What does "Sp 12" mean?

Solution 1:

The reference is almost certainly to an E-mu SP-12—which Wikipedia refers to as a "sampling drum computer." As the Wikipedia article on the SP-12 notes,

The name SP-12 stands for sampling percussion at twelve bits, demonstrating the power of the sampler. The E-mu SP-12 is credited with helping usher in the era of digital sampling by being one of the first digital samplers in production, and allowing musicians to take digital sampling in a completely different direction.

Drum samples provide the backing percussion and beats for many songs—rap and otherwise. Rappin 4-Tay credits the SP-12—a vintage machine from 1985–1986—for making "the beats that you hear [come] real tight."

I also suspect that the "hoe named Real de Real" is actually named "Reel-to-Reel," a reference to old-school reel-to-reel audiotape used in recording and sampling.

Followup: The Wikipedia article confirms my surmises above in a comment in the "Trivia" section of the entry for "E-mu SP-12":

The Beastie Boys reference the SP-12 in their song "Putting Shame In Your Game" from their 1998 album Hello Nasty with the line, "Well I'm the Benihana chef on the SP12." Rappin 4 Tay in Players Club (1994) says "I gotta ho named reel-to-reel, she got a buddy named SP-12, now you know the deal." Young MC raps in the song Album Filler (1991) "It's just me, a mic, and an SP-12."

Solution 2:

Here's the lyrics:

I got a ho named Reel-to-Reel
She got a buddy named SP 12, now you know the deal
We gets freaky in the studio late night
That's why the beats that you hear are coming real tight

Note his ho is named "Reel-to-Reel", not "Real de Real". Rap Genius explains:

4-Tay talks about the physical act of making a record. Reel-to-reel is the old fashioned large reel cassette recording style, and the SP-12 was a 1980s drum machine.