Here’s a focused, technical-but-readable breakdown of how the Woojer Vest Edge’s six haptic modules (Osci™ TRX52 transducers) actually produce that “feel the music” effect. I’ll cover the signal path, the transducer mechanics, placement/stereo mapping, frequency/feel, power/drive electronics, and practical implications (latency, safety).

I’ll cite the primary sources where the device and its tech are described.
[ https://www.woojer.com/ ] 

1) Signal path — how audio becomes haptics

The Vest accepts an audio input from your source (USB-C, wired analog, or paired Bluetooth) and routes that audio both to your headphones output and to the vest’s haptic drive circuitry. The vest uses an internal amplifier / haptic driver stage that converts the incoming audio (an electrical waveform) into physical motion in each transducer — essentially the audio waveform is used to drive the haptic actuators so the vibrations match the original bass and rhythm content. This is why Woojer recommends driving the source loud enough to maximize the haptic effect.

2) The transducers — Osci™ TRX52 (what they are and why they matter)

Woojer’s transducers are their patented Osci™ design (often named TRX52 in product docs). Key points about the Osci design: it uses an “I”-shaped core and oscillating permanent magnets in a closed-loop frame; the human body itself acts as the resonator, so the actuator can be compact and silent while producing strong low-frequency (tactile) output. The company states Osci transducers reproduce frequencies up to ~200 Hz and can even render subsonic bands (1–20 Hz) that you don’t hear but can feel as pressure or pulses. These are polyphonic — capable of rendering complex low-frequency waveforms (not just single-tone buzz). 

Practical note: independent reviews and teardowns name the TRX52 part and confirm six of these transducers are distributed across the vest (two front, two back, two sides) to create a stereo/spatial haptic field. 

3) Placement & stereo/spatial mapping

Because the Vest has six transducers arranged around chest, sides and back, Woojer divides the actuators into left/right groups to give a basic stereo haptic image: side/front/back transducers can be driven at different amplitudes (and slightly different timing) to make bass feel localized (e.g., a left-heavy kick will be stronger on the left side). This spatial mapping plus the body-as-resonator concept is what makes the brain interpret the sensation as “full-body” bass rather than a single-point buzz. 

4) Frequency response & perceived sensation

• Subsonic (1–20 Hz): felt as slow pressure changes or “sweeps” across the torso; great for rumble and very deep bass.

• Low bass (20–80 Hz): perceived as thumps and kicks — chest/torso pulses.

• Upper haptic band (80–200 Hz): provides texture and rhythmic detail (helps convey percussion and higher-energy components).
  Woojer’s Osci tech is tuned for these bands (they emphasize up to ~200 Hz), which is the sweet spot for tactile music reproduction because higher audio frequencies are less effectively perceived through the body. 

5) Drive electronics, amplification and power

The Vest contains battery packs and internal amplification designed to supply the transducers with sufficient current/voltage to move their magnetic elements strongly at low frequencies. Product docs and support pages mention multi-cell lithium packs and advise full volume on the source to maximize haptic output; the Vest also exposes user controls to adjust sensation independently from headphone volume. Some reviews list a TI-based analog headphone amp in the Strap variant — the Vest uses a higher capacity battery arrangement (multiple 3350 mAh cells in series) to provide sustained power for six transducers. 

6) Latency & synchronization

Because the system is essentially driven by the same audio signal you’re hearing (analog passthrough or low-latency Bluetooth/USB paths), timing between audio and haptic is normally tight — the haptics follow the waveform in near real-time. However, Bluetooth codecs and the source device can introduce audio latency; Woojer recommends wired/USB connections or low-latency codecs for the best sync in VR/gaming scenarios. Reviews note that system-level limitations (source latency, codec buffering) are more likely to create noticeable audio-haptic mismatch than the Vest’s internal processing.

7) Real-world trade-offs & design choices

• Why only six points? Woojer’s philosophy with Osci is “less is more”: by placing robust, high-output transducers on body hotspots and relying on the body as resonator, they aim for convincing whole-body sensation with fewer, more powerful actuators (vs. many small vibrotactors). That reduces complexity, weight and power needs while still creating immersive effects.

• Sound quality vs. haptic fidelity: the Vest doesn’t attempt to reproduce mid/high audio via touch — its job is low-frequency tactile reproduction. Expect deep, musical bass and rhythmic pulses, not fine high-frequency detail.

• Energy & heat: strong low-frequency motion requires current; Woojer balances battery capacity and thermal design (and warns about health considerations in the manual).

8) Safety & usage notes (practical)

Woojer’s documentation includes standard safety warnings: consult a physician if you have heart conditions, pacemakers, or pregnancy; don’t use while charging; and moderate intensity if you feel discomfort. Because the system intentionally produces subsonic pressure, people with certain medical conditions should be cautious.