Seems like people are a bit all over the place.
There is no reason to solder to make your own cables and compression connectors for coax cables are industry standard. There is no reason not to use cables that don't require soldering.
That said, it is completely unclear how these cables work and what wire they are designed to work with.
For a subwoofer, as previously mentioned, you should be using RG6 cable. This is the same cable that is run to all your cable boxes throughout your home and is the proper wire to use for subwoofers.
If your goal is to go from your receiver, to some remote location, I typically go with F-type connectors to wall plates at both ends, then use a standard RCA cable of the proper length to the walls.
Like these:
https://www.amazon.com/Skywalker-Signature-Keystone-Female-Insert/dp/B00AU3QVKU/ref=sr_1_1_sspa?ie=UTF8&qid=1524840083&sr=8-1-spons&keywords=f+to+rca+keystone&psc=1
But, if you are truly making the cables for a point to point connection of custom length, then you need to find out if what you bought is designed to work with standard coaxial cable, or if it is designed to work with something else. Many are designed to work with coax cable (RG6/59) and that will work out just fine for you.
There is certainly zero need to learn to solder for this. In any world, even with RCAs, there is zero need to ever solder as compression connectors tend to provide a more accurate 75ohm connection through the connection point over soldering.
I wish I could find a good video on YouTube about the connectors you got. I did find a few on MX branded connectors, and they are using coaxial cable.
This takes about ten times as long as just using a compression F connector and a F to RCA adapter like I linked to above.
You do want a decent coaxial cable stripper. They are cheap online.