Street Fighter V Pachislo... Advice fitting potentiometer's

[Fishy Pete]

So after a long time and many machines...back in the fold with a Street Fighter V.. (5)
Had a Thunderbirds for a short while... but liked my previous PopEye.. plenty of video screen and game play

Pushed the boat out with a modern Street Fighter 5 and its EPIC..!

Theme, game play and sound is amazing..

Far too loud, so want to fit a couple of potentiometers.. The more i read the more confused i am
Happy to solder etc ..

2 x Speakers are 20w each and 8ohms.. so want to fit 2 x volume controls but have so much conflicting advice
some say 500k some say 10k..? So now totally confused... HELP!

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