Hummng

[Toril S]

Hello friends. I have two Bose speakers that I use on gigs. But I often get too much humming and other annoying noises from them. I fiddle wth volume all the time, turn up and down on the units and on the keyboard. But the noises wont go completely away. Any smart tips out there?

[travlin-easy]

You should not get a humming sound from anything, unless it's not properly grounded. Make sure that all the power supplies are grounded and that should solve your problem. If not, try unplugging all the plugs one at a time until the humming sound goes away. This will determine the culprit and then you can go about ways to fix the problem. Sometimes it as simple of a bad cable between the keyboard and amp.

Hope this helps,

Gary

[Toril S]

Thanks Gary.

[RoyceM]

Does the hum occur at all gig locations, or just a certain one?

I carry a little wiring tester in my gear bag so I can trouble shoot whether a room's wiring was done correctly.

Possibly, you might be getting a 60 cycle hum from interference across your cables and power cables. I've never had this happen to me, but I am always alert incase it happens. i suppose that would occur within your setup rather than at a specific gig location.

Sure would like to know what you find out.

- Royce

[overover]

Hello friends. I have two Bose speakers that I use on gigs. But I often get too much humming and other annoying noises from them. I fiddle wth volume all the time, turn up and down on the units and on the keyboard. But the noises wont go completely away. Any smart tips out there?

Hi Toril,

It is important that the Bose speakers and the keyboard are connected to the same mains socket (socket strip), i.e. to the same electrical phase of the power supply. If you use unbalanced audio cables (mono TS jack plugs on both sides), they should be as short as possible and not run parallel to a mains power cable over a long distance. Note that balanced cables (TRS plugs) should not be used on Yamaha keyboards because all outputs are unbalanced (RING contact is internally not connected).

If you haven't already, I recommend trying other audio cables. There may be a defect in one of the currently used cables.

If your Bose speakers have balanced inputs (see manual), you can use a stereo DI box (or two mono DI boxes): The keyboard is connected to the DI box with two very short unbalanced TS cables, and from there you go to the Bose speakers with balanced cables of any length (XLR female to XLR male or TRS jack plug, depending on the version of the balanced input). However, if there is a hum, this can usually be remedied by pressing the GROUND LIFT switch on the DI box. (This will break the ground connection of the balanced audio cable.)

I use a "Palmer PAN 04 A" active stereo DI box. However, this requires phantom power (e.g. from an external mixer) or an external power adapter. The passive variant "Palmer PAN 04" does not require a power supply and still has a sufficiently good audio quality.


Hope this helps!

Best regards,
Chris

[Toril S]

Thanks Chris. I have one Bose compact that i connect to the keyboard with unbalanced cables. No hum. But when I add my second speaker, that is a Bose S1 Pro going on batteries, the fun begins. I connect this little Bose to  the bigger one with a jack cable. This makes the small Bose buzz and hum. The sound s clear, but as soon as I stop playing I hear the humming of the smaller speaker.

[overover]

Thanks Chris. I have one Bose compact that i connect to the keyboard with unbalanced cables. No hum. But when I add my second speaker, that is a Bose S1 Pro going on batteries, the fun begins. I connect this little Bose to  the bigger one with a jack cable. This makes the small Bose buzz and hum. The sound s clear, but as soon as I stop playing I hear the humming of the smaller speaker.

Hi Toril,

Does the small speaker (Bose S1) also hum when you connect it directly to the keyboard (e.g. the L1 Compact to Main Out R and the S1 to Main Out L)?

Have you already replaced the connection cable from the L1 Compact to the S1 (e.g. with the cable that connects the Compact to the keyboard)?

If you have a balanced cable (TRS to TRS), use this to connect the two Bose speakers. Then it must not hum under any circumstances.

By the way, you wrote that you connected the Bose Compact to the keyboard with "unbalanced cables". In this case ONE cable is enough, connected to the main output "L/L+R" of the keyboard, since you are working in Mono anyway.


Best regards,
Chris

[Toril S]

Thanks again Chris. The S1 pro has limited options, I will try to do as you said.

[MarkF_48]

Chris, the Bose S1 manual seems to suggest its 1/4" input combo jack is an unbalanced input that accepts a TS style plug. To keep things balanced with just a cable connection perhaps a 1/4" TRS to XLR could be tried so long as the S1's input gain can handle a hotter signal than the mic.

S1 manual excerpt...
"Channel input: Analog input for connecting microphone (XLR) and instrument (TS unbalanced) cables."

Toril, As an experiment have you or can try a different signal path   keyboard >>>> Bose S1 (Line Out)>>>> Bose Compact (Ch2) ? The S1 Line out is balanced (TRS) and the Ch2 of the Compact's Line 1/4" in is balanced (TRS) as well. Try a TS to TS jack cable if that's all you have at present. This may not be the way you want it configured, but would be interesting if the hum were present or not.

[overover]

Chris, the Bose S1 manual seems to suggest its 1/4" input combo jack is an unbalanced input that accepts a TS style plug. To keep things balanced with just a cable connection perhaps a 1/4" TRS to XLR could be tried so long as the S1's input gain can handle a hotter signal than the mic.

S1 manual excerpt...
"Channel input: Analog input for connecting microphone (XLR) and instrument (TS unbalanced) cables."

...

Hi Mark,

As I already suspected, the 6.3 mm jack inputs on the Bose S1 Pro are balanced. So balanced sources (TRS jack plug) or unbalanced sources (TS jack plug) can be connected here. Please see here:
>>> https://toonz.ca/bose/wiki/index.php?title=S1_Pro_system#Input_Gain


Best regards,
Chris

[Toril S]

Thanks Mark and Chris. Hum is still there. I will go to the music store and try some other cables.

[Nova227]

If the Bose S1 is running on battery do you still get noise ?

[Toril S]

Yes. It is always running on batteries when I take it out. That way I can place it where I want, so it can function both as a monitor for me and as an additional source of sound for my audience.

[Paula]

HI chris
why must the key board and speakers be  on the same power strip ?just wondering
   Thanks
  Paula