rethm philosophy

              Simplicity of design to attain purity of reproduction.

And we go to extreme lengths to make this happen.

We at ReTHM subscribe to the philosophy that all truly great design embodies an “elegance” – conceived of simplicity. A full range driver is 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. We have reinvented this idea - to take it to the next level of its evolution.

The standard list of transgressions that multi-driver speaker systems are guilty of perpetrating:

• Phase shifts introduced by crossovers.

• Colourations, a subtle veiling and power loss that are endemic to crossovers.

• Lobing and other wave interference anomalies produced by multi-driver arrays.

• The difficulties of tonally matching multiple drivers of varying size, materials and design.

or in other words a lack of “coherence”, simply does not exist with a full-range driver system.

We use only very high efficiency paper-cone drivers in our loudspeakers. The high efficiency contributes speed (which translates into detail and transparency) and spectacular dynamics (both macro and micro), while the paper imparts a tonal naturalness unmatched by other materials. And we believe that both these attributes are crucial to the recreation of a believable simulation of “reality”.

The drivers made by Lowther Loudspeakers are truly amazing, and are capable of reproducing music in a manner unmatched by any other driver in production. However, it may be noted that none of the Lowther-based loudspeakers have been able to achieve “mainstream” status, or enjoy continued popularity. We believe that there are two reasons for this unfortunate phenomenon. The first is that nobody has designed an enclosure that, while being relatively compact (as far as horn-loaded loudspeakers go), exploits the bass performance these drivers are capable of. And the second is the fact that the Lowthers have rather prominent “peaks” in their midrange frequency response that most audiophiles react adversely to. Our aim was to solve both these problems and bring into the market a loudspeaker that had all the inarguably phenomenal qualities of a high-efficiency (dynamic) single-driver (coherent) system, while delivering decent bass (admittedly not in the sub-woofer class) and an absolutely smooth midrange and treble performance.

The bass performance has to do purely with enclosure and compression chamber design – and our enclosures and compression chamber designs are consequently unique.

But the mid-upper frequency anomalies have to do with the drivers themselves – and we had to look at ways of modifying them. Our first modification to the DX 4, with which the loudspeaker was launched, went a long way towards solving the problem. But it was not perfect. In may 2002, we have gone into production with a completely different modification to the Lowther DX 4 driver, which has smoothened the frequency response out completely, increased the perceived bass response and therefore given the loudspeaker a fuller, warmer balance than its predecessor, while retaining all the incredible speed, detail and dynamics that the Lowthers are famous for.

 

 

 

 

We believe that the reproduction that we get from our Lowther DX 4’s is unique among Lowther-based loudspeakers. The DX 55 driver, a smaller Lowther driver that we use on the 3rd Rethms, had similar problems (through with the peak at a different point in the frequency spectrum), and had to be modified accordingly too.

 

 

 

 

The new modifications comprise of a new phase plug of our own design, made in wood, and additional (perforated) paper cones which are attached to the driver and/or the phase plug. Extensive empirical work was done to determine the size of these add-on cones, its geometry, and the pattern of perforations on them. With the DX 4 drivers, as two new cones are involved, there was the additional complication of working out the best combination of these.

However, any driver is only as good as the enclosure it inhabits:

Sealed or vented boxes, naturally, impart a “boxed-in” quality 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 compression chamber has been designed to eliminate, completely, any back-wave reflections re-impacting the driver. Driver colouration therefore does not exist.

• 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 secondary cabinet vibrations as a result of the inherent rigidity of this geometry, 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.

As you can see, 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”.

We are constantly improving on our details

 

 

 

..... like the new radiused driver surround trim ring. By having a semi-circular cross section, we ensure that no unwanted upper frequency reflected waves beam at the listener from the rim around the driver.

 

 

 

 

..... or the new internal wiring of our loudspeakers. After having tried several wires from reputed manufactures, our first production run used Goertz wire. 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 too much. However, with further careful listening, we realized that we could do better than the Goertz by, first, allowing the two conductors to run independent of each other, and second, by not having any insulation over the copper wire. We do not understand the physics of this phenomenon completely, but bare, uninsulated wire tends to sound more open and dynamically unconstrained. We therefore use bare solid core copper wires that run through individual loose linen sleeves (for short protection)

 

 

 

...... or our new loudspeaker terminals: We started out using WBT terminals. However, as of May 2002, all our loudspeakers use out own proprietary terminals designed and manufactured in house. Our terminals are made entirely from a Teflon-like material called Derlin, and there is no metal in it whatsoever. The internal wiring of the speaker is not terminated at the terminal through a solder joint, as per usual practice. It instead passes along a groove on one side of the slot that accepts the banana plug from the loudspeaker cable in such a way that the banana plug makes direct contact with the internal wire – thereby eliminating the joint, and eliminating any soldering. We went through this considerable effort because we feel that all that metal, and the joint, and the solder in regular terminals only contribute to a degradatory “smearing” of the signal.