Like many audiophiles, I guess we should agree to disagree. You seem to be adding $80-90 to the perceived features of the A2+ such as the BT and DAC, but the first page of Google results gives multiple independent teardowns which show the DAC to be a low-end Texas Instruments PCM2704 and the BT implementation to be an in-house design that seems on the basic side. I feel I was overly generous in comparing it to a $20 receiver, especially since $6 receivers off Amazon include name-brand DACs of equivalent quality that pop up in plenty of other multimedia applications (phones, consoles, televisions and monitors, to name a few). Either way, it's not worth getting worked up over the cost of the DAC or the BT receiver, because neither of them are the bottleneck to the sound quality for this class of product. Assume that the DACs and receivers are all fine at this level of fidelity and just move on.
I lived with an AV32.1 setup (and its flaws) for two years and demoed the A2 with the goal of upgrading my AV32.1 by connecting them via the (poorly documented) variable RCA connectors to a Polk active 10" subwoofer. Sadly no amount of DSP could undo the damage that Audioengine have engineered into these units in an attempt to compensate for the tiny cabinets and undersized drivers. They sounded no better or worse than the AV32s with the sub disconnected; but unlike M-Audio they weren't neutral enough to pair with a sub and get a balanced result.
Like any ported, directional speaker of this type, positioning/alignment of the speaker and room interference will have a lot more impact on the frequency balance than the speaker design themselves. This is why I don't rely solely on subjective testing but double-check my purchases against third-party calibrated open-air test results. For my own experience, the AV32's required a DSP reduction at about 2KHz but at that point were passable as studio monitors until they started to roll off at 80-90Hz. The A2s seem to produce bass (impressively so for such small drivers) and clear treble without breakup so that you can be tricked into thinking these are VERY good speakers with the right type of music. The minute you want presence in vocals the A2s fall flat - some kind of weird frequency dip around 5K, and yet a little higher in the frequency response, the sibilance of pronounced t, s, and c sounds was cutting - harsh and unpleasant. I spent a full day trying to make them work with two completely different DSP programs and gave up, for a refund.
Simply put, I should not have had to work so hard and still fail to get monitor-quality audio out of speakers that were easily twice the price of good monitors. Especially not when the compeition that I have since used (Presonus, JBL) can do so at half the price. Yeah, they're nicely made, and yeah they have a convenient feature set but that is - in my opinion - simply lipstick on the proverbial pig.