From the time Pierre first started using brass footers under his studio recording equipment, he has been using weights on top of the footer-supported components. Adding the weights almost always resulted in a satisfying magnification of the brass footer's good effects. The weights help kill the resonances in equipment enclosures and, by adding downward force, they increase contact pressure between equipment and footers.
In these early listening experiments, it soon became obvious that the choice of material, mass and shape of the weights dominated how much improvement could be gained:
• Material: our first material experiment tested lead weights head-to-head against brass ones of equal mass. Much to our surprise at the time, the brass sounded much, much better than lead. It became clear that the high internal damping of lead (which leads to the dead "thunk" when you tap it) was seriously detrimental, despite the intuitive appeal of the idea of killing vibrations through the heaviest possible damping. This is confirmed by other experiments we have done in applying high damping materials (sorbothane, asphalted felt, composites, lead sheet) to speaker cabinets and component enclosures: extra mass and/or extra stiffening always sounded better than damping. Testing other common weight materials--steel, iron, bricks, granite, marble, wood, ceramics, carbon fiber, etc.—led to the same result: brass sounded better.
• Mass: it became obvious very quickly that, even with the right material, loading on more and more mass didn't keep on improving sound. Instead, on every component tested we reached a point at which adding a small increment of weight suddenly caused a dramatic deadening of the sound. Unfortunately, this optimum weight was quite different for different components. This is why we recommend using mixed sets of small and large Heavyhats to make it easier to build up to the optimum weight for each component you're upgrading. Our testing also revealed that tweaking where you place the weights can further refine sound quality—simply because of the large changes in vibration amplitude from one spot to another on the enclosure, chassis or plinth of any component (see the Owners Manual for tips on how to make finding the sweet spots easier).
• Shape: we found a slight advantage for a well-radiused cylindrical shape over a sharp-edged rectangular shape. On the other hand, changing from a flat bottom contact area to supporting the brass weights on three tiny points resulted in significant gains in sound quality, particularly in treble detail and bass articulation—exactly the same result that we found in developing our brass footers. Unfortunately, machining the bottom of the brass weight to the three point shape adds cost, so we offer both flat-bottomed standard Heavyhats as well as Micropoint Heavyhats.
In testing Heavyhats across the wide range of components that they benefit—including speakers, amps, preamps, phono stages, turntables, home theater receivers, power supplies, power conditioners, CD/BluRay players, DACs, satellite/cable boxes, streamers, servers, routers, modems, computers and hard or solid state drives—we found a number of surprises. For example, Heavyhats placed on top of speakers always improved sound audibly, particularly in the treble—but really surprising was that they helped 150 pound floorstanding speakers as much as they helped 10 pound mini monitors. Less surprising was that there were always several sweet spots on turntable plinths that yielded good sonic gains, one of which was always right next to the arm base. Quite surprising was that digital components almost always showed more improvement than analog components—and that weights on routers, modems, satellite/cable boxes and music-storing drives did just as much good as weights on on CD/BluRay players, streamers and DACs.