Noisy main outputs from T4S when using TRS 1/4" to XLR male to FOH

Hi all. On the T4S whenever I use TRS 1/4" to XLR male cables from the main outputs of the T4S to a mixer/FOH via XLR I can hear background noise , which resembles rumble and hiss. Even when all channels are muted, master volume down and nothing plugged in the inputs, I can still hear the noise. The headphone output does not contain the noise. I've tried different cables (Mogami Gold and Van Damme), and even a noise/hum eliminator in between the T4S and the FOH mixer, but still noise . However, when I use 1/4" TS to 1/4" TS cables the noise doesn't exist. Has anyone else experienced similar issues when using 1/4" TRS to XLR cables? It's important I use XLR connections, because it's easier when I turn up to gigs and connect to the FOH via XLR on the stage. Thank you Note: the firmware is up to date.

Original Post

Hi obsidian,

Welcome to the Bose Portable PA Community. Thanks for your question.

I'm sorry you're hearing excessive noise from the T4S when you connect the 1/4 inch (6.3 mm) Tip-Ring-Sleeve output to an XLR input on a FOH/Mixer.

I just replicated your setup here.  When I set the input level on the FOH/Mixer to LINE LEVEL there is almost no noise. When I set it to MIC LEVEL on the FOH/Mixer, the noise level is much more noticeable. That's to be expected. The output of the T4S is line level.

Please try this.

T4S

  • Run backing tracks with the T4S
  • Set the trim lights showing solid green, with occasional flickers of red
  • Channel Volume at 12:00
  • Master Volume at 12:00



FOH/Mixer

  • Set the input level to LINE LEVEL (or if there is a 20 dB pad, turn it on)
  • Set the input trim on the FOH/Mixer so you get a solid signal with no clipping



Now turn down the Master Output of the T4S. How is the noise level now?

ST

Hi. I use the noise gate feature on my channels to help reduce ambient hiss from FX pedals, etc, which is normal. The issue I have is rumbling noise and low level static in the main output signal, even when the volume is turned all the way down. I thought it might be a grounding issue, hoping premium cables would help eliminate the issue, but no success. When I have music coming through the T4S the noise is less apparent, but when I stop playing or mute all channels (and even when I've completely turn down the T4S master volume) the noise is obvious.

Next I will try using 1/4" TS to XLR cables and see if that helps.

 

Thanks

Hi obsidian,

obsidian posted:

Hi. I use the noise gate feature on my channels to help reduce ambient hiss from FX pedals, etc, which is normal. The issue I have is rumbling noise and low level static in the main output signal, even when the volume is turned all the way down. I thought it might be a grounding issue, hoping premium cables would help eliminate the issue, but no success. When I have music coming through the T4S the noise is less apparent, but when I stop playing or mute all channels (and even when I've completely turn down the T4S master volume) the noise is obvious.

Next I will try using 1/4" TS to XLR cables and see if that helps.

You will lose the balanced connection between the T4S and the FOH/Mixer. This will result in up to -6 dB in signal loss, and increase your vulnerability to line noise. Since it will lower the signal level hitting the FOH/Mixer, it may reduce the noise you are hearing now - BUT - a better solution is to turn on the MIC/LINE Level switch or -20 dB pad on the FOH/Mixer.  (or turn down the input trim on the mixer).





Thanks

Please see my post above - Noisy main outputs from T4S when using TRS 1/4" to XLR male to FOH

before spending money on cables.

Thanks,

ST

Hi again. Thanks ST and Codydog19 for the extra info.

I tried the above tips and processes, but no success. I have both the T4S and T1. Here's what I tried today:

a) Cable 1/4" TS / XLR male

b) Cable 1/4" TS / 1/4" TS

c) Cable 1/4" TRS / XLR male

T4S using cables a and b = white noise, c (worst) = white noise and static/rumble.

T1 - a, b, c cables = minimal/normal white noise;

Note - this was tested with all channels muted on the Tonematch, and master volume at zero. I plug the Tonematch to the Mixer via the cable, and as I increase the Mixer gain the noise begins background noise. The mixer preamps are quiet on their own. Side by side the T4S has more background noise, but worst when using TRS to XLR cable. Whereas the T1 was surprisingly clear and low noise will any cable.

I'm lost with what to do next.

Thanks all.

 

Hi obsidian,

Thanks for the results of your tests.

obsidian posted:

Hi again. Thanks ST and Codydog19 for the extra info.

