Well there are on the ear heaphones that isolate really well, like the Sennheiser HD-25s.
Then there are really good over the ear headphones that isolate well (like the Reloop RHP-20/30 or the Zomo HD-1200).
But there are also bad headphones in both version. I once tested really huge over the ear things which wont be named, but their isolation was totally bogus as they had very small ventilation holes…
So if you pick over or on the ear is a lot of personal preference and also how your ear is made. Especially people with rather large ears (Prince Charles like hehe) have problems with over the ears as they find them uncomfy. Beware that as a DJ you wear your headphones for long periods of times and sometimes only on one ear and clamp them around etc.
So if you have any chance to try them on, I would recommend that.
IMHO you cannot get wrong with the following headphones which are my favorites:
– Sennheiser HD-25
– Reloop RHP 20 and 30
– Zomo HD 1200 if you are on a budget
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