spikes under a subwoofer ?

I think that you're going to get BIG differences if the floor is suspended or not when using spikes. Directly coupling it to a suspended floor with spikes can REALLY excite the floor, especially when we are talking about a downloaded subwoofer. As mentioned, driver to floor distance can also affect the loading characteristics of said speaker too.

One trick that you can use is to spike the speaker cabinet and then place that on top of a board or large flat surface. The surface should be slightly larger than the cabinet. The panel lies directly on top of the carpet, which spreads the load out on the floor somewhat. This rigidly couples the cabinet to the board while the board is somewhat isolated from the floor by the carpet and padding. You still get the correct loading for proper driver output due to the panels' flat and smooth surface AND minimize floor excitation due to the slight carpet / pad insulating effect. Playing with the type of and mass of the panel and adding weight via mass loading can be used to "fine tune" the results somewhat. I've found that adding too much weight to the cabinet will tend to deaden the bass and make it slower though, so be careful. Just a thought... Sean
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Good point : )

The effects mentioned above should still be similar but possibly not quite as drastic. Sean
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