I'd check out the Woojer Strap/Vest [0] or maybe the ButtKicker [1] from the article if you're ok with being seated. I have stereo ButtKicker Concerts on my couch and they're awesome.
If he is looking to get the bass feeling of the music you want the pure input.
And the ButtKickers are purely mechanical, so no DSP. I would steer towards their Concert line as it's meant specifically for music, whereas the LFE has a stronger response from 20-30hz for home theater type applications.
For the buttkicker the real issue is the chair itself. It filters a ton of stuff and rattles.
A good experience are the Dbox chairs, the problem is that they cost 5 k.
Relevant club podcast with the CTO https://open.spotify.com/episode/6ERkgfJxm7QCZlp1p5eIGD?si=E...
I wrote few of these algorithms myself for some other products.
There is always a trade off between fidelity and immersive feeling because the basses were not meant to be used with such product in mind.
With my company, Interhaptics, we built a full stack pipeline only for haptics. Our tech is at the basis of the MPEG haptics encoding standard coming out shortly.
We have been recently acquired by Razer, look out for news of you are interested to build for touch natively