Bam Margera Responds to Restraining Order Taken Out Against Him

Bam Margera allegedly threatened to use brass knuckles to kill a man ... and the man thinks loud sex might be the reason why.

According to new legal docs, obtained by TMZ, a 28-year-old man named Daniel Cardenas claims Bam burst into his home in the middle of the night last month, waking him from his sleep and getting in his face to make a death threat.

Cardenas claims Bam told him something along the lines of, "You have 12 hours to leave the house or I will kill you with my brass knuckles."

The guy claims his roommate heard the alleged threat, came in the room and forced Bam to leave ... but he says Bam came back 90 minutes later and again slammed his door open, waking him and telling him, "You have 12 seconds to leave," while shoving a clenched fist with a handful of rings in his face in another perceived threat.

For context, Cardenas claims he lives in an Oceanside, CA home where Bam's girlfriend, Jessica, and her 8-year-old daughter have been staying in the wake of Bam's domestic violence arrest.

TMZ broke the story ... Bam was arrested for domestic violence after a woman told police the former "Jackass" star kicked her ... and our sources said the woman was Bam's current girlfriend.

In the docs, Cardenas claims Jessica and her daughter have been staying in his home since Bam's arrest, and he says the folks living in the home got mad at him a couple days after Bam's arrest because he says he was having "some very loud sex in the house" and Jessica's kid may have overheard.

In seeking court-ordered protection from Bam, Cardenas says ... "All I can figure is Jessica told Bam about the loud sex which her daughter overheard and this is why he was so upset, although it of course gives him no right to attack me, threaten my life, or kick me out of a home he has no rights to."

Cardenas also claims Bam told him, "That girl will have PTSD for the rest of her life," when making the alleged threats.

The judge signed off on a temporary restraining order ... and now Bam has to stay 100 yards away from Cardenas and the home.