Too Much A Novice To Ask This On Electronics forum

To have any hope of good sound sync, you need BT transmitters and receivers that support APTX-LL (Low Latency). A couple of these could do it (I bought one and it works):
Amazon low latency unit

Looking for something like this
Bluetooth TX/RX pair
to put between your laptop and speakers? Or just a receiver to hook the speakers to?

Do be aware that bluetooth adds some noticeable latency to the audio, so mixing a bluetooth subwoofer with non-bluetooth speakers is almost certainly not going to work out very well (and might not be very readily done with many computer operating systems), and similarly separate bluetooth connections to various different speaker systems might be problematic.

MEXICOWANDERER wrote:
Conversion to wireless sound?

BLUETOOTH

I realize a little chip can allow a PC or laptop to broadcast a bluetooth signal.

Does another gizmo exist that will turn an amplified speaker into a wireless speaker? Like a Polk 10" subwoofer?

A whole bunch of them.. You can buy "Blue Tooth Receivers" starting at around 15 bucks some do not even require the speakers be amplified.

A common Raspberry Pi. Any model with BT or a BT adapter can also be used (Belana Etcher is the program I use to burn Raspberen (the Linux Operating system for the pi's) to the memory card. They advertise a downloadable set of instructions for doing the job, I've not done it because I've no need to do it).

A Pi-Zero-W is 10 bucks at Micro Center .plus 10 bucks for the memory plus the BT adapter So the ones I found with a quick search are possily less expensive (The Belana option allows multiple pi's to receive the same signal but Well. I'm still learning Linux for other reasons and if you don't know it... )

I searched on blue tooth receiver to find the 15 dollar and up units.
I have one. Don't use it but I have one

Don't feel bad. I was and am still a blue tooth novice. I have one on a bedroom tv for night time. I use blue tooth from my phone to my trucks radio or my RV's radio. With the blue tooth "pairing" of the devices I can listen to talk radio and have my Waze App going at the same time. The two audios pass wirelessly to the radio and are both coming out of my radio speakers.

As for wireless speakers. My grandson has a set and they work quite well. As suggested, wires are always better and easier to deal with for reliability.

The more I play with blue tooth the better I like it. If you are some place and expecting a call you can have a blue tooth ear piece and the phone in your holder or pocket. Often there is a button right on the earpiece to answer the call.

As the owner of three cell phone stores at one time it took me a long time to become acquainted with blue tooth. The name just belies what it does.

Blue tooth headphones can be had for less than $20.

MEXICOWANDERER wrote:
Conversion to wireless sound?

BLUETOOTH

I realize a little chip can allow a PC or laptop to broadcast a bluetooth signal.

Does another gizmo exist that will turn an amplified speaker into a wireless speaker? Like a Polk 10" subwoofer?

Yes.

What you need is a BT TRANSMITTER for your audio source (phone, tablet, laptop stereo, ect).

Then you need a BT RECEIVER for the device you are sending the audio to like a speaker.

Amazon search for BT transmitter

Note, some of these may transmit only and some transmit/receive, you will need to read the descriptions closely before buying.

Personally, for the hassle and the poor quality of BT I would just find a way to run some speaker wire to your subwoofer. BT was never intended for "High Fidelity" nor is it "robust" from interference and can have "pairing issues".

I can always tell when someone is using a BT handsfree headset on their phone..

A simple wire works 100% of the time with no loss in fidelity or interference.