When the essential is invisible to the eye...

Solving the problems inherent in coaxial loudspeakers as well as two-way or more-way systems the YOCTO radiates sound in space from a single diaphragm with consistent directivity and high-end performance representing something as an ideal in loudspeaker design. There is no crossover point between midrange and tweeter and this has consistent advantages in terms of performance. Another improvement is the absence of any decoupling technology between the driver and the cabinet because the driver is part of a strong and stiff CNC machined aluminum enclosure. The distinctive shape of the enclosure eliminates diffraction present in loudspeakers that have a baffle hosting numerous drivers granting an almost perfect interaction with the listening room and opening new opportunities in multi-speaker systems & 3D panning / MPEG-H 3D Audio.

Furthermore, the back radiated energy of the diaphragm is diffused into 5 concentric channels milled around the diaphragm area: back radiated energy flows into those channels and around a slug-type magnet instead of bouncing back and hitting the diaphragm.

YOCTO is meant to be crossed at 100Hz 24dB/Octave and to be coupled to a dedicated subwoofer such as the Lange Loudspeakers TERA. Small loudspeaker diaphragms can’t overcome the laws of physics and reproduce efficiently low frequencies unless they are implemented into horns or transmission lines. Low frequency horns as well as transmission lines add energy to the diaphragm either by coupling or by resonating. Coupling to the air is what horns do and this implies a phenomenon called reactance; resonating as the word suggests is a resonance artifact that is interpreted as loudness. Both reactance and resonance are phenomena in contrast with high end reproduction.

The YOCTO is an entirely Aluminum CNC machined loudspeaker as well as the most compact model Lange Loudspeakers SA is introducing in 2022, hence its name YOCTO, which corresponds to One Septillionth of a unit in the SI Metric System. The transducer incorporates different advances and reinterpretations of loudspeaker manufacturing techniques. From a CNC machined diaphragm to a CNC-machined frame and a dedicated, individually tuned passive network every detail has been carefully considered to achieve the best possible performance.

YOCTO is designed and manufactured by Lange Loudspeakers SA in Switzerland, including the drive unit.

Spectacular 3D soundstage

The soundstage allows the audiophile to hear the position of instruments when listening to a soundtrack. YOCTO provides a holographic soundstage and is perhaps the most indicated loudspeaker system for today’s more involving sound experience offered by Dolby Atmos™, Flux Spat™, 3D Soundstage™ etc. where loudspeaker interaction with the room must be close to ideal and phase coherence is a must. YOCTO has just one diaphragm that provides credible high-end performance with exceptional, identical vertical & horizontal off-axis response.

Absence of tonal coloration

In a YOCTO system most of the parts that are known to degrade a good soundtrack are absent. There is no baffle adding diffracted energy, there is no crossover dividing tweeter from midrange, there is no tweeter and there is not even a dust cap on top of the high-tech diaphragm, there is no reflex tube, no passive radiator, no need for Baffle Step Compensation either passive or active... Every item in a system adds something unwanted to the result and in loudspeaker design it is called distortion. More than sixty different prototypes have been designed, manufactured, tested, evaluated to get the right diaphragm geometry and the best possible enclosure shape. A YOCTO loudspeaker system is made of massive, CNC machined aluminum whose internal geometry excludes internal resonances to take place. The area in front of the diaphragm includes a phase plug that promotes an extremely smooth polar response further enhancing the concept of a point source that perfectly interacts with the room.

No sweet spot nor critical positioning

Loudspeakers are designed to deliver a coherent frequency response in one single point in space, where all drivers are synchronized and in phase. Moving apart a few inches from this sweet spot inevitably leads to poor performance. YOCTO delivers almost the entire audible spectrum from one single High-Tech diaphragm, creating a consistent and coherent room interaction. Due to the absence of a front baffle that includes multiple drivers YOCTO delivers the best technically possible in-room performance. If you are an audiophile you won't be forced to be in reach of the loudspeaker sweet spot to enjoy a soundtrack, you will experience exceptional performance also far away from the loudspeaker center. The polar pattern is similar to wave-guide tweeters!

