Yes, small sub could be ok in office audio system or maybe bedroom, if you're not too serious about it.
These BMR speakers will play more lower bass and better than $70 polk sub
You may not even need a sub with them. I mentioned sub as it would more prudent to pair sub with HSU, Ascend or PSA speakers, not so much with BMRs.
One last thing, BMRs are rear ported so these won't be perfect wall mounted, too close to wall.