a speaker i tried for a bit [then put back into their shipping boxes] was a vandy 1Ci, in the oversized demo room of a local dealer, they sounded very 3-dimensional [utterly non-boxy if you kept your head in a vice] and warm yet sufficiently clear, run from a rega amp [which doubtless added to the perceived warmth], utterly non-harsh. but when i tried them in my 14' wide by 14" deep listening room, they sounded obnoxiously bright and forward and shouty while simultaneously veiled [driven by old jvc 130 wpc amp]. a disappointment. was told i needed twice the listening room size and another rega amp to duplicate the dealer's experience. no thank you. enter my gently used set of Thiel cs.5 speakers, about half the size of the vandys. the Thiels combine all 3 [aforementioned] attributes. it is the warmest-sounding of all the other Thiel speakers, the only one that can be driven satisfactorily by non-audiophile non-powerhouse amps and the only one that can be used in a small listening room. these speakers are neutrally transparent and image solidly, while the vandys did not, in the same listening room with same amp driving them. the only other speakers i've heard with my own two ears, did not quite have all three attributes in one package. the maggie tympani IIIs were transparent, neutral, but not a trace of warmth. never harsh, just ease and a cold accuracy and images that floated in the room regardless of listener position. no other speaker i've heard could do all that. back in the 80s i heard KEF 105.2 speakers in a fancy schmancy dealer in DC, they were also transparent, neutral but not warm at all. later that decade i heard the revised Snell class A speakers, in a room slightly too small by about half, they were decidedly warm but not KEF-level transparent and not KEF-level neutral, but i could easily have lived with them. i remember they had a visceral deep bass.
all this reminiscing aside, transparent to me = being able to hear deep [all the way to the back of the recording venue and all around it, from FFF to PPP and everything in between, hearing in between the notes] into the recording without any haze or hash or resonance getting in the way, IOW low distortion. neutral to me means an announcer's voice sounds like you are in the announcer's booth with him, no shriek or boom or overhang/resonance, just clean accurate sound with the same tonal balance as the real thing. warm to me can mean both a bias towards the lower half of the frequency spectrum esp. below about 2k, but also a lack of strain, an ease, a sheer clear naturalness of sound that ties in with transparency and neutrality.