Stuart has an HTC Android smartphone and would like to connect an external microphone

Last modified on Tue 21 Feb 2017 13.19 EST

Can I use an external mic with my HTC One M8 for better sound quality? I would like to record talks/meetings/outdoor sounds etc. Stuart

One of the odd things about smartphones is that they are generally not very good at audio. This is partly a handset design problem, and partly a network design problem. Using an external microphone to record sounds avoids both problems, so the results should be acceptable. However, as with cameras and other features, a smartphone won’t match a dedicated device, such as a handheld digital recorder.

When it comes to handset design, smartphones are optimised for on-screen operations such as apps and browsing, not for voice. The microphones are tiny and you might well have a problem locating them. Mobile phones also operate with a very restricted frequency range, perhaps 300Hz to 3.4kHz, and use low-cut filters and noise gates to suppress background noise. Worse, most only support mono recording, not stereo. Handsets that support HD Voice (Wideband audio) or 4G’s Voice over LTE (VoLTE) should have better audio capabilities, though they still can’t provide the twice-CD-quality stereo of a handheld recorder.

Some smartphones have more than one built-in mic: one is used for recording while others are generally used to detect and remove background noises. (The Lumia 1020 is one of the few smartphones that records good quality stereo.)

When it comes to network problems, mobile phones are designed to use very low bit-rates. In fact, the Enhanced Full Rate (EFR) codec used for GSM voice calls offers a maximum of 12.2kbps, which is a fraction of what you’d get from a landline. Again, HD Voice offers better quality, but both handsets have to support it, and so does all the network equipment between the two phones.

There are two main ways to fit an external microphone to a smartphone: either it plugs into the headphone/mic socket, or connects via a microUSB or similar port. (The third way is via Bluetooth, but this seems to be very limiting.)

In this case, you need a jack-plug with three rings on the end, which is capable of making four connections, ie there’s one extra band for the mic. Technically, these plugs are known as TRS (Tip Ring Sleeve) connectors, and you will need a TRRS version to make mono recordings. TRRS jacks can’t handle stereo.

Just to complicate things, TRRS plugs come in two different types, with the mic connection being in a different place. The original Nokia standard for GSM was called OMTP (Open Mobile Terminal Platform), while the newer one is called AHJ (American Headset Jack). I note that Nokia switched to AHJ when it launched its Lumia phones, and it has also been used by HTC and other Android manufacturers. Apple uses an AHJ layout with non-standard signalling and controls: it’s sometimes referred to as CTIA. Software may be able to handle some of the differences.

GSM Arena only says “3.5mm jack - Yes” for the HTC One M8, so I don’t know if it has an AHJ socket. There are adapters, but jack plugs are flaky at best -- the design goes back to 19th century switchboards -- so I’d recommend getting the right type.

There are lots of mics available, and I have no idea which is best. Most seem to be Lavalier microphones, which are generally used as lapel mics for TV and theatre performances, and for interviews. Examples include the Boya BY M1 (£11.99) and the Rode Smartlav+ Lavalier Microphone for Smartphone (£40.33). There are also traditional condenser mics like the Prodipe iMic 70051 Microphone for Apple and Android-Based Smartphones/Tablets (£27.23). I don’t know if these will work with your M8. Perhaps Ask Jack readers can recommend products they have used, ideally with HTC phones.

Personally, I’d lean towards the IK Multimedia iRig Mic Cast based solely on its reputation in the Apple market. The website says it now works with Android devices “compliant with the CTIA/AHJ wiring standard” including “Samsung, LG, Motorola, Google Nexus, HTC, Huawei and Sony”.

USB recording has some significant advantages. It’s digital rather than analogue, it bypasses the audio circuitry built into the smartphone, and it enables better-than-CD-quality recording. The HTC One M8 does have a powered USB Host port -- it supports USB-OTG (USB On-The-Go) so it should be able to handle a USB microphone or a mic plugged in via a USB-to-audio-jack adapter.

The USB approach has become better known thanks to the Apogee MiC 96k, which adds a “studio quality cardioid condenser microphone” to an Apple iPhone or iPad. However, at the Apogee’s £169.99 UK price, it would be cheaper to buy a separate handheld recorder.

You might be able to do the same sort of thing with a Yeti USB microphone from Blue Mic -- Amazon UK has one for £99.99 -- and eXtreme’s USB Audio Recorder Pro app. (The blurb says: “eXtream Software Development has written custom USB audio code from scratch because Android does not support USB audio.”)

The HTC One M8 is on the list of “working Android devices”. If you already have or can borrow a supported USB microphone and a USB-OTG cable then it might be worth downloading the trial version of USB Audio Recorder Pro and having a go. If not, it’s probably better to leave this idea until the Android operating system and supporting ecosystem have caught up with iOS.

It’s true that smartphones can be very convenient for recording audio, and it’s also true that an external mic will improve the quality of the recordings. If you had an iPhone, you could just buy an IK Multimedia iRig Mic Cast, plug it in, and expect it to work. However, Android lags iOS in support for recording audio, and it’s trickier to select a microphone and suitable software. You might be able to find a solution, but there are plenty of reasonably priced stereo digital recorders from companies such as Tascam, Zoom, Sony and Yamaha. You’d probably be better off buying one of those, for now.

Have you got a query? Email it to Ask.Jack@theguardian.com

This article contains affiliate links, which means we may earn a small commission if a reader clicks through and makes a purchase. All our journalism is independent and is in no way influenced by any advertiser or commercial initiative. By clicking on an affiliate link, you accept that third-party cookies will be set. More information.