Yes, so much better to avoid isolation. I mean, those subwoofers just don't seem as cool if they're not making my walls rattle, or vibrating things off shelves, or making the woofers pump on my speakers when I'm spinning vinyl on the turntable.
Subwoofer Footing - Connect or Isolate?
What is considered the best way to "foot" a subwoofer, should one try to connect it with the floor or isolate it? I have a REL 7i that I have firmly coupled to my wood floor with the weight of a 42 lb curling stone, mainly because it looks cool. Would some sort of isolation be better and reduce resonance from the floor, or could the connection with the floor help "drain" resonance from the subwoofer cabinet?
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The last thing you want to do is put a subwoofer on springs. At some low frequency it will start shaking. Vibration/shaking in any speaker equals distortion. Just put your hand on the sub while playing an organ piece or better yet run a sine wave sweep and you can find all the resonance points. Keeping a subwoofer from shaking is not easy. Certainly, mass helps as does containment. In the home environment spiking it to a concrete floor would be best followed by spiking it to a wooden floor. The wooden floor's resonance point will hopefully and usually be above the subwoofer's range. Even so the floor is going to resonate regardless from airborne excitation. New designs Like Magico's big subs are using a method of force cancelation. They put drivers in opposite ends of the enclosure running in phase with each other thus their Newtonian forces cancel. This effectively stops the enclosure from shaking but does not stop cabinet resonances, another issue all together. Magico does it by building a battleship enclosure. |
Somewhere Richard Vandersteen posted an excellent article on speaker isolation and he makes a very good point I've made before: You want to prevent the speaker's ability from moving back and forth. The forces of the drivers push against the cabinet and can cause it to move, which is audible even when there's very little of it. So, I would stick to IsoAcoustic style of pucks for a subwoofer and nothing more springy. |
Wow a lot of bad info here. Isolating things that move is important when you don't want to excite other elements of the listening room that add to and change the total sound you perceive. This is an issue of mass vs frequency. The total sound you perceive is the speaker direct sound + speaker indirect [reflected] sound + room dimensional sound + all vibrating materials in the room [tables, floors, walls etc]. Wooden speaker stands vs heavy Sound Anchor stands is clear evidence of this idea as the wooden stands will vibrate at an audible frequency (knock on them with your knuckles to hear an example) vs hi mass Sound Anchors which vibrate differently due to high mass. For the spring idea to work, it must be tuned for the weight of thing moving. Random springs set for an unknown weight will not solve your problem. Look at a car or truck, springs are set very specifically depending on weight and the many factors of behavior once excited. Decoupling sources of LF is important to not waste unwanted mechanical energy vs the energy you want: acoustic energy. Giant generators are isolated from the concrete pad they sit to control vibration that turns into LF hum that can penetrate an entire building and make it impossible to work. See Noisia Studio Tour | Razer Music - Bing video this shows the springs used under some fairly heavy (150+ lbs) ATC monitors. Very specific spring rates. Brad |
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