Miscellaneous

Jim Austin reviewed the Isoacoustics isolation feet in October 2020 (Vol.43 No.10):

Loudspeaker cabinets move in response to the motion of their dynamic drivers, especially heavy woofers—that's Newton's third law of motion. In principle at least, that motion can smear a loudspeaker's sound. The usual solution is to use spikes to couple loudspeakers rigidly to the floor—although those spikes must be carefully leveled and tightened to ensure rigidity; spikes that aren't sitting square on the floor are useless. A rigidly grounded cabinet has a large effective mass, so it will move very little, and smearing will be reduced. Sounds good, no? The problem is that when you rigidly couple a loudspeaker to the floor, its energy is shared with the floor, and that has consequences. Those consequences depend on the acoustic/vibrational properties of the floor, and anything it's coupled with. A suspended wooden floor has a different impact on a speaker's vibrations—hence, potentially, its sound—than, say, a concrete slab. As anyone who has ever put their ear to a solid surface can attest, surfaces themselves can radiate sound. They can also store vibrational energy and release it later.

Isolating a loudspeaker from the surface it sits on takes the floor's construction out of the equation. Designers have experimented with this. Magico offers M-Pods, designed for the company's M-series speakers; I've experienced their unambiguous effects when used with the company's M-2 loudspeakers. Q Acoustics uses stands with spring-loaded bases to decouple loudspeaker bodies from the floor. IsoAcoustics makes a wide variety of footers and stands aimed at reducing coupling between loudspeakers (and other components) and the surfaces they sit on, for both professional and domestic applications. Marten, the Swedish loudspeaker company, recently announced that their new Parker series—review forthcoming—will ship with IsoAcoustics "pucks."

These products are not interchangeable. They take distinct approaches and pursue different technical objectives. The Magico footers, for example, act as low-pass filters, coupling bass-range frequencies to the floor while isolating and damping higher-frequency vibrations.

Isolation, too, has downsides, at least potentially. A loudspeaker that's mechanically isolated from its surroundings will move more because there's nowhere else for the energy to go. As stated at the outset, that motion can smear sound. Heavier speakers—those whose cabinets weigh far more than their drivers—are affected less than lighter speakers. That's Newton III in action.

After witnessing an impressive demo at the 2019 High-End Munich show, I asked Dave Morrison, IsoAcoustics's proprietor, to send me some Gaias. He sent the GAIA-Titan Theis, made for loudspeakers weighing up to 320lb (footnote 1). I auditioned them with a pair of Revel Ultima Salon2s (footnote 2).

The Gaias altered the sound of my system unmistakably. The effect was more spatial than tonal. They reshaped my system's sonic space. A previously unnoticed soundstage curvature, wrapping around to the sides of my listening chair, went away or at least was dramatically reduced. What's more, while the soundstage already seemed untethered from the speaker enclosures, it became even less tethered: Center-fill increased, and the soundstage became more rectilinear, extending farther and straighter out to the sides.

I wrote above that moving drivers can smear the sound. Yet, I did not notice a reduction in transient smearing—no change in articulateness. Indeed, I noticed little change in, if you will, the sound of the sound. The changes I heard were spatial and they were not subtle.

It's worth considering that the designer of these speakers—the Revels I used to audition the IsoAcoustics footers—does not recommend isolation. I discussed my observations, by email, with Kevin Voecks, the designer of the Revel Salon2. He told me that in his experience, loudspeakers always benefit from rigid coupling to the floor. "Ideally, they would be glued to a concrete slab. ... All the evidence I have points to isolation as a negative, so I do not recommend it." In any case, the "Salon2s were voiced placed directly on wood floors, or on industrial carpeting glued to the floor."

But how would they sound on other surfaces? Would other surfaces alter the sound and possibly degrade it?

Voecks's view is certainly food for thought; many people would hesitate to modify a component in ways the designer disapproves of (although "modification" with the IsoAcoustics footers is, of course, completely reversible). Clearly though, Voecks's opinion is not shared by all loudspeaker designers: As previously stated, the designers at Magico, Marten, and Q Acoustics—and probably others I'm not thinking of right now—have embraced isolation in various forms.

I've been referring to the sonic effects of the IsoAcoustics footers with neutral language: "Altered" was the word I chose. So, was it an improvement? I thought it was an improvement overall, but both presentations—with and without—were valid.

I don't discount the opinions of skilled speaker designers, and I deeply admire Voecks's no-BS technical approach. Still, I liked what I heard.

Earlier, I mentioned the Magico M-Pods: Those Revels were replaced in my listening room by the Magico M2s, including the 'Pods. When he visited to help with their installation, Magico's Peter Mackay demonstrated the efficacy—Magic—of the M-Pods with a before-and-after demo, playing a high-quality bass-heavy passage of my choosing before and after the pins were pulled to engage the M-Pods' isolating and dampening materials. So, what did I hear? I'll tell you when I write my Follow-Up review on the M2.—Jim Austin

---

Footnote 1: $899 for a set of four. Robert Deutsch wrote about the IsoAcoustics Gaia-Titan Theis in the October 2017 issue of Stereophile. IsoAcoustics Inc., 39 Main St. North, Unit 5, Markham, ON, Canada L3P 1X3. Tel: (905)294-4672. Web: isoacoustics.com.

Footnote 2: See Larry Greenhill's review here and also my follow-up review here.