Boss dual cube bass lx is quite an awesome amp. It’s loud and full of extras plus the battery power option. It’s beyond what a portable amp should be able to do and punch way above it’s weight. What’s it’s not is best amp for the money.
It’s not as warm as the spark40. While the bass sounds great it’s not deep and warm it’s a bit more mid forward and can get nasally with the wrong turn of the dial. In the way it make sense especially, for street performer deep low is almost useless as you need more mid to cut through the mix in the live open space.
We did a cube street and cube bass battery powered performance here at school with 2 guitars and one bass and backing track through PA. It sounded great no one believed that all of that volume came from 2 little amps.
If you want the portability feature and not really concern about being deep and loud in the bedroom this might be the answer as you can record directly to your computer and for $60 more you can get the Bluetooth adapter and do the backing track from your phone.
I’m happy with my purchase as it usually tag along with me when I buy a used bass it’s better than the spark mini and the blackstars.