Technology

Field Test: Lawson L251 Tube Condenser Microphone

The Lawson L251 is a side-address, dual-diaphragm tube condenser mic that offers many extras, including an infinitely variable polar pattern, two bass-frequency contour settings and a 10dB pad. 2/01/2004 7:00 AM Eastern

The Lawson L251 is a side-address, dual-diaphragm tube condenser micthat offers many extras, including an infinitely variable polarpattern, two bass-frequency contour settings and a 10dB pad. The mic'smodel number is derived from its faithful reproduction of the 1-inch,6-micron capsule used in the venerable Telefunken Ela M 251 tube mic.Like Lawson's other mics, the L251 oozes artistic coloration and has adistinctly vintage vibe.

MAINTAINING FAMILY TIES


The L251 will look familiar to anyone who has worked with thecompany's L47MP. Both mics have a cylindrical shape and roughly thesame dimensions. There are two cosmetic finish options: Buyers canorder the L251 with either a nickel-plated or 24-karat-gold head grilleand base for the same price. All of Lawson's head assemblies (capsuleand grille) are interchangeable, allowing you to easily mix and matchcapsules with different mic bodies and electronics. The company alsooffers head assemblies for sale a la carte.

Weighing a full two pounds and measuring 9¾ inches in lengthand 2⅜ inches in diameter, the L251 demands a sturdy mic standwith a short, counterbalanced boom arm to keep it from sagging out ofposition. The included mic stand adapter secures the L251 via anintegral O-shaped ring that slips over and tightens around the mic'sconnector housing. This is a bomb-proof design that allows the L251 tosecurely hang upside down. As the L251's capsule is internallyshock-mounted, an external shock-mount is not required.

The L251 connects to its remote power supply using the supplied30-foot cable with latching 7-pin, gold-plated Neutrik connectors. Thecable is long enough in most situations to place the power supply inthe control room while tracking with the mic in the studio. That's areal advantage, because most of the controls for the L251 —including the infinitely variable polar pattern control, 10dB pad andbass frequency contour switch — are on the power supply, and theychange the response of the mic quite dramatically.

The rotary polar pattern control smoothly transitions through allpossible responses, from omni mode through cardioid to figure-8. TheL251's 10dB pad lowers the capsule's polarizing voltage, thus loweringthe input level to the vacuum tube. The bass frequency contour switchprovides two alternate settings: One, labeled “-BASS/L251,”introduces a 6dB/octave roll-off at 100 Hz to emulate the original ElaM 251's bass frequency response. (A fixed roll-off was engineered intothe vintage mic to counteract its gargantuan bass proximity effect.)The other setting, labeled “+BASS/L47,” flattens theresponse to provide extended lows and a more dramatic proximity effect.Lawson generally recommends that users choose the +BASS/L47 settingwhen using the power supply with a Lawson L47MP MKII mic, but there'sno reason why you can't use this setting with the L251, as well. Igenerally preferred using the -BASS/L251 setting, because it lent moretransparency to the mic's overall sound.

POLAR STROLLER


Turning the power supply's polar pattern control knob yieldsdifferent frequency responses for the L251. The supplied specs andfrequency response charts are not exact enough to cite responses downto the precise dB and kHz, but here's the general scoop: All patternsproduce a broad 3 to 4dB peak at around 10 kHz and a response roughly 7to 9 dB down at 20 kHz, yielding a nice presence peak and a softvintage-style top end. As the polar pattern becomes increasingly moredirectional, a smooth hump between 3 and 7 kHz develops, culminating inroughly a 5dB boost in bidirectional mode in this band. Likewise, bassresponse below 200 Hz increases as the pattern becomes moredirectional.

A switch on the bottom of the L251 disables the power supply's polarpattern control and puts the mic into fixed-cardioid mode. (Acool-looking blue LED lights up inside the windscreen when you're inmultipattern mode — a nice reminder.) This“cardioid-only” mode takes the mic's rear diaphragmcompletely out of circuit, resulting in 3dB lower self-noise and 3dBhotter output. Sensitivity is specified to be 18 mv/Pa (at 1 kHz) incardioid-only mode vs. 11.6 mv/Pa in multipattern mode.

The L251 uses a dual-triode 6N1P (6922) tube — currently inproduction and widely available — in a configuration that usesboth halves of the triode wired in parallel. This scheme lowers thenoise floor an additional 3 dB (resulting in a conservatively rated13dBA equivalent noise level in cardioid-only mode) and halves thetube's output impedance, reducing the possibility of current limitingand therefore increasing headroom. Maximum SPL is rated to be 134dB SPL(for 3% THD at 1 kHz) with the pad switched out, and 144dB SPL with itswitched in. One other touch: The tube socket uses gold-platedberyllium-copper contacts with secure grip and low contact resistanceto further thwart noise.

Lawson includes a foam-lined, water- and air-tight Pelican case tostore and transport the L251 and all accessories. It's a tight fit toget everything in the case, but there's no denying that this is a greatextra.

TAKING THE L251 FOR A RIDE


My first test with the L251 was an A/B comparison with an originalLawson L47MP (not the newer mkII version), with both mics recordingmale vocals in cardioid (cardioid-only mode for the L251). To avoidadditional coloration, I used my ultratransparent, Millennia HV-3D8-channel mic pre and Apogee Rosetta 96 A/D with the two mics. The L251in -BASS/L251 mode reproduced much more depth than the L47MP, as wellas a fuller bottom end, more highly resolved midrange and more detailed(yet still soft) highs. The L251 also exhibited markedly lower noiseand a tad higher output compared to the L47MP.

Recording another male vocalist with the L251 set to cardioid-onlyand -BASS/L251 modes, I was struck by the mic's warm, velvety characterand sweetly articulated highs. In order to achieve the pop sound I wasafter, I needed to apply a highpass filter at 105 Hz and a fair amountof high-shelving EQ boost to the track, but that's typical treatmentfor a pop mix with almost any mic. The end result sounded gorgeous,brimming with sweet tube character. On female vocals, the L251reproduced a similarly full bottom, soft highs and velvety texture.

I once again chose the -BASS/L251 setting when using the L251 as aroom mic to record drums. I found the +BASS/L47 setting captured toomuch kick drum and was too boomy in this application. In -BASS/L251mode, however, the L251 is an outstanding room mic. The creamy textureit lent to the sound was the perfect complement to the solid-state micsplaced close in on the kit.

Finally, when recording acoustic guitar, the L251 lacked thehigh-end sparkle and detail I was after and had too round of a bottomend for my taste.

CONCLUSIONS


At $2,495 (factory-direct), the L251 is fairly pricey, but no moreso than other mics of the same ilk. The mic's plethora of controlsproduce many useful timbres, while always maintaining a creamy texture.For those who seek a new tube mic with vintage character, the L251 is avery worthy candidate.

Lawson, 615/269-5542, www.lawsonmicrophones.com.


Mix contributing editor Michael Cooper is the owner of MichaelCooper Recording, located in beautiful Sisters, Ore. Cooper's studiooffers recording, mixing and mastering services.