Interesting discovery when my carpets were cleaned yesterday!

I have some bookshelf speakers that sitting on some Dynaudio Stand 20 speakers stands. They are each filled with 50lbs of lead shot and my speakers are attached using some blue tack stuff (it helps hold them in place kind of like mounting them with screws). 

Anyways, while having the carpets cleaned I removed the Dynaudio spikes that came with the stands so that the speakers would be easier to move around as a whole because they weight 110lbs-ish each. 
When the carpet guy was done we put the speakers stands on some foam blocks to keeps them off the wet carpet until it dried. 
Later that night after getting the speakers dialed back in (I have certain measurements to get them back to where they were), I kept the foam blocks on the stands until I know they were right. 
Well, it actually sounds better with the foam blocks than the spikes. So now I’m on the hunt for something to actually use instead of the spikes. 
My room is carpeted  with carpet padding underneath on a second floor (a wood sub floor). So I need the ability to lock them down so they won’t get knocked over as I have a five year old. 
I’m not sure which type of feet I should use. Should I isolate or what what?
I don’t think I’d spend tons of money on something like this but I want to see what you guys would say. I’ve looked at the Gaia II feet and although they seem to come recommend I would prefer not to see them being silver in color...don’t know. 
My house has wooden floorboards so I prefer to isolate rather than acoustically couple using spikes. It might be worth you looking at Auralex Propads. I've no experience using the Gaia feet but from a theoretical perspective to achieve optimum decoupling you really need to spread the load across a large surface area (the opposite of spikes). 
I need the ability to lock them down so they won’t get knocked over as I have a five year old.
This is probably going to be your main issue because as soon as you do that you'll be directly coupled into the floor again... unless you mean lock them down while you're not using them. Another approach could be to see if the sound is improved by standing the speakers and stands on heavy slabs.
What about some 16”x16” solid granite placed on the carpet and then use something?
If you have plenty of dough, the Townshend Audio Seismic Podiums are worth looking into. Start with the YouTube video in which Max Townshend explains and demonstrates.
The IsoAcoustic Gaia feet under my speakers have the "smoked" chrome finish so they are more subdued in appearance than the plain chrome finish version. They have performed exactly as well as their reviewers stated they would too. Imagine that.

@glupson Phase Technology Speakers PC 3.5 according to Virtual System listing. 38lbs. 4ohms.
I started my decoupling experiment a little over a month ago as documented in this thread:

Currently, I have in my room, Herbie's Giant Fat Gliders under my two large subs (about 150 pounds each), Herbie's Giant Fat Dots under a multi-support system for my monoblocks (about 110 pounds each, and springs under my two large stand-mounted speakers (about 175 pounds each, including the stands).  I am still trying the various options but all of those sound better than my former spiked set-up.

There are many purpose built products at a wide price range and, as you found out, there are also options to accomplish decoupling relatively inexpensively:

Elastomeric materials:
  • Sorbothane (check out IsolateIT!)
  • Silicone (check out Hudson Hi-Fi)
  • Herbie's dBNeutralizer footers (dots and gliders)
Isolation Pads:
  • Closed Cell Foam or Cork Isolation Pads (check out Diversitech)
  • Owens Corning 705 DIY (similar to EVP Isolation Pads)
  • Hockey Pucks 
Air Spring
  • Air Bladder under a platform
Regarding springs, I have found loose springs to work quite well (similar to Townshend products) when they are,
  • properly sized for capacity and stiffness, 
  • properly positioned under the equipment based on the center of mass, 
  • damped - I cover them with heat shrink, which provides damping and a padded top and bottom so equipment and racks are not scratched, and I put a hole in the heat shrink to allow air to release from inside the spring without creating an air lock (do not use adhesive lined heat shrink)
Good luck
Wood floors here too. Herbie's threaded gliders on leather mats. Bit of dispersion with some muffling. Works for me, at least for now.
There is certainly a difference between isolation and coupling! I have a pair of Magico A3 towers in one system. They come with spikes. But I didn’t want to put 100lb speakers on spikes and risk them getting knocked off. So I put them on Isoacoustics Gaia I feet. They are great for that. They add a lot of stability. I have Magnepans on MyeStands which are lighter with a big base and are on spikes on pads. No problem. I thought I was being smart and removed the stock legs off my REL T/9i subwoofers and I put Gaia III feet on them. Mistake! I have hardwood floors and on certain tracks those RELs coupled to the floor shake the house! I will be removing them and will be putting the stock legs back on!
I have the GAIA II feet under my speakers instead of the spikes.  Really opened up the system, well worth the money.
Symposium Svelte Shelf is your solution. Completely decouples speaker from floor resonances
After I heard that Gaia demo at a show and was totally impressed.

