The Active Wave Focusing Solution
A loop hole in acoustics says that small directive speakers are possible – if you have enough drivers and you feed them the exact right signal. The THREE has a total of 6 (six) ways, front, side and rear, working together to throw the sound in one direction only without relying on a baffle. The THREE’s ability to direct bass is comparable to, but much better controlled than that of a traditional speaker several meters wide.
The THREE is the first compact speaker that exceeds the clarity of a full size sound system in a large room while its small size means it’s equally at home in much more modest spaces. In fact, smaller rooms will benefit most from the THREE’s controlled bass. Better than big speakers at sounding big and better adapted for small rooms than other small speakers, the Kii THREE is a truly no-compromise product.
How do Active Wave Focusing filters work?
Active Wave Focusing filters mark a complete departure from the classical crossover filter. Instead of just splitting the spectrum into bands, it forces the specially positioned drive units to create a completely coherent wave front that is only emitted forward and behaves as though all of it came from the midrange driver.
With classical crossover filters, loudspeakers can only have a time aligned impulse response on the main axis. The animations on the right show the wave front as it’s built up by a typical modern three-way speaker with side-firing woofers. This example is crossed over at 250Hz, time aligned and phase equalised. Indeed the wave travelling towards the listener is coherent. Towards the sides and the rear the picture breaks down and the impulse is completely smeared. Also, low frequencies get emitted in all directions. In a real room (bottom animation) the sound that escapes toward the back will strike the wall behind the speaker and reflect towards the listener, who actually hears the speaker twice: once from the front and a bit later from the rear. Moving the speaker out into the room doesn’t help. The overall bass balance looks better but the impulse response gets worse as the reflection now comes even later.
The animations on the right side of the GIFs show how the Active Wave Focusing method retains full time alignment all around the speaker and how the presence of the rear wall has no impact. Sonically, the effect is a very even, unusually detailed bass. Even in problematic rooms, a drum kick has that visceral thud that previously only very big or in-wall speakers could achieve.
HIGH END TECHNIC IN COMPACT HOUSING!
Each Kii THREE contains six channels of DSP, D/A conversion and power amplification. Few companies could pull off such a densely packed design with truly world class performance electronics. But then again, few active speakers are designed by people who have previously turned high end power amplification and digital conversion around.
Each Kii THREE holds 6x250W power amplifier boards, designed by Bruno Putzeys using the latest iteration of the Ncore class D technology which he invented for Hypex. Unique to the implementation used in the Kii THREE is a combined voltage/current control loop that goes beyond merely a better amp – it actively improves the distortion performance of the drive units which contributes significantly to the extreme resolution of the speaker.
Naturally, this means that the performance of the AD/DA conversion has to match that of the amps. This task fell to Bart van der Laan who has a long track record designing DSP and converter boards for high-end professional audio equipment. Kii Audio’s implementation is a runaway success: a complete pass through the AD/DA circuitry of the THREE’s signal processing board is entirely inaudible, a feat not duplicated by the most expensive audiophile standalone units.
Alongside the Active Wave Focusing filters the DSP is responsible for keeping the drive units within their safe operating range by gently adapting the filters instead of brutally limiting the signal, allowing the THREE to play significantly louder and cleaner than much bigger traditional designs.
On the input side there is a choice of analogue, digital inputs. All digital inputs are re-sampled and reclocked using Kii’s own jitter rejection algorithm that guarantees actual “bits is bits” audio performance for any digital source.
The electronics package alone sets a milestone. What it does in concert with the unique acoustic design defies imagination. You have to hear it to realise the magnitude of the revolution the Kii THREE represents.
Compact DSP controlled monitor speaker
4 x 6.5” woofer,
1 x 5” midrange,
1 x 1” waveguided tweeter, all individually driven
Amplification: 6x250W full-custom Ncore
Active Wave Focusing crossover filter
Frequency response: ± 0,5dB – 25 kHz, 20Hz -6dB (*)
Integrated tone control
Phase response: selectable, linear phase or minimum latency
Controlled Directivity: 4.8dB (54Hz – 1kHz, slowly rising thereafter)
Size: 20x40x40cm, 8”x16”x16” (WxHxD)
Weight: 19kg (40lbs)
Inputs: Analogue, AES/EBU, KiiLink
SPDIF, TOSLink, USB on Kii Control.
Selectable correction for free-standing, near wall or in corner (14 positions)
Automatic Standby Mode
(*) IEC60268-5 Paragraphe 20.6