After approximately 6,000 cumulative hours of research and development, mechanical and electronic prototyping, card debugging, programming with the development of exclusive processing, testing, and measuring (electrical, acoustic, mechanical, and thermal), we are pleased and proud to present our ATOHM RS700 power amplifier.

This highly innovative and resolutely "hi-fi" power amplifier is based on a "dual mono" structure controlled by a high-performance analog/digital card integrating a DSP. Its signal processing capabilities are used to drive the power stages (limiting, soft clipping, phase and amplitude correction, etc.) but also and above all to offer advanced coupling of this amplifier with speakers through exclusive processing based, among other things, on our knowledge of electroacoustics and, ultimately, on the exact specifications of our coupled driver units & enclosures.

The culmination of such a project requires a very significant amount of expertise in many fields. We have largely favored French partners for development as well as for the manufacturing of parts and cards. Thus, the design of the main cards (DSP) and ventilation is the result of a close technical partnership with SOLEDGE, specialized in the design of audio-digital circuits. The production of these "SMD" cards is then entrusted to a highly qualified French Alsatian company with exceptional machinery. The sheet metal work, just as technical, is also carried out in France. In the end, this unit is entirely assembled, wired, tested, and programmed in our workshops.

The device's topology, vast programming and digital chaining possibilities make the ATOHM RS700 base very versatile. We have thus developed a version totally dedicated to WATERFALL AUDIO. Other specific versions for dedicated applications will therefore be gradually introduced.

In this first ATOHM "RS700 GT EDITION" opus, we offer a power unit operating in 4 modes. The first mode allows driving any type of speaker with (high)power, dynamism, finesse, and precision. The U-GUARD processing limits the power stages just before they saturate and provides smooth clipping. Just like for the other 3 modes, this first setup allows, if necessary, filtering (digitally) the speakers in "high pass" in order to truly relieve them in the bass and to associate one or two subwoofers to relay them in the lower spectrum.

The other three modes are specific to each model of our GT SERIES speakers. Amplification and speakers then function in symbiosis. The exclusive X-GUARD, T-GUARD, U-GUARD, and X-TEND processing come into play, allowing to increase the performance of our speakers in order to get the ultimate quintessence out of them. Consequently, they ensure unparalleled operation, even when reproducing musical tracks with sometimes explosive dynamics!



New subwoofer amplifier S500 and S250 MK2-X

New subwoofer amplifier S500 and S250 MK2-X

Mars 2023

Specialized in designing and manufacturing high-end driver units and acoustic speakers, ATOHM has also been designing and offering high-performance amplifier modules for subwoofers for many years. Significant consecutive studies have been conducted on components, schematics, implementation topology, general construction, thermal behavior, and reliability. Thanks to our expertise in electro-acoustics, these studies take into account the actual behavior of speakers and their limits. Our exclusive X-GUARD™ technology ensures that the excursions of bass drivers never exceed an absolute limit at the lowest frequencies.

For over 10 years, our modules have been equipped with ICE POWER® power and supply stages. These ensure flawless power output. With exceptional current capabilities and very high damping factors, they are capable of powering any type of speaker. Combined with our exclusive U-GUARD™ technology, these stages provide smooth clipping and remain protected from any massive saturation.

ATOHM modules offer a purely analog signal processing that is designed to perfect the coupling of the woofer(s) with their load and to exploit all the dynamics without abrupt tonal changes or suspicious behavior when the system reaches its limits. Devoid of subsonic filters and latency, the adjustable dual low-pass filters allow for an ideal acoustic summation with any type of speaker. ATOHM modules offer a wide range of settings and connections to meet all audiophile Hi-Fi and home theater applications.

In these latest MK2 versions, we have prioritized French partners for the development and manufacturing of our CMS circuits and various parts. Ultimately, each unit is fully assembled, wired, and tested in our workshops, ensuring optimal quality.


High-quality technical and musical performances in a minimalist footprint.

S500-MK2-X (new) - ATOHM

S250-MK2-X (NEW) - ATOHM






Sept 2019
The ATOHM RAFALE VR1-X active subwoofer is the worthy successor of the celebrated V35, V38 and V38S models. It benefits from all the knowledge acquired by the company in the ongoing development of high performance compact loudspeakers and subwoofers.


