There is a lot to like about the Bose S1 Pro from its lightweight 13.5 lb adaptable form-factor, durable construction, and its built-in 3-channel mixer. This specific version does not include the rechargeable lithium-ion battery pack, reducing the upfront cost and weight of the speaker, but limits you to spaces where you can plug the speaker into an outlet 6 feet away to use it. A battery can be purchased separately or you can opt for the bundled version for on-the-go use. Thankfully, a battery is trivial to install in the bottom of the speaker beneath a panel attached with two easy-to-remove screws, if you decide you need this feature, and I like that this design allows you to easily replace the battery, if needed. There’s a chunky handle inlaid on the top of the speaker so that it sits flush with the body, allowing you to carry and move it around easily.
This speaker can be used in a number of orientations including upright, horizontal, tilted back, and stand mounted (35mm), each providing a different sound profile that automatically adjusts EQ to achieve optimal projection. There are rubber non-slip pads on all the surfaces that you can use when the unit is freestanding. While it seems a small bother, the logo on the front of the speaker can be rotated 360° in 90° intervals (counter-clockwise only) in order to match the orientation of the speaker as well.
This speaker has 3 input channels, 2 XLR and one 3.5mm AUX/Bluetooth combo channel. The two XLR inputs also accept ¼” jack inputs and can be used with any powered input device, like a microphone, mixer, looper, or instrument, for example a guitar or keyboard, but neither channel offers phantom power so would not be suitable for condenser microphones that require it. There are individual volume controls for each channel, though only the XLR channels have EQ adjustment dials: treble, bass, and reverb. Additionally, you can enable ToneMatch for mic or guitar input, which applies additional presets accordingly like a low-cut filter. Setting ToneMatch to ‘off’ is equivalent to line level input.
The PA system can pair with a Bluetooth audio source by pressing the Bluetooth button for several seconds to enter pairing mode. Note that if AUX input is used, Bluetooth input will be overridden even if a Bluetooth source is paired with the speaker and transmitting audio. When paired with a phone, you can receive notification sounds through the speaker, but if you receive a phone call, ringing and call audio will not be played through the speaker. With my Android phone, I had to download the Bose Connect app in order to pair to the S1 Pro, though I was able to directly pair an iPhone to the speaker without the app.
The Bose Connect app does offer more functionality for you to manage the speaker’s settings like paired Bluetooth devices, enable ‘Party Mode’ to sync audio output to other Bose SoundLink Bluetooth speakers for multi-speaker playback, toggle on/off ‘auto-off’ (to save battery power), and check remaining battery life (if installed). If you do have a second speaker paired in Party Mode, you can subsequently switch to ‘Stereo’ mode for left and right track separation on each speaker rather than playing the same audio in unison. You can also daisy chain a second S1 Pro with a ¼” TRS cable using the Line Out port, however, it is not possible to achieve true stereo output with this method.
In terms of audio quality, the sound is very good. While mono only, it’s clean and balanced with a decent amount of bass reproduction; however, I felt channel 3 lacked a little bit of treble depth both over Bluetooth and via AUX input, and unfortunately it’s the only channel that doesn’t allow for onboard EQ adjustments, so you’ll need to set the EQ from the source device when possible. The other thing to keep in mind is that at high volumes, it is possible to experience some clipping and distortion, and the LED next to each channel’s volume dial will display red when the input signal exceeds the limiters, indicating the volume should be reduced in order to protect the speaker from damage and improve sound quality.
Performance of my dynamic microphone with the S1 Pro was awesome. The audio is clear and very crisp, but keep in mind the ToneMatch Mic mode is optimized for close usage with your mouth nearly touching the mic. The reverb controls are also nice for creating a sense of space and dimension without muddying the sound too much, depending on the experience you’re going for. The PA system is perfect for both solo and duo singers/musicians. We love using it for karaoke since we can have two mics attached for duet numbers and the music input on channel 3.
The one thing I don't recommend the speaker for is pairing over Bluetooth with a video source, for example to watch video on a mobile device or stream audio from a movie projector because there is a miniscule but noticeable (to me) amount of lag/delay between the audio and the image on the screen when used this way. It's just not designed to be used as a soundbar. Overall, the Bose S1 Pro is a powerful, compact speaker with great sounding audio designed for PA system use. It has a few onboard essential EQ controls and 3 flexible input channels which are expandable, so whether you are a professional musician, performer, or a casual home user, you can start small or incorporate it into a larger setup to fit your needs.