should I suspend a floor-standing turntable?

Yes, I owned a house like that in VT .Oil man loved us.
Back in the day you had to have money to plaster, in rural areas at least.

Schubert, yeah, here expensive houses have nine foot ceilings rather than eight foot ceilings, and really expensive houses have eleven or even fifteen foot ceilings. But all are drywalling, usually using eight foot tall pieces. But we had friends with an old house where the wall were just laths with heavy wall paper glued to them. You could see them move when the wind blew. I guess it must have been like heating a tent in the winter.

It varies, in apts electric is usually in half-moon pipe strips running up the wall painted same color as wall, you hardly notice them. Most rewire every 20 years.most sockets look like Hubbel grade .
Average German house has 2-3 foot space between outside and inside walls with cylindical terra-cotta round pipe between them.Walls are plaster over wood.
I live near one of the most up-scale suburbs in the twin cities and it amazes me that houses going for 750K use same
drywall as a 100k condo.

Schubert, I can see where that would make a big difference. Where do they run piping and wiring? Or is it just plastering over the walling?

Thank you all for your responses. I've decided to purchase a 1'' wood block from Timbernation and am currently looking into footers that are good for carpets.

Wall shelf worked great for me in Germany.
Germans don't use drywall .

Stringreen, this certainly has not been my experience and neither is hanging from the ceiling. In one home I had earth below where the turntable was and used a three inch pipe with a screwable plate that really did help and in another house built on a slab putting the turntable on the floor was quite good. Elsewhere sheer mass was the answer. I once heard a system in Chicago where the guy got curbstones under his turntable. Each weighed about three hundred pounds.

..just remembered....another excellent way to support the turntable is to attach the stand to the wall using turnbuckles (at Home Depot). Tighten the rig and you'll be amazed at how much better things sound.

After you select one of the above options, if there is still any uncertainty whether you have overcome all manner of vibrations, there is one more inexpensive step that I have found to complete the job.
Try positioning three or four Cryo'ed hardened steel compression springs named "Cryo Baby Promethean Mini Isolators" (from Machina Dynamica) between the turntable bottom and the support surface of wood or granite. And/or try a set beneath the wood or granite, itself.
You are now better protected, and may proceed to engage in safe sound.
Listening to some favorite recordings will tell you whether each step you take toward better isolation is actually delivering more natural and satisfying audio in your system.

Wood blocks can be found at lumber stores cheap and granite slabs can be found in monument shops -- work out the best price there. You don't need one size of monument for sure :-)

You could hang it from the ceiling with monofilament, etc. I heard one like this and this method is very effective

IMO, if the floors are truly bouncy, putting the TT on an end
table will not help. It must be wall mounted, which is really
no big deal. Try this test - take a half glass of water and put
it on the table where you plan to mount the TT. If the water
wobbles significantly when you walk normally, the table isn't
going to work. If the water stays pretty still, you're OK. IMO,
heavy wood or granite does not stop the vibrations caused by
springy floors - assuming they fail the water test. BTW, I
disagree with TBG about wall mounting not helping. Yes, walls
vibrate too, but not like floors. Good luck.

There is no real solution to your problem. Soft things like wood, rubber, etc. will just rob you of dynamics. About the only thing that is realistic, I think, is a three inch thick piece of granite, not marble which just rings like a bell. Place the granite into a larger wooden box that is partially full of sand. This will dampen the ringing of the granite. My wooden box had a sheet metal bottom and had no projecting screw heads or feet, which would ruin what you were seeking. Mass and the irregularities of sand were where you were placing your bet.

This does nothing for springy floors. Nothing other than an adjustable pole placed under your floor and run up tight against the floor from below. I doubt if you can do this. Wall mounting is no real solution as the walls vibrate also. Perhaps using the rafters above might be useful, but I've never tried that.

The floors of a high-rise building are often worse than the suspended timber floors of a house for Structure-Borne feedback (and that's the only feedback that you need to worry about)...😫
Your safest bet is as close as possible to a structural column or the core containing the fire stairs and lifts if that is possible.
Being in Southern California.....the building will have been designed for earthquake loading with flexible steel columns and beams and probably prestressed concrete floors....😱
Good for staying alive....but the worst recipe for audio happiness unfortunately....😢
Good luck....🏢

Although these are fairly expensive, they illustrate the kind of arrangement I would suggest. A maple block on top of rubber/cork footers. I think you might be able to find similar material for the footers less expensively at Home Depot, or via Amazon.com (search for "vibration damping pads"). Or you can buy the "Isoblock" footers from Mapleshade separately for $24, and obtain the maple block elsewhere.

Regards,
-- Al

Unfortunately I live in Southern California. Thank you for the offer though Dorkwad.

and @Brf I live with my parents (I'm a student) and I don't think they'd let me do the mounting, hah.

At this point, I'm considering just buying a block of maplewood or granite and somehow affixing it the floor. My desk is quite wobby as well, and there's not really a place to put a turntable. Does anyone have suggestions for places to acquire such wood blocks for cheap?

Go ahead and mount it on the wall. Most wall mounts are secured by 4 screws that go into the studs. A little puddy and paint will fix the wall "if" your landlord finds out and insists that you take it down.

Put a few very heavy concrete paving slabs stacked on a sturdy table.
Optionally a slab of maple.

Toxic,
Where are you located? I just happen to have a very good sounding for the money 4 shelf rack that is a definite step up in sound vs. my own super solid built wood rack with spikes on both. It also sounded considerably better than a custom wall mount shelf I had. I was very surprised at this fact. Would sell cheap because I now have a pretty darn expensive and awesome sounding rack which I'm currently having made into 2 shorter ones very soon. I'm in the Chicago area. I don't have the boxes it came in so local would be best. Plus all the rods are already filled.