I don't own a pair of RC4's but, have been over to Rick's house to audition them about 6 months or so ago.
Lets start with the midrange since it often dominates the listening experience. These speakers will deliver a midrange as good as any speaker that I have ever heard - and that list includes the big Sound Labs, Innersounds, Vandersteen 5's, Revels, Wilsons, etc. The immediacy, transparency and body in the sound is arresting to say the least. The midrange presentation is uncannily realistic. Yes, the artist will be in the room with you - and properly placed within the soundstage. No laid back sound here. Image placement will be exactly where the recording media calls for it to be - well behind the speaker plane, in your lap, or anywhere in between. Rick uses well respected drivers and, I suspect a lot of this sound character is due to driver selection (mostly high end Seas as I remember).
The treble basically doesn't call attention to itself and, during my audition I was so engulfed and/or impressed with the midrange that I probably did not lend a critical ear to the treble area. However, we all know that if there is an aberration in the treble, it often sticks out like a sore thumb. And, in the case with these RC4's, there was none of that. The blend was very seamless and I never felt the speaker was soft or, bright or grainy in any way. Just very coherent. Like I originally stated, it did not call attention to itself. I believe the RC4 is offered (or was offered) with a choice of tweeters - dome (Seas I believe) or ribbon.
The bass area left me a bit puzzled. On one hand the definition was good, and extension was good, and it was full sounding but, on the other hand it did not strike me as being even balanced. Now the room will obviously affect bass balance so, take what I say here with the usual grain of salt. At times I thought bass notes were a bit peaky or overly dominant. Nor did I think the bass was the most transparent that I have heard (the Sound Labs have this distinction). But, the bass does blend reasonably well. I think it was actually only the lower bass notes that I had mixed feelings about. And that most likely is a room node issue. As I remember Rick indicated the room was responsible for any bass imbalances as his room was not ideal ( only two feet to the back wall). I should add that the RC4 is available with built in active subwoofer or, passive. The version that I auditioned was to include the built in active subwoofer but, the drivers had not been delivered so Rick used a pair of his subwoofers (identical components and volume/box dimensions) located next to the RC4s and adjusted identical to the intended built in subwoofer. Could this "substituted" sub set-up led to the perceived imbalance in the lowest registers? Well, I don't know. It was likely a room issue.
My advice is to try and hear them somehow. Auditioning is always the best guidance. Panel freaks, including myself, generally always say the "box" sound is unmistakable and, the 'box" signature always manifests itself somewhere in the spectrum and, can't be totally eliminated. Just well mitigated. For the most part a box just can't sound such as an open air speaker like an electrostatic dipole. Well, with the RC4, I could detect absolutely zero "box" aberrations throughout the midrange and treble. But, I am still out to lunch on the bass. I wish I had gone back over after the low frequency drivers arrived and were placed in the cabinets but, I didn't.
To be honest, I simply can't understand how someone would not be happy with these speakers. I say this because of their realistic sound especially through the wide midrange area (lower through upper). The entire midrange just sounded spectacular to me. The cabinetry is superb as well. Its just a well finished and engineered speaker in my opinion. And, I am still considering a pair myself. If it wasn't for a few financial issues, I would already own a pair. But $4K+ is still a significant bit of money for me at this time.
Not a perfect review but, I hope these comments help.
