KAB RF1 Turntable Rumble Filter

The KAB RF1 Turntable Rumble Filter is designed to remove turntable subsonic noise. Turntable Subsonic noise or rumble can rob your music of power and cause your woofers to slowly move in and out. Woofer oscillation can be caused by low-frequency noise that is cut into the record.

However, the main source of noise is feedback caused by resonance from the stylus/arm assembly. The noise is generated at around 7 to 12 Hz. Filter this out and your woofers will be at peace. Additionally, a “wump wump” noise can be caused by warped records. The unit also filters “vertical noise” out of the audio chain.

Rumble on record payback

There can be several sources of rumble, low quality turntables were once prone to it. The noise came primarily from the motor and bearing assembly. However, nowadays low-frequency resonance can be caused by the stylus and arm assembly. The assembly has a natural low-frequency resonance. Rumble is also more common when playing 78 RPM records, where the stylus can drag along the bottom of the groove.

The effects of low-frequency resonance

The effects of low-frequency resonance are mainly visible with your speaker's woofers. If you can see the woofer pulsing in and out then the the KAB RF1 Turntable Rumble Filter will solve your problem. The pulsing can rob the bass of power due to the amplifier being overdriven by the oscillation. The soundstage becomes clearer and the bass tightens up without the noise. Lastly, the unit helps to suppress acoustic feedback that can be caused by having the turntable too close to the speakers.

Warped records

Another source of noise is warped records. The warping can cause the stylus arm to “bob” up and down. This can cause a “wump wump” noise” that can be very distracting. The KAB RF1 Turntable Rumble Filter also has a very fine transparent rumble filter that actively cancels out vertical rumble. It is also good to use a rumble filter when transferring records to digital. In that way, your woofers are protected.

Connecting the unit

If you are using a separate phono preamp the KAB RF1 Turntable Rumble Filter is fitted between the preamp and main amplifier. With an integrated amplifier that has a built-in phono stage, the KAB RF1 Turntable Rumble Filter should be placed in the pre-out / aux input loop or a tape loop.

Key Features

- 1 Year Warranty
- Gold Teflon RCA's
- Active Vertical Cancellation
- Dual Voltage Regulation
- Wima Propylene Caps
- Metal Film Resistors
- Star Grounding
- Steel Chassis
- Hi Current Power Pak