The Rythmik subs are gaining in popularity amongst planar owners, They are very "fast", the patented Direct Servo Feedback design keeping the cone under tight control. The space between notes is not filled in with inter-transient noise, and the cone returns to "rest" without over-shoot. The DSF circuit even compensates for the change in electrical characteristics that is found in all woofers as their voice coil temperature increases under heavy load. Rythmiks are characterized as sounding "leaner" than other subs, with none of their often thick, heavy-footed bloat.