Anyways, back on topic...try to expand your options. I dunno what gear other people have tried with those, but I've tried it in a local pro audio store and it sounds too thin but I can hear some bass notes that are all over the place. Sloppy, just not loud. I'd normally suggest Swans, but for some reason nobody has them in stock anymore, even if the dealers still have the product pages on their sites. Ad a little bit to your budget and there's the Emotiva AirMotiv. Haven't tried that one so I can't really vouch for it, but given I heard the AV40 and didn't like it, I'd rather suggest you read up on the AirMotivs at the very least. They might have a nice return policy too so that might mean you can at least try them at home for the cost of shipping (IF you return it, but do check the details at their website)
Also, if you don't need to move them around the house and use it more like a shelf system (even if not literally on a shelf), some affordable speakers have cabinets of reasonable quality and enough sensitivity that they can be run off a 10wpc T-Amp. Like this Dayton
T-Amp and
speakers. If you're not into super hi-fi signal, here's also a
wireless solution (from source to amp) for it with the transmitter in the same kind of chassis as the amp, but that restricts you to keeping the tablet on a table with a wire going into the transmitter. Otherwise you can get some Bluetooth solutions from that site. Some have a combo sender and receiver, but if your tablet has BT, you can try using its own BT sender instead of hooking up the sender into its earphone output. What I like about the latter option is if it's a lounge system, I have the tablet both as a source unit and a remote control. I don't have to walk far from the kitchen or bar to mess with the playlist. I'm using a similar radio transmitter (not BT though) that has a receiver powerful enough to get my HD600 loud enough, as it was meant for headphones, but I use it with my Swan monitors and iPad or Android phone. I even take the transmitter with me when the grill and beer party is at somebody else's house, so by the time the beer's cold and the steaks are done, no one gets up from the table until we're bloated. (At my house though I take the speakers out of the office and into the living room)