Kab RF-1 Rumble Filter Getting into LP's and startled at the big speaker cone movements that you're seeing? Thinking a better turntable will help? It may not! This very low frequency energy is called rumble. Much of it is actually cut into the record groove when the master disc was made. Other sources are mis matched tonearms, poorly damped tonearms and acoustic feedback. Often, the only way to suppress rumble is with a really good rumble filter. With rumble eliminated, the soundstage becomes more "still" and the bass actually tightens up because the woofers are no longer modulating and the power amp is no longer wasting current resources on sub audible noise. The KAB Great Sound Escort RF-1 is a very fine transparent rumble filter that not only suppresses very low frequency .
