Discussions about the Bose S1 Pro system

Bose S1 Pro

Designed for musicians, DJs and general PA use, the S1 Pro is the ultimate all-in-one PA, floor monitor and practice amplifier that's ready to be your go-anywhere Bluetooth music system for nearly any occasion. 

This is the place to discuss the S1 Pro system.

Hi Everyone,

I'm starting a new discussion to provide the Bose reply to this question

Question: Why do I have to turn up the microphone higher than guitar?

Answer: The output level of the guitar is louder than the output level of the microphone. That's why we have to turn up the microphone higher.

This is how my S1 Pro looks most of the time. The microphone is connected to channel 1 and the guitar is connected to channel 2. 

More information:

There’s been a lot of discussion here lately about

  • Unity gain
  • The center détente is unity
  • Not enough reaction to the volume controls below unity
  • Not enough headroom when the volume control (for a microphone) is at 3:00 o’clock or greater


 Let me address these points.

The volume controls are trim controls:

  • Note how quiet the S1 Pro is when there’s no input source and the volume, is all the way up – The volume controls are trim not preamp/gain controls
  • The concept of unity gain does not apply
  • The concept of headroom doesn’t apply
  • The center détente is a convenient point of reference, especially when you can't see the controls well at a gig


The power amps are running at full volume

  • When you turn the volume controls all the way up, you have reached the maximum volume the S1 Pro is capable of producing for that source
  • Note the clip lights. If you see red, turn down to avoid distortion. You have reached the maximum usable volume just below clipping


We hit maximum usable volume for an input is just before the clip lights come on. With a guitar with a preamp, that might be at 12:00 o’clock compared to a microphone at 3:00-4:00 o’clock.  There’s no dysfunction here. It’s a reflection that the output level of the guitar is higher than the microphone.



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Original Post

I figured that the volume was due to output levels. It hasn't been a problem yet. I just didn't know if the volume was supposed to be almost non existant and then jump up suddenly at midpoint. If it is normal, that is fine. Making sure there wasn't a defect.

ST posted:

Hi Everyone,

I'm starting a new discussion to provide the Bose reply to this question

Question: Why do I have to turn up the microphone higher than guitar?

Answer: The output level of the guitar is louder than the output level of the microphone. That's why we have to turn up the microphone higher.

✄ - ✂ - ✄ - ✂ - ✄ - ✂ - ✄ - ✂ - ✄ 

Now what people seem to think is this is a comparison of THE volume of mic to THE volume of guitar. This is NOT A COMPARISON at all, the instrument volume knob works as it should.

We have started a new discussion for your question.

S1 Pro - Microphone volume between 0 and 12:00 o'clock

This post was forked into a new topic here: S1 Pro - Microphone volume between 0 and 12:00 o'clock

Hi Rick W

Rick W posted:

I figured that the volume was due to output levels.


It hasn't been a problem yet. I just didn't know if the volume was supposed to be almost non existant and then jump up suddenly at midpoint. If it is normal, that is fine. Making sure there wasn't a defect.

Please see this new discussion about the volume.

S1 Pro - Microphone volume between 0 and 12:00 o'clock



 "For people who notice very little difference in volume change between 0 and 12:00 o'clock, turning up the volume at the source will give them a greater audible difference below 12:00 o'clock."

This does not apply mic pos. (SM58) tone match mic switch should compensate for low signal mics as Bose does not offer a separate boost or phantom power.

Hi ccc,

The quote above is taken out of context, and in a different discussion.

Here is my comment in its larger context. For others reading along, note that at this point, I was talking about S1 Pro channel 3.

That's not surprising. If something is too quiet to hear, twice as loud may still too quiet to hear. You can keep doing that until you can hear it and then twice as loud will be noticeable.  With a microphone (very low signal) you may not hear it at all until you get to around 11:00 o'clock when we reach the just-noticeable difference threshold. This point will vary based on the strength of the input volume.

The ideas above apply to S1 Pro channel 3 too (Bluetooth and wired connections).  For people who notice very little difference in volume change between 0 and 12:00 o'clock, turning up the volume at the source will give them a greater audible difference below 12:00 o'clock.

The larger discussion is here: S1 Pro - Microphone volume between 0 and 12:00 o'clock. And in that discussion, I explain why we have to turn a microphone higher than a line level input.

The ToneMatch switch tunes the EQ on the channel to give great results with handheld microphones. You're correct, the switch does not affect the signal level. All you have to do is turn up the volume, likely over 12:00 o'clock.

