Couplers - what they are and what they do
Large Couplers are polished, 2"x1"x3/4" solid blocks of 7075 aircraft alloy aluminum. 7075 is the premium grade of aircraft alloy aluminum, endowed with extreme hardness and strength, and is chosen for its excellent thermal transmission and self-damping characteristics. Each coupler is cut from a solid bar of 7075 aluminum, and hand finished, preserving flatness on each of its six surfaces. There are two standard varieties: Large Couplers, and the new Supercoupler, which is covered elsewhere.
Most Symposium Platforms (except Point Pods and Svelte Speaker Sets) are supplied with Large Couplers.
Svelte Speaker Sets, which come in pairs, are sold without couplers, because they should be used with the loudspeaker placed directly onto the Svelte's top surface. Large Couplers are standard with all Svelte, Super Plus and Ultra Platforms. Large Couplers are also available separately.
So what IS a "Coupler" - and what do I do with it?
The Coupler is a very simple device - and is supplied because it's important to make good mechanical contact to the chassis of your component. The reason for this is that mechanical energy "conducts" through materials analogously to electrical energy - that is, certain types of materials conduct mechanical energy (or vibration) well, and others don't. Examples of materials that conduct energy well are metals; a material that is a poor mechanical energy conductor is rubber. Usually, the denser the material, the better it can conduct energy. For instance, everyone knows that sounds underwater can be "heard" from great distances - greater distances than through air. This is due to water's superior density over air. Metals, because of their relatively high density, and also because of their atomic structure, are able to transfer energy with less loss than compliant materials. Thus, Symposium Couplers are made of a high grade, "aircraft" aluminum alloy, with good transmission characteristics. In all cases, using three or four couplers under your equipment instead of simply placing your equipment down on its original feet provides significant advantages by mechanically connecting the component's chassis to the top layer or "plate" of the Symposium platform. In this way, the Symposium Platform becomes an extension of the component's metal chassis, providing a mechanical ground for energy to be drained off and dissipated without extraneous resonance or reflections back into the component.
Special notes about coupling the component
In general, we've found that the more contact with the chassis of the component, the better the results. Taken to its logical extreme, this would necessitate removing the original feet of the component - something which we don't advocate unless adequate ventilation can be preserved through the chassis, or in cases where ventilation isn't an issue (specifically, in components where the bottom of the chassis is sealed).
Placement
Where couplers are placed can have a considerable effect upon overall results. This is due to several factors, including the construction of the component's chassis bottom and location of protruding screws and other solid constructs linked to the interior of the component (which can be additional conduits for internal energy drainage). We have found that one should start with placement near the outer corner of the component, where the chassis is most rigid, and move the couplers in toward the center. In general, the best locations, as with Rollerblocks, seem to be approximately 1 to 3 inches in from any outside edges.
What to do if your component's feet are too high
If your component has very large and high feet (more than 1 inch), the Large Couplers will not touch the bottom of the chassis. While we can recommend a metal "shim" in the form of folded aluminum foil, coins, metal plates or other solid metal with relatively smooth, flat surfaces to increase overall height, the best solution in these rare cases is usually a second set of Couplers, stacked upon the first set, for a total height of 1.5 inches. We do NOT recommend that you try to use the Large Couplers with the 2" dimension vertically, because this is unstable and can have disastrous effects if the component topples over!
