Does a Subwoofer Make Spiking Redundant?

Hello Miller, boing boing, you are still wrong.

Heretobuy.  Your are saved from suffering bad SQ from Miller's heresy not by your own wisdom but by shortage of funds.  Whatever!  More than one way to save yourself!

Most of you have misunderstood OP's question.  He asks: if you have subwoofer(s) does this mean you don't have to spike your main speakers because you don't need them to produce articulate low bass.

OP misunderstands the reason for spiking.  It is to prevent the whole speaker moving around and adding that movement to the signal driven movement of the cones etc.  We need to listen to the signal and not the extraneous movement that smears the sound and the soundstage, across the whole frequency range, not just the bass.  Remember, even if you add subwoofer(s) your main speakers are still reproducing low frequencies as before, unless you mess with their electronics.

PMM.  If you bolt (or spike) your speakers to a concrete floor laid on the ground with a good rigid foundation, the vibration passed into the speakers is the vibration of the mass of planet Earth.  That's quite a lot of mass to move around!  There again, Red Indians used to put their ear to the ground and heard riders and horses miles away.  At least they did in movies.

lt would be fun to do a blind test with and without spikes.  Then demo the subwoofers without spikes and tell the listener they are listening to subwoofers with spikes how many would either hear the difference or because they were told they were listening to a subwoofer with spikes automatically convince themselves because they were told they were listening to subs with spikes they sounded better.  I call this the EMERORS NEW CLOTHS SYNDROME.

My speakers are spiked, heavy carpet, pad and plywood underneath.
   If I place on rug, they are tipsy.

The job of the spikes is to pierce the carpet. Lose the plywood and pad.  But you may leave a mark on the underlay if it is hardwood.

OP misunderstands the reason for spiking. It is to prevent the whole speaker moving around and adding that movement to the signal driven movement of the cones etc.

right. A different way of phrasing what i wrote above.  It is modulation.

When I put spikes under my speakers I could definitely hear a marked difference. If a blindfolded person could not hear the difference then I think it would be more a matter of The Emperor's Cloth Ears. The thing was, I wasn't really sure at the time that the difference was an improvement. Getting the spikes in the puckies I was putting the tips of the spikes into was such a nuisance, me working alone and all, I didn't want to go through the trouble of removing the spikes only to find I liked it better spiked and have to do it again. I might give it a try, but I wouldn't want to do it before the subwoofer burned in. I'm not the sort of person who runs his gear hour after hour to get it burned in - I live in an apartment. (In fact, when I watched a move - Many Saints of Newark, as it happened - the movie soundtrack bass was so thumpy that I might have to turn the subwoofer off when watching moves.) So I will let the subwoofer to burn in the course of nature. I did the same thing with my front speakers - at first I was a bit underwhelmed, but a month or so afterward I started to become aware of how much better they sounded.