You can add your suggestions about making the ToneMatch switch boost a microphone signal, and adding phantom power to 

S1 Pro system: Feature Requests



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I find the volume with the SM58 quite inadequate unless turned up beyond 3 o clock. If I add an impedance matching transformer it is much better. This was suggested by Shure tech support. Bose told me they test all their systems with the SM58 so it’s surprising this is an issue. I should not have to add an impedance transformer!3AB3739D-1C6C-4EE5-BD06-6387A4D78282


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Bose is using a technical means that was abandoned by some amp companies some years ago, where they used a split for low level and line level. 12 o'clock being the the mid point. Low level mics like the 58 are at a voice level at 12 o'clock. This was extremely unpopular in the past and amps in the past did away with this by master volumes, because people wanted control of their volume and always felt the unit was defective by not audible response below 12 for weak output mics. Bose needs a master volume. The 58 is a very low output mic, I solved this issue by running my mic thru a balance direct box. If you use some pre or something like voice live or a boss voice you can put your mic in the balance output and internally boost the output to get the volume to a decent level. They also have phantom power so you can use condenser mics I also use a volume pedal this allows me to set the mic and line levels and then add  the volume with my foot pedal. I personally feel this is poorly thought out for a unit used for busking or singer songwriters.  This is as simple as I can explain this without going into electronics but this was how I found a solution.  = I set my volume for the 58 and boost it thru a balance out from DI box or Boss VE-20 I use a volume pedal to then control the volume with my volume pedal.

Thanks for your explanation but my comment is about solving the lack of a master volume on this unit also the lack of a boost or phantom power. As I mentioned by using a pre of some sort to boost my 58's inaudibility before 11 o'clock and using a volume pedal to solve the lack of ability to set the line level of instrument and mic without repeated fiddling.  This has been a topic of discourse.  If you feel this does not apply you can delete it.

Hi Ted,

I tried using an impedance matching transformer here. That was interesting, and I'll dig into that further at this end.

Have you found that you've managed to increase the maximum volume from the microphone? I didn't. All that happened was - I reached the maximum volume at a lower setting on the volume control.  Based on that, I'd keep it simple, skip the transformer, and turn up the volume.  There's no harm in that, and the S1 Pro is operating as intended.


Yes you are probably right.  The female singer has a soft voice, but I can get a boost at lower volume control levels with the impedance transformer. But overall it may not be louder, not sure.  Anyway after a lot of troubleshooting and reading what's on this forum I think its just the nature of the beast (See reply from ccc) and I will just crank up the volume control. I am not getting a red line unless I really yell in to the mic. Cheers


Just a note this is not unusual for amps in development as I remember reading about some companies who used this but found them unpopular for singer/song writers. People could not get used to the fact they had to turn their volume knob up to 12. So they stopped making that design in amps like that. Bose is using the S1 as a monitor, busking, and singer song writer format. For the monitor this may prove to be fine but for a busker on the go it gets fussy. Although I understand the mechanics around it as a single busking amp it lingers. Balancing the mic and the instrument to the appropriate levels and then having to readjust everything with a change of output is time consuming and fussy. So by adding a mic pre to boost the mic levels with the guitar, I could balance for loud outputs and then use a volume pedal to place the volume at a different lower levels. It is not the norm so It just takes getting used to. 

Can confirm there's the same "issue" if you want to call it that with my S1 and mics like the SM58. Sound comes out before 12 on the dials if you yell into a mic, but to a point nobody could ever hear it without using an aid or being Superman. I have normal wired SM58 and a GLXD24/SM58 both suffering the same issue unless you turn gains up on the GLXD receiver.

What was posted about using an impedance XLR to 1/4 jack works to "remedy" this "issue" with or without tonematching. Whether or not the overall volume ceiling gets raised by doing this is beyond me because after a certain point you reach unpleasant distortion or feedback in a live situation. This seems to be done by design for what ever reason and hopefully can be tweaked with software or firmware updates later.


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THIS IS A simplified explanation: Bose is trying to make a unit for all media use. PA Monitor, Busking, Singer/songwriter, to do this and keep this unit compact Bose has used standard mix board strategy, think of it like a half of a circle, 12 being the mid point. The left half is tweaked for high gain line level, the right half for low mic level. This has been done many times before by many amp companies but people just do not adjust to it well.  They always think it is defective. This works well for a board pa, but not for a single player who then has no master volume. As stated I fixed this for me by using a pre for my mic and a volume pedal so I can adjust the volume levels by foot. There is nothing inherently wrong with this method Bose is using, it combines two separate controls into one sort of. People just react poorly to it, always thinking it is defective. Takes getting used to. A master volume would solve the problem. I am ok with my solution as long as Bose continues with extreme high quality in its build. If it is made for a PA system which takes a whole lot of abuse then you can at least be assured it will stand up well under busking abuse. If you want technical on this perhaps ST can get it for you. 

Going to give a little more input here and my thoughts with experimenting. The first time I fired up my SM58 wireless system doing a test with a S1 the gain was set +7db. When you have it set at 0db the difference between a wired SM58 is very little, but you are right it does appear a smidge more "hot" requiring less volume on the dial by not a lot. It is a solution really only because the receiver allows setting gain output which then makes the S1's volume knob more responsive. Similar to using the 1/4 transformer jack method and not so much at all because of the other technical hardware specs.

