Active Monitors

Monitors / Monitoring

Published June 2024

Single‑driver, two‑way nearfield or three‑way monitors? Focal’s new flagship design can be all three...

Focal have a strong track record in producing serious studio monitors, and while some of their models are on the costly side for the home studio operator, they are actually very competitively priced in professional terms. The ST6 Trio6 is the latest in the ST6 series, and while you might assume that the Trio in its name relates to the number of drivers (there are indeed three), it in fact refers to the fact that the speaker can play three different roles, all of which are valuable in today’s studios. This is down to what Focal call 'Focus mode'. It’s a feature we have seen before in earlier models, but whereas those offered two operating modes, the ST6 Trio6 offers three.

The ST6 Trio6 is a three‑way speaker, then, incorporating an 8‑inch woofer for the bass, a 5‑inch driver for the mids and a 1.5‑inch tweeter for the highs. Perhaps unusually for a modern premium monitor, its signal path is all analogue.

Theory Of Evolution

Like other models in the ST6 range, the new Trio6 is an evolution of the earlier ‘Be’ version, where Be denoted the use of a beryllium tweeter. Curiously, the beryllium tweeter remains, but the ‘Be’ in the product name doesn’t. However, the ST6 series includes a number of other technical improvements to the components, such as the use of Focal’s W composite woofer cone construction, which features layers of woven glass‑fibre composite around a structural foam inner core. The midrange driver has also been tweaked so that it now includes Focal’s distinctive ridged roll surround, with the aim of further minimising resonances — Focal call this their Tuned Mass Damper resonance‑reduction technology. We’re informed that the radial rings moulded into the surround behave as tuned mass dampers to create anti‑resonance nodes that dissipate energy rather than allowing it to reflect back into the diaphragm. And although the beryllium tweeter diaphragm itself is the same, it gains a newly designed asymmetric waveguide to control its dispersion.

The rear panel houses the analogue inputs, EQ controls, and the switches and footswitch jacks for engaging the Focus modes.There’s plenty of amplifier power on board, with a 100 Watt Class‑G amplifier driving the bass end and another handling the mids. Class‑G amplifiers are analogue and utilise multiple power rails at different voltages. They switch from lower to higher power rails as the signal output approaches the maximum that each rail can handle, which in turn reduces power wastage in the output transistors. A 50W Class‑A/B amplifier drives the tweeter. Maximum SPL is quoted as 113dB in full‑range mode and 112dB in Focus mode.

The beautifully styled cabinet housing these components has also been re‑engineered, with upgraded bracing to further minimise resonances. With each speaker weighing around 20kg, you may need help to lift them onto your meter bridge. Internally the cabinet is divided into separate compartments for each driver, and the tweeter enclosure is apparently designed to behave as though it contains an infinite volume of air, in order to optimise acoustic loading. Unusually, both the mid and bass driver enclosures are ported, presumably so that in two‑way mode, the midrange driver can behave in the same way as the woofer in a smaller ported system. Both sets of ports are flared not only externally but also internally where they terminate inside the cabinet, to encourage non‑turbulent airflow, which reduces port noise at higher playback volumes.

Conscious of the fact that some studio layouts make it more practical to use monitors in landscape rather than portrait orientation, Focal have engineered the baffle such that the tweeter and midrange driver share a rotatable faceplate to optimise performance in either role. Rotation is achieved by removing the four cap‑head bolts with an Allen key, rotating the plate by 90 degrees, then replacing the bolts.

In Focus

Returning to Focus mode, this reconfigures the drivers and crossovers from their usual three‑way mode of working to provide two alternative monitoring options, using either one or two of the drivers.

Previous Focus‑enabled monitors from Focal have allowed the tweeter, woofer and crossovers to be temporarily reconfigured so that the midrange driver handles the full audio range, rather like the revered Auratone. That mode is still available, but Focal have added a third mode that utilises the midrange driver and the tweeter but bypasses the woofer, to approximate the characteristics of a smaller two‑way speaker such as those used in some hi‑fi systems or small studio monitors — though the fidelity on offer here is rather higher than from typical home hi‑fi speakers! Likewise, the single‑driver mode sounds better than I remember my old Auratones sounding, though you do lose high‑frequency detail in a rather similar way. That said, these additions mean that more mix checks can be made without switching to alternate monitors; if you find yourself doing this a lot and want to make changing modes straightforward, a footswitch can be connected via a jack to one monitor, with another jack cable to link the two speakers so that they both switch modes together.

Controls

The input sensitivity can be switched between +4dBu and ‑10dBV, and to help tune the speakers to different rooms and proximity to boundaries, there’s a useful amount of EQ. An HF shelving filter works above 4.5kHz over a ±3dB range, while a LMF EQ provides adjustment around 160Hz with a Q=1 to help compensate for desk mounting. LF shelving offers an adjustment range of ±3dB below 150Hz. The power indicator LED shows green when the speakers are operating and red when in power saving mode. Power saving can be turned on or off using a rear‑panel switch.

Although the Focus mode can be turned on and off remotely, the choice of Focus mode is set using a three‑way switch on the rear panel. In the first mode, which uses only the mid driver, the frequency response is 100Hz‑15kHz. The second Focus mode is the two‑way mid/tweeter arrangement, with a much extended frequency range of 80Hz‑40kHz. When Focus 1 mode is activate, the ‘Focus’ LED on the front panel lights up green. In Focus 2 mode it lights up orange. The 1+2 Focus switch position allows for remote selection of Focus mode one or two using a Boss FS‑6 double control pedal or equivalent (this requires connection using a TRS jack). Alternatively, you could use two single footswitches to do the same job.

Testing

Set up on my studio desk bridge shelf, the Trio6s sounded impressive on a wide range of material before I even considered adjusting the EQ or indeed giving the drivers time to run in. Loudspeakers do take time to run in, as the material properties of the drivers, particularly the surrounds, change slightly after being flexed in normal use; you can either wait for days for that to happen naturally as you use the speakers, or you can play some loud dance music through them for a day and hope the neighbours don’t complain!

The Trio6s exhibit a tight, well‑controlled low end, with a sense of openness and detail extending right up the audio spectrum.

As with other really high‑quality speakers, the Trio6s exhibit a tight, well‑controlled low end, with a sense of openness and detail extending right up the audio spectrum. They deliver that sense of three‑dimensional sound and transparency that lets you hear right into a mix but without adding harshness. The tweeter extends an octave higher than most, and if you find its detailed sound a hint too forward in character, a small tweak to the rear‑panel EQ brings it back into line. Their sense of stereo imaging is also solid. For my monitoring location I’d probably drop the tweeter level by a dB but that’s about it. However, it may well be beneficial to use serious speaker platforms rather than the small stick‑on feet that come with the monitors.

Overall I couldn’t fault these speakers in their usual full‑range mode where their format makes them suitable for use in small‑to‑medium sized professional studios as well as being a good fit for serious project studios. The alternative modes work as expected, though I’m not sure how useful they are, as the results sound simply too good in comparison with Auratone cubes or domestic two‑way speakers! Nevertheless, the facility is there if you need it.

In summary, then, these are extremely fine speakers that fulfil the need for accurate monitoring and give you the two Focus modes as a bonus, whether or not you decide to use them.

Pros

Accurate, open and detailed sound.
Excellent stereo imaging.
Focus modes might be useful to some.

Cons

None.

Summary

In their full‑fat three‑way mode these are serious, professional tools that will let you know exactly what your audio is doing. The Focus modes increase their flexibility, but sound rather better than the ‘grotboxes’ they try to emulate!