In an era where bright highs and ultimate resolution are pursued, many seem to have forgotten the warm, smooth, and musical foundational tone in recording history. The newly released Alctron RM821 and RM822 passive ribbon microphones pay tribute to this pure tradition. They do not seek deliberate embellishment but aim to faithfully capture the most authentic nuances and dynamics of sound.

Alctron RM821&RM822

 A Heart for Purity

    The True Sound of Passive Design

As new models, both the RM821 and RM822 feature Alctron’s independently developed 3-micron ultra-thin aluminum ribbon diaphragm, ensuring a naturally smooth full-frequency response at the physical level. While delivering rich high-frequency details without harshness, they carry forward the classic warmth and fluid transient response characteristic of traditional ribbon microphones.

They adopt a classic passive design—plug-and-play with no external power required. This eliminates the hassle of power supply while fundamentally reducing circuit interference on the signal. Sound is transmitted through electromagnetic induction, preserving the purest "original essence" of ribbon microphones throughout the entire process. The result is a warm, solid tonal quality free from any extraneous coloration.

      Figure-8 Polar Pattern

The figure-8 pickup pattern blocks or eliminates unwanted noise from the sides (90° and 270°) during recording. This is because microphones with a figure-8 pattern simultaneously capture signals from both the front and rear of the microphone.

This design ensures excellent axial response while efficiently suppressing lateral interference, making them an ideal choice for stereo recording applications.

Compared to microphones that use dual capsules to mimic the figure-8 pattern, the RM821 and RM822—as physically inherent figure-8 ribbon microphones—deliver superior sound and frequency consistency.

Pairing two RM821/22 series microphones enables the creation of a classic Blumlein stereo setup, ideal for capturing premium ambient sound. When deployed in Mid-Side (M/S) stereo recording, they deliver exceptional results:

· As Side (S) channels: Pairing an RM821 with a CM6 MKII cardioid condenser microphone captures richly detailed and naturally spatialized stereo fields for vocals, acoustic guitars, and other sources.

· Alternative pairing: Combining one RM822 (or RM821) with a PM05 supercardioid dynamic microphone is perfect for high-dynamic sources like guitar amplifiers or percussion.

            Wide Frequency Response & Refined Transient Handling

The RM821 and RM822 boast an extended frequency response down to 30Hz, delivering full-bodied, articulate low-end reproduction for bass instruments, cellos, and more. This ensures layered, high-fidelity audio with exceptional accuracy.

   Polar Pattern Diagram

Leveraging lightweight ribbon elements and precision shaping technology, these microphones offer rapid transient response. They faithfully reproduce nuanced dynamics—from guitar plucks to brass staccatos—infusing tones with palpable vitality.

· Frequency Response Curve

While sharing identical core acoustic performance, the RM821 and RM822 differentiate through unique exterior designs.

Both models adopt the classic compact cylindrical form factor synonymous with ribbon microphones, featuring a clean, professional profile.

· RM821: Features signature symmetrical mounting rings at both ends of the grille, creating a visually distinctive "ear" motif.

· RM822: Employs an ultra-minimalist single-body cylindrical design with uninterrupted contours for ultimate sleekness.

At the heart of these microphones lies a handcrafted 3-micron (0.003mm) ultra-thin pure aluminum ribbon, precisely secured within a sub-millimeter magnetic gap. Alctron’s specialized ribbon shaping technology ensures optimal positioning in the magnetic field, guaranteeing exceptional transient response and pristine audio fidelity.

Full-metal housing finished with pearl nickel plating delivers both premium tactile quality and enduring durability. Stainless steel mesh grille provides tight-fitting protection for the internal ribbon element while resisting dents and deformation. Comprehensive electromagnetic shielding minimizes interference, ensuring clean and transparent signal transmission. Compact form factor universally compatible with standard microphone stands, merging practicality with professional aesthetics.

The newly launched Alctron RM821 & RM822 passive ribbon microphones embody，true passive operation (no power required), warm fundamental tonal character, extended low-end response down to 30Hz and  classic figure-8 polar pattern. These attributes make them ideal partners for capturing vocal nuances, guitar amplifier textures, and the soul of acoustic instruments.

More than just tools—they represent a revival of vintage sonic principles. For recording engineers and musicians pursuing authentic sound, they stand as rare finds where performance transcends price.