USB / Stereo / Binaural Recording This help section discusses how to do Stereo Recording using: - built-in microphones (mono, stereo) - external wired microphones (mono, but not stereo) - external USB mono and stereo microphones - Binaural stereo recording (realistic) Most devices will allow recording using the built-in microphones on android devices. There are exceptions however, such as the Nexus 4 which did not support stereo audio, and the LG G6 which famously would record stereo in their Camera app, but not with audio recorder apps. However, most modern android devices (including the cheaper devices) have 2 microphones or more built into the device. The extra microphones are used for noise cancellation, and for allowing stereo audio recording. Limitations of the earphone jack on android and iPhone devices The earphone jack on android devices (and iPhone devices when they used to have earphone jacks) can only support mono microphones. This is called a TRRS 3.5mm jack, and only has support for one wire for microphone - i.e. mono audio only. This is the reason you don't want your headset (with mic) plugged in when you want to record stereo audio. Unplugging the headset ensures that the android device's built-in microphones are used. However, if you use an earphone (without any microphone in it), then you can keep that plugged in while recording, and it will allow use of the device's built-in microphones. Since the earphone jack allows mono microphone input, you can plug in an external wired lapel mic (the type you would use with your PC or Mac computer), and it will record mono audio using external lapel mic. Summary: the earphone jack on android phones accepts input from mono microphones, and outputs stereo audio. Testing stereo recording with built-in microphones First try stereo recording using the built-in microphones of your android device. To test if stereo audio recording works on your device, first click Settings - Record Settings - Stereo Recording - and turn it On. NOTE: the earphone jack on android devices (and iPhone devices when they used to have earphone jacks) can only support mono audio (the earphone jack standard only has support for one wire for microphone - thus mono audio only). This is the reason you don't want your headset (with mic) plugged in when you want to record stereo audio. Now unplug any headset from your android device. This will ensure that the android device microphones are used (instead of the external microphone on the headset). Now when you press Record button, your device will record in stereo audio. Blow on the bottom side of the phone or say 'bottom', and then on the top side of the phone and say 'top'. To check if the recording is indeed stereo, now plug in headset or earphones, and then press Play button. You will hear the words 'bottom' and 'top', that you said during recording, and will know which ear corresponds to which side of your phone. Summary: to test stereo recording, you should Record without any headset plugged in, and then plug in headset or earphones before you press Play, to listen to the recording. Troubleshooting when stereo audio is not working If you carried out the above test, and the sound in both ears was the same, and you heard 'top' and 'bottom' in both ears with equal volume, that means the device is not recording in stereo. NOTE: to be precise, the audio is being saved correctly as a stereo audio file (since you have turned on the Stereo Recording setting), but the actual data for left and right ear is identical, so when you listen to it, it sounds just like a mono audio file. This is quite common with android devices, and there is a simple fix for this - click Settings - Record Settings - Audio Source for Stereo - and try the different settings. After changing this setting, repeat the testing procedure above to check for stereo. Eventually you should find a setting that works, and is giving you good quality stereo audio in both ears. NOTE: as described in the testing procedure above, you should Record without any headset plugged in, and then plug in headset or earphones before you press Play, to listen to the recording. So for some audio devices, you will find that stereo audio recording works great with the default settings in our app. But on other android devices, you will find that some other setting of the Audio Source for Stereo is required before stereo recording starts working. Once you are comfortable that stereo audio recording works, you can hold the phone in landscape mode (this way one of the device microphones is on the left and one is on the right - similar to how your ears are aligned), and you will be able to capture good quality stereo audio of concerts, lectures, and environmental sounds. Monitoring recording with earphones while stereo recording You can use the field recorder features of the app to monitor using earphones, while recording in real-time. This can be useful for getting a sense of the stereo sound quality, or for setting the volume level (Effects - Volume), or if you want to adjust the built-in 3-band equalizer (Effects - Equalizer) while recording. NOTE: again, if you really want to monitor the recording while recording in stereo, you have to make sure you use earphones (that don't