T1 settings - Feedback problem

I've just got a new L1 1S with B2 and T1, and my main application is karaoke. My problem is I have pretty loud feedback occasionally when I move around (not the high pitch, but low frequency bassy/humming feedback). The setup is in my home, the room is about 20x25 feet. I've followed several videos to setup the connections, the trim, and the volumes, so I don't think there's any problems in these areas. The current settings I have are:

Channel1 (Mic):
- ToneMatch: Vocal Mics Shure SM58
- zEQ: Low 3db, Mid 0.4db, High 0.4db
- Com/Gate: Comp3, Thresh -14.5db, Gain 5db. Noise Gate: Thresh -30db, Speed 50%
- Delay: Type Analog, Mix 20%, Fdbk 11%
- Reverb: Mix 35%, Bright 50%

Channel 4/5 (Music):
- DJ Playback - High Volume Music
- Everything else Bypass

Also, I was told by someone that the T1 can "Auto Calibrate" after I use it for sometime and the problem maybe gone. Is there any truth to this?


Hi Tylaus,

Thank you for joining the Bose Pro Portable PA Community.

Congratulations on getting your new L1® Model 1S with B2 and T1®.

Here's a couple of things to try.

  1. zEQ: Low 0db, Mid 0.4db, High 0.4db
    1. Sing closer to the microphone to get a fuller tone
  2. Try different settings for the B2
    1. Have you tried the Minus or Normal settings?
  3. Move the B2 a few feet in any direction
    1. It may be sitting in a position where it is resonating with the room. Moving it a few feet can make a huge difference. If you find this helps, you can get a longer cable (NL4 -  must be 4 conductor). Then put the L1® wherever it suits you and the longer cable will give you more flexibility.

Does that help?


Hi again Tylaus,

Tylaus posted:
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Also, I was told by someone that the T1 can "Auto Calibrate" after I use it for sometime and the problem maybe gone. Is there any truth to this?


There's no "Auto Calibrate" feature.


Thanks ST for your quick replies. My B2 currently has Normal setting. I will try your other suggestions (zEQ Low to 0db, and move the B2 around a little), and will report back. Thanks again!

Would like to provide some update. Setting the zEQ to 0db, and moving the B2 around didn't seem to do much. I did these 2 things, and they seem to help quite a bit: (1) Reduce the gain on my Shure SM58 mic by -10db; (2) Set the B2 to Low (instead of Normal). This means I'm losing some power from the mic, and some bass, but they help with the feedback problem. Thanks.

I have had L1 with T1 toneMatch for a number of years. I recently bought TC-Helicon Voicelive Play mainly for my wife to have some vocal effects when she sings with piano. Unfortunately, I do not know how to set these systems to work together. We have been very frustrated with an extremely annoying high frequency feedback. Only if the volume on L1 is very low, the system is somehow usable, however, we really cannot use the combination at all when performing to audience.  I admit that I only know how to play my sax and do not understand much about these devices. But I bet some of you guys have experienced the same and can help to sort this out.


Hey HeikkiS and welcome to Pro-Portable Community,


If it is feedback specifically that you are experiencing, it may be best to start our troubleshooting with the positioning/setup of the L1. is the L1 next to, or behind the microphone? Also, can you specify the type (make/model) of microphone you are using?


Hope this helps.


I have tried to position the L1 all possible ways. It doesn't seem to matter (much) if it is facing away the mic 5 meters away or facing it just 2 meters away - which is strange to me. I have tried two kinds of mics: Shure C606 and Rode NT1-A. I have managed to set the TC-Helicon accordingly. But makes no difference, the high frequence feedback is always there unless volume is low.

I am now more or less convinced that the cause to my problem is on the TC-Helicon device, not an Bose ToneMatch. So, please, unless I post stating otherwise, ignore this problem on this forum. Probably nothing wrong in hardware or settings of Bose products.