A BHSE with 007 or 009 will give you much more satisfying bass than the HD800 for sure. I never liked the Sennheisers, and lack of bass was one of the big reasons why. I’m still scratching my head as to why the HD800 has had such a stellar reputation all these years. Again Stax isn’t for bass heads, but they can deliver enough bass impact for many audiophiles, including myself. The balance of the 009/BHSE is sort of roughly comparable to the Focal Utopia.
If you’re still worried about bass, the 007 can give a more overall energy down low than the 009. Though the 009 is more fast and precise and can still slam - I prefer them. The KGSShv Carbon will also give a bit more bass impact and extension than the BHSE, but I prefer the sweeter midrange and overall sound of the BHSE. A Carbon paired with 007 will give you the most bass this side of a DIY T2 (which is an absurdly wonderful amp).
If you’re still worried about bass, the 007 can give a more overall energy down low than the 009. Though the 009 is more fast and precise and can still slam - I prefer them. The KGSShv Carbon will also give a bit more bass impact and extension than the BHSE, but I prefer the sweeter midrange and overall sound of the BHSE. A Carbon paired with 007 will give you the most bass this side of a DIY T2 (which is an absurdly wonderful amp).