have a built-in microphone). As explained above, if you use a headset which includes a built-in mono microphone, then that mono microphone will be used for recording, and both ears will sound the same i.e. will not sound like stereo, but like a mono recording. So if you plan on having earphone plugged in while making stereo audio recordings, make sure the earphones have no microphone built into them. Just to be sure, do a test stereo recording with your earphones plugged in, to make sure the result is stereo, before recording an important event. Stereo recording with external stereo microphones As explained above, the earphone jack on android devices (and iPhone devices) can only support single microphone input (because there is only one wire for microphones in the earphone jack standard). This means if you want to use external stereo microphones, it will have to be some other way. Fortunately, since Android Lollipop, android devices support USB microphones. This means you can use USB mono microphones, and USB stereo microphones. These can be plugged into the USB port on android devices. If the ports don't match, you can use an OTG adapter dongle, which is plugged into your android device, and the external USB device is plugged into the OTG adapter dongle. Summary: if you want to use external stereo microphones, you have to use the USB method - for that your device needs to be running Android Lollipop or later. External USB stereo microphones A variety of USB stereo microphone are available. These can be plugged directly into the USB port of your android phone (if the USB plug is larger, then using an OTG adapter). Here are some videos from Youtube demonstrating use of USB microphones with android devices: https://www.youtube.com/watch?v=VVUrNucSU3o Android Lollipop USB Audio by Dave Bennett https://www.youtube.com/watch?v=gqOxD2Tq6e4 Blue Snowball USB Mic and Phone - How To Use A USB Mic With Smart Devices by Kingsley's Tech Channel Some of our users have used the Andrea SB-205 binaural stereo microphones, which provide a USB dongle, and stereo microphones that make binaural stereo recording easy. See below for the section on binaural recording. NOTE: when using a USB mono, or USB stereo microphone with your android device, you may need to do the same steps that were required to get stereo recording with built-in microphones working on your android device. Click Settings - Record Settings - Stereo Recording - and set that to On. Click Settings - Record Settings - Audio Source for Stereo - and try the different settings. After changing this setting, repeat the testing procedure above to check for stereo. Eventually you should find a setting that works, and is giving you good quality stereo audio in both ears. Some USB microphones may require use of a powered USB hub The power requirements of some higher quality USB stereo microphones maybe higher - and thus require use of a powered USB hub, to ensure the microphones are adequately powered. Here are some examples of USB microphones that may require extra power using a powered USB hub: http://www.shure.com/americas/products/microphones/motiv/mv5-condenser-microphone-for-ios-and-usb Shure MV5 https://www.amazon.com/Audio-Technica-AT2020USB-Cardioid-Condenser-Microphone/dp/B00B5ZX9FM Audio-Technica AT2020USB+ Cardioid Condenser USB Microphone, Black USD 150 A review for the AT2020USB+ is given below: https://www.youtube.com/watch?v=kA4RvltO9e0 Audio Technica AT2020 USB+ Review / Test Podcastage Published on Jul 12, 2016 When using large USB microphones like the Shure MV5, that requires 'USB Audio Class 2.0', the microphones may draw too much power - in which case a powered USB hub should be used - as explained below: https://www.head-fi.org/threads/android-phones-and-usb-dacs.595071/page-452 Android phones and USB DACs Quote: USB Audio Class 2.0 mode was drawing way too much power and those PMICs (power management integrated circuits) got deep fried, plenty of victims fried their Android devices before USB hub could be added between XS and your phone, that's what they've been doing after their incidents. End of quote. Here is an example of a USB hub (mentioned in above link) for better safety with these larger mics: https://www.amazon.com/gp/product/B00CXAC1ZW DSYJ Micro USB Host OTG Cable with Micro USB Power for Samsung S7 S7 Edge, S6 S6+ S6 Edge, S5, S4 and Nexus 10 9 7 4 Player + ALL OTHERS USD 3 Binaural stereo microphones - USB dongle (sound card), plus stereo microphones Here we describe the Andrea SB-205 product which includes USB stereo microphones (which are arranged in a way that makes binaural stereo recording easy). This device has been used by our app's users, and seems to work well, without needing a powered hub. The advantage of this product is that it includes a separate USB dongle (USB sound card), and includes separate stereo microphones with line-in type jack. The stereo microphones are plugged into the USB dongle. The USB dongle is then plugged into the USB port on your android device. You can plug any other stereo microphone with line-in type jack (3.5mm) into the USB dongle. The Andrea SB-205 provides good quality (according to feedback from our users). However, there may be other standalone USB dongles which provide