Because of the tremendous interest in audio recording on smartphones, I decided to do a little testing of my own. I tested the onboard mics, plus two external mics (a lavalier and a shotgun) connected through the headset (TRRS) port, and compared the results to those obtained with a dedicated recorder, my Sony PCM-M10 (see “My decisions in choosing a sound recorder”). For smartphones, I used my Galaxy S3 (Android Jelly Bean) and a friend’s iPhone 5 (with iOS 7). I also compared a friends iPad mini (iOS 6) to the Sony recorder. I used a KVConnection TRRS adapter for powered condenser mics, as both my lavalier (Pearstone OLM-10 omni) and shotgun (Audio Technica AT897) were battery-powered mics.
Samsung Galaxy S3
This was the US-Verizon version of the phone, using the Smart Voice Recorder and RecForge Pro apps. For recording, the phone was set to airplane mode and the noise reduction feature for calling was turned off.
I discovered right away that Samsung has modified the ability of the microphones to record sound. All recordings made through the TRRS port show the results of a noise gate and low-cut filter. What this means is that background noises (if they are not too loud) and low frequency noises are cut from the recordings. Close, loud sounds, like a voice spoken or sung into a microphone are recorded, but everything else is silenced. This only occurs when an external mic is attached, not with the onboard mics. The effects of the noise gate varied by mic; the lavalier sounded fine, but the shotgun sounded warbled, as the mic didn’t ramp up fast enough, sometimes missing the start of the speech. Using the onboard mics didn’t have a noise gate, but the quality was only so-so. Reviewing videos of external mics, like the iRig MicCast, the noise gate was obvious. If you are trying to record close dialog and want to exclude background noise, this is a good feature. If you want to record ambient sounds, this is horrible. Some of the fancier recording apps allow you to apply a noise gate; I wish Samsung had left that option with the user, rather than taking it away from us. There are many reports of poor audio quality when recording video with the Samsung Galaxy S3, which may have something to do with the noise reduction features.
The following video of the iRig Mic Cast shows how a noise gate works. In this case, the Mic Cast is supplying its own noise gate on top of the Galaxy S3 noise gate to reduce background noise.
I previously tested the SmartTech.com MUYHSMFF 3.5 headset splitter adapter and the Rockit headset splitter adapter on the Samsung S3. I first thought the noise gate was a problem of incompatibility with the connectors and returned them. The SmartTech adapter worked the same as the adapter from KVConnections. The Rockit headset splitter was even worse; it appears to be an adapter for a different set of microphones.
This was an iPhone 5 running iOS 7.1, using the Voice Memos app. I used the same microphones as above, plus the onboard mics of the phone. The phone was set to airplane mode before testing.
The iPhone had none of the modifications of the Samsung phone, and did a reasonable recording job with onboard mics, and the lav and shotgun mics. The lack of preamps was obvious though, resulting in a lower recording level compared to the Sony PCM-M10. When the recordings were normalized to the same level, the recordings from the iPhone was noticeably noisier than the dedicated recorder. But overall, the quality was quite acceptable, especially for vocal work. The sound from the onboard mics was quite impressive, although mono, and not as good as the dedicated recorder. Using a relatively inexpensive shotgun, like the AT897, greatly increased the reach of the recording. A higher quality (less noisy) mic might add some very good sound to videos.
This was an iPad Mini that had not been upgraded to iOS 7 yet. I used the AT897 shotgun plus the onboard mics for comparison. We used the Recorder Plus app.
The recording on the iPad was similar to the iPhone except that a low-cut filter was obvious. As with the iPhone, the recordings were a little noisier than the dedicated recorder, but would be good for vocals and louder sounds, but not for distant, quiet sounds. The sound from the onboard mics was quite good, but pulled in a lot of ambient sounds.
Although this was just a test of the headset port on a couple of smartphones and an iPad, the results were surprising, at least to me. I expected better performance from the Samsung, and was startled at how good the iOS devices sounded. The headset port is an analog port; better quality sound can probably be obtained from the charging ports using either dedicated mics (for iOS) or USB mics (for either iOS or Android). Either of these options would be suitable for note-taking, vocal and instrumental work, but smartphones have a way to go before they replace dedicated recorders for nature recording. Sound levels could be increased by adding a preamp or USB audio interface. However, if you are looking to set up a home studio, it is quite feasible to connect your studio mics and preamps to a tablet as your DAW. iOS devices are light years ahead of Android when it comes to sound recording. The software and hardware are more mature. Currently Android devices are limited by hardware inconsistencies and lack of suitable apps for anything but the most basic recording.
I think the noise gate really limits the usefulness of the Samsung galaxy phones as recording devices. I do not know if the Note or Galaxy Tabs also have this noise gate. Other smartphones, like the HTC One and several recent Nokia Lumias are reported to be decent audio recorders.
Last modified June 2016.