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Today we’re going to talk about how not to put your subwoofer on the floor. See it all the time, I see it in corners. Be careful here, this is a huge energy producing source. Not only it produces energy but it produces low frequency energy which is very difficult to deal with in today’s small rooms and volumes.

So what kind of energy does it produce? Well, it’s got a huge driver in it that’s moving back and forth, right? So this pristine-like quality of the diaphragm moving creates all kinds of vibrations, creates all kinds of energy through the cabinet in all direction. So we have this vibration which couples directly with the floor if you set it on the floor then obviously we have the pressure generated from the subwoofer itself.

So we need to address the vibrations to the floor first. So we decouple the subwoofer. Now there are spikes and all kinds of other things but I’m going to propose something else. Excuse me, that works a little bit better. We have to isolate from the floor with our speaker cabinet, correct? Okay. Because we want to minimize the transmission of noise or vibration if you will to the floor itself.

So we put a structure underneath it. This elevates it, let’s say 12 inches off the floor. And if we make this a diaphragmatic absorber we also can locate pressure-activated absorption closest to the source. I mean the subwoofer sitting on it. We have platforms on our site where you can look into do that.

So we use diaphragmatic absorption as the platform itself which minimizes the transmission of noise, decouples the subwoofer from the floor but more importantly, adds a huge amount of absorption right at the source. So that’s critical when you’re dealing with subwoofer energy which is radiated from all sides of a subwoofer not just out at the front.

Another thing we have to realize, it is a huge pressure device. Okay? So we put everything on the floor of our room. We have a home theater situation, we have all our subwoofers on the floor of the room. We’re pressurizing a big part of the room, coupled to these actual structure itself. But in order to get a smoother frequency response we need to raise the height of these subwoofers within our room. So that they’re not all the same. This is what we found. In our studio we have them at 12 inches off the floor. We have some that are 18 and we have some that are even 24.

And what this uneven distance does is it balances out the pressure fields within the room better. We have it all on one plane down here. The pressure and the floor combination could give you more room sound so if you elevate them put them on equal distances and then obviously you have to locate where they are, where they’re going to be within the room itself and that’s depending on size and total volume. So you have to look at all those variables.

But the nice thing about decoupling the subwoofer from the floors that you can use diaphragmatic absorption and absorb energy right at the source and decouple it also, so you minimize noise transmission also. And then if you raise the platforms at different heights, you balance out the pressure distribution within the sound fields in the room.

This is an unedited transcript from our video series from Acoustic Fields. There will be some errors in grammar and sentence structure that occur during this translation process.

For complete understanding and comprehension, please view the video which is included in this text. For any additional information regarding this topic or others relating to room acoustics, please contact us directly at:

P: 520 – 392 – 9486

Dennis Foley

I am an acoustic engineer with over 30 years’ experience in the business. My technology has been used in Electric Lady Land Studios, Sony Music of New York, Cello Music and Films founded by Mark Levinson, and Saltmines Studios in Mesa, Arizona, along with hundreds of others.


  • I am a self-titled audiophile for 35 plus years. Reading Denis Foley’s ideas is akin to expanding one’s mind in all directions. The music when played and treated( e.g., the room, etc.) properly makes a highly significant difference, more than simply buying more expensive speakers, amps, etc.. Denis, a real person and yet genius who shares.

  • Issam says:

    Dear Denis,
    I wonder if setting a Subwoofer under our viewing/ listening Sofa will do better! Afterall, the frequencies it is reproducing are usually below 50Hz of wavelengths more than 5 meters which no wood panel or fabric will effect its sounding. One can control the volume of it down enough to feel the vibrations and hence avoiding the risk of exciting the room modes on high FX volumes.

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