SLS Audio: S8R studio monitor

I love attending sessions at Peerless Mastering with Jeff Lipton (Tape Op #34). His "A Room" is the most accurate listening environment I've ever experienced. The room is so well designed and treated that it imparts very little of its character on what you're hearing in it; and the monitoring system-made up of precisely-positioned Bag End subwoofers and SLS Audio monitors with planar ribbon tweeters-is extremely transparent. My studio is nowhere near as perfect a listening environment as Peerless, but I've spent a good deal of time tweaking the acoustic treatment in my studio to good effect. With a single Bag End subwoofer and a pair of ADAM S3-A active monitors, my room measures flat to +/-4 dB at mix position to the extent my ATB-1 analyzer can measure, from 30 Hz to 20 kHz (even at 1 Hz measurements below 120 Hz), and the reverb time is fairly even throughout the whole spectrum. When SLS offered me a pair of their S8R monitors on demo loan, I gladly donned my propeller hat and set up the speakers with the enthusiasm (um... nitpickiness) of the true geek that I am.

The S8R is a passive 2-way loudspeaker with an 8'' woofer and a planar ribbon tweeter mounted in a waveguide. The crossover is at 1.5 kHz, and 5-way binding posts on the rear allow for bi-wiring. The speaker is designed so that the woofer is above the tweeter to align the drivers correctly with your ear when placed on or behind the console's meterbridge, but the waveguide can be rotated if you want to mount the speaker sideways. I carefully placed the pair of S8Rs on stands to prevent first reflections from not only the room surfaces, but also the top surface of my console, while remaining cognizant of the room's resonant modes. I powered the S8R pair with a Hafler Trans•ana power amp. Here's what I discovered in my listening, recording, and mixing tests.

The first revelation was that the S8R exhibits near- perfect imaging. If you place a sound in the stereo mix between the left and right speakers, you perceive it exactly where it should be. If you hard pan a sound, it appears exactly out of one speaker. In comparison, the image from the S3-A always comes from a small "cloud" where the sound has been placed. But the S8R's extreme image accuracy is kinda eerie. In fact, I found it downright distracting if the speakers were positioned less than 7 ft away from me because the center-to-center distance between the S8R's woofer and tweeter is great enough (relative to your distance to them) that you can actually identify elements of hard-panned sounds as coming directly from the woofer or from the tweeter. I do a lot of hard- panning of two-mic tracks, and I kept finding myself staring at the individual drivers as I located sounds coming from them-that's how precise these speakers are! I also noticed very quickly that even with the waveguide (which I tried rotating), the S8R's tweeter is beamy. There's a well-defined sweet spot, and venturing out of that sweet spot changes the sound of the speaker significantly. Beyond these two initial discoveries, I was quite impressed with the capability of these monitors, and I was immediately comfortable trusting what I was hearing out of them.

Over time, as I recorded and mixed with the S8R, I perceived a general sense of smoothness with the S8R that was hard to quantify until I took measurements. In my room, the S8R's frequency response measured a 3 dB peak at 1.7 kHz (just above the 1.5 kHz crossover) and a 3 dB trough from 250-500 Hz. If you could view the graph, you'd see only a few broad, wave-like peaks and dips that are an octave wide or wider-very smooth response. I never heard any harshness, and more importantly, I never felt that individual sounds jumped in and out as they varied in pitch or timbre. This smoothness, especially in the upper mids and high frequencies, really made it easy to build mixes that translated well to other environments. Concurrently, I heard lots of detail from the ribbon tweeter, so getting each sound "right" was also quite easy.

With my subwoofer off, the lowest lows from the S8R, although very balanced with lots of extension (even down to 30 Hz), weren't as tight as the lows from the S3-A (which has a second powered woofer kick in at 150 Hz and below to augment the first powered woofer). But again, there was a smoothness in the low end, just like in the upper mids and highs, that made mixing easy. Also, there's a very real chance that the Hafler amp driving the S8R was contributing to the loss of focus in the extreme lows. Unfortunately, I had no other power amp in my studio at my disposal. (Of course, kicking in the Bag End sub cleared up the low end immediately.)

For additional testing, I moved the pair of S8Rs into my living room at home to compare them to my Bag End M6 Time-Align speakers. Coming out of the S8R, I could hear a bit of transient smear listening to a kick drum close- mic'ed with an Earthworks omni that I didn't hear from the M6, but otherwise, the S8R's detail, especially in the high end, easily trounced the M6 in that respect. The S8R's efficiency is also significantly higher, so my 1982 Yamaha M-80 power amp didn't even break into a sweat, even at uncomfortable volumes.

Despite my ears being accustomed to ADAM monitors costing three times as much, I think the SLS Audio S8R is an excellent speaker that does what a professional monitor should do. It inspires confidence because projects done on it translate so well, the incredible detail heard in its upper mids and highs facilitates the process of sculpting sounds, and its near-perfect imaging helps you place tracks with precision. Isn't this what recording and mixing are all about? I bought the demo pair. ($775 MSRP each; www.slsaudio.com)