I returned home and cut four maple blocks attached to my speakers base with that thick clear rubbery two sided Gorilla tape and that felt like slider stuff cut to fit the bottoms of the blocks to my wood floored Avalon’s.

I slid the now easily moved speaker to the one using three gravity mounted spikes. Playing a mono recording the sonic difference was a noticeable improvement, nothing like the Gaia’s but what the hell. Surly results will vary.

Compounded with the fact that the deadly, you don’t ever want to move to California’s Loma Prieta fault is about three miles away. I could easily be jaded. Regardless, my only worries now are tsunami and vehicles without ashtrays.
I wouldn't jump to the conclusion that decoupling the speakers led to your experience of better sound it might have been the height from being on the foam carpet pads. Maybe they sound better because they are aligned better with your ears at the higher position. Just a thought. 
What no one has asked thus far is in what way do they sound "better" to you? Ppl might have a better clue in their recommendations. 
I have the Gaia II's on my Spatial M'3 Sapphires on a hard wood floor.
They are very open and dynamic sounding especially in the bass and lower midrange. They were a huge improvement to just spikes or the rubber feet. On carpeted floors I would imagine spikes would be the way to go as they connect with the hardwood floor underneath your carpeting. My Vandersteen's were spiked to the carpeting and also were greatly improved in the bass and dynamics as well.
i say olde chaps have you heard of terrestrial coupling - the ultimate sink? what i done is buy a plot over a zone literally dotted with fracking sites. i then put be mighty JB-Ell 305s over meters and meters of cement and tubes (not pipes, there is money to think aboot) and connected my drivers with the very core of our earth. i use methane to run the generators. Motorhead never sounded so good.
Responding to someone that asked why it sounded better...When I say that it had a very distinct center imaging (I checked to see if some how my center channel was wasn’t). Now this could be that the speakers were slightly different than before but I have a laser level that produces lines for me to get my speakers exactly back where they were. I have specific measurements that sound superb to me for my room. 
Mostly the imaging was better and instruments were very defined. 
Lots of users here report good results using the IsoAcoustic Gaia footers under their speakers.  While I am certainly not questioning the sonic effectiveness of the Gaia footers, I am interested in learning more about the technology behind how they work their I did a little searching.  The reviews mostly seem shrouded in mystery with the most revealing I could find stating:
The Gaia ‘pod’ itself comprises a machined and dark-chromed stainless steel top and base section, separated internally by a secret-sauce internal elastomer structure, this prevents any resonance from the ground interacting with the loudspeaker and vice versa. There is decoupling in the vertical and horizontal planes, which is why the positioning of the Gaia logo is important: it aligns the decoupling with the plane of the drive units. Hocus-pocus status: revoked!
I am envisioning an internal structure supported on both the bottom and sides by an elastomer material with the material being stiffer in one direction, which is why they want the Gaia logo oriented to the front or back.  Anyone here able to pull back the curtain and provide more specific information?

The Gaia II’s are a front runner for my choices but I just fell like it’s expansive for what it is. I’m not saying they aren’t worth it I just feel like I may be able to obtain something doing the same sting for a lot less. Trust me, I called my local store about ordering them until I realized all they had in stock was the silver ones and if I were to buy them it would be the black chrome ones. 

I did find these interesting at a fraction of the Gaia II’s but don’t know anything about them.

Why not just stick with the foam pads. The price is right and you hear a  know they are effective!
Regarding safty:
One aspect that are seldom talked about is how manufacturer determine no of degrees when the tipping point occur.
When a stand manufacturer test their stands (with speaker it of course change) they just tip them until they get to the point where they are on the point to tip. They note that angle.

It is all about the stands center of gravity.
How we can change that?
If we fill the stands like in the OP case with lead (sand or whatever) to the top. Then the center of gravity of those stands will be higher up. And give us a stand that tip earlier and in other words will tip easier with less number of degrees before it reached amd passed its tipping point.

