Vandersteen 3A Sig vs. Von Schweikert VR4 Jr.

One thing Vandy speakers are lacking is gross distortion and they can sometimes be underpowered, the 3s do like/need power to be driven at their best.

My experience with the 3As is that they produce wonderful, fulfilling bass on their own, and the 2Wqs perhaps improve the bass and a sense of scale a bit, but more importantly, the midrange becomes that much better - it is not just a matter of adding bass.

By removing (filetering) low bass from the 3A to the subs, the speakers cabinets of the 3As are exposed to much less internal vibration and this makes the midrange performance of the 3As much better; technically, I think it is a reduction in intermodulation distortion. I found that when the 2wqs were tuned in, you almost could not tell they were on, even if you went right next to the subwoofer; but the whole soundstage and sense of venue opened way up; I suspect that alot of hall or room ambinece from a recording includes a lot of low bass information.

Precisely. It is a hard subwoofer to audition because a musical subwoofer is not impressive in an obvious our loud way; it is about quality and that does not "blow you away"; but the improvements are real and musicall satisfying in the long term. If you are looking for bombastic bass, that's not what the Vandersteen approach is all about.