Yea I wouldn't ever describe the HD650 as a "bassy" open headphone. There are many other open or semi-open headphones that have stronger bass and more extension. Like I said, they are simply a warm sound headphone, and IMO the strength of the HD 650 is its versatile nature with almost anything you throw at it. There are plenty of better "bassy" options such as DT 990, HE-400, and Pro 2900.
I would question the ears of those that think the HD650 has more bass than the DT990. To my ears, they lacked the extension and punch of the DT990. Pro and cons to both, but as far as bass goes DT990 is pretty darn good.
Thanks, I would be interested to see how the bass of the HD650 compares to the bass of the DT880, which apparently use similar drivers to the DT990, and are 'semi-open' as opposed to 'fully open' like the DT990, so they might have potential to have good bass?