I think the bass response on the Pioneer bs41 is very good for music for a bookshelf speaker, and you get something that, in my opinion, no sub stat can provide - - great integration. I have a bookshelf sub system in my bedroom, and even with a receiver with bass management, you just don't get the integration you get with a single well designed speaker. Even though bass is not very directional, there is just something off on the timing. I highly recommend the 41s. They just sound lovely, and nothing can touch them at the price when they go on sale for $85. Now you don't get home theater slam in your chest bass, but articulation of cello, string bass and even organ is excellent. And it opens up using 20 watt class D amps to power them.
As for the comment about bass reflex v acoustic suspension, I think acoustic suspension produces better sound but is less efficient, which is why it's going extinct except at the very high end. You'd be hard pressed to find an acoustic suspension budget speaker, with the exception of something like a super zero which is basically not usable without a sub.
So, my very strong recommendation would be the bs41s when they next go on sale. I think you'll be shocked at just how good they sound. I say this as someone who has listened to a lot of speakers over the years and owns many pairs of budget bookshelves, including superzeros, infinity p142, b&w 302, infinity betas, kef chorals 3s, boston acoustics something or others, and have heard lots of others.
One there is also a small floorstander in the series with 3 midwoofers which must sound great, and there have been good deals on them too, but it's not a bookshelf sized speaker.
If you're looking for home theater surround sound bass slam, then yes you'll need to sub, but for listening to music on a desk, the pioneer bs41 is a winner. And, no, I have no financial interest in Pioneer. Just a very happy owner.
Sent from my Nexus 7