The JBL ES series is somehow a class of its own. In terms of volume the speakers are quite comparable with those of the competition, the performance in a league (eg Magnat monitor Supreme). But the additional super tweeter, which is installed in all the speakers of the ES series, giving the sound a special freshness. Also JBL can not outwit and generate from a bookshelf speaker with a few liters volume the abdomen massaged deep bass physics. But for a bookshelf speaker is also not provided. You should produce clean sound, thereby making the upper bass still audible and reflect first and foremost the mid and high frequencies cleanly and precisely. This makes the ES 20 with flying colors. Compared to the (still) smaller ES 10, which is almost a rarity now and trades at exorbitant prices, makes the ES 20 much more powerful and brings a much crisper bass to ear. When installing it is quite frugal and still sounds comfortable even in a full bookcase. Resonances go from housing almost to the ground over and the few vibrations that arrive on the shelf, can even be caught with a small woolen cloth.
The connections are, as with all ES boxes, at 45 degrees in the terminal and allow both the screw thick cables as well to connect banana plugs. The latter are naturally a little way at the back, but so close to the wall that this could interfere with the boxes should not be anyway.
To use the ES 20 come with me as surround speakers in a 5.1 setup. Previously there were the ES 10, of which I have, however, broke up. Both the surround mode and in 5 channel stereo operation make a very good figure. Whether they would be enough for me as a main speaker, I doubt. But they are just a little too small and could not play the bandwidth that you would expect from stereo speakers without a subwoofer.
In short, the ES series has grown really fond of me, and after a couple ES 10, a 25C ES and that pair ES 20 come over time certainly more cases saved. If the space should be even because eventually, surely a few of the large floorstanding speakers ES 80/90/100.