Rethm Design

There is one unifying conceptual thread that runs through all our products, and that is: that we will bring a product to the market only if it is something uniquely different from the competition; and only of it can be sold at " real world" prices.

We are not interested in bringing out "more of the same".

Having been in the Audio Industry for 16 years, we know that it is impossible to get a consensus on what exactly is the "right" reproduction. Rightly or wrongly, this has become a matter of personal taste. But that having been said, we at Rethm go to great lengths to convert OUR aural convictions into audio products that can be enjoyed by music-lovers. Apart from all the usual audiophile boxes that need to be ticked, the most important factor for us is whether an audio system has the ablilty to connect emotionally with the listener.

Almost as important as the sonic performance is the aesthetics of each model. As architects, both form and function are given importance when we design anything. Yes, here again, we are dealing with an area of great subjectivity. But the fact remains -- that painstaking care is given to the way the loudspeakers are physically designed. It is often said that most people buy products with their eyes.

Being Architects, we start with a distinct advantage over the competition – as innovation and "looking at things differently" are ingrained in our psyche.


We believe that all truly great design embodies an "elegance" – that comes from simplicity. A full range driver is such an example within the realm of music reproduction. Loudspeakers designed around this concept are capable of an aural magic like no other - IF done right.

“It sounds so real and natural…” …….is a comment we hear time and again from non-audiophile music lovers.

“it has everything -- tonal accuracy. detail, dynamics, transparency, imaging, -- and yet is totally relaxed and relaxing to listen to. … what we often hear from the more experienced listeners.

Fundamental and critical to getting closest to a live reproduction, we believe, is the use of wideband drivers….which reproduce the frequencies from 60 hz to 20khz.

Multiple drivers create multiple problems.

Wave interaction anomalies between the drivers, like the comb effect.

Tonal anomalies as a result of different drivers of different sizes and different construction and materials trying to reproduce the same sounds

Disturbances resulting from the the same music coming from more than one source.

And the cross-over -- which creates its own set of problems, including phase shifts, a subtle veiling of the signal, and the robbing of drivers of some of its dynamic potential.

And these effects -- combined -- also create inaccuracies in imaging. We are great believers in the importance of imaging. This is because, in the absence of a "visual" ( a live concert, or a video ), it is accurate imaging that creates very important spacial cues that allow us to "see" the performance -- in our minds eye.

In a word, the crucial phenomenon wide-band driver based loudspeakers present the listener with, is "cohesion".

While some of these effects are audible, others are not. But -- they can be “felt”. Critical to good audio is the absence of these aberrations that the mind picks up subconsciously. This is part of “psychoacoustics”. The brain is an amazing thing -- highly flexible and adaptable. It can work around these anomalies and present the listener with a “listenable whole”. However, there is a price one pays. Just as a CPU gets hot when it is “processing”, the brain gets tired when it is asked to do this subconscious work of smoothing over the problems created by a loudspeaker. And this is the “fatigue” that is talked about in Audio circles.

Which ceases to exist when a good single source produces all the music.

But -- not all wide-banders are made equal.

We design and manufacture our own custom drivers which underwent several years of development. And this is at the heart of the “Rethm advantage”. We have a different custom driver for each model. We use only paper for our cones as we think it sounds best. We use Neodymium magnets as all our drivers are high-efficiency drivers because we believe that the subtleties and nuances of the music is best revealed and communicated through high-efficiency loudspeakers. Even at low volumes. There is also the added advantage of being able to use even the least powerful valve amplification. High efficiency loudspeakers are extremely dynamic and transparent as a result of its ultra-fast reaction to the inputted signal.


Any driver is only as good as the enclosure it inhabits:

Sealed or vented boxes, naturally, impart a "boxed-in" quality to the sound. It is also well known that because of the pressures these boxes are subjected to, it does add its own signature to the sound. The horn-loaded enclosure (one of the earliest enclosure designs) if designed well, can eliminate this problem as it provides the driver with an unrestricted free-breathing environment which, while extending bass response, also allows it to retain immediacy and naturality. Although we have chosen to adopt the horn-loaded enclosure as the basis for our loudspeaker, we have broken with traditional horn-load design principles and geometries, and invented our own.

At ReTHM we believe that the flat-sided box favoured by most manufacturers (horn-loaded or otherwise) is anathema to good loudspeaker design because of the various "colourations" it induces. The use of bracing, damping/absorbing materials and massively heavy enclosures can only mollify these colourations, never eliminate them. We have chosen to take a fresh approach that enables us to circumvent these problems entirely:

The geometry of the enclosure eliminates standing waves, thereby removing the spectre of box colouration.

The curved surfaces of the enclosure eliminate performance – degrading baffle reflections and edge diffraction, thereby enabling the loudspeakers to image and reproduce soundstage depth and width with astounding clarity, scale and realism.

The curved sections minimize both standing waves and cabinet vibrations while simultaneously nullifying the detrimental effects of the propagation of any residual vibrations as these do not beam at the listener from a large flat surface congruent with the driver. We believe that attention to the smallest details do make a difference to the ultimate quality of our loudspeakers performance. We therefore do things "our way" which is often a departure from what many would consider "the norm".

The compression chamber has been designed to eliminate, completely, any back-wave reflections re-impacting the driver. Driver colouration therefore does not exist.

The perforated driver surround rings: The diagonal patterned perforations break up upper-frequency reflections that typically come off the area surrounding the driver.

The phase plugs. With its unique shape ( a result of weeks of testing various geometries….) these were designed to smoothen out the frequency response. Each model has a different phase plug.

The internal wiring of our loudspeakers. We believe in single-core wire. Splitting a signal at one end, allowing it to pass through multiple conductors and bringing it all together at the other end with absolute concurrence and coherence, we feel, is asking for a miracle. We therefore use a single flat copper tape; cryogenically treated (we could hear the difference the treatment made) .


The big question that is almost always asked about single-driver horn loaded loudspeakers: what about some REAL bass? This is because virtually ALL pure single driver loudspeakers do not have serious bass energy below 60 Hz. We know – from the first hand experience of struggling to do this for 7 years.

We finally decided that the only way to achieve good bass – was to add a bass module to each speaker Getting bass was not the problem. Any sub-woofer can do that. However, getting great bass that was capable of keeping up with the incredible speed and dynamics of the our wide band driver,s blending in perfectly, seamlessly – was a BIG problem – and took several months of experimenting to solve.

The first decision was that each channel would have its own bass module – as we believe that even bass frequencies have to be reproduced in "stereo" to enable realistic reproduction of depth and texture.

The second was that it had to be powered – as there were NO bass drivers available that was 98 db efficient. We therefore have individual amplifier modules within each enclosure, driving a pair of bass drivers ( except for the Saadhana which has 3 drivers per enclosure ) in isobaric configuration, in sealed chambers. This we felt would produce the most accurate bass. It was decided that the drivers had to be small (similar in size to the wide-banders) so they could be light and quick. We also decided it had to be paper, to match the tonal characteristics of the wide-banders.

The greatest challenge? Getting the bass to integrate seamlessly with the high efficiency wide-band drivers. This is where most systems with “bass augmentation” tend to fall apart. And to help with this task, the bass modules are widely adjustable both in level and in its cross-over setting. We believe this is critical to getting the bass to suit the room acoustics, the front end equipment, or -- just personal taste.Each model also has different driver types, amplifier powers, and filter typologies and settings.

And this is where the story trifurcates into the 3 different models…z