# Humming when connected in stereo **URL:** \ **Category:** Quad Cortex\ **Tags:** quad-cortex, support\ **Created:** [January 26, 2024, 12:05am UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281 "2024-01-26T00:05:22Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![Cheems](https://avatars.discourse-cdn.com/v4/letter/c/77aa72/32.png) [@Cheems](https://unity.neuraldsp.com/u/Cheems)\ **Post date:** [January 26, 2024, 12:05am UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/1 "2024-01-26T00:05:22Z")
Hey y´all . I recently got 2 Presonus Eris E5 studio monitors, when i got the first one i plugged it with no problem to the QC output 3 for mono output, barely a small hiss associated to the guitar, when volume was down there was no noise. Then i got the second monitor and when i plug both the output 3 and 4 it´s a massive buzzing/hissing sound even with the guitar down I´ve tested both monitors in each output by themselves and the issue only arises when they are both connected. They are connected through the same 1/4 " plugs as i use for guitar. So: Monitor 1 to output 3 with cable 1 works fine Monitor 1 to output 4 with cable 1 works fine Monitor 1 to output 3 with cable 2 works fine Monitor 1 to output 4 with cable 2 works fine Monitor 2 to output 3 with cable 1 works fine Monitor 2 to output 4 with cable 1 works fine Monitor 2 to output 3 with cable 2 works fine Monitor 2 to output 4 with cable 2 works fine only when they are both connected regardless of output, cable, etc theres this loud hum, my guess it´s something to do with the having a grounding issue when connecting both speakers what do you guys think? has anyone dealt with this? ---
**Author:** ![xush](https://sea2.discourse-cdn.com/flex020/user_avatar/unity.neuraldsp.com/xush/32/5100_2.png) [@xush](https://unity.neuraldsp.com/u/xush)\ **Post date:** [January 26, 2024, 1:17am UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/2 "2024-01-26T01:17:01Z")
Have you tried the Ground Lifts? Is everything plugged into the same outlet? ---
**Author:** ![Cheems](https://avatars.discourse-cdn.com/v4/letter/c/77aa72/32.png) [@Cheems](https://unity.neuraldsp.com/u/Cheems)\ **Post date:** [January 26, 2024, 1:18am UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/3 "2024-01-26T01:18:31Z")
they are plugged to different outlets, not sure how to ground lift tho ---
**Author:** ![xush](https://sea2.discourse-cdn.com/flex020/user_avatar/unity.neuraldsp.com/xush/32/5100_2.png) [@xush](https://unity.neuraldsp.com/u/xush)\ **Post date:** [January 26, 2024, 1:30am UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/4 "2024-01-26T01:30:59Z")
Sounds like you’re creating a ground loop. Try the ground lifts, they’re found in the swipe-down I/O menu ![Screenshot_20240125_193252_Microsoft 365 (Office)](https://us1.discourse-cdn.com/flex020/uploads/neuraldsp/original/2X/9/9ecb1256a94983deefc318d0aad330afaeee73a4.jpeg) ---
**Author:** ![Cheems](https://avatars.discourse-cdn.com/v4/letter/c/77aa72/32.png) [@Cheems](https://unity.neuraldsp.com/u/Cheems)\ **Post date:** [January 26, 2024, 5:08am UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/5 "2024-01-26T05:08:31Z")
oh man but the outputs 3 and 4 have no ground lift option, maybe if i try with xlr cables i guess ---
**Author:** ![MP\_Mod](https://avatars.discourse-cdn.com/v4/letter/m/ccd318/32.png) [@MP\_Mod](https://unity.neuraldsp.com/u/MP_Mod)\ **Post date:** [January 26, 2024, 2:56pm UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/6 "2024-01-26T14:56:37Z")
Are you using TS or TRS cables? Definitely sounds like a ground loop ---
**Author:** ![xush](https://sea2.discourse-cdn.com/flex020/user_avatar/unity.neuraldsp.com/xush/32/5100_2.png) [@xush](https://unity.neuraldsp.com/u/xush)\ **Post date:** [January 26, 2024, 3:07pm UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/7 "2024-01-26T15:07:58Z")
try the Input ground lift, just in case ---
