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.

When I plug in an instrument cable into either input from an acoustic guitar I'm hearing a low hum sound. It's get louder as I turn the volume up louder. It occurs both on AC power and on battery. I've tried multiple instrument cables. I've plugged it into multiple outlets in the house. I've used multiple acoustic guitars with active pickups. If I plug in a microphone into either input I'm not hearing the low hum at all only instrument cables. Is this normal or do I need to send in for service I haven't had it for more than 60 days at the most.

Original Post

Hi HumdingerChas,

Welcome to the Bose Portable PA Community.

It sounds like a lot of good troubleshooting and diagnostics.

I'd expect some hum if the cable is inserted into the S1 Pro, but not connected to something at the other end. This is just a big antenna for noise. But it should stop when you connect it to a properly wired guitar.

If the hum persists even when you are running unconnected to AC power, this eliminates common ground-loop problems.

If you've tried different cables, that eliminates any one cable as the source, but you want to make sure the cables are not running near any other devices or cables.

Do you have a short cable (less than 10 feet)?  The longer the cable, the greater the likelihood you'll pick up noise. That is much less likely with XLR cables because they are balanced.

There's another thing to try - take the S1 Pro and out to a different physical location, run it on the battery. Do you still hear the hum?

If so, then please call Bose Support.

Bose® Product & Technical Support at (877) 335-2673
(U.S. and Canada only)
Monday-Friday: 9:00 AM - 9:00 PM ET



Hi ST I've used a 6ft cable in my kitchen and den and also on my back deck with just the battery on and still have the hum with a guitar plugged in. I've plugged the guitars into a Crate Taxi Limo amp and don't get a hum through it. I'll call support on Monday seems like I have a defective unit.

I received a new unit and it has the same issue. A low hum when an instrument cable or trr cable from a mixer is plugged in but not if a mic cable is plugged in. The hum gets louder as you turn up the volume and occurs when unplugged as well. Any ideas anyone as I've tried many cables guitars mixers etc. At this point it's unusable for playing acoustic guitar through it which is what I bought it for.

HumdingerChas posted:

Well I think I've found the issue seems to be caused by my Prodx4 mixer. If i go directly into the S1 there's very little hum unplugged still a little plugged in.

Thanks for getting back to let us know about your progress. It's always great getting feedback after discussing problems as it can quite often help others who may have something similar.

No idea why I didn't check that first I apologize for the overreaction folks.

Sometimes we just can't see the wood for trees.  Great to to hear that you've got it sorted. We've all made similar mistakes at some time or other, and we don't usually repeat them.

A small tip for anyone reading this thread who may have problems when troubleshooting with regards to signal paths. It's usually a good idea to start out with the simplest connection (e.g. here with guitar/cable/amp) and then continue adding things until the problem occurs (e.g. here mixer). This way you can generally localise the culprit (even if you can't repair it yourself).


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