Take a closer look at R.J. Ronquillo and Helen Ibe's killer, Martin-driven acoustic blues showcases

Martin – in partnership with Guitar World – recently launched the No Limits Challenge, a contest that sees eight YouTube-savvy guitarists face off against one another and cover tunes you wouldn't normally associate with an acoustic, using one of the company's offset SC models.

In this week's semifinal matchup, R.J Ronquillo and Helen Ibe catch a mean case of the blues.

Ronquillo salutes the great Stevie Ray Vaughan with a rollicking acoustic version of Rude Mood, while Ibe breaks with competition convention with her own original acoustic blues instrumental. 

We've recruited GW's resident tech/gear guru Paul Riario and video editor Alan Chaput to take a closer look at the performances and share their thoughts on the them. You can check out their commentary above. 

Alan and Paul might be our judges, but they don't actually choose the winner of each face-off. That task happens to be in your hands. Check out our breakdown of the covers above – and/or give each of them a spin below without the commentary – scroll down to the box at the bottom of the article, and cast a ballot for your favorite.

You get to decide which guitarist – Ibe or Ronquillo – makes the cut for the final round.

Be sure to check back next week, too, for the second semifinal matchup. 

For more info on Martin's SC acoustics, visit the company's website.