The VR1-X incorporates the superb LD230 CRA 04 woofer. Endowed with the latest technical refinements, this unit redefines the expectations of what came be achieved from a driver unit of this diameter. Its specific alloy cone offers perfect rigidity and a wide bandwidth - even under the highest levels of mechanical strain. The surround and spider, each a result of extensive development and simulations, provide a very wide range of linear excursion as well as perfect dynamic stability (with perfectly symmetrical compliance). An impressive motorization of 156mm (Technology FWI technology : force without inductance) confers a remarkable level of sensitivity for a "subwoofer" driver application. The S250 amplifier module propels this exceptional driver with up to +/- 20mm of excursion. Its class D power stage offers an ideal damping factor. X-GUARD (active excursion control) technology limits distortion as well as maximum excursion when required by an inappropriate level. U-GUARD technology provides "soft" clipping by reducing the creation of harmonics. The bass reflex system features a wide port whose floor is the extension tuned at the lowest frequency. The layout and geometry of this vent have been optimized to allow strong amplitudes while minimizing port noise. The cabinet is crafted of MDF and the weight of the complete assembly renders this subwoofer perfectly stable. The 4 feet are equipped with EPDM high damping foam to significantly reduce the transmission of vibrations, thus contributing to the extreme precision of the sound.


The size of the VR1-X remains similar to many sealed subwoofer models. However, with it exceptional driver and its optimized vented load, the VR1-X is distinguished by a nice extension in the bass, very low rate of distortion in its bandwidth and breathtaking dynamic capabilities (111 dB rms @ 1M ). At listening, the timbres are both accurate and faithful. The VR1-X surprises by the density and the dynamics it provides without "coloring" the system it completes. Superb and in either stereo or home cinema applications, it perfectly integrates into any system based on bookshelf or medium sized floorstanding speakers.


Finishes : black or white satin

GT-SW2 subwoofer becomes  " HD"

GT-SW2 subwoofer becomes " HD"

July 2019

Following the release of the new LD230 CRA "Absolute Series" units, the GT-SW2 subwoofer is evolving to become "HD". If the cabinet, rather massive, remains the same, this new version is now equipped with 2 units LD230CRA08M specifically optimized for closed applications of low volume (22l here!) In order to benefit from the additional excursion provided (+/- 19mm) by this fabulous tandem of driver units, the "X GUARD" circuit (active excursion control) of the S500 module is modified accordingly. The GT-SW2 -HD therefore provides a greater SPL MAX between 20 and 35 Hz with a significant decrease in distortion.

What better to accompany our famous GT1 or their sisters GT2 and GT3 (or any other high-end speakers).




Finishes :  piano white or black





New versions of our 23 cm unit :    LD230 "CRA"

New versions of our 23 cm unit : LD230 "CRA"

Fevrier 2019


LD 230 CRA  : an “ATOHM ‘s concentrate” !


The suspension  with its LDS profile and the spider with its progressive geometry have undergone extensive studies and many computer simulations ( finite elements method) in order to guarantee a wide range of linear excursion .

The spider features a special material chosen for its very low level of creeping and offers a steady stiffness coefficient on its nominal excursion. As for the suspension, not only does it feature a virtually perfect linearity during maximum excursion, but it also keeps a perfect geometry under the strongest mechanical strains. ( for example : low volume closed enclosure  or physical pressure at the  tuned frequency of a bass reflex speaker  ) In order to limit “dynamic DC shifts, these 2 components are acting in a totally symmetric way. The cone , made up in a specific alloy , has also been optimized in order to guarantee perfect rigidity  on a very large frequency range and under the strongest mechanical strains.

The imposing size of the Motor ( 156mm diameter) benefits from the  FWI (Force without Inductance) technology. Skillfully sized, the polar parts and the copper ring allow for great reduction and linearization of the inductance value. Depending on the driver units, the voice coils are fabricated with copper wire or with copper clad aluminum wire ( CCAW ) . There as well, the system is optimized to provide a force factor which is linear and symmetrical on the broadest range possible of power and excursion. In order to reduce drastically functioning noises, under high amplitudes and to improve cooling, the frame , made up of injected aluminum, and the cone have  large openings for ventilation.