QGuy asked me this question. Others have too although not as perfectly worded as the Q.
Here's my opinion as posted in another thread.
The Von Schweikert sonic signature is a bit tricky to pin down from the VR-1 on up the VSA Totem pole. It is difficult to describe in the usual audiophile language and make generalizations the way we often do with other makes. Yes the highs are smooth, the midrange sweet (too sweet according to jonathan Valin of TAS but what does he know ) and the bass tight and deep but that isn't what makes them different.
It took for example myself and VD to listen to no less than 5 different VSA models to pin it down. (VR-1, VR-2, VR-4 Gen III HSE, VR-4 SR and DB-99)
What makes it difficult is their transparency to the source equipment. For example using a VR-1 with 2a3 vs. 300B or el84 vs. KT88 all amps we have on hand make them sound ALMOST like different speakers altogether. The same is the case with the VR-4SRs driven by Plinius, Levinson or BAT.
It is in this ALMOST that the sonic signature lies. To disect this means foregoing the usual his are like this, mids are like this, bass are like this kind of thing. One has to look into the presentation.
All VSA speakers play BIG. by this I mean that they energize the room very well. Soundstages are huge compared to most other brands and likewise the images are larger. The difference between models is refinment across the entire audible range and increases in clean distortion free extension on both extremes.
The differences between models are due to real world sacrifices that must be made in order to produce the speakers within marketable price points. For example The VR-5 uses teflon and oil V-Caps for the tweeters. The VR-4 SR uses Hovland musicaps. These 2 caps in a vr-5 alone cost more than a pair of VR-1s by a good $200. Using all V-Caps for a VR-5 would bring the price up to almost $50,000.
What we all noticed however is that between models the improvements come in equal measure as you go up provided you don't have a room with serious anomalies that have been left uncorrected.
for example in a scale of one to ten applied only within the VSA product lines
VR-1 highs 6 mids 6 bass 6
VR-2 highs 7.7 mids 7.7 bass 7.7
VR-4jr highs 8 mids 8 bass 8
etc....
The VSA Engineering team strives to make the spectrum equally good or equally great.
In other words: balanced. So there are other speakers in their price range that may give better highs or better mids or better bass (this last one I have yet to encounter ) but will fall short in other areas.
VSA designs try to minimize these discrepancies within each design because they cause distractions. Maganda nga ang highs payat o boomy naman ang bass so you will always be nagged by the negative despite the abundance of positive attributes of your speaker.
Lastly, VSA produces speakers you can feel not just hear. This is a product of the patented crossover and over built in house designed motor structures used with ultra stiff ultra light domes cones and ribbons.
The crossover contributes because of the extremely wide clean off axis dispersion that will energize air all the way to the 8 corners of your room leading to a feeling of being immersed.
The motors because you need a lot of low distortion force to energize a space this way.
You may not be able to feel the earth move with the smaller models but you will feel the air move.
So the VSA Sonic signature is BIG, BALANCED and TEXTURED.