Twopit: Breaking the barriers of data transmission over audio channels

Twopit has achieved a stable 12 kbit/s transmission over a standard audio card, far beyond conventional methods like FSK, which rarely exceed 2 kbit/s. By year’s end, it targets 20 kbit/s in analog mode, marking a true paradigm shift in secure and resilient audio communications.

For decades, transmitting data over standard audio hardware has been constrained by the physical limitations of microphones, speakers, and soundcards. Noise, multipath distortion, and limited frequency response have kept real world throughput modest, often just a few hundred bits per second, rarely exceeding a couple of kilobits.

The state of the art: conventional modulation hits the wall

On a standard consumer soundcard, techniques such as frequency shift keying (FSK) or phase shift keying (PSK) typically achieve between 300 bit/s and 2 kbit/s under real conditions.
Even advanced data over sound experiments rarely sustain more than 2 kbit/s without severe degradation. This has long been considered the practical ceiling for audio based communications.

The proof of concept: Twopit redefines the limit

In a groundbreaking proof of concept demonstration, Twopit, a patented technology based on geometric envelope modulation, achieved a stable transmission of 12 kbit/s over a standard audio channel.

This performance is more than an order of magnitude beyond what conventional audio modulations such as FSK can deliver.
And the roadmap is even more ambitious: by the end of the year, Twopit is projected to reach 20 kbit/s in analog mode, all while operating on off the shelf audio hardware, with no need for shared clocks or conventional digital protocols.

Why it matters

Twopit’s unique approach separates amplitude from temporal geometry, encoding data into narrowband envelopes as small as 30 Hz per symbol. The result:

• Massively higher throughput on the same bandwidth

• Superior resilience against noise and interference

• Scalable architecture that can multiply capacity by stacking parallel narrowband channels

This is not just an incremental improvement, it is a paradigm shift. Twopit demonstrates that the theoretical limits once thought to constrain audio based communications can be broken, paving the way for a new class of ultra efficient, secure, and resilient analog communications.

Source: Experimental PoC results on patented technology Twopit – Geometric Envelope Narrowband Modulation (Italian patent no. 102022000025623, PCT WO2024/127439).