What to do to increase the safety?
By fill the stands only up to 2/3 or 3/4. Then we actually lower the center of gravity and also increase the number of degrees that is needed to get it to the tipping point. (It will even be better performing in this regard than if the stands were empty)

In short have in mind the center of gravity. :)
I have tried many devices, but by far the best, IMO, are cheap Harbor Freight Dollys. I had been using them to position speakers, but eventually left them under the speakers
If I could find a way to do so without damaging the speaker cabinet top? Suspending speakers on chains gives the most open sound I ever heard. Putting on spikes is like connecting the cabinet to the floor, and will tend to choke the sound. I experimented with this back in the 80’s and was amazed how much better my Sequerra Met 7’s sounded. I called Dick Sequerra and let him know what I found. To my amazement, he told me he has his speakers suspended as well. His speakers were I believe some sort of panel speaker. Suspending them lets them breath and opens up the sound.    So,  having something flexible underneath may be also a better approach than spiking them.
+1 on the Gaias and similar experience, improved definition, lower noise.  Good job OP on checking speaker position so carefully, I remember when I got a new chair it took me a couple weeks to realize it positioned my ears about 2" higher off the ground.  Luckily some quick math and adjustments to the Gaias got me tuned back up.
Well guys/gals I purchased the Gaia II's along with the carpet spikes and I'm very impressed with the quality of the products and overall the sound in general. 

One thing I noticed is that I have a couple of go to songs that I generally play at (on my system & room at -25db) and noticed immediately that I actually raised the volume higher than I normally do by about 2-4db. 

Although these things are nice...very nice! My big complaint about them is that they make my speakers about 2" higher than before. Its something I could probably get used to but the other thing is that they are very noticeable items and actually bulky for my tastes. I would rather not need to see them at all. 

Given all that, I just don't believe they check all the of the boxes for the price point of these things. I mean if they sounded overwhelming of what I had/have, looked almost invisible, and didn't raise my speakers a couple of inches I'd keep them. 

I actually just put in my order for the Herbie's Spike/Decoupling Sliders. So we'll see how these things go. 
Yes I gather that Stand Mount speakers do not seem to benefit 
from Footers /Isolators/etc. I was told by the Manufacturer of one Hi End brand that his products would not work under speakers on Stands.

Caveat Emptor

Stand Mount speakers do not seem to benefit from Footers /Isolators/etc.
You cannot lump all stand mount speakers together.  Some are small light boxes on lightweight stands, others like Harbeth 40 series speakers are even heavier but have somewhat resonant cabinets, while others like my Aerial LR5s have cabinets as solid a brick and weigh quite a bit - 175 pounds for speakers and stands.  My experience has been either Herbies Giant Fat Dots/Gliders or properly sized individual springs (not so different from what Townshend uses) result in a better sound than when the stands are spiked to the concrete floor.
Harbeths have resonate cabinets, just the way they're designed to contribute to the midrange fullness. Mine sound cleaner and more dynamic with the addition of IsoAcoustic pucks between speaker and stand.
I agree with optimize about filling the stands partially for better stability.
+1 todd1010,
Cork or cork board(if you can find it) - granite tile -1/4" to 1/2" layer closed cell polyethylene foam - granite tile, this makes a excellent layered sandwich base for wood floors.
1+ djones, Just changing the height of the speaker can make a significant change is sonic quality. You can actually measure this. If a floor is really bad decoupling the speaker physically from the floor will not stop it's resonation. Whether or not a move makes a system sound better or worse is a judgement call. You can certainly say it sounds different. This is particularly true in terms of bass. 
Having a calibrated microphone and measurement program is very useful when it comes to setting up speakers. IMHO, thinking your ears are accurate measurement devices is a mistake. 
I used to be a carpet cleaner so this spiked my attention. One thing that came to mind is the blocks changed the height of your speaker which changed the height of your speaker to your ear. Sometimes even a fraction of an inch can make all the difference. It could be the decoupling too and/ or both. Be careful about dropping money on something that might be fixed with a blue foam block which do hold more weight than the traditional white styrofoam blocks. Try putting a coaster under each spike and see if that does the trick. Also put an older copper penny under each spike. What are you out .08 cents? I hope you get it sorted out. Now I am going to try the foam block test. 
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I did order the Herbie titanium spike/decoupling sliders and this way I can use my OEM spikes and still keep them at the current level   
I'm not sure if I’ll like the herbie items better but I’m willing to give them a try. 
I do know relation to the isoacoustic feet and the carpet spikes. I absolutely did not like the way it made my speakers sound. It sounded distorted or messy. I removed the spikes immediately as it was very annoying to listen to. Made my ears hurt.
I’m might try my OEM spikes with some penny’s while I wait on the herbie items to arrive.