Speaker Isolation, The Tweak That Actually Works (2024)

I bolted them to a pair of Axiom LFR1100s and a pair of Axiom M80s along with my EP800 and EP350 subwoofers. I also found silicon half-spheres in different sizes on Amazon and stuck them under my center channel speakers, an Axiom VP180 and a VP150. I was immediately struck by what I didn’t hear, namely, the room modes. I have found that I prefer to avoid room correction, no matter how good the technology because it takes away some of the liveliness from the sound I experience in my room. Even though I experienced some bass bloat, I enjoyed the midrange more and was willing to live with the occasional boominess.

Adding the feet was almost like dialing in a response filter. The bass modes weren’t completely erased but they were so much quieter that I quickly stopped noticing them. If you want to try this for yourself, cue up the nightclub scene in the first Matrix film. It has a pounding bass and drum track that will expose poorly controlled bass no matter what your room or system is. Bolting on the feet made this scene far more watchable and I could now hear Neo and Trinity’s conversation without straining.

I’m always partial to logic and science in everything I do with audio and home theater. If something sounds better to me, I want to know why. My research and experience with speaker isolation was no different. To find an analogy, I turned to my past automotive endeavors. About 20 years ago, I had a Mazda Miata that I took to track day events around the Northeast. I made many modifications to this car but the one that applies to this editorial is the decision I made regarding engine mounts. A full-on race car has almost no rubber bushings in its chassis and the engine is bolted directly to the frame. By contrast, a street-going vehicle has soft material between the engine and frame to prevent vibration from reaching the cabin. Trust me, if your car had solid engine mounts, it would literally vibrate itself to bits in short order. But there is a performance advantage there. When you rev an engine up and down, it shifts from side to side. This movement affects balance and handling, especially during cornering. It’s simple logic – the engine weighs a lot, and a lump of cast iron or aluminum will shift the entire car as it moves, regardless of the driver’s inputs. This is a bad thing.

To affect compromise, I installed aftermarket engine mounts. They are stiffer than the stock rubber pieces but still soft enough to keep vibration at a reasonable level. Yes, I felt some buzzing in the cabin. But the car was much better behaved in corners where I had to get on or off the throttle.

How does this translate? It’s simple. When a driver cone moves air, it produces sound. It’s precisely controlled by its motor and magnet. If that driver also vibrates the cabinet, it dissipates some energy that could be used to, you guessed it, produce sound. If less energy is wasted on extraneous vibration, the sound is better controlled and balanced.

One of my pairs of speakers, the Axiom M80s, is up on a wooden bench rather than on the floor. This piece of furniture will vibrate. Clearly, that removes some energy from the speaker’s ability to produce sound. By isolating the M80s from the bench, I was able to turn the volume down by 2dB to achieve the same perceived loudness. My other speakers and subs? They are on the floor, carpet over concrete. While concrete might seem to be an inert material, it is not. It will vibrate at high volumes enough that you can feel it through your bare feet. Adding the SVS SoundPath isolators allowed me to stand right next to my EP800 sub as it thumped away while I felt nothing from the floor. Again, I had to adjust the speaker and subwoofer levels to maintain the correct balance.