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Maselec MLA-4 Stereo Triband Compressor/Expander

Unique Processor Offers Powerful Features, Superb Sound

Boutique British manufacturer Maselec is highly regarded for its top-tier recording, mixing and mastering gear. The company’s new MLA-4 Stereo Triband Compressor/Expander essentially retrofits the legacy MLA-3 3-band stereo compressor with upward-expansion capabilities. But it’s the unusual sidechain linking and compression-expansion interplay that make the MLA-4 truly powerful and one of a kind.

Mastering Quality

The MLA-4’s beautiful front-panel features all stepped rotary controls and bipolar switches with solid, positive action. The consistent use of switches (think extremely accurate recall) and selection of mild to moderate compression and expansion ratios suggest mastering as a principal use, but there’s no reason why you can’t use the MLA-4 for mixing duties.

The solid-state processor splits its left- and right-channel in- put signals into three frequency bands—Low, Mid and High—for stereo dynamics processing. Dual-mono processing isn’t afforded, but separate input-gain controls for the two channels each provide ±5dB adjustment range in 0.5dB steps.

The two crossovers between bands each have a 6dB/octave slope; their filters are passive, promising minimal coloration and accurate summing for the three bands. You can select 100, 200, 400 or 800 Hz for the crossover between low and mid bands. Selections for the midrange-high crossover are 1.5, 3, 6 and 12 kHz.

Each band has separate stepped controls for adjusting threshold, ratio, attack and release times, and makeup gain. (An additional master threshold control proportionally adjusts the thresholds for the three bands at once.) Rotating a band’s ratio control counter-clockwise from the noon position (which provides 1:1 ratio) affects compression, while clockwise rotation produces upward expansion. Each band offers the same selection of compression and expansion ratios (five each): The compression ratios are 1.4:1, 1.6:1, 2:1, 3:1 and 6:1, while the expansion selections include 1:1.2, 1:1.4, 1:1.6, 1:1.8 and 1:2.0 ratios. Each band’s gain control provides up to 2.5 dB of boost or cut in 0.5dB steps.

The selection of attack and release times differs for each band, with each control offering six switched positions. The actual release times are program-dependent. Switching in the S/C (sidechain) Boost function provides a shelving boost to high frequencies in the High band’s sidechain, causing greater compression or expansion in that band.

Novel Linking and Metering

A five-position switch links the three bands’ sidechains in various—some unusual—ways and provides an Off position to unlink them. The L->M setting makes the Mid band compress or expand the same amount as the Low band, but not vice versa. The L->H setting causes the High band to compress or expand as much as the Low band, but not vice versa. The L->MH setting makes both the Mid and High bands compress or expand the same amount as the Low band, without linking the Mid and High sidechains to each other or causing them to affect the Low sidechain’s detector. With the L->M, L->H and L->MH settings, there is an exception to the behavior detailed thus far: The bands linked to the Low band’s sidechain won’t follow the Low band’s gain changes if they are by themselves producing higher gain changes than the Low band. (This is one of several key operational points omitted in the somewhat vague owner’s manual.) Another setting, dubbed Linked, links all three frequency-bands so that they are compressed or expanded the same amount (tantamount to wideband dynamics processing). With all link settings, compression and expansion functions are linked separately.

Three vertically oriented, high-resolution LED ladders show compression and expansion amounts for the three bands, respectively: up to 4 dB of gain expansion is displayed by the top six (red) LEDs, while the bottom ten (green) LEDs show up to 8 dB of gain reduction. When bands are linked, it’s possible to see both gain expansion and reduction simultaneously displayed on one or more meters. For example, say you’ve selected the L->M link setting, the Low band is compressing 3dB, and the Mid band is expanding 3 dB. In this case, the Mid band’s meter would show 3 dB of compression and 3 dB of expansion simultaneously. The net effect would be 0 dB gain change due to the equal expansion and compression cancelling each other out. But the meters would still show what each process is contributing to the net gain change so you can discerningly adjust each.

A five-way switch lets you select what signal is routed to the MLA-4’s outputs: the combined multiband signal; discrete signal from either the Low, Mid or High band; or unprocessed input via hardwire bypass. A large output-gain control adjusts post-processing gain ±5 dB in 0.5dB steps.

On the rear panel, separate latching XLR connectors are provided for the left and right I/O, which are all electronically balanced but can be unbalanced by grounding pin 2 or 3. Roughly five feet in length, the detachable AC cord is rather short.

The MLA-4 boasts superb specs. Respective maximum I/O levels are +29 and +28 dBu—high enough to strap the unit across the stereo bus of virtually any mixing console. The frequency response is stated to vary no more than 0.05 dB from 20 Hz to 20 kHz, and the bandwidth is said to extend beyond 500 kHz. Typical noise is -90 dBu, and THD (with 1:1 ratios selected) is less than -90 dB.

Mastering Sessions

A country pop mix had a somewhat loud, boomy and muddy-sounding kick drum to go with slightly weak and dull-sounding snare hits. I set the MLA-4’s crossovers to 200 Hz and 3 kHz. I selected a 2:1 compression ratio for the Low band, and then dialed in the fastest possible attack and release times and the highest threshold so that only the kick drum’s low end was audibly compressed. Next, I selected a 1:2.0 expansion ratio for the High band, switched in its S/C Boost circuit, and chose fast attack and release times. I adjusted the High band’s threshold so that only snare (and, unavoidably, kick) hits would be expanded; doing so made the snare sound brighter and louder, but it also made the kick’s beater sound too slappy (now that the kick’s bass frequencies were attenuated in the Low band). No problem: By linking the Low and High band’s sidechains, I could make the kick’s high frequencies compress simultaneously with the same amount as its lows—fully nulling the kick’s High-band expansion and without affecting expansion on snare hits. The net effect was the kick sounded leaner, tighter, clearer and quieter, while the snare sounded louder and brighter. I know of no other device that can achieve quite the same balance. Awesome!

Unfortunately, during the same song’s choruses, the lead vocal became louder than the snare and was expanded along with it—not what I wanted. I wished the MLA-4 had separate bypasses for each band so I could’ve instantly defeated only the high-frequency expansion during those song sections. The solution was to master the track’s verses and choruses in separate passes and then splice together the whole enchilada.

Next up was an Americana mix propelled by a very percussive, slow groove played on acoustic guitar. The mix was nevertheless not quite dynamic enough, and it sounded slightly midrange-y. Mild compression in the Mid band softened the glare. But the mojo really ignited when I expanded both the Low and High bands and linked their sidechains; fast attack and release times gave the guitar groove a smiley-curve pulse and accented the male singer’s deep and raspy voice in sync with the music.

With all ratios set to 1:1, I could also use the MLA-4 as an equalizer for broad tone sculpting. The MLA-4’s passive filters sound excellent, with crystalline clarity and depth that goes all the way to China. Powerful and pristine, the MLA-4 is a fantastic tool for both mixing and mastering.

Michael Cooper is a recording, mix, mastering and post-production engineer and a contributing editor for Mix magazine.

Product Summary

COMPANY: Maselec (distributed by Prism Media Products)

PRODUCT: MLA-4 Stereo Triband Compressor/Expander


PRICE: $5,740

PROS: Superb sound quality. Unique and powerful sidechain linking. Robust build.

CONS: No separate band bypasses. Somewhat-vague documentation. Short AC cord.