How many subwoofers, and where? Trinnov expands its WaveForming design tool

On 26 October Trinnov published an update to its WaveForming Design Tool, the online resource that helps plan a WaveForming installation. The company's point is plain: the tool now covers “a broader range of placement considerations” and answers more of the questions that come up during design. In other words, it is there to settle how many subwoofers go where before anyone drills into a wall.

That matters more than it sounds, because in WaveForming placement is not a comfort setting: it is what caps the result.

Bass does not get better with foam

The problem WaveForming attacks is room modes: standing waves that make frequency response swing wildly from one seat to the next, and that cause bass energy to dissipate far more slowly than midrange or treble. Trinnov is categorical here — no amount of passive treatment fully resolves it. You would need material thicknesses nobody wants in their living room.

So Trinnov's answer is not to absorb but to steer: use several subwoofers, each with its own drive signal, to take control of how bass propagates through the room.

What WaveForming actually does

The technology rests on four parts. First, 3D acoustic field measurement: each subwoofer is measured at multiple points across the listening area — 9 to 25 points depending on how wide an area you need to cover — to map the soundfield in three dimensions. Then Acoustic Reshaping, which uses that map to remove excessive decay times while keeping what is desirable in the original response, and to even out decay across all seats.

Next comes 3D wavefront synthesis, which makes the subwoofers work together to produce a single coherent wavefront, steered towards the listening area and limiting unwanted reflections off side walls, floor and ceiling. And finally the algorithmic core, MSMC (Multiple Sources, Multiple Controllers), which computes the filters driving each subwoofer individually to produce a room-matched planar wavefront.

The placement hierarchy, best to worst

This is where the design tool earns its place, because Trinnov owns a clear hierarchy. The reference configuration is the regular planar array: subwoofers on the front wall and the rear wall, at different heights. That is what unlocks the full range of the system's capabilities.

Where the room will not allow it, the irregular planar array takes over: a reduced number of subwoofers on one or both walls still delivers strong results. With one useful rule to remember — if subwoofers have to go, drop rear-wall units rather than front-wall ones.

Below that, the subwoofer line array puts every unit on the floor, spread horizontally: decay control stays good, but seat-to-seat consistency suffers and vertical mode control drops. Then there is the front-only configuration, possible from just two front subwoofers, which Trinnov presents not as a compromise but as a viable long-term solution in its own right — it already brings significant control of decay times and real consistency between positions.

Finally, conventional corner placement, by far the most common, is also the least favourable: the laws of physics prevent the formation of a properly controlled wavefront. WaveForming still applies, but with reduced effectiveness. The recommended first step is to move the subwoofers towards the centre of the front and rear walls.

What to expect from it

The figure Trinnov puts forward is seat-to-seat consistency down to ±0.5 dB up to 100 Hz. In home theatre, the company says this can qualify every seat to CEDIA RP22 Level 4, not just the two primary positions. Add a dramatic reduction in low-frequency reverberation time, plus user-side fine tuning: decay control, adjustable boost limits per frequency, infrasonic pressurisation.

Which machines, and how far the tool goes

Two honest caveats before getting carried away. WaveForming remains the preserve of the Altitude range and the JBL Synthesis SDP-75: Trinnov's technology page does not list the NOVA among compatible processors. And the design tool, by Trinnov's own account, is built for initial planning: it complements the brand's published WaveForming Subwoofer Placement Guidelines, and projects with genuine acoustic constraints will still call for detailed design work.

For integrators, the real value is having something presentable to show a client early on, while subwoofer positions are still negotiable. For curious enthusiasts, it is a sound introduction to the logic behind a layout that holds up.

The updated tool is available at waveforming.trinnov.audio, from the WaveForming technology page, or via the Resources menu on Trinnov's website.