even better quality. Here are some links that have been used by our users to purchase the product: https://www.amazon.com/Andrea-Communications-Surround-Recording-SB-205B/dp/B005GAW69M/Andrea Communications 3D Surround Sound Recording Ear Buds SB-205B, Black USD 25.82 https://www.amazon.com/Andrea-Communications-Surround-Recording-SB-205W/dp/B005GAW6BA/Andrea Communications 3D Surround Sound Recording Ear Buds SB-205W, White USD 71 Making Binaural stereo recordings While the Andrea SB-205 has stereo microphones, and also includes the USB dongle (which can be used with other line-in microphones as well), it actually also allows for convenient binaural stereo recordings. The stereo microphones on the Andrea SB-205 are actually mounted inside the headset itself - so when you wear the headset, the two microphones are placed near the left and right ear on your head - which is the location usually used for binaural stereo recordings. Binaural recordings are made to reproduce the sound as heard by a human being, and thus try to include the effects of the human head (the 'head transfer function') on the recorded sound. In practice, binaural stereo recordings do sound more realistic, with a better perception of actually being there. To be clear, the only difference between a binaural stereo recording, and a regular stereo recording, is that for binaural stereo recordings, care is taken to mount the microphones around a real head, or a dummy head meant to mimic the 'head transfer function' of a real human head. So only difference is the placement of the microphones while recording. There are many examples of binaural stereo recordings available on Youtube - here is one example: https://www.youtube.com/watch?v=jc4E27Z3lS4 Binaural Microphones for 3D Sound: Sennheiser Smart Headset vs Scenes Lifelike! Justin Brown - Primal Video Published on Sep 24, 2017 Here is a Youtube video where the Andrea SB-205 headset part (with stereo microphones) is being connected directly into the line-in port on a video camera (not using the USB dongle): https://www.youtube.com/watch?v=lOTrQFeXxCQ My Binaural Microphones - Andrea Electronics SB-205 John Chu Published on Apr 21, 2016 External wired stereo microphones with a line-in jack For external wired stereo microphones with line-in jack (TRS 3.5mm), you need a USB dongle (USB sound card) that has a line-in port where the microphones can be plugged in, and then plug the USB dongle to your android USB port. This will then behave like the USB stereo microphones described above. Here are some examples of wired stereo microphones with line-in type jacks: https://www.amazon.com/Olympus-145037-ME-51S-Stereo-Microphone/dp/B000BTAH62 Olympus ME-51S Stereo Microphone However, you cannot plug a line-in type jack into android earphone jack and expect stereo recording. As explained above, the android earphone jack only has contacts for one channel audio i.e. mono microphone. For that you will need to use a USB dongle (USB sound card) that has a line-in port for stereo microphones. You will then plug in the stereo microphones into this line-in port on the USB dongle. And this USB dongle will be plugged into your android device's USB port. This combination will thus behave like the USB microphones mentioned above. Sony Xperia stereo microphone support (obsolete) Some of the Sony Xperia devices - Xperia Z2, Z2 tablet, Z3 - did support line-in stereo microphones, but only using their proprietary stereo microphone products - but this is not how most android devices behave, which can only accept mono from external microphones via the earphone port. https://geardiary.com/2014/08/02/sony-stereo-microphone-stm10-review Sony Stereo Microphone STM10 Review: Excellent Mic for Android Phones As you can see from the Amazon webpage below, it has a TRRRS (or T3RS) 3.5mm jack (and not the usual TRRS 3.5mm jack). The T3RS jack allows it to support two microphones: https://www.amazon.com/gp/product/B00HX9AJ2A Sony STM10 Stereo Microphone - Silver USB dongles for stereo microphones with line-in type jacks For the USB dongle (USB sound card), you can use the USB dongle supplied with the Andrea SB-205 mentioned above, or use a separate USB sound card product. Here are examples of USB devices which have a line-in port i.e. will accept stereo microphone input: https://www.amazon.com/Griffin-Technology-iMic-original-Adapter/dp/B003Y5D776 Griffin Technology iMic - The original USB Stereo Input and Output Audio Adapter USD 29.99 https://www.amazon.com/USBGear-Audio-Adapter-Line-Input/dp/B01N2RPZTU USBGear USB 2.0 Audio Adapter Box with Line Input and Mic Input USD 41.27 This forum thread has a list of more expensive stereo microphones: https://www.gearslutz.com/board/remote-possibilities-in-acoustic-music-and-location-recording/129674-good-stereo-mic-recording-audience-during-live-recording.html Good stereo mic for recording the audience during live recording? USB dongles for mono microphones and stereo earphones For completeness, here are examples of USB devices which allow you to plug a lapel mono microphone and stereo earphones to the USB dongle: https://www.amazon.ca/TROND-AC2-Microphone-Plug-N-Play-Compatible/dp/B014ANW4VU TROND AC2 Aluminum USB Audio Adapter with 3.5mm Stereo Headphone/Speaker