Speaker spikes-worse sound-what gives?

Your speaker was probably light in the bass to begin with. You became accustomed to the sound WITHOUT the spikes. Then when you put them in, the sound was different, that is less bass. Oftentimes, the floor acts as a bass addition, especially if the floor joists are running in the direction of the sound (read not perpendicular, which would break up the flow of the sound)allowing for more bass. The first rule of audio is, there are no rules. What works for Billy Bob, may not work for you, your tastes, and more important your environment. Place the speakers where they are acceptable to the wife, and sound the best to you. That will keep the peace and sonically give you the best result.
Spikes are intended to eliminate (ameliorate) the rocking of the speaker, as well as to minimize the amusical sound coming from the bottom of the speaker, when it sits directly on the carpet. I have experienced many occassions in which I liked the sound better, sans spikes. Don't let it worry you. Just do what works best.
Best,
Larry
PS If you want a private consultation you may email me for a more detailed explanation. I traveled the country as Director of Sales for a speaker manufacturer,and have 20 years in the industry, so my input may help. Although the group here seems to be doing a pretty good job already.

Thanks Lrsky.

Wow, I am glad I found this thread today. After moving my Tekton 6.5t monitors from the top of my low and wide wooden stereo cabinet to older sound organisation 25" metal speaker stands (usually sold to pair with Linn Tukans), I was getting a much bigger sound stage and imaging but also a level of harshness and edgyness. The sound organisation stands have some very aggressive floor spikes and after removing them, I am very happy. The edgyness and harshness is gone but the great imaging and soundstage remained. I also think I got a little more bass out of the removal. I have the stand bases weighted down and hope to fill the hollow columns very soon. The Tektons are both on spikes and also screwed into the top platform of the stands since I do not want my cat to tip them off. I was thinking of adding some blue tack / fun tack between the stand platforms and the bottom of the Tektons, but I am very very pleases with the results I have now. Who knew that the floor spikes could have such an impact?

Also, interesting is that the sound is different depending on the spikes you use.

My speakers are on a carpeted concrete basement floor.
The original spikes were replaced with updated ones from the manufacturer, and they did make for an improvement.

But I felt like experimenting some more, so I used some BDR cones in place of the spikes, and things improved again.

Then I tilted the speaker foward slightly by placing some thin ceramic tiles under the rear two cones of each speaker.

Now for the first time in over two years of trial, error and frustration,am I getting the snapped into focus I have read about with my speakers.

It may sound a bit extreme, but if you have the ability to place supports under the floor (like steel jack posts directly under the joists), you may hear significant improvements. I've done this in a couple of installations, and the improvement was substantial... helped with turntable vibration as well. On older houses especially, the floors really tend to bounce!

Cliff