Good question.
It depends on ones definition of "need" in needing a subwoofer.
I have Von Schweikert VR3.5's and have owned speakers with built in subs (Mirage 1295is). I admittedly have not listened to the VR4.
Even if a speaker can go down to 20Hz, a substantially powerful subwoofer like the VonSchweikert S/3 which I have owned or the Velodyne HGS 18 can add a fullness and richness to music (esp piano) and theater that even a very fine main speaker alone cannot. It also gives relief to the amp driving the speakers which may improve clarity to the treble and midrange (depending on what amp is being used and how much reserve it has.) I believe Von Schweikert Audio will tell you that while a subwoofer is not essential, it will improve the soundstage and auditory experience even for their best speakers (and other brands.)
My personal goal in a system and listening is to feel sonic richness and fullness that gives one "goosebumps" or that "palpably real" experience.
It depends on ones definition of "need" in needing a subwoofer.
I have Von Schweikert VR3.5's and have owned speakers with built in subs (Mirage 1295is). I admittedly have not listened to the VR4.
Even if a speaker can go down to 20Hz, a substantially powerful subwoofer like the VonSchweikert S/3 which I have owned or the Velodyne HGS 18 can add a fullness and richness to music (esp piano) and theater that even a very fine main speaker alone cannot. It also gives relief to the amp driving the speakers which may improve clarity to the treble and midrange (depending on what amp is being used and how much reserve it has.) I believe Von Schweikert Audio will tell you that while a subwoofer is not essential, it will improve the soundstage and auditory experience even for their best speakers (and other brands.)
My personal goal in a system and listening is to feel sonic richness and fullness that gives one "goosebumps" or that "palpably real" experience.