Allen Heath GL2400 Consolebr/

The job of producing a professional grade, small/medium format analog console gets more challenging each year. Live mixing has become more complex with things like aux-fed subs, ambient mics (for IEMs or audio for video mixes), multiple mix outputs (cry rooms, delay speakers, etc.), and more.
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The job of producing a professional grade, small/medium format analog console gets more challenging each year. Live mixing has become more complex with things like aux-fed subs, ambient mics (for IEMs or audio for video mixes), multiple mix outputs (cry rooms, delay speakers, etc.), and more.

Fast FactsApplications: Live sound, installation, sound reinforcement

Key Features: 16, 24, 32 and 40-channel frames; four-band semiparametric EQ; six aux sends; 7 x 4 matrix; 20 dB pad; high-pass filter; FOH, monitor modes

Price: GL2400-16 - $1,699; GL2400-24 - $1,999; GL2400-32 - $2,499; GL2400-40 - $2,999

Contact: Allen & Heath/North American Pro Audio at 800-431-2609, The job of producing a professional grade, small/medium format analog console gets more challenging each year. Live mixing has become more complex with things like aux-fed subs, ambient mics (for IEMs or audio for video mixes), multiple mix outputs (cry rooms, delay speakers, etc.), and more. This, combined with a falling small/medium digital console price threshold, has made it tougher for manufacturers to field a competitive analog board. Allen & Heath's GL series boards are industry stalwarts and can be found in worship houses (I just worked on an installed GL3300 a few days before this writing), schools and live music venues. Having proven the GL series to be reliable and competent, the folks at Allen & Heath figured it was time for an upgrade. Enter the new GL2400 - available in 16, 24, 32 and 40-channel frames.

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The GL2400-24 I received for review had 22 mono mic/line channels and two mic/dual stereo channels (more on this in a moment), four subgroups, six aux sends, a 7 x 4 matrix and, in A&H tradition, dual functionality to address both FOH and monitors. The board is 32.2 inches wide, 22 inches deep, 6 inches high and it weighs 47.3 pounds.

As a rule, I try to avoid making evaluative statements while describing a review item's features, but in this instance, I must. This console is remarkably feature packed. It will be difficult for me to cover all of its capabilities within the format of this review. Therefore, I'll examine the features that seem most relevant to potential users, with the knowledge that there is likely more below the surface that should affect a buying decision.

As mentioned, the GL2400-24 has 22 mono channels. Each of those channels has an XLR mic/line input and a 1/4-inch balanced line input. These mono channels have individual switches for phantom power, polarity, a line input/ 20 dB mic pad, and a high-pass filter (100 Hz, 12 dB per octave, pre-insert, pre-EQ). Each mono channel also has an unbalanced insert point (pre-EQ, post HPF) and a balanced direct out (pre-fade but switchable to post). The channel EQ is a four-band semiparametric with high and low shelving (12 kHz and 80 Hz) and two sweepable midrange controls (35 Hz - 1 kHz and 500 Hz - 15 kHz, ±15dB, Q1.8). Each of these mono channels is also equipped with 6 aux sends, all of which are switchable pre/post (grouped 1 - 4 and 5 - 6). As a default, the aux sends are wired pre-insert and pre-EQ. However, you can alter that by repositioning the console's internal jumpers - a simple process detailed in the user guide. Rounding out the mono channel strip is a pan pot, a mute button, a solo button (with LED indicator), a four segment signal LED, assignment buttons (1 - 2,3 - 4 and L/R) and a 100mm fader.

There are two stereo input channels on the GL2400. This statement is somewhat misleading because each stereo channel has two pairs of stereo inputs that can be used separately, mixed together or split so that one feeds the channel and one is routed directly the L/R buss. While the stereo channels share many features with the mono channels, they have a scaled back EQ (fixed mid bands at 250 Hz and 2.5 kHz) and the line inputs are summed mono at the aux sends. This can also be altered with the console's internal jumper adjustment system - making the left side line-input feed the odd auxes and the right side feed the even auxes. It is possible to have four pairs of stereo inputs (effects returns, CD playback, etc.) routed directly to L/R and two mics running through the two channel strips.

A significant feature of this board is its dual functionality. In FOH mode, the subgroups and the Left, Right and Mono outputs are controlled by the faders and appear on the board's XLR outs. However, the Mono fader (and its respective output) can be switched to be the master for Aux 6 to control an 'aux-fed sub' arrangement. For those unfamiliar, it entails feeding signal from the kick drum, bass, keyboard (or any other source with substantial low frequency character) to an aux and then routing the output to a crossover that would low pass at roughly 80 Hz - 120 Hz. This eliminates a lot of unnecessary material from the sub-bass signal chain Ñ resulting in a cleaner mix.

Continuing in FOH mode, the aux masters are controlled by rotary pots and their output signal appears on balanced 1/4-inch (TRS) jacks. When the board is converted to Monitor mode (via recessed switches), the outputs and attenuators are swapped. This puts the group and main outs on the rotary pots and TRS output jacks. At the same time, the six auxes flow through the faders (1-4, left and right) and exit via the XLR jacks. What about the seventh M fader? In monitor mode, that becomes a cue wedge control. The M fader's AFL no longer works but the M output becomes the repository for any solo activity (allowing the user to monitor the other monitor mixes).

The most striking new feature to grace this generation of GL boards is the addition of a matrix to the console's master section. On the 2400, there are four matrix outputs that appear on balanced 1/4-inch jacks. There is also a line level input on each matrix for adding external sources like ambience or an "amen" signal for church recordings made from an FOH console. These external in jacks are normalled in a way that allows the user to add one source to all matrices or a stereo source to the pairs of matrices. In a cool twist, this signal can be derived from the mic output of one of the stereo channels (while not interfering with the line inputs on that channel strip).

The master section of the board is also home to a number of LED displays (dual 12-step for mains and a four-step for each master fader), a talkback system, two-track attenuation and routing controls, headphone controls, and a tone/pink noise generator.

In Use

Wow, the bar has definitely been raised for small/medium format analog consoles. The GL2400 is a remarkably well-designed desk. Its level of utility exceeds my "top-of-the-line" medium format analog board (which costs more than double the GL2400-24 $1,999). In fact, I have never seen a board this comprehensive in this price range or in such a small package - regardless of brand.

My first use of the GL2400 was with a large variety band. The board was quickly up to speed running FOH with an aux fed sub, two effects sends, and three monitor mixes. Headroom was excellent and the mic preamps sound very clean. While all the switches and connectors seem very sturdy, the faders feel lightweight with a grainy travel sensation. In the past I was frustrated using some GL series boards for the 'one or the other' method of utilizing auxes or groups. That is no longer a concern as this desk has true dual functionality. The matrix is a very welcome addition that adds flexibility and I found the tone generator and the individual polarity switches to be assets too. Having direct outs on all the mono channels is a boon to multitrack recording or feeding an Aviom-style personal monitoring system. I love the fact that you can alter the signal chain by way of the internal mechanical jumper system. It should be noted that the GL2400 has provisions for an external backup power supply and linkage to other A&H consoles.

On the downside, I noticed that the board has an internal cooling fan that generates an audible tone-- possibly confused for a distant feedback cycle. Also, given the attention to detail and function of this board, I was very disappointed to see the aux master outputs appear as TRS connectors.


Analog is alive and well! If the GL2400 proves to be as durable as its predecessors, it is destined for widespread acceptance. Given its size and price, it is an amazingly comprehensive board that will be perfectly suited to worship houses, nightclubs and small sound companies like mine (where a board might be used for FOH one night and monitors the next). It is easy to use and powerful - a must for analog boards to continue in this digital era.