Oh I don't know about hearing everything outside the phones. I guess it depends on how quiet your studio is. All I know is I mixed through the 280s and the mix was dreadful. I remixed and balanced through the 650s and the results were astonishing.
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Yamaha 920 / Yamaha DGX-670 / Maui 5 Go (2) / Senn e935 / Sony C80 / Tascam DP24sd / ATEM Mini Pro switcher (studio)