SLS Loudspeakers has manufactured loudspeakers for the touring market for more than three decades. The company's development of ribbon tweeter technology suited for sound reinforcement monitors has distinguished its modern products from the competition. SLS is now shipping the PS8R studio reference monitor, which combines this "Push Pull Neodymium Ribbon Driver Technology" with an 8-inch woofer, biamped through a pair of PWM (Sigma-Delta) digital amplifiers.
A pair of the PS8Rs was recently sent to bluegrass virtuoso Ricky Skaggs for evaluation at Skaggs Family Records' Skaggs Place studios in Hendersonville, TN, where PSN visited the monitors, studio manager/engineer Lee Groitzsch and independent engineer Brent King. The standard house nearfield monitor at Skaggs Place is from another manufacturer's popular line of powered, ribbon tweeter-loaded speakers, and the PS8Rs were compared to those monitors and the horn-loaded, soffit-mounted main monitors. For the extended low end, the PS8Rs were paired with a PSS12 subwoofer from SLS.
King had just come off a mixing session where he'd employed the PS8Rs and felt pleased with the results. He reports that the balance of his mix held up, and it translated well. King did feel he EQ'd a few things a little different with the SLS's than he might have otherwise, but was happy with the results, nonetheless ("That's cool, that works."). Shuffling through a range of reference tracks during some listening with Groitzsch and King--much of it with instrumentation that varied markedly from the daily fare at Skaggs Place--King added additional kudos for the "nice clarity and separation." Groitzsch agreed, stating, "Clarity is definitely through the moon."
Switching back and forth between the two sets of nearfields and the main monitors revealed a smooth, open character with the SLS's, extending flatter further out on the high end than the response of the horn-loaded, modified Durr mains and with more detail and resolution than the other ribbon tweeter nearfields.
If anything, the SLS's had perhaps a bit too much high end. Groitzsch comments, "If you mixed on them, you'd probably park things too far back." The PS8Rs have no user-adjustable HF adjustments. Despite the inclination to eschew horizontal positioning of vertically oriented components, and the resulting potential limitations to the horizontal sweet spot, laying the PS8Rs down proved beneficial to their performance in this application.
Groitzsch reported a few days later that the positioning continued to work in their favor, and that they also were experimenting with positioning the ribbon on the bottom with the monitors back in a vertical orientation, something SLS appears to do in some of their high-end consumer models. The ribbon tweeter is rotatable, to achieve its standard dispersion pattern when the cabinet is horizontally mounted, though that was not attempted here as it seemed it would not achieve the desired results.
King originally thought the PS8Rs a "little shy" on the bottom, but was happy when the monitors were paired with the SLS 300W PSS12 sub. The PS8Rs have an integral 80 Hz high-pass filter for use with a subwoofer. Groitzsch also reported that the PS8Rs' performance shone when used while tracking with stereo miking--the phase of the tracked instruments being "much more apparent."
Advantages touted for SLS' ribbon tweeters are smooth performance at high SPL with fast transient performance, and the PS8Rs don't disappoint. They get plenty loud, "they've got plenty of gas," says King. SLS cites the amplifier topology as being 90+ percent efficient, helping the system run cool. The ribbon tweeter is also efficient, requiring only a 50W amp to the woofer's 270W spec.
SLS delivers premium performance with the premium-priced PS8Rs--excellent detail, punch, power and clarity. "You can hear great detail," says King, "and you wouldn't have to crank it up. You could listen to them all day, and if you wanted to have fun [by pushing up the volume], you could have fun."
PS8R: $1,570 each