These nifty little ISO_PUCK mini shock absorbers isolate speaker cabinets from the surface they ... [+] would normally sit on. The result is a more focused soundstage.

I’ve always been a bit of a skeptic when it comes to those “miracle products” that some companies sell along with the solemn promise that they will definitely improve the sound of your hi-fi. You know the sort of thing: expensive speaker cables, costly interconnects, chunky power conditioners, and even record clamps. 

I’ve seen enough of these products over the years, complete with their promises to make your average hi-fi sound like a top-of-the-range McIntosh system costing thousands, to know that few of them deliver huge differences in sound. I distinctly remember when CDs were launched and some companies began selling green felt-tip marker pens that promised improved sound from your CDs if you colored the edge of the disc with said pen. The theory was that the green ink would absorb the laser light from the CD player and make the CD sound better. Utter nonsense, of course, but there were plenty of people willing to give those miracle pens a try.

The ISO-PUCK mini consists of two parts. The top half has a section cup to adhere firmly to the ... [+] speaker case, while the lower half is isolated from the top half and absorbs vibrations from the speaker.

I felt a certain amount of that skepticism recently when I was asked to review a new product from ISOACOUSTICS called ISO-PUCK mini. These small isolator feet are designed to sit underneath a pair of bookshelf speakers and can withstand a weight of up to 2.75 kg per puck. So if four pucks are placed under a speaker, they can withstand a load of up to 11 kg (24 lb). They’re designed to absorb resonances from the speakers and so produce a better, more solid sound. The price for eight mini pucks is $100 and was, to my mind, a bit on the steep side. However, my contact was persuasive and he urged me to try them out for myself.

The top half of the ISO-PUCK minis are made from a resilient synthetic rubber material and each has a dished suction cup on its top which adheres firmly to the base of the speaker without any nasty sticky residue and can be easily removed and repositioned over and over again. The pucks are ideal for speakers with delicate gloss finishes that might otherwise be damaged by a self-adhesive rubber pad. The lower half of the mini pucks are decoupled from the upper half with what feels like a sophisticated sprung-loaded shock absorber system. The lower puck housing is made of plastic and has a black powder coat finish. It can move up and down with pressure and absorbs the vibrations from the speaker, stopping resonances from being transmitted down into the surface the speakers are standing on.

With a ISO-PUCK mini at each corner of the base of a speaker, the cabinet is effectively isolated ... [+] from the surface it is sitting on.

The second advantage of the ISO-PUCK minis is that they are 24 mm tall and so elevate the speakers sufficiently to allow sound to travel under the cabinet as well as around the sides and over the top. My bookshelf speakers are housed in two small rectangular alcoves that are built into my bookshelf unit, and there can be a tendency for the sound to boom a little, especially speakers that have a bass reflex port at the base of their cabinet. The extra space created by the height of the pucks enables bass vibrations to escape more easily and definitely produced a less boomy effect and a more focused sound than I usually get with my speakers placed directly on the wooden shelf. That was something I wasn’t expecting. I suppose I wanted these little devices to be another case of snake oil, but I was pleasantly surprised at how effective they are. 

At $100/£100 for a set of eight, the ISO-PUCK minis are good value once you take a closer look and see how well they are made. The price is certainly less than a good pair of speaker stands, and the resulting improvement in sound is every bit as good. For anyone who doesn’t have the space for speaker stands, or who wants to use bookshelf speakers on an actual bookshelf, the ISO-PUCK minis are an effective solution. I’d be the first person to call out accessories that promise the earth and yet deliver little, but in this case, having listened to the ISO-PUCK minis for a month, and having conducting blind tests with and without the pucks in place, I have to admit to being a convert.

Verdict: The ISO-PUCK mini shock absorbers for placing under speakers are a genuinely worthwhile investment if you want to place your speakers on a surface instead of using speaker stands. The improvement in sound is most definitely audible, producing a cleaner and deeper bass, and a more focused soundstage. Obviously, the amount of effect the pucks have will depend on individual circumstances and speaker placement, but if you own a good pair of bookshelf speakers they deserve to be set up properly with decent speaker cable and something that will effectively isolate and steady them for their best possible performance.

More info: www.isoacoustics.com

The ISO-PUCK minis work especially well if the speakers have a large bass driver likely to set up ... [+] considerable resonances.