This article is for this kit: https://www.diyretroarcade.com/collections/2021-a1u-3-4-scale-kits/products/horizontal-arcade1up-fully-assembled-drop-in-legacy-pandora-kit-select-your-machine
When attaching the speakers to the easy pandora board you have two options:
Option #1
You can use the factory speakers. To do this cut the 3.5mm male off the end of the cable that is hooked to the speakers. Then use the included 48" red/black wires to splice into these cable. Each speakers will have 2 wires attached to it. Cut the gold ends off the red/black included wires. Use the quick splice to attach the red to the + and the black to the -. The speaker itself will be labeled. Once you have these wires spliced then simply plug them into the easy pandora board at the locations L-SPK and R-SPK
Option #2
You the provided 4" speakers and the red/black 48" included wires. Before you mount them simply look at the speaker and attach the red to the + terminal and the black to the - terminal of the speaker. Those gold terminals can be tight sometimes, if they do not want to slide on then use a small flat screwdriver to space them out a bit before you slide it onto the terminal. Once you have the 48" wires connected simply plug them into the easy pandora board at the locations L-SPK and R-SPK.
Game on ;)