We recommend using unattached footers in sets of three to avoid shimming. One exception: long, very narrow may need four footers for stability. Using four may require shimming the height of one footer to compensate for slight unevenness of the surface below. Other than improved stability, there is no sonic advantage to using four.
For a modest increase in cost, the Heavyfoot—2-1/2 times heavier than the Surefoot—will give you significantly better sonic bang for your buck. They yield much deeper bass and warmer midrange. Only for uncarpeted surfaces. For even better sound, see our Micropoint and Triplepoint footers.
If you can't stand leaving dings on your valuable furniture and wood floors, we offer the rounded bottom option for our Radiused Heavyfeet. Though it preserves single point contact, rounding doesn't sound quite as good as sharp points, costing you 5% to 10% of the footers sonic upgrade—but this option sounds way better than the widely used flat brass (or lead) discs that degrade the footers effect by at least 50%. Since nothing sounds good floating on carpet, it is essential for the tip of the footer to contact the solid floor beneath. For high pile carpets with padding (more than 1/2" deep), you need the thick carpet version to penetrate to the floor. For relatively thin commercial wall-to-wall carpet (less than 1/2"), the thin carpet version with its somewhat shorter point will sound slightly better.
If there is any doubt, use the thick carpet version. For the footer to sever its purpose, the point of the brass footer penetrate all the way through the carpet to make firm contact with floor underneath.