[TooPoorForHiFi]

• Budget - Around $150 but I can stretch a little bit.
• Source - PC & Mobile Phone.
• Requirements for Isolation - Not Sure, but I want Something that is Capable of wearing them Outside.
• Preferred Type of Headphone - Over-Ear
• Preferred tonal balance - I prefer something that isn't Harsh, Something I can listen to hours without feeling fatigue.
• Past headphones - Philips SHP9500S - [Likes]Comfortable, Clarity, Soundstage, Imaging. [Dislikes] Lacking Bass, Can't really wear them outside.
• Preferred Music - I listen to everything except RAP, COUNTRY, & HIP-HOP.
• What would you like to improve on from your set-up - What are you looking for going into your next headphone? - Something that is "Capable" of wearing them Outside, Better / More Bass than my Current @Home Open-Back Philips SHP9500S.

I did a little searching but not sure if they're good.

• MonoPrice M560
• Hifiman Edition S
• Audio-Technica ATH-M40x

If there's any others Headphone you guys could recommend that'd great.

 

[Pete7874]

If you are looking for plentiful bass, then scratch M40x off your list. These are studio monitors and as such have a pretty flat bass curve. M50x, on the other hand has plenty of bass and would still fit within your budget.
Sorry, I can't comment on the other two models you listed.

 

[cossix]

Perhaps a used MDR-1A? I don't quite like them but others seem to. Has entry of bass, is closed back, portable, and looks nice

 

[san14]

Maybe B&O Beoplay H6

 

[harry501501]

Soundmagic HP100. Great for wearing outside, very comfy and don't get the same crazy looks as they aren't ones that stick way out. They go over ear. They have all the things that the SHP9500 does and does them ten times better... especially bass. Well within your budget. Can be played from phones and PC

 

[harry501501]

I'm surprised you liked the SPH9500 as it's one of the most sibilant headphones I've ever used... far from non fatiguing!