July 17, 2026

An Update on the BA Driver Configuration

Hello everyone.

It's been a little quiet lately, and there was a reason for that.

Behind the scenes, we made an important decision to revise part of Aura Nebula's internal design. The reason was simple: if there was even a chance to achieve better sound, we felt it was worth pursuing.

For us at SOUNDPEATS, refining a product until the very last moment isn't unusual. But making this kind of change with mass production just around the corner meant coordinating across multiple teams and reworking plans that were already in motion. It certainly wasn't the easiest decision, but it was one we believed was worth making.

Rethinking How the BA Drivers Work Together

The change involves the way our balanced armature (BA) drivers are driven.

Originally, the two BA drivers were assigned different frequency ranges through a crossover network, with one handling the midrange and the other focusing on the upper mids. (Related article: The Hybrid 5-Driver Architecture and BA Drivers.)

After extensive evaluation, however, we decided to adopt a Parallel Boost configuration instead, allowing both BA drivers to work together across the same frequency range rather than dividing it.

Why make this change?

Compared with a traditional crossover design, the Parallel Boost approach effectively increases the active diaphragm area while providing greater driving force. This results in higher sound pressure and improved dynamic performance. Because the two BA drivers are no longer separated by frequency bands, it also helps reduce the sense of discontinuity that can sometimes occur around crossover points, as well as minimizing phase inconsistencies.

Another benefit is lower distortion. Since two drivers now share the workload, each diaphragm requires significantly less excursion to produce the same sound pressure level. That means cleaner reproduction, especially at higher listening volumes where distortion is more likely to appear.

For true wireless earbuds, where both physical space and power consumption are tightly constrained, eliminating an entire crossover circuit is also a meaningful advantage.

Taking Another Look at the Planar Driver

Of course, crossover-based designs have their own strengths.

Aura Nebula, however, has another powerful component in its acoustic system: the micro planar magnetic driver.

Our original plan was for the planar driver to take over frequencies above roughly 4–5 kHz. (Related article: About the Aura Nebula.)

Once we committed to the Parallel Boost configuration, we revisited that part of the tuning as well. Rather than simply swapping one design for another, we re-evaluated how every driver should contribute so the entire system could perform at its best.

Choosing the Sound We Believe In

In the end, this wasn't about changing specifications for the sake of change.

It was about choosing the approach that sounded better.

We spent countless hours listening, comparing, adjusting, and listening again, carefully asking ourselves which tuning best represented the sound we wanted Aura Nebula to deliver, and which one would ultimately bring the most enjoyment to listeners around the world.

The result of that process was our decision to move to the Parallel Boost configuration for the BA drivers.

We hope you'll see this not simply as a specification update, but as the latest step in our engineers' ongoing pursuit of better sound.