Cabinet grounding for speakers?
By Roy Gregory
Applying parallel grounding to the signal path and chassis of electrical components has become commonplace in recent years. As the wider benefits of reducing system noise-floor have become more widely appreciated, a number of companies have started to offer passive, parallel grounding solutions and products from CAD, Telos and The Chord Co. have become an essential part of my set-up and review process, ranging from Chord’s neat, petite GroundARAY plug-ins, all the way up to the massive and massively heavy, CAD GroundControl GC-R and Telos Earth Grounding unit. But by far the most frequently used and versatile options are Nordost’s various QKORE units. Compact and available with a range of capacities/connections, the QKORE3 and QKORE6 are pretty much ever-present in my ever-changing systems.
None of this is exactly news. As noted above, some form of parallel grounding, whether it involves standalone units placed next to the system, or a separate clean ground that runs parallel to your AC supply/ground, has become an essential part of maximising system performance, while at the other end of the spectrum, ever more complex and convoluted grounding topologies are emerging or developing. Not only are the various products complementary, their impact is cumulative. It’s not quite a case of the more parallel grounds the better – but sometimes it seems like it’s getting close. As always, the key is in listening to the various combinations, adding them by stages and assessing the benefits as you go. It’s not as simple as plug-and-play: different devices will suit different situations and systems, so experimentation is the order of the day. Which brings me to the subject of this review…
For some time now, listeners (myself included) have been using parallel grounding units to drain the induced eddy currents from metal loudspeaker cabinets. Now, before going any further I should point out that this practice isn’t actively recommended by the manufacturers listed above – partly because, if you get it wrong you can damage your amplifier and/or speakers. In this case, getting it wrong means attaching the parallel ground unit to one of the speaker’s signal binding posts: you know, the ones you attach the speaker cables to. Just to further complicate matters, some speaker manufacturers are starting to fit a grounding point – normally an additional binding post – to their loudspeaker cabinets.
So, just to be clear: DO NOT attach a parallel ground to the binding posts provided for (single or bi-wired) speaker cables. Any parallel ground should be connected directly to the cabinet itself, normally using a fixing bolt or specifically provided grounding point. If in doubt, ask the speaker manufacturer.
Because it is possible to get it wrong, I’d always been reluctant to write about grounding speaker cabinets, despite it being standard practice, both in my own listening room and on show systems. But recent experience with the Diptyque Reference loudspeakers produced such a profound improvement that it’s too important an option to ignore.
