#MOJO Demystifying Microphone/Headphone Interfaces

As soon as you start working on mobile journalism pieces, two things become apparent. Bad audio can completely wreck a video and to be confident you need to monitor the sound you are recording, using headphones (see my article here).

Whilst the on-board mics in your phone are fine for ambient sound, to isolate people you need to use some form of external microphone. A popular choice for #mojo reporters is the Lavaliere (lapel/tie clip) mic, which can be discreetly placed on your subject. For reporters working to camera, some may prefer a stick mic (some models are specifically designed with longer bodies, to facilitate a good working distance)

XLR Connectors Microphone/iRig/Rode Lav

XLR Connectors Microphone/iRig/Rode Lav

No matter what you choose, most professional microphones use XLR connectors (see note below) and some require a power source to work (referred to as Phantom Power). So your first consideration is to find a way to plug these into your phone, some kind of interface box.

There are a few options currently available and a few new models about to be released. The most popular options for #mojo reporters at the moment, are the iRig Pre and iRig Pro. These are made by IK Multimedia, a company that produce recording interfaces for musicians using tablets and phones. Both of these models are essentially high quality preamps. They boost the microphone output so that the gain in the phone can be kept low, to avoid introducing noise.

The iRig Pre is the cheaper of the two options (around £24 in the UK). The output is analogue. It contains a 9V PP3 battery to provide phantom power for microphones and has a gain control. It connects to the phone via the headphone socket. It also has its own built in headphone socket, to allow you to monitor the output. The sound quality is good.
• Relatively cheap but still good quality.
• Compact.
• Allows you to use phantom powered microphones.
• Has an attachment point so that you can connect it to your tripod, with a Velcro strap.
• With older phones that have short battery life, it leaves the lightening connector free so you can still use an external battery.
• Works with many Android Phones (see here)
• Slight loss of quality because its analogue. Introduces a little bit of hiss at high levels, but still very good sound.

I wrote a longer review of the iRig Pre last December here

The other option is the  iRig Pro (£97 in the UK). This converts the analogue signal from a microphone to a digital output and connects via the lightening connector. Again it has a gain dial and is powered by a PP3 battery. You monitor your sound by plugging your headphones directly into your phone. Sound quality is excellent with a good microphone.
• Excellent clean sound.
• Allows you to use phantom powered mics.
• Comes with adapters to fit iPhones (old and new) and even your computer.
• Relatively Expensive.
• Slightly bigger than the Pre.
• If you are using an older phone that has a short battery life, you can’t plug in an external battery.
• No convenient attachment point.
• Only works with iPhones.

The other option shown in the picture is the RØDE SC6 (£11.50). This is the cheapest solution, I featured it in my budget kit for students. It is passive, there is no built in preamp. It will allow you to monitor your sound, but only works with TRRS microphones designed specifically for smart phones. The most popular of these is the RØDE Smart Lav+.
• Good sound with the RØDE Smart Lav+.
• If you are on a tight budget this is a great start.
• Doesn’t require a battery.
• It is so small and convenient that I carry this and a Smart Lav+ all the time.
• Not very versatile, only works with TRRS wired microphones.
• No gain control, so levels must be set in the app you are using.

So what to buy? All three options are much better than nothing at all and even with the cheapest option, the Røde SC6 you get good sound. For a balance of cost and versatility my choice would probably be for the iRig Pre. At £24 it is relatively cheap and will allow you to use a variety of microphones. Sound is analogue, but still very good. If you need to plug in an external battery to power your phone this is also the best option. If cost is not an important consideration and you are using an iPhone, the iRig Pro with its digital converter delivers the best sound. Hope that helps!

Note: Balanced XLR Connectors are used for professional microphones. They allows for the use of long cables while reducing susceptibility to external interference. They are also more robust, than consumer plugs.


3 thoughts on “#MOJO Demystifying Microphone/Headphone Interfaces

  1. This is very timely, I’ve been trying to decide between these recently. The SC6 and the Smart Lav have just arrived in the post, although I can see myself getting a hand held mic soon. An article with your thoughts on XLR mics compared to something like the iRig HD would be appreciated! Thanks, I enjoy the blog.

  2. I have now to decide between the audio technica lavalier mic with long cable and the smartlave which sounds better with short cabe. I bought the pre ireg but there is only an xlr input connector which the label mics don’t have?? Help please

  3. Angelina
    Neither of those mics are ideal for use with the iRig Pre, which is designed to work with XLR connected microphones.

    The Audio Technica (do you mean the ATR-3350 ATR?) uses a standard 3.5mm stereo plug and the other uses a 3.5 mm TRRS connector. So there are a few solutions:
    • Forget the iRig and buy the Rode Smartlav+ and the SC6 interface and a TRRS extension (Rode do the SC1 or Amazon do a very cheap 2 mtr option at £3.50).
    • If you want to use the iRig, as a compromise you could try an XLR to 3.5mm converter (Røde VXLR) with the Audio Technica. I have not used this combination, but it should work.
    • The other option would be to use the iRig Pre with a budget Lavaliere/XLR mic. I know the guys at RTÉ like the MXL FR 361 which is very competitively priced, but not available everywhere (see here). It sounds excellent in Glen’s test. I have not been able to source them in the UK.

    Hope that helps. Let me know ho you get on, or if you have any more questions.

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