We use exclusively marine grade birch plywood from Finland in 18mm for the body & 15mm for the midrange truncated baffle, totalling 33mm thickness for the main driver. The stepped baffle aligns the tweeter and midrange for time coherence and together with the very small size of the cabinet - 180x250x250mm - is the simplest approximation of a sphere.
The drivers
We use two bespoke drivers from Audax:
!3 cm midrange with phase plug, paper membrane, stronger magnet & long moving coil.
17 cm subwoofer at the back, with paper membrane.
Both drivers are vented through the magnet for faster transient response/slew rate.
25 mm tweeter from Vifa/Peerless soft fabric dome, extending to 40kHz.
Note the bespoke 3D printed faceplate
The crossovers We use two different crossovers to enable bi-wiring or bi-amplification.
The subwoofer is cut at 150Hz with a 12dB/octave slope.
The midrange is only rolled off at 4kHz with a 6dB/octave slope.
The tweeter is filtered at the bottom of its range, way above its Fs, at 4kHz and 6dB/oct.
We use only Mundorf components in both cells for the highest quality/size/price ratio.
All components are wired directly and glued to a 6.5mm thick plywood.
The boards are then secured in the cabinets with screws and little rubber isolators.
We use high quality cables of 2 different gauges to connect the drivers to the crossovers.
The two cells are connected at the back of the speaker with two rods of solid copper when bi-wiring or bi-amplification is not required.
The push-pull isobaric effect
The midrange and the back driver are working in push pull rather than ‘fighting’ each other.So when you push - gently - the back driver in, the midrange moves out and vice versa.After many experiments, we found this to be the most effective solution for clean, tight bass.It significantly reduces the distortion of the midrange driver primarily as well. Also, as the volume is shared, the virtual volume seen by each driver is the entire internal volume of the cabinet, essentially doubling it. This combined with a much lower Fs than in the MK2 - which works on the same principle - results in almost an octave more in the bass, which in most cases, will remove the need for a subwoofer, unlike with the MK1 and MK2.
In conclusion
Our design principles are totally inspired by the research of Joseph Leon, the founder of French speaker brand Elipson. Our aim has always been to design speakers with the same principles while reducing the cabinets to their smallest possible sizes without compromising performance. The raving reviews we got both for the MK1 and MK2 are the independent proof that we have somehow succeeded while maintaining a reasonable price by selling direct online.