**Author:** ![Cheems](https://avatars.discourse-cdn.com/v4/letter/c/77aa72/32.png) [@Cheems](https://unity.neuraldsp.com/u/Cheems)\ **Post date:** [January 26, 2024, 3:40pm UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/8 "2024-01-26T15:40:06Z")
ts cables, haven´t tried trs cables but would that fix it? ---
**Author:** ![Cheems](https://avatars.discourse-cdn.com/v4/letter/c/77aa72/32.png) [@Cheems](https://unity.neuraldsp.com/u/Cheems)\ **Post date:** [January 26, 2024, 3:40pm UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/9 "2024-01-26T15:40:27Z")
tried it but didn´t change it ---
**Author:** ![Cheems](https://avatars.discourse-cdn.com/v4/letter/c/77aa72/32.png) [@Cheems](https://unity.neuraldsp.com/u/Cheems)\ **Post date:** [January 26, 2024, 4:06pm UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/10 "2024-01-26T16:06:01Z")
i don´t have trs cables and im trying not to buy more stuff unless it could be a fixing issue hehe ---
**Author:** ![xush](https://sea2.discourse-cdn.com/flex020/user_avatar/unity.neuraldsp.com/xush/32/5100_2.png) [@xush](https://unity.neuraldsp.com/u/xush)\ **Post date:** [January 26, 2024, 4:08pm UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/11 "2024-01-26T16:08:21Z")
TRS are for balancing the signal, or you can get a ‘humbuster’ version (if you’re willing to use Send1 or 2), that could indeed mitigate the noise problem, but it’s hard to guarantee. That was going to be my next suggestion, other than plugging everything into the same outlet if possible > [@Quad Cortex hidden hum canceling feature! - Ground loops, 4CM](https://unity.neuraldsp.com/t/quad-cortex-hidden-hum-canceling-feature-ground-loops-4cm/11911): > > Just stumbled across this in the QC manual. The QC has hum canceling technology built in. It looks similar to Fractal’s Humbuster feature, if you are familiar with Fractal Audio’s devices. You can apparently connect a TRS to TS cable from Sends 1 or 2 and reduce hum. This can come in really handy. You can order a Humbuster cable directly from Fractal or if you search the Fractal FM9 manual for “Humbuster”, you can see how to make your own. They may be available from other sources as well. Not … ---
**Author:** ![Cheems](https://avatars.discourse-cdn.com/v4/letter/c/77aa72/32.png) [@Cheems](https://unity.neuraldsp.com/u/Cheems)\ **Post date:** [January 26, 2024, 8:23pm UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/12 "2024-01-26T20:23:33Z")
in the sends i can just use them as outputs or do i need to do something different? im gonna look for some trs cables and see if that fixes it first thoug thank you so much ---
**Author:** ![xush](https://sea2.discourse-cdn.com/flex020/user_avatar/unity.neuraldsp.com/xush/32/5100_2.png) [@xush](https://unity.neuraldsp.com/u/xush)\ **Post date:** [January 26, 2024, 8:30pm UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/13 "2024-01-26T20:30:00Z")
they’re good to go as Outputs- just need to connect them and change your Output Block to correspond to the send you use ![Screenshot 2024-01-26 143147](https://us1.discourse-cdn.com/flex020/uploads/neuraldsp/original/2X/5/57ae60d7a53625e564b7b1c91f6fd1d67bc20e54.jpeg) ---
**Author:** ![Cheems](https://avatars.discourse-cdn.com/v4/letter/c/77aa72/32.png) [@Cheems](https://unity.neuraldsp.com/u/Cheems)\ **Post date:** [January 27, 2024, 12:22am UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/14 "2024-01-27T00:22:17Z")
HELLO EVERYONE THE TRS CABLES FIXED IT i am dumb and have no job in electronics so i didn´t know the balanced cables would fix it, thank you all again for your disposition and help!!! love you ---
**Author:** ![xush](https://sea2.discourse-cdn.com/flex020/user_avatar/unity.neuraldsp.com/xush/32/5100_2.png) [@xush](https://unity.neuraldsp.com/u/xush)\ **Post date:** [January 27, 2024, 1:28am UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/16 "2024-01-27T01:28:29Z")
Fantastic! That’s what we like to hear ---
**Author:** ![MP\_Mod](https://avatars.discourse-cdn.com/v4/letter/m/ccd318/32.png) [@MP\_Mod](https://unity.neuraldsp.com/u/MP_Mod)\ **Post date:** [January 29, 2024, 1:53pm UTC](https://unity.neuraldsp.com/t/humming-when-connected-in-stereo/13281/17 "2024-01-29T13:53:49Z")