I'm not sure it gets better than this.
I've always preferred the sound of the 3 rotor compared to the 4. It has a far broader range of sound. From low RPM it's very guttural, but it screams nearly as hard on the top end as a 4. To me it sounds like a straight 6 that's been possessed by the devil.
My RX-7 is sitting at home, in the garage, with no engine in it right now............