and Mono Microphone Jacks (Black, C-Media CM108 Chip, Plug-N-Play, Compatible with Windows, Mac and Linux) https://www.amazon.ca/UGREEN-Universal-3-Position-Headphone-Microphone/dp/B01N905VOY UGREEN Universal USB Stereo Audio Adapter L/R Channel 3-Position with 3.5mm USB to 3.5mm Speaker/Headphone Output and Mono Microphone Input Plug Play with Windows/Mac/Linux/Chrome/PS4/Surface 3 pro/Raspberry Pi with 5.9 inch Cable https://www.amazon.ca/LONGYAO-External-Channel-Headphone-Notebook/dp/B07B729218 LONGYAO USB External Stereo Sound Card 5.1 Channel Stereo USB to 3.5mm Headphone Jack Adapter with Mic 3D Sound Card Audio Adapter for Windows PC, Notebook https://www.amazon.ca/Plugable-Headphone-Microphone-Aluminum-Compatibility/dp/B00NMXY2MO Plugable USB Audio Adapter with 3.5mm Speaker/Headphone and Microphone Jacks (Black Aluminum; C-Media HS 100B Chip; Built-In Compatibility with Windows, Mac, and Linux External wired mono microphones (using 2 lapel mics as stereo mics) If you have two separate wired mono microphones (for example two separate lapel microphones of the type you would use with your PC or Mac computers, or with android devices), and would like to use them as stereo microphones, that is also possible. For this you will need to use an appropriate Y-splitter dongle or cable which would combine the signals from the two microphones into one line-in jack. This line-in jack could then be plugged directly into a USB dongle as mentioned above. Thus one side of the Y-splitter dongle will have to have two earphone type ports (for the two lapel mics). The other side of the Y-splitter dongle will have a line-in jack, that can be plugged into the USB dongle mentioned above. Here are some examples of Y-splitters for converting two mono mics to a stereo line-in jack - the stereo line-in jack can then be plugged into a USB dongle: https://www.amazon.com/Hosa-YMM-261-Stereo-Breakout-Cable/dp/B000068O5H Hosa YMM-261 3.5 mm TRS to Dual 3.5 mm TSF Stereo Breakout Cable Here are some examples of lapel mono microphones: https://www.amazon.com/Neewerx9886-x53E3-x9EA6-Computer-Microphone/dp/B005DJOIHE Neewer 3.5mm Hands Free Computer Clip on Mini Lapel Microphone (3X Lapel Microphone) USD 8.99 https://www.amazon.com/dp/B077P3DCLR Lavalier microphone, ashina Mic Microphone Professional Design with 1 Adapter for Apple Products iPhone and Android Smartphone USD 7.99 https://www.amazon.com/dp/B0799DSGDY Lavalier Lapel Microphone,Omnidirectional Condenser Microphone Recording Clip-On for Computer PC Macbook iPhone iPod iPad Samsung All Smartphones USD 10.99 https://www.amazon.com/dp/B01E3L1ESS Lavalier Lapel Microphone with Easy Clip On System - Perfect for Recording Youtube Vlog Interview/Podcast - Best Lapel Mic for iPhone 5, 6, 6s, 7, 7 plus, 8, X iPad iPod Android Mac PC ASMR USD 17.99 More information on audio jack types - TRRS, TRS 3.5mm More information about recording audio with android and iPhone devices, and about the various plug types: https://www.wildmountainechoes.com/equipment/audio-recording-with-a-smartphone Audio Recording With a Smartphone Many of the Y-splitters look similar to each other - with one male jack on one side, and two female ports on the other side, which can be confusing to users. Here are some of the common types of Y-splitters: - headphone splitter - these allow two friends to listen to the same stereo music - you plug these into your android earphone port, and it has two female ports where you can plug in two separate stereo earphones, so two users can listen to the same stereo music. - stereo breakout cable - these allow you to split the stereo signal into two mono signals (one for left side, and the other for right side). These allow you to connect two mono lapel mics, and thus create a stereo microphone set, with a line-in type jack that can be plugged into the line-in port of digital cameras, or audio equipment. These stereo audio line-in type jacks, when plugged into android earphone ports, will not give you stereo audio because the android earphone jack has only contacts for mono audio input. So you would plug the stereo line-in type jack into a USB dongle - like the one which ships with the Andrea SB-205, and then that USB dongle can be plugged into an android USB port, thus allowing stereo audio recording with external microphones. - headset splitter - these allow you to connect separate earphones and separate mono microphone to your android earphone jack - so instead of using a headset with built-in mono mic, you can use a separate earphone or headphone (that has no built-in mic), and a separate lapel microphone. This can be useful for cosplay where you want a lapel microphone close to your mouth, and want to place the external speaker on your cosplay costume so it can be heard by an audience. - mic splitter - having two lapel mono microphones appear as one mono microphone (not stereo) - useful for recording two people at the same time. Although the stereo breakout cable mentioned above could be used for such situations as well i.e. converting two lapel microphones to a stereo audio signal (2 channel) - this approach will actually give better control in post-processing, as each channel can be independently processed in your favorite audio editor application.