I use my Helix output via 1/4" to a Tech 21 Power Engine 60. I don't hear much difference, if at all, between XLR output to the Tech 21 Power Engine 60 and the 1/4" output but this little, lightweight powered speaker is crystal clear when using the Helix and sounds phenomenal. My cover band, Thrown Together, performs music from Ray Charles, Ozzie, Collective Soul, the Allman Brothers, Bob Marley, Sublime, Primus, Nathaniel Rateliffe and the Night Sweats, Flogging Molly, the Dropkick Murphy's, ZZ Top, Tom Petty and more. The Helix handles it all through this terrific little powered speaker. It's LOUD, too.