Just how many options does 1 need in a 2 way bookshelf design?

Andrew Jones talked about his considerations for speaker design in general, that are bass, size and efficiency.  The debut product, Sourcepoint 10, he comes up with after joining MoFi turns out a good balance of these imo.  With the 2-way concentric driver design, he was able to squeez larger 10" woofer into a larger cabinet comparable to Tannoy Eaton to enhance the scale of music that would otherwise be difficult reproduced by a normal size of bookshelfs or stand mounts.  According to a reliable reviewer, this speaker also images quite well, leading me to believe it will handle more complicated genre of music like classical well.  Although not superly deep, the bass is rated 42 hz at -6dB. I don't like a designer purposely boost the midbass in order to get better low bass extension.  Its efficiency/sensitivity just passes 90dB, not superly high but is high enough to be considered high efficient speakers.  I actually have a concern on a speaker with extremely high as 94dB or above because the noise floor of the amp can be audible.  All these design elements were finetuned to sweet spots in SP 10.

I remember "back in the day" when the designers of high quality British compact 2-way monitors discovered something interesting. How their speakers actually sounded -- in the room.

They determined that the "average" listening room was not very large and definitely not acoustically treated. So, side reflections were a factor. The wide dispersion characteristics of those small mid/woofers were actually a detriment to sound quality. Taking the driver size up a notch, thus intentionally limiting dispersion actually produced more detail, focus and imaging in the average room than the smaller diameter drivers. Thus was born the next generation of polite British 2-way monitors.

@waytoomuchstuff Okay but how big? Can we have some examples? 

@kokakolia 

From 5" +/- to 6"-7"ish