sE Electronics RF-X Portable Microphone Isolation Filter

The sE Electronics RF-X is a portable Reflexion Filter designed to reduce the room reflections a microphone can capture during recording. It mounts behind a microphone to create a more controlled recording area in home studios and other untreated spaces. It is suited to vocal recording, spoken-word work, acoustic guitar, and drum applications.

Rather than functioning as a microphone or audio interface, the RF-X is an acoustic accessory that works with an existing microphone and stand. Its purpose is to help the direct sound from the performer remain more prominent relative to nearby wall and room reflections. This can support a drier, more focused starting point for recording and later mixing.

The RF-X uses sE Electronics' four-layer acoustic filter design. A vented composite outer panel, wool fabric layer, air gap, and inner acoustic foam layer work together to filter reflections across the frequency spectrum. The design is intended to minimize unwanted tonal coloration while reducing room influence.

A lightweight, ventilated body makes the RF-X practical for portable and fixed recording setups. The supplied mounting hardware allows adjustment of the microphone's distance from the filter and the filter's height. This helps place the microphone capsule in an appropriate position for the source and stand arrangement.

The RF-X fits naturally into a recording system built around a microphone, mic stand, clip or shockmount, and recording interface or mixer. It is a useful acoustic add-on when a dedicated vocal booth or permanently treated room is not available. For best stability, sE Electronics designs its Reflexion Filters primarily for conventional vertical microphone stands.

Key Features

• Four-Layer Acoustic Filter: Combines a composite panel, wool, air gap, and acoustic foam.
• Vented Outer Body: Supports a lighter design while retaining a durable acoustic structure.
• Adjustable Mounting Hardware: Lets you set microphone distance and filter height.
• Portable Recording Control: Helps reduce room reflections around the microphone position.
• Mic Stand Thread Adapter: Supports European and US mic stand thread arrangements.
• Hand-Assembled Construction: Each RF-X is assembled in sE Electronics' factory.

Design & Installation

The RF-X has a black, ventilated composite-panel body with a four-layer acoustic structure. Its internal layers include wool fabric, an air gap, and acoustic foam, while the outer panel is vented. The filter measures 410 x 310 x 200 mm and weighs 1.6 kg with its clamp assembly.

Install the bracket on top of a conventional microphone stand, then attach the filter with the two supplied screws. Attach the microphone in a compatible clip or shockmount using the supplied standoff, then adjust its horizontal position and the filter height. sE Electronics suggests starting with the microphone capsule approximately even with the front edge of the filter and centered vertically.