do planar or electrostatic speakers inherently

I don't know about sounding "fuller", but...

Full-range electrostats tend to maintain the same tonal balance across a wide range of volume levels including very low levels, and usually have excellent detail and articulation so that you can still hear everything that's going on at low volume levels. In my opinion, full-range electrostatics are unsurpassed at low volume levels.

Planar magnetics tend to be not as good at maintaining tonal balance nor inner detail at very low volume levels.

Direct radiators may or may not do a good job with tonal balance at low volume levels; higher efficiency ones do best. Degree of detail also varies. When there's not enough, you have the urge to keep turning it up.

Note that these comments are generalizations.

Duke

Itigap,

Yessss! When I give a SoundLab demo, I like to show off just how good they sound way down at very low volume levels. I think the bass holds so much better than with other speakers at low volume level well because a woofer's suspension system is to a certain extent "sticky", and the stickiness is overwhelmed at normal listening levels but looms dominant at very low output levels. The ultrathin diaphragm of the SoundLabs (still to the best of my knowledge the thinnest in the industry) has no such "stickiness".

When I bought my first pair of SoundLabs, I had to sell just about everything else to afford them. I drove them with a three hundred fifty dollar solid state amp, and while the volume level was limited it was still the best sound I had yet heard in any audio system. I could listen way down at barely audible levels and still enjoy it immensely, and so far I haven't encountered any other speaker with that characteristic. Of course when I eventually got bigger amps they sounded better, but nothing was as huge of a leap as bringing in the SoundLabs that first time.

In case anyone doesn't know I'm a SoundLab dealer folks, so grains of salt all around.

Duke