How To Choose the Right Speaker Microphone for Your Two-Way Radio


6/28/22 – The article has been updated with information regarding the R7 and Ion radios.

Once you’ve decided on the best Motorola Radio for your needs, the next step is to determine the right audio accessory for your two-way radio. For many businesses the Remote Speaker Microphone (RSM) is the accessory of choice for audio clarity, wear-ability, and durability.

Carefully selecting the right speaker microphone for your use case and operational environments can make a huge difference in terms of user satisfaction and adoption of the equipment. After all, without a usable microphone that’s suited to the requirements of your personnel, two-way radios would cease to provide the reliable, instantaneous communication that you need.

Carefully consider the following factors to choose the right microphone for your two-way radio.

Operational Features

Your operating environment will dictate some of your microphone needs for your two-way radio solution. Consider the following categories.

Noise Suppression Technologies

Many Motorola speaker microphones will include a noise reduction feature to help you operate in loud environments that could otherwise interfere with your audio. However, due to the nature of the noise reduction technology, these mics may provide diminished performance if used improperly.

Pay careful attention to the features of each.

  • Windporting: Two-way radio microphones from Motorola Solutions that boast Windporting technology are specifically designed to reduce wind or highway noise when transmitting. The microphone is omnidirectional, meaning speaking directly into the mic is less critical.  This can be helpful for inexperienced radio users.
  • Noise cancelling: Mics that are listed as noise cancelling are able to remove background noise when transmitting. However, the microphone is considered directional. They should be used two to three inches from your mouth for the best audio.
  • Dual-mic noise suppression: These two-way radio microphones leverage a second mic and the user can talk across them, meaning you get the benefit of noise cancellation/suppression with the forgiveness of a more omnidirectional type of microphone.

Also while it is a bit of a misnomer, the windporting mics perform best of the three in extremely loud environments.  The noise cancelling/noise suppression mics have a sweet spot of about 70-100 db in ambient noise, while the windporting mics will perform through a wider spectrum of background noise.

Protection from water and dust – IP Rating

Radio users who work outdoors or in rugged environments may need a higher ingress protection (IP) rating than office or light duty workers. The first digit in an IP rating refers to the ingress of solids, while the second digit refers to the ingress of liquids.

All Motorola speaker mics have at least a “5” rating for dust and particles, meaning dust protected.  A few models have a “6” rating which is the maximum on the scale which would be considered dust tight.

All Motorola speaker mics have at least a “4” rating for water, meaning it can handle splashing water.  Speaker mics that are considered water submersible carry a “7” rating or better, meaning they can handle water submersion for 1 meter for at least 30 minutes.

Collaborate with internal stakeholders to determine the IP rating that’s necessary for safe, continuous operation of your two-way speaker microphones.

Intrinsically Safe

Are Motorola speaker microphones intrinsically safe?

This question comes up quite often as some models specifically call out intrinsically safe as a feature, but all wired Motorola original speaker mics for the 3000/6000/7000 series are actually intrinsically safe.  Since 2012 Motorola has used the intrinsically safe standard set by the Telecommunications Industry Association (TIA) for equipment used in Class I, Division 1 hazardous locations.  That means that the equipment will not create a spark in hazardous environments.  The TIA4950 certification is modeled after the Underwriters Laboratory (UL) standard test, so certified equipment may be marketed as TIA or UL certified.  Older mics may use the Factory Mutual (FM) standard so pay careful attention to the specific language in your safety and insurance requirements.  Ask your safety manager if you need clarification.


Ambient Noise and Receive Audio Quality

What is the ambient noise level of your work environment?  Is it low, medium, or high, or a combination?  Ambient noise is of the utmost importance when deciding which two-way radio microphone will work best for your needs. Motorola has developed some specific technologies to tackle accessory use in low, medium, high, and mixed noise environments.

  • IMPRES: This feature ensures that your radio will be optimized for use with the mic. If you speak quietly or normally, but not directly into a microphone, IMPRES Audio detects changes in your voice and automatically adjusts the transmitted volume so your listener won’t have to adjust volume up and down.
  • Intelligent Audio: Mics with this feature adjust audio come through at the right volume based on the ambient environment of the user. (no loud radio squawk in a quiet office)
  • SINC+: With this capability, you’ll enjoy enhanced noise suppression.

Some of these features can be programmed in the radio itself and can have adverse effects if a microphone is used in conjunction with these features.  For instance, you may have negative experience if using a SINC+ microphone together with a radio with SINC+ enabled.  Speak to your rep if you have a question on your radio audio profile.

Miscellaneous features

In addition to the high-tech considerations that influence which microphone is right for your two-way radio, look for these features. Together, they can add up to a big impact on overall usability for your PTT solution.

  • Volume control: Does the speaker microphone make it easy for you to adjust the volume to a level that works for your operating environment?
  • Programmable button: In addition to PTT’s simplicity and convenience, are you able to program your button to support other functions as needed, IE emergency button?
  • Audio jack: Do you have the option of attaching a wired earpiece for easier listening or more private/discreet communication?

Need a Longer Cord?

Some taller users just need a longer cord to reduce strain on the connector and cord.  Starting in mid to late 2020, most speaker mics will be orderable with a 12 inch longer cord.  It will have the same main part number but it will end with a L, for “longer cord”.

For instance, the part number would look like this PMMN4025AL.  Speak with your Day Wireless sales representative if you need to check the availability of the “longer cord” mic in your desired model.


Remote Speaker Microphone Models for Mid and High Tier Portables


  • PMMN4127 – WM500 Wireless Bluetooth
  • PMMN4128 – RM780 IMPRES, IP68, HAZLOC
  • PMMN4131 – RM730 IMPRES, Windporting, SM, IP68*
  • PMMN4140 – RM760 IMPRES, Windporting, LG, IP68*
    *R7 only


XPR 7000e, XPR 7000, or XPR 6000 Series

  • PMMN4024 – Windporting, SM
  • PMMN4025 – IMPRES Windporting, SM
  • PMMN4040 – Windporting Submersible IP57, SM
  • PMMN4046 – IMPRES Windporting Submersible IP57, LG
  • PMMN4050 – IMPRES Noise Cancelling, LG
  • PMMN4099 – IMPRES Windporting Submersible IP68, LG
  • NNTN8382 – IMPRES Industrial Noise Cancelling, Dual Mic, Submersible IP57, LG
  • NNTN8383 – IMPRES Industrial Noise Cancelling, Dual Mic, LG
  • RLN6561 – Wireless Bluetooth Windporting, LG


XPR 3000e or XPR3000 Series

  • PMMN4073 – IMPRES Windporting Remote Speaker Mic, SM
  • PMMN4071 – IMPRES Noise Cancelling Remote Speaker Mic, LG
  • PMMN4075 – Windporting Submersible IP57 Speaker Mic, SM
  • PMMN4076 – Windporting Speaker Mic, SM

Top Choices

As you can see there are many options and considerations to make when selecting a remote speaker microphone for your radios.

The top seller compatible with the MOTOTRBO R7 & ION radios is the PMMN4128.

The top sellers compatible with the MOTOTRBO 6000/7000/e series radios are the PMMN4025 and the PMMN4050.

The top sellers compatible with the MOTOTRBO 3000/e series radios are the PMMN4073 and PMMN4071.

Let Day Wireless Help You Select the Right Microphone for Your Two-Way Radio

At Day Wireless, we’re experts in finding the right equipment for your specific needs. Find out what accessories are available for your two-way radio or contact us today to speak with a representative.

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