RT60 are the inventors of Headphone-Free Recording, which is a ground-breaking AI technology that makes multitrack recording, without the need to wear headphones, a reality.
Our pioneering HFR machine-learning technology isolates playback ‘bleed’ from backing tracks and overdubs, freeing musicians from having to wear headphones or use any kind of external device. Just sing or play straight into a device mic, record layers and get ready to be amazed. Crystal-clear arrangements with no artefacts or spill.
What’s more, it works in real-time, meaning the bleed removal is instantaneous, with no need to wait for any online processing to run or complete. By the time you hit ‘stop’, a new recording has already been isolated from any backing tracks or previous recordings blasting out of the phone or device speaker.
Headphone-Free Recording
Unlike current stem-isolation technologies, our HFR algorithm is also source agnostic. That means, it will isolate elements such as vocal recordings from previously captured vocal layers, which is perfect for songwriters and top-liners creating ideas and harmonies on the go, and you don't need to tell the system what type of instrument is being recorded or isolated either.
HFR is already incorporated into our award-winning Songzap V3 mobile app, making it the first DAW software to allow multitrack recording without the need to wear headphones.
RT60 CTO Professor Rob Toulson demonstrates Headphone-Free Recording
The HFR Demo App
You can experience Headphone-Free Recording for yourself, either in the Songzap V3 app or in our simple HFR iPhone demo app, which has been released to allow potential users and collaborators to experience the technology immediately, without needing to create an app user account or subscribe to a premium service.
The demo app is quite self-explanatory, being very similar in layout to a standard multitrack audio recording application - the only difference is that headphones are not required! Simply press the record-enable button for a particular track, then press the play button, and start singing or playing an instrument into the device microphone. The recording will be captured and the playback bleed that was heard and captured is automatically removed to give a clear and clean recording of your performance. Solo your recording to hear it back. Record multiple layers and listen how each time the playback audio is automatically removed from the recording.
If you want to hear a 'before and after' comparison between what was actually captured and the post-AI cleanup version, you can tap the small headphones button to open the pink 'headphone-free audio mixers' for each channel. Again, you might want to solo a particular channel and then move the pink slider during playback; you'll hear the playback bleed being removed and you can see the bleed that has been removed visually too in the audio waveform.
The HFR technology works on any device and with any source material. The reason it can do this is because the playback audio is captured from the device output and used alongside the recorded audio data within a deep neural net (DNN). To make this algorithm device and instrument/source independent, the playback and the recording data need to be time-aligned when input into the DNN, but of course every device has different output, input and internal processing latencies with respect to audio. For this reason, the app needs to measure the device's roundtrip latency on the first launch. It does this by outputting a quick audio pulse and recording it back in, then measuring the time difference between the two.
You'll be prompted to run this latency calibration on first launch, just follow the on-screen instructions and make sure your device volume is turned up to a reasonable level. The latency routine can be repeated at any time via the settings which are accessed in the app information menu.
HFR In Action
Watch Ethan Ash track guitar & vocals headphone-free with Songzap V3
Theanò records & arranges vocals headphone-free in Songzap V3.
Watch Kai loop-record raps plus layers headphone-free with Songzap V3.
HFR Vs Conventional Stem Separation
Our Headphone-Free Recording technology is a one-of-a-kind cutting-edge system that is PCT (worldwide) patent applied. The difference between HFR and conventional audio source separation algorithms is summarised in the table below:
Work With Us
Our Headphone-Free Recording technology is available as a licensable Swift package that can be incorporated into any iOS audio recording application. Installation is simple, with a single function that inputs both recorded and playback data, and returns recorded data with playback bleed removed.
We are also able to develop HFR packages for different platforms and bespoke devices and applications.
If you would like to add HFR to your iOS app or work with us to develop a bespoke version for your specific hardware or platform, please get in touch at the email address below or through the website contact form.