Are Sub JBL Speakers good?

I think JBL is a fairly well-known speaker brand in the world. Choosing the right speaker for JBL is always the best.
If you are talking about the best Sub speakers, you should choose this speaker: http://thietbiamthanh24h.com/loa-hoi-truong/loa-sub-jbl-f18s.html. It uses a Power Converter (AES 2 hours) 2000W up to 8000W peak. To be more specific you please provide the requested capacity?

Thanks for supporting me. We have chosen the speaker line with the same capacity.

I think you should refer to one of JBL's 3 speakers, it will definitely satisfy you. Link to your reference: https://danamthanhdamcuoi.com/top-3-loa-dam-cuoi-jbl-tot-nhat/