Now the trade off and real dangers here of doing all this stuff. When I mention feedback I really do seriously mean it and starting to understand this possible design choice here. If you pump gains on the wireless receiver or use the transformer jack method at high volume, bend/move over to adjust volume up/down on the S1's dials it starts to feedback like crazy. Sound 101 to not have a hot microphone near a monitor I know, but imagine the buskers or people out there without on/off switches on their microphones making a simple mistake when adjusting volume on the S1.

Then when you start getting into world of supercardiods or condenser microphones you are really looking for trouble by pumping up volume within proximity of the microphone. I have a Beta 57A plugged in here using the 1/4 transformer jack pictured below. Even standing exactly at the back of a S1 while holding the microphone capsule end outward at opposite direction from the speaker drivers you will get feedback after going high enough with volume. Obviously like I said you just don't do this or work around it with any number of adapters and peripherals to put on/off or control volume remotely ect ect.

This is quite possibly the real reason microphones don't come in as loud on a S1 to prevent feedback. There is a hilarious video review on youtube from a couple Guitar Center guys testing an S1 that I'll leave here:



Photos (1)

Thanks, first off I had no idea I could change the input on my Shure 57 wireless mic.  I still can’t see how you do that, and I have had 3 years or more - maybe an older model? Mic and receiver have only channel indicators.

Secondly, gigging outside last weekend we had no feedback issue, although we are caferul and the wired Shure 57 has an on/off switch.  Also we were using the impedance transformer. Lots of volume, could be heard a block away. Presumably when outside with no walls to bounce off feedback is less of an issue anyway?

In short I think we can work with this. Thanks for this input.


Hi Everybody,

Thank you for this lively discussion. 

We've been talking about this at Bose too, and we'd like to confirm a few things.

We want you to enjoy your S1 Pro system without having to be concerned about the inner workings.  Just plug in your microphone and instrument, turn up the volume and perform.

Please use the volume controls to get the loudness you need for your show. It's not necessary to have the volume controls at the same level. And unless you have similar input sources it's unlikely the controls will be at the same level.

Maximum Usable Volume

When the channel is clipping (red light), or you hear audible distortion, you have reached the maximum usable volume the S1 Pro can provide. This can happen lower or higher on the volume control depending on the signal strength of your source.

Unless you have an input source that is lower than a typical microphone or guitar with a passive pickup, you should not need to add another device between your source and the S1 Pro. You can add preamps, processors, pedals, or transformers if you like, but it's unlikely that any of these will change the maximum volume the S1 Pro system can provide.

Volume below and above 12:00 o'clock on volume controls.

There is no special processing or split in the way we handle the signals below and above 12:00 o'clock on the volume control.

What you are experiencing is directly related to the input signal. If you have a very low input signal (e.g., microphone or bare piezo pickup), you will need to turn up volume control to hear that signal, compared to a higher input signal (e.g., microphone through a mixer or wireless receiver or a guitar with a built-in preamp). 

If you connect a microphone or a guitar to a ToneMatch (or other) mixer, turn the output volume down, connect it to the S1 Pro through a 1/4 inch input, you can get the same behavior as connecting a microphone to the XLR input - very little response until you turn up the volume. The point at which you hear sound will be directly related to the output volume on the mixer. That point is may not be 12:00 o'clock. It will depend on the output of the mixer.

Impedance Matching Transformer

There's nothing gained by using an impedance matching transformer. To match the performance you get with the impedance matching transformer, without one, turn up the volume control.  Either way, you have reached maximum usable volume when the input clips and you hear distortion. You may get to that point at a lower setting on the volume control with the impedance matching transformer, but with or without it, the maximum output available is the same.

You may feel better if the volume controls are closer to the same setting (using an impedance matching transformer), there's no benefit to adding another device to your signal chain. It's another potential point of failure, and a relatively large device to plug directly into the S1 Pro.  You don't want to damage the input if you knock over the S1 Pro and it hits the impedance matching transformer.

Wireless Microphone Receiver

Some wireless microphone receivers have output level controls or different outputs with different signal levels. 

If there is a line-level output and you use that, then the signal level will be higher than a wired microphone. You will reach the maximum usable volume at a lower setting on the volume control.

Enjoy your S1 Pro!


I do not like the lack of a master volume, just asking for trouble. If I have any feedback issues I throw in a parametric into the loop of effects. S1's reverb is ok not crazy good but will do for vocals.  I throw in the acoustic fly rig by  tech 21 good effects: reverb, chorus, delay, compression, and eq with mid sweep plus notch filter in one very little pedal just about twice the size of a pencil box. (12.5”l x 2.5”w x 1.25”h • Weight: 20.7 oz) Very small footprint can fit into a small backpack or carryon, great for instruments. The heaviest thing I have going is the volume mini but it allows for complete volume control without having to play tag with the volume on the unit trying to match the guitar and vocals. No accidents with the pedal. The mic pre works well also the is control on my board. I am not running back to the speaker testing balance and running back to the speaker. I like the foot control, would it be nice if Bose came up with a unit with a removable panel with effects and volume for channels so one would never have to play with back and forth adjustments.  Think about it Bose no is doing it as of yet.

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