sound proof floor - practical examples?

hello. i am in a condo on the top floor, it has decent sound proofing but was built in 2000 or 2001. i've read up on sound proofing, preventing my stereo sound from being too loud downstairs, but i'm wondering if anyone has an practical examples where it helped or didn't help.

for example i was thinking of 2.0lb/ft MLV and closed cell foam under carpet pad and carpet to help me turn up my volume a little. right now i'll pop in jazz or vocal, classical and get anywhere from 40db (which is pretty much silence in my space) to 77db peaks. i'd like to go a little more than that, 88db peaks maybe?

You want a lot of mass under the speaker.
I used a concret patio slab, 2" thick and 24" around. about 90 pounds each up on tiptoes over the carpet. then the speaker base stuck on that when I had Infinity RSIIA speakers.
The extra mass of the concrete really keeps any cabinet vibrations out of the floor. and helps dampen the floor in front of the speakers too. so the woofer first reflection makes less of a problem into the floor too.
I painted my slabs black.

Another means is use Magnepans. they have good sound but tend to not shove bass into the walls or through the floor.
Yep. Same here. I have my stands on spikes and on painted black concrete slabs (14X14). Works very well.
Lead is the answer, but it could be hazardous to your health.
I've found that not everything drains vibrations the same so there's going to be some feedback into the speaker. Different surfaces will or can make a speaker sound brighter or duller than what you'd like.

Don't be afraid to experiment with footers, spikes, discs for the spikes, wood, granite, concrete, etc. Eventually, some combinatin will work best for you.

I've read somewhere about some type of rubber layer (not that thick) that lies under the padding that works wonders to quell sound. Good luck.

All the best,
I would go with monitor speakers and a sub woofer. At night you can lower the output of the sub.

Keep it simple.

Or you can pour 3" of light weight concrete over your existing flooring. Then you can go with monitor speakers and a sub woofer.

Speaking from experience.

Good luck.
Anything you put under the speakers will change the sound. You may be able to increase volume, but not like the results.
Your problem is not unique. There is an entire industry of using engineered elements to sound proof rooms. If you do an internet search you can find a number of solutions. Granted these are on a different scale but should give you a few ideas to help soundproof your floor. I found these web sites looking damping materials myself.
Sounds_Real - so you've poured the lightweight concrete and had a good result?

the more i read, the more i think about it, it sounds like MLV which i think is like dynamat for car audio, which is layered/glued onto a 1/4" to 3/4" thick closed cell foam is likely to reduce both impact noise and airborne noise. the mass loaded vinyl (MLV) should be lifted off the floor, thus the closed cell foam attached to it.

i've even wondered about 2 layers of the foam/MLV, then carpet pad and carpet.

but like i said, there doesn't seem to be any actual experience.

i think i realize that lower frequencies, say 400 and below are going to continue to be a problem. i wish i could find someone who actually did some type of floor treatment and then was able to measure at the apartment/condo below to see what results were had.
It would be nice if soundproofing was one of the prime considerations in apartment and condo construction. I remeber way back in the day when friends would brag about how their apartment was soundproof. They just don't build them like they used to.

All the best,