EQ Magazine
September 1999
First Look
by Roger Maycock

Curtis Technology AL-2 Stereo Microphone System

During the past several months, a truly impressive assortment of microphones has been introduced into the pro audio marketplace. Not to be left behind, Curtis Technology of Rockford, IL recently introduced its latest offering — the AL-2 Stereo Microphone System. The AL-2 takes the high ground for this category, and does so with a very innovative approach. But first things first. Who is Curtis Technology?

Curtis Technology started as an electronics and software design consulting company. William Curtis, the company founder, directs the firm and its network of associate designers and contractors. Consulting on a wide range of products, the company has designed digital computer graphics hardware, machine control systems, touch screen systems, video arcade games and custom industrial software and hardware. Curtis Technology began designing audio products in the mid '90s and introduced their first offering, the AL-1 Stereo Tube Condenser Microphone System in 1995.

The Curtis Technology AL-2 Stereo Microphone System consists of a matched pair of tube mics with an associated rackmount power supply. The AL-2 has been gaining considerable popularity among top producers who seek a sense of unrestricted ambience and dimension in their recordings. Of particular note, the balanced microphone inputs are positioned on the front panel of the power supply to address the growing trend of rackmount equipment in the performance room to better accomodate project and commercial facilities.

Intended to be used as a pair, the microphones feature an elongated cardioid pattern. Not to be confused with an omni pattern, Curtis has intentionally designed a sort of elongation into this system that enables the engineer to employ the microphones in a type of unidirectional approach. In essence, the result yields the best of both worlds: the spaciousness of an omni mic with the focus of a unidirectional mic. The hard panned stereo configurations provide a virtually limitless number of composite acoustical patterns.

In terms of frequency response, the AL-2 microphones, like any mics, vary with the sound pressure level (SPL). As a general rule, they are flat from 20Hz — 30kHz and accept maximum input levels of 125dB SPL. Much more relevant to the issue of music reproduction, however, is the issue of speed, or slew rate. According to William Curtis, "The AL-2s preserve transient speed and intensity far better than other comparable microphones — and this is what you really need to ensure your recordings will sound like the source."

The diaphragms of the AL-2 microphones are gold free and measure 22mm exposed with an overall assembly size of 32mm. These microphones employ handpicked audiophile grade matched 12AU7 tubes. When I queried about the choice of 12AU7s as opposed to the more common 12AX7 tubes, I was informed that under extensive company testing, the 12AU7 proved to be substatially more immediate and neutral in terms of its reproductive characteristics. Rounding out the tech talk, the AL-2 microphones use close-tolerance metal film matched resistors and custom designed capacitors. The impedance rating of the AL-2 microphones is 600 ohms nominal.

In terms of the type of recording application best suited for the Curtis AL-2, the system is non-instrument restrictive. On instruments such as drums, acoustic pianos, acoustic guitars, saxophones and cellos, the microphone's performance is, in the words of William Curtis, "world class." Curtis also noted that, "More importantly, the AL-2's are unprecedented in their ability to sort out and translate the super complex harmonic interaction that occurs during events that are symphonic in nature."

The Curtis Technology AL-2 Stereo Microphone System ships with two microphones, the rackmount power supply, Canare cables (reportedly the best the company has tested), shockmounts and a case. With a suggested retail price of $3495, this is hardly an impulse studio purchase. However, if you're in the market for an extraordinarily well-crafted set of microphones that have been built to exceptionally close tolerances, you simply cannot ignore a close look at the Curtis AL-2s.

MSRP: $3495