Playr Audibly 2.6.3 Instruction Manual

How to Perfect Syncing

Audibly was tested with ten devices and all of them stayed perfectly in sync for multiple, continuous hours. Audibly is theorized to potentially work with 100 devices as speakers, but Playr Inc does not have the budget to test for this. If music is not in sync, press the sync button.

In Audibly 2.6.3, there are two new features for syncing. The first is Hotspot Mode. If there is not a WiFi network available that all of the devices can share, this new feature is available so the broadcaster can become a personal hotspot for all of the speaker devices. Go into the Settings app on your device and turn on the personal hotspot. Connect all of the devices to the hotspot that you want to use as speakers. Last, switch on Hotspot Mode in Playr Audibly settings. Now the broadcaster can work without a local WiFi network. Hotspot mode is also interesting because all of the speakers skip the router and jump straight to the main device as the main network. This means it could have potentially better results than the usual way of all being on the same WiFi network. The next feature is Long Sync. This new sync feature is a completely different syncing experience. The default syncing syncs all of the devices instantaneously. With long sync enabled, the syncing takes about 3 seconds. Instanteaneous syncing is already very accurate, but long sync can sometimes provide more accurate results. Both are unique syncing experiences and could be preferred for different reasons.

In Audibly 2.6.2, there is a new feature called Automatic Offsets, which is switched on by default. This feature is a new layer to the syncing system and provides a very good audio quality. The Network Audio Latency Tuning setting is always useful, even if Automatic Offsets is on. The best way to test Audibly is to leave the slider at the default value or 0.00, and to play some music. If syncing is not completely perfect, try adjusting the Network Audio Latency a bit to the right. Adjust by 0.01 increments to find the best sound to you. You can even adjust by 0.005 for the slightest extra quality. Test how it sounds on 0.00. Test a few different values. You can open settings while the music is playing to adjust the latency slider before pressing the sync button. Also, you can switch Automatic Offsets on and off just to make syncing more customized. The latency setting has different default values if Automatic Offsets is on or off.

There are many reasons you may want to adjust the Latency. Maybe the Sync sounds close to perfect or perfect, but you want to fine tune the sync to be even more perfect and specific to your Audibly configuration. The sync could also be slightly off due to a number of complex reasons. The default Latency settings in Audibly should be just fine for most Audibly configurations.

Audibly is tested with both older devices and newer devices. When Automatic Latency is on, the recommended offset ranges for Macs is -0.015 to 0.015, iPad is 0.000 to 0.025, and iPhone is 0.000 to 0.050. When Automatic Latency is off, the recommended offset range for Mac is 0.000 to 0.025, iPad is 0.000 to 0.050, and iPhone is 0.015 to 0.060. Latency Offset goes beyond the hardware and software of each device. If you are using the newest and fastest devices and/or networks, your offset could be lower, while older and slower devices and/or networks could require a higher offset. Latency values cannot be perfectly calculated (in nature) for every layer of the syncing system that involves the concept of latency. This current, proprietary, syncing algorithm has many layers of logic to help perfect the syncing to be as accurate as possible. For example, in one instance of testing, an iPhone 6 as broadcaster seemed happy to sync at 0.015s, while an iPhone 13 Pro Max as broadcaster seemed happy at 0.040. On Mac, the music sounded perfect at both -0.015 and 0.005.

This is the sixth version (2.6.2) and seventh version (2.6.3) of the Playr Audibly syncing algorithm. There might even more Audibly algorithms coming soon, even though this one sounds incredible, like a Home Theater system and room full of speakers. In fact, if you have any number of devices in an Audibly session, you can plug each device into external speakers or a home theather system and synchronize all of the systems. This would only make sense if you do not want to run wires between the systems.

Also, The speed of sound in air is about 343 meters per second (1125.25 feet per second). This means that with 10ft between the devices, the sound of the devices will be offset by 0.0089s of time. With 20ft between the devices, the sound will be offset by 0.018s; 30ft is 0.027s. This means if all of your devices are placed in a circle with a radius of 20ft, you could adjust the Latency setting backwards to a negative value around 0.020 to adjust the location of the sound. There wasn't a need to add location-based audio into Audibly yet, but if it was in there, the listener would have to have a 1cm accuracy GPS on their body and each device would need 1cm GPS accuracy. Then, as the listener walks around, each device would shift its timing very slightly, based on the location of the listener in reference to each individual device. A feature like that is unrealistic but fun to think about. There are six additional layers to the Audibly syncing system that could be added to the existing seven, but the current version sounded so perfect, when correctly configured, that these layers are not considered necessary yet and would only be added in the future for super complex configurations.

If the sound is 0.01-0.02s off of sync, it could sound slightly off from super, crystal clear, perfect. 10ft between the devices provides almost 0.01s of loss of accuracy. Audibly was tested by holding many different iOS devices up to each ear while they were playing in sync. Almost all of the time, the devices would be in extremely perfect sync, even while very close to each other. In rare occasions, if using two devices, if the slider is set to the right offset, and after pressing the sync button, the audio might achieve a rare accuracy level of 0.00[0-2]-0.000x seconds. In this magic range, the sound waves all sound like they are coming from one place. Combined with the offset of audio wave timing from air distortion in physics, based on the distance between devices, and the exciting new accuracy of the Audibly syncing logic, the wireless surround sound has some special, spatial, audio effects that can only be heard in low-latency, WiFi-network-based, wireless, surround sound.

Currently, Audibly sounds very perfect when playing music over a wireless surround sound environment with many simultaneously connected devices. Playr Inc has many additional theories to add extra and more complex layers to the syncing logic, but due to a few factors, most of these theories will probably just stay in the notebooks. The first factor is that the average human ear cannot hear that the audio is out of sync past a certain level of seconds of sync accuracy. Different people will have a different threshold of noticing this offset when listening very closely. Additionally, there are many unpredictable factors of the millisecond regions of the computing system and network hardware.

History of Audibly

Audibly was first prototyped in the summer of 2013. It went through a year of revisions before it was able to sync up perfectly and was released in 2014. A quarter of the time, it would be slightly out of sync but was pretty close. Audibly worked pretty well with up to three iOS devices. Sometimes, it could handle a few more. After iOS 7 launched the same week as Audibly 1.0, most of the logic of Audibly became incompatible with iOS, so for the app to continue working, the entire app would have to be built with completely different logic. None of the team members, at the time, were able to contribute the necessary work to make the app function on iOS devices after 2016. Audibly stopped working for everyone in 2017. The app was not updated again until near the end of 2018 when it was acquired by Playr Inc. All of the code in Audibly needed to be rewritten. An update was released in 2019 that had syncing that worked about half of the time. A few complex syncing logic additions were added in updates between 2019 and 2021 which made it more accurate. Now in 2023, the most accurate version of Audibly syncing was developed.

Audibly and Music Services

There are many music streaming services on the Internet. Apple Music is the closest service to Audibly. In 2019, an Audibly beta was developed that synced multiple iOS devices to play Apple Music content. This feature was not developed more because there were a few major flaws. Audibly users typically have multiple iOS devices that share the same Apple account. Apple Music only allows a music stream to play on a single device. If three devices share an Apple account, only one is authorized to play at the same time. Only in a situation where each device in the Audibly session were to have its own Apple Music subscription could this work. Playr Inc does not have the budget to build out this feature. For all other music streaming services outside of Apple Music, Playr Inc would probably have to make some complex, difficult-to-obtain, business partnership with them to combine the technologies and features together. There could be one or more of many unique forms of stream integration in the future, but for twenty years, digital music files were the primary way to listen to music on computing platforms. Audibly performs best with files.