Allen & Heath AHM-32 audio matrix processor: rear panel, wiring and setup guide
The AHM-32 is a 1U audio matrix processor for installs: paging, zoning, conferencing and speaker processing. It has 12 mic/line inputs and 12 line outputs on Phoenix connectors, a 2 x 2 GPIO, a control network port and an I/O Port slot for expansion or Dante. Click any connector on the panels below to see what it does.
- 1U rack mount
- 12 x mic/line in (Phoenix)
- 12 x line out (Phoenix)
- 32 x 32 matrix
- 2 x 2 GPIO
- I/O Port slot
- 96 kHz
AHM-32 specifications
| Model | AHM-32 |
| Form factor | 1U, 19 in. rack mount or free standing |
| Dimensions (W x D x H) | 482.6 x 270 x 44 mm (19 x 10.6 x 1.7 in.) |
| Weight | 4.0 kg (8.8 lb) |
| Processing matrix | 32 x 32 |
| Local analogue I/O | 12 mic/line inputs, 12 line outputs |
| Zones | Up to 32 mono or 16 stereo |
| Expansion | I/O Port, up to 128 x 128 |
| Mic/line inputs | Balanced, recallable preamps, +5 to +60 dB gain, -20 dB pad, +48V |
| Line outputs | Balanced, +4 dBu nominal, +21 dBu max, relay protected |
| GPIO | 2 inputs (switch to ground), 2 relay outputs, +10V DC out (200 mA max) |
| Control | Gigabit RJ45 network port |
| Front panel | LCD screen, select buttons, 8 SoftKeys |
| Sample rate | 96 kHz |
| Playback | About 2.6 GB internal storage, WAV and MP3 |
| Power | 100 to 240V AC, 50/60 Hz, 70 W max, IEC inlet |
| Operating temperature | 0 to 40 °C (32 to 104 °F) |
| Default IP address | 192.168.1.91 (subnet 255.255.255.0) |
Every connector on the AHM-32, explained
Click a card to light up those connectors on the panels above.
12 mic/line inputs and 12 line outputs24 on the panel
The top row holds 12 mic/line inputs on 3-pin Phoenix connectors. Each one is a recallable preamp with gain, pad and 48V phantom power set in software, so any socket can feed any input channel.
The bottom row holds 12 balanced line outputs at +4 dBu. They are relay protected, so the amps downstream do not get a thump at power on or off.
Each socket takes one of the supplied 3-pin Phoenix plugs (+, - and ground). Use the strain relief on each plug to keep the wiring tidy.
GPIO2 on the panel
One 10-pin Phoenix plug covers the GPIO: 2 relay outputs and a +10V DC supply on the GPIO Out side, and 2 inputs that switch to ground on the GPIO In side. Use them for things like a fire alarm mute, a paging button or a room combine switch.
Output 1 can be wired normally closed or normally open, output 2 is normally open. The +10V supply can deliver 200 mA in total. For more current, use an external supply up to +24V DC, with up to 400 mA through any output.
Network (control)1 on the panel
Gigabit RJ45 port for control. Connect a laptop, a switch or a wireless router to reach AHM System Manager, the IP remote controllers, the Custom Control app or a TCP control system such as Crestron or AMX.
This port carries control only. Audio expansion goes through the card in the I/O Port.
AC mains in1 on the panel
IEC inlet for the internal universal power supply, 100 to 240V AC at 50/60 Hz. The unit draws up to 70 W.
Bring your own cable. The Phoenix plugs ship in the box (1 x 10-pin and one 3-pin plug per socket), so you only need balanced audio cable and a small flat screwdriver.
The I/O Port slot
The large blank plate on the back is the I/O Port. Fit an option card there for up to 128 x 128 channels of expansion or audio networking. The card you choose decides what plugs in.
- SLink card: connects Allen & Heath expanders such as the DX168, DX32, GX4816, AR2412, AR84 and AB168, a DX Hub, another AHM, or an SQ, Avantis or dLive system. It detects the expander and sets the protocol and speed itself.