I tried the above tips and processes, but no success. I have both the T4S and T1. Here's what I tried today:

a) Cable 1/4" TS / XLR male

b) Cable 1/4" TS / 1/4" TS

c) Cable 1/4" TRS / XLR male

T4S using cables a and b = white noise, c (worst) = white noise and static/rumble.

If you are connected to the XLR inputs on the FOH and those inputs are set for microphone inputs (not line level inputs), then I can understand why you got these results.

T1 - a, b, c cables = minimal/normal white noise;

The T4S has a much higher output than the T1. With that comes a higher noise floor. You compensate for that by lowering the input sensitivity on the FOH mixer.



Note - this was tested with all channels muted on the Tonematch, and master volume at zero. I plug the Tonematch to the Mixer via the cable, and as I increase the Mixer gain the noise begins background noise. The mixer preamps are quiet on their own. Side by side the T4S has more background noise, but worst when using TRS to XLR cable. Whereas the T1 was surprisingly clear and low noise will any cable.

I'm lost with what to do next.

Thanks all.

Have you tried these steps from my post above?



Please try this.

T4S

  • Run backing tracks with the T4S
  • Set the trim lights showing solid green, with occasional flickers of red
  • Channel Volume at 12:00
  • Master Volume at 12:00



FOH/Mixer

  • Set the input level to LINE LEVEL (or if there is a 20 dB pad, turn it on)
  • Set the input trim on the FOH/Mixer so you get a solid signal with no clipping



Now turn down the Master Output of the T4S. How is the noise level now?



ST

Hi ST. Yes I tried the previous advice, plus the above. The noise level exists even when the  T4S master Output level is turned down - so it could be a grounding issue....I'm not sure. I noticed it again when I used a TRS/XLR cable to the FOH. Its sounds like the ocean. My friend was using a T1 with the same type of cable, but had no noise. I had to change to a TRS/TRS cable to eliminate the noise.  Thanks

Hi obsidian,

What kind of mixer is the FOH? Please give us the make and model designation.

Does it have a Mic/Line Level switch or a pad on the inputs?

Since the connection is fine using 1/4 inch (6.3 mm) Tip-Ring-Sleeve cables, it sounds like there's an issue with the XLR connection at the FOH end of the connection. Have you tried using different inputs on the FOH?

Is this issue specific to one FOH system? Have you tried the T4S with another mixer?

Thanks,

ST

Hi. I've tried it with the Allen Heath ZED16FX, Behringer X32, Audio Interfaces (UAD Apollo), and AER mobile 60 amp. Different inputs made no difference. Like I've mentioned the T1 compared ok, but the T4S was noisy. I understand the volumes of mic, line and pad, but its strange the noise exists in the connection, even when the Tonematch master output volume is turned down. I'll try do a video next opportunity.

Thanks

Hi obsidian,

obsidian posted:

Hi. I've tried it with the Allen Heath ZED16FX, Behringer X32, Audio Interfaces (UAD Apollo), and AER mobile 60 amp. Like I've mentioned the T1 compared ok, but the T4S was noisy. 

Thanks

Thanks for the added information.



The T4S outputs are line level. The outputs are too high for microphone level inputs. 

Allen Heath ZED16FX

Please use the 1/4 inch (6.3 mm) LINE level inputs. The XLR inputs are for microphones. There is no signal attenuation on the MIC inputs. You must use the LINE inputs.

Allen Heath ZED 16FX Mic Line Inputs

Behringer X32

Try setting the input gain to -20dB OR connect the T4S to the Aux Return Channels (1-8).

AER mobile 60 amp

Be sure to set the line/mic switch is set to line.

Audio Interfaces (UAD Apollo)

I couldn't specific information for these devices, but the principles and ideas for the others should apply. You need to set the input sensitivity for a line-level source.

Comparison to T1

About the comparison to the T1 - that's not helpful in terms of diagnostics. From my previous post.

T1 - a, b, c cables = minimal/normal white noise;

The T4S has a much higher output than the T1. With that comes a higher noise floor. You compensate for that by lowering the input sensitivity on the FOH mixer.

ST

Attachments

Photos (4)

Add Reply

Likes (0)
Having trouble signing in?

We recently updated our sign-in procedure and if you have old sign-in data cached, this can create a problem. Please:

  1. Clear your browser cache and cookies
  2. Then close the browser (not just the window)
  3. Open the browser and try again
Thank you

Please make sure that your profile is up to date
×
×
×
×