Wireless Microphone Buying Guide (2026): TrueWave Pro AIR-B2 vs AIR-B4

Choosing a UHF wireless microphone system for your church, school, conference room or events business comes down to two questions: how many microphones do you need at once, and how reliable is the system in the real world?

The TrueWave Pro AIR series gives you two answers: the two-channel AIR-B2 and the four-channel AIR-B4. Both are RCM compliant, rechargeable and supported locally in Australia. This guide shows you exactly which one to buy.

Jump to: Quick answer · Side by side · How to choose · Setup · Replacing a Phenyx PTU · FAQ

The quick answer

Both are true-diversity UHF systems with rechargeable lithium microphones, individual balanced XLR outputs and IR sync.

What both systems have in common

• RCM compliant for Australia. Tested to AS/NZS 4268 and operating below 694 MHz, inside the band set aside for wireless microphones here.
• Rechargeable microphones. Each handheld uses a removable 18650 rechargeable lithium cell (about 10 hours per charge), with magnetic charging cables in the box. No disposable batteries.
• True Diversity reception. Two antennas per channel constantly pick the stronger signal, which means fewer dropouts on stage and across a room.
• IR sync. Point a microphone at the receiver and it pairs in seconds, with no manual channel matching.
• Clean, flexible outputs. A balanced XLR output for every channel plus a 6.35 mm mixed output to feed a single input.
• Local warranty and spares. 12-month warranty handled in Australia, with spare handhelds, bodypacks and charging docks sold separately.

AIR-B2 vs AIR-B4: side by side

How to choose the right one

• Counting your microphones is the main decision. If you'll never need more than two live mics at once (a presenter + a Q&A mic, a vocalist + a guest), the AIR-B2 is all you need. If you run panels, worship teams or multi-speaker events, step up to the AIR-B4.
• Think about growth. If you're close to needing three mics, the AIR-B4 gives you headroom without buying a second system later.
• Consider the install. Fixed rack? The AIR-B4's 1U receiver drops straight in, and Auto Scan finds clear frequencies for you. Portable or outdoor? The AIR-B2's compact receiver runs from USB-C, including a laptop or power bank.
• Handhelds vs lapel/headset. Both ship with handheld mics. For hands-free use, add the AIR-BX-B1 bodypack, which includes a lapel and a headset mic and pairs with either system.

Setup: find a clear frequency, then sync the mic

Every wireless system needs to sit on a frequency that is clear at your venue. The two-step process is the same on both models:

1. Find a clear frequency. On the AIR-B4, Auto Scan searches for a clean frequency for you. On the AIR-B2, you choose a clear channel on the receiver yourself. Television shares the wireless microphone band, so check the ACMA Channel Finder for the TV channels active at your address.
2. Share it with the microphone using IR sync. Point the microphone's IR window at the receiver and the frequency is copied across in seconds. Repeat for each mic.

Running more than one wireless system in the same room? Give every microphone its own frequency.

Replacing a Phenyx PTU system?

The Phenyx PTU-71-2H, PTU-52-2H, PTU-2U-2H and PTAU-2 two-mic systems are no longer available from MSM AV. The AIR-B2 is the like-for-like replacement for two-microphone setups. For four-mic setups previously on the PTU-7000-4H or PTU-5000-4H, choose the AIR-B4. Some Phenyx systems are still in stock: see the Phenyx Pro wireless microphones collection.

Frequently asked questions

Are these legal to use in Australia?
Yes. Both systems are RCM compliant and operate below 694 MHz, in the Australian wireless microphone band. Television shares the band, so choose channels that are clear at your venue.

Do I still need batteries?
No disposables. Each microphone uses a removable rechargeable lithium cell and comes with a magnetic charging cable. Keep a spare cell charged for back-to-back events, or add an AIR-BX charging dock.

How many systems can I run in the same room?
Each channel has 100 selectable frequencies, so several systems can run together on different frequencies. The AIR-B4's Auto Scan makes this easier. For large multi-system setups, get in touch and we'll help you plan channels.

What do I plug them into?
Any mixer, powered speaker or interface with XLR or 6.35 mm (1/4") inputs. Use the individual XLR outputs for full control, or the single mixed output to feed one channel.

Can I buy a spare microphone?
Yes. The AIR-BX-H1 handheld pairs with both the AIR-B2 and AIR-B4.

Related guides

• What is True Diversity wireless microphone technology?
• How many wireless microphones do you need? A venue-by-venue guide
• Rechargeable vs AA battery wireless microphones: the real running costs
• Wireless microphones for churches in Australia
• AIR-BX-H1 handheld vs AIR-BX-B1 bodypack

Not sure which fits your venue? Contact the MSM AV team and we'll help you pick the right system.

Prices in AUD including GST at the time of writing. See product pages for current pricing.