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Review: SPL Crimson Monitor Controller

This summer has allowed me to enjoy a wide variety of musical styles and some interesting new sonic horizons, challenging my usual work assumptions.

Rob Tavaglione
PAR Contributor

This summer has allowed me to enjoy a wide variety of musical styles and some interesting new sonic horizons, challenging my usual work assumptions. It’s all a part of this ever-changing landscape of “how an audio engineer survives in this DIYD (do it yourself digitally) age.” Thus I try to keep my competitive edge with superior gear and informed ears, and these review subjects all fit the bill, which ultimately helps keep my united nations of clients—from Russia, Sierra Leone, the U.K., from metropolitan suburbs to small country churches—all sonically satisfied.

Up until this review, I’ve never used a desktop interface or monitor controller, as I drive a console with rack-mounted converters/interfaces. Sure, I’ve watched my less-fortunate colleagues and students struggle with some pretty bad (and quite popular and cheap) devices that are inadequate for pro use in many ways—including their mic preamps, converters, headphone amps and general build quality. The SPL Crimson appears to solve these problems and offer enough flexibility to claim the top perch in this category.


Input section: two single-transistor discrete mic preamps (with phantom power, HPF, XLR inputs), two pairs of line inputs on quarter-inch balanced TRS connections, two Hi-Z instrument inputs on quarter-inch TS, a pair of RCAs and an eighth-inch stereo miniplug for -10 dB consumer devices (with an automatic, bypassable gain boost to pro level), and a digital input via SPDIF.

Monitor section: a large unstepped control-room level control, two sets of control room outputs (set A on XLR, set B on quarter-inch TRS with “tweaker” trim controls), two headphone amps with quarter-inch TRS outputs and high output, a balance control for blending between the analog input section and the DAW returns.

DAW implementation: two pairs of DAW returns via one USB 2.0 input (not 3.0, but 2.0 for its faster and more stable drivers with 1 ms of latency), a total of six simultaneous channels of conversion to/from DAW, 24-bit processing, sample rates up to 192 kHz, and low-jitter fixed internal master clock. The Crimson will operate sans drivers (using Core Audio), but high sample rates and low latency requires SPL drivers.

In Use

I started out using the Crimson simply as a stand-alone monitor controller and was immediately struck by its “feel.” The steel chassis, the large control room level pot, the trim and headphone level pots, the switches—they all had that firm and smooth operation that inspires long-term confidence. The rear-panel legend was printed twice, once upside down, for easy connecting from either viewpoint. Savvy ergonomics? My interest was immediately piqued.

As I ran through the functions in my mix session, the Crimson did not disappoint. I summed to mono to check for phasing issues; monitor switching was convenient with a single button push between A and B; and I kept two sets of cans (for me and the client) always connected for quick comparison checks. I noticed that the control room level did not go all the way down to muting the hot +4 outputs of my D/A converter, but the manual explained that these pots offer about -80 dB of attenuation, enough to silence most sources. I did notice that the control room level was not balanced and centered at lower levels; I’d prefer stepped attenuators for such very low-level balance checks.

I downloaded the Mac drivers from SPL’s website (they offer Windows drivers, too, for XP and Vista 7 and 8) and suffered a bad install. Once I reinstalled the drivers, I received stable and excellent operation from the Crimson as a front end/DAW companion. For a naked, no-bed voice over, the Crimson mic preamps did a fine job. I’d describe their voicing as “neutral and flat” as they lacked any significant color but were super quiet and distortion free, even with lots (up to 60 dB) of gain. They are maybe not as euphonic as some out there, but wisely clean and non-obtrusive. The instrument inputs were quite similar; with passive basses, active basses, acoustic guitars and electric guitars I received ample gain, low noise and neutral voicing (again, not as “pretty” as my reference preamp, the Millennia-Media STT-1, but smartly flat and flexible) with plenty of headroom.

For overdubbing vocals and such, the Crimson again nailed the job. The blend control allows no-latency monitoring of the analog input signal and acts as a convenient one-knob “more me” control when the singer needs just a little more level over the music. The multiple sets of DAW returns are also quite useful for setting up separate monitor mixes or wet/dry balances.

For more complicated scenarios (two headphone mixes, the need for talkback, and checking reference mixes) the Crimson has a number of advanced routing flexibilities. These are basically achieved with the “Artist mode” which routes analog inputs in realtime, monitoring of DAW returns 1/2 to producer via Phones 1, returns 1/2 or 3/4 routing out to Speaker B for a headphone amp and Phones 2. Talkback is achievable with a externally amplified mic into analog source 1-left; upon hitting the “talk” button, talkback routes to Phones 2 and Speakers B, while Speaker A is dimmed to prevent feedback.

With so many functions available for a number of the jacks and connections, I had to constantly re-patch to achieve different set-ups (e.g. inserting plugs in quarter-inch inputs 1/2 will override mic inputs 1/2, instrument inputs 3/4 override lines 3/4, etc.). Nonetheless, there’s enough flexibility and utility here to satisfy the needs of all but a traditional pro facility—and that’s a lot more function than typical out of a desktop device.

I used the Crimson at at 44.1 and 48 kHz and it sounded even better at 96 kHz (a bit more open, shiny and precise) with basses, vox, guitars, acoustic guitars and percussion.

To My Ears

In my opinion, the performance of the Crimson measures up to professional grade. Clean and neutral mic pres and converters as well as excellent sonic performance (high headroom, wide frequency response, ample bottom end, excellent imaging) from all the analog inputs are highlights (surely due to the Crimson’s high internal 34 VDC operating voltage). Digital capabilities are up to par as well with excellent, stable and fast drivers, low latency and a lack of issues from sample rate conversions or external clocks.

Despite a few technical concerns, I am going to give the Crimson an unmitigated approval for the most basic reasons. For $699, buyers get a steel chassis and a set of strong components that I estimate will last four to five times longer than those plastic toys which populate the desktops of my studio students/interns and newbie clients.