help, weird electrical problem

[snp_ethan]

I changed my alternator and starter last week, cuz it died on me, and on superbowl weekend, my car died on me while driving. at first we changed the battery. and it ran good for a while, but today(the very next day) it died again, same problem. First radio flickers, and then turns off. lights are dim and rpm starts to drop dramatically. and so the only way i can get my car running is byt keeping rpm above 1 so that i can keep combustion going. I really dont know what the problem is, and I know is not the alternator and is not the ignition. althoguh lately the car has been doing a weird sound, as if the belts were kinda loose. anybody could help me?

btw my car settings, if they are needed to give me any help:

s14
ka24 213100 miles
pretty much stock except for the clutch, and well yeah the parts that i said i've changed.