- Dante card: use the M-SQ-DANT32 or M-SQ-DANT64 (SQ Dante V2). The original M-SQ-DANTE card is not supported. DT168 and DT164-W Dante expanders need one of these cards for preamp control.
Network reset lives here too. Behind the I/O Port panel is a DIP switch block. Set switch 6 to On, power up, wait 10 seconds, power off and set it back to Off to return the network settings to default. Leave the other switches alone.
What is on the front
- LCD screen and select buttons. Use the arrow keys to step through firmware version, network settings and diagnostics. Handy for reading the IP address before you connect.
- 8 SoftKeys. Assigned in AHM System Manager for mutes, levels, preset recall, preset select, paging and zone source select.
Rack mounting and cooling
The AHM-32 is 19 in. wide, 1U high and 270 mm (10.6 in.) deep. Remove the stick-on feet before you rack it and keep them for later.
- Leave air space in front of and behind the unit so it can cool by natural convection.
- Do not mount it directly above or below gear that runs hot, such as power amplifiers.
- In a tight or warm rack, add a rack fan tray.
Processing expansion module
The AHM-32 takes an optional internal processing module for features like AEC (acoustic echo cancelling) in conference rooms. A qualified technician should fit it, following the instructions that come with the module.
First connection
- Wire your inputs and outputs to the Phoenix plugs and push them into the rear sockets.
- Connect the Network port to your laptop or control switch with a CAT5e (or better) cable up to 100 m.
- Set your laptop to a static IP address on the same range, for example 192.168.1.10. The processor ships at 192.168.1.91.
- Open AHM System Manager to set up inputs, zones, SoftKeys and presets.
- For apps on a phone or tablet, set your Wi-Fi router to 192.168.1.254 with a DHCP range such as 192.168.1.100 to 192.168.1.200.
Remote access. For System Manager or Custom Control over the internet, use a VPN. If you must forward ports, the processor uses TCP 51321 and UDP 51324, and TCP 51325 (or 51327 with TLS) for third party control.
Processing at a glance
- 32 x 32 processing matrix with up to 32 mono or 16 stereo zones.
- 4 automatic mic mixers, ambient noise compensation and priority ducking. AEC with the optional processing module.
- 8-band PEQ, dynamics and delay on every input and zone.
- Speaker processing with crossover filter, delay, limiter and PEQ.
- Event scheduler and 16 user profiles.
- Works with the IP1, IP6 and IP8 remote controllers and the GPIO interface.
Frequently asked questions
What connectors does the AHM-32 use for audio?+
3-pin Phoenix (Euroblock) connectors: 12 mic/line inputs and 12 line outputs. The plugs come in the box.
Does the AHM-32 support Dante?+
Yes, with an option card in the I/O Port. Use the M-SQ-DANT32 or M-SQ-DANT64 (SQ Dante V2), not the original M-SQ-DANTE card.
What is the default IP address of the AHM-32?+
192.168.1.91 with subnet mask 255.255.255.0 and gateway 192.168.1.254.
How do I reset the AHM-32 network settings?+
Remove the I/O Port panel, set DIP switch 6 to On, power up, wait 10 seconds, power off and set switch 6 back to Off.
How much power does the AHM-32 use?+
Up to 70 W from 100 to 240V AC, through an IEC inlet.
Can the AHM-32 work with third party control systems?+
Yes. Use the GPIO for contact closures, or the TCP protocol over the Network port. Allen & Heath publishes drivers for systems such as Crestron and AMX.
Plan this audio dsp in your rack
The AHM-32 is in the Allen & Heath library for DaMatrix, with every port mapped so you can drag it into a rack, patch it and print the documentation.
Related Allen & Heath devices
Summarized from the Allen & Heath AHM-16 / AHM-32 Getting Started Guide, Issue 3. This page is a quick reference; check the full manual for safety warnings and model-specific limits.