spikes under a subwoofer ?

nine inch nails. -cfb

2001impala, I also use a Velodyne sub. I installed four PolyCrystal speaker spikes in place of the rubber feet. WOW what an improvement! I think any brand of good quality spike would work well. (If anyones interested I have 6 used PolyCrystal speaker spikes left that I would let go very inexpensively. Email me if your interested). There are also other posts on file regarding the same question. Good luck.

I use the spikes on my REL Storm III

CFB, I have to say you've been in rare form this week:~)

And now back to the subject matter at hand. I own the Velodyne HGS 15 and use to have it sitting on my carpet. I know what your thinking. Energy is escaping through the bottom of your speaker. It was recommended to me to use spikes and load some weight atop the speaker. About the time I was shopping for spikes I remembered having an amp stand in the closet. That's when the light came on! (The closet light). I set the sub on top of the amp stand raising it off the carpet. IT WORKED! I have not loaded any weight yet but will experiment with that this year.

You may want to decouple the sub from the floor,and get
an even better result! Most people believe in old truth,
without understanding too much about this complex matters.
Vibration control is indeed a complex subject, but according to an inverstigation made here in Sweden, spikes often endsup with an inferior result, because when you couple the sub to the floor,AND the floor is prone to resonate!These are unwanted contributions to the sound that you want! There are decoupling devices that prevent this from happening(altough having a soft carpet to place the sub on makes the whole thing more complicated).

For my part, using soft non-elastic feets called the"SD-fot"
that are made in different"densities", for loudspeakers or subs with a specific weight, and which makes it almost impossible for the transducer, to feed the vibrations to the floor,has in my opinion cleared up the bass as well as the the other registers.
This metod has been accepted here in Sweden, even among the
rather conservative magazines. One test one of them made,
was simply to place a coin on end at the top of the loudspeaker, while playing some bass-notes;without the SD-feet, the coin fell, with the SD-feet it stood up.
This decoupling tecnique was accepted several years ago,
when it came to tone-arms an pick-ups(warped records).
Time to rethink some loudspeaker-truths maybe?One italian reviewer of these devices, clearly misunderstood the fact that with the damping feet under a loudspeakers, you can swing them a bit
back and forth, by hand;it might feel as it they are a bit unstable,BUT that is intentional! That resonance is to low in frequency(say 8Hz) to be engaged by the woofer.The loudspeakers enclosures will stand more still with the soft feet Not too uncommon with less educated reviewers
and conclusions that are wrong,eh?

I feel that I may get a lot of opposition, for writing negatively about the "holy" spikes.But please try to be open-minded, there may be another truth!
Regards
Håkan