujigiri]

Yes, I've found that when it's very noisy outside, a little extra bass helps to make things sound more balanced. Also, I usually wear sunglasses when I'm outside, which breaks the seal of the ear pads on closed headphones. This cuts out a lot of bass, so a bass boost helps to compensate for that.

 

[GREQ]

Quote:

I don't think open and semi open headphones are meant for street use. 

There is one famous semi open headphone you may have heard of - Koss Portapro - the clue is in the name (hint - Porta is short for portable).
They are bass boosted, and are excellent for outdoor use.