No bass…and for good reasons

Low frequencies impose large diaphragm movements, the smaller the diaphragm the larger the movement. It is practically impossible to reproduce faithfully low frequencies with ideal midranges whose diameter ranges from 75 mm up to about 140 mm. Contemporary music as well as movie soundtracks easily push loudspeaker drivers to their excursion limits causing distortion. In terms of intermodulation (IMD) distortion a full-range loudspeaker driver that also covers frequencies below 100 Hz generates consistent and, in some cases, unacceptable IMD. This phenomenon can be defined as a Doppler effect and is evident when a loudspeaker diaphragm generates for example a 50 Hz tone together with a 2,5kHz tone. Adding a subwoofer has only advantages and this is the reason Lange Loudspeakers SA designs mid-high frequency loudspeaker systems that must be coupled to a subwoofer to get a correct, coherent, and qualitative soundtrack reproduction. 

Technical features

One way 100 Hz to 22 kHz coverage

Anti-Resonance full aluminum CNC machined enclosure

CNC machined 3D diaphragm

Phase Plug enhanced response

Coherent coverage on stated frequency response

Exceptionally realistic reproduction

Suitable applications

High End home entertainment

Studio Monitoring 

Home Cinema – THX/Dolby Atmos

Technical Description

Configuration 1-way sealed-box system

Recommended amplifier power 25W – 100W into 8Ω on unclipped program

Net weight  3.55kg

Finishes   Finely sand blasted, black anodized 

Drive units   1x 65mm long excursion / extended range diaphragm

Frequency range   100Hz to 22kHz

Frequency response   100Hz to 6kHz (+/-1dB from reference axis)

Sensitivity   81dB (on axis at 1W /4Ohm (2.00 Vrms) at 1m)

Harmonic distortion  (1W 1mt) <0.8% 130Hz – 20kHz

Ambient temperature 21°C to 27°C for maximum linearity

Complimentary Products

Frequency response measured in the free field, 1W @ 1 meter - 24dB/Oct. High Pass inserted @ 100Hz

Impedance remains above 4 Ohms and allows the coupling to any amplifier class including tube amplifiers

THD referred to 1W input on a 4 Ohm load

IMD Distortion in full-range loudspeakers...

In terms of intermodulation distortion (IMD) a full-range loudspeaker driver that also covers frequencies below 100 Hz generates consistent, and in some cases, unacceptable IMD. This phenomenon can be defined as a Doppler effect and is evident when a loudspeaker diaphragm generates for example a 50 Hz tone together with a 2,5kHz tone.  Loudspeakers usually have a tweeter and a woofer crossed in most cases at 2,5 kHz and therefore IMD is an issue in both two-way loudspeakers as well as full-range concepts. Small diaphragm's IMD can only be minimized by reducing the excursion amplitude implementing high order High-Pass Filters at around 100Hz.

Distortion measurements do not directly predict how a speaker will sound, rather they help us judge driver linearity and by implication driver quality. We believe that intermodulation distortion tests are more revealing of loudspeaker performance. We can tolerate reasonably high levels of harmonic distortion because, as their name implies, the spurious components added to the program are harmonically related to the original program. Intermodulation distortion (IMD) produces output frequencies that are not harmonically related to the input. These frequencies are much more audible and annoying than harmonic distortion.

Hereafter graphs show the YOCTO Loudspeaker system behavior when excited with a pure 2,5kHz tone, a 50Hz tone and a 2,5kHz tone with high pass crossover in the signal path and, worst case, while 50Hz and 2,5kHz tones are reproduced without high pass crossover.

YOCTO Loudspeaker System - Second harmonic located at -50dB when a pure 2,5kHz tone is applied - (1W input @ 4 Ohm - near field measurement).

Two tones are applied, 50Hz & 2,5kHz. In this case the signal is fed through a 100Hz, 24dB. Oct. Active High-Pass Filter (Sublime-Acoustic K231). Distortion components remain as low as -50dB - (1W input @ 4 Ohm - near field measurement). The 50Hz tone is actually coming from the TERA subwoofer, located app. 1,5 meters away.

Two tones are applied, 50Hz & 2,5kHz. In this case the YOCTO is used as a typical full-range loudspeaker reproducing the full spectrum. Distortion components rise to an unacceptable, -24dB level - (1W input @ 4 Ohm - near field measurement). The 2,5kHz tone is modulated by the 50Hz tone creating multiple side tones not present in the signal.

Polar response of YOCTO Loudspeakers is identical in both the horizontal and vertical plane

YOCTO - Directivity Index - Horizontal & Vertical coverages are identical

YOCTO - Directivity Pattern / Filled Color - 1/3 Oct. Horizontal & Vertical coverages are identical

YOCTO - Directivity Index - Horizontal & Vertical coverages are identical