The IRS2092S audio amplifier IC is an integrated building block for class D amplifiers, and when configured correctly can support up to 500W output powers.
The audio jacks was invented in the 19th century for the purpose of use in telephone switchboards and still used widely to transfer analog audio signals.
The TDA2030 IC is a powerful audio amplifier IC able to deliver up to 20W of output power, so you can use it to run a 4Ω speaker at 12W or a 8Ω speaker at 8W.