Changing audio interfaces problem!

Greetings!
 
Im a first time writer, but a long time reader of this forum, and I hope you can help me with my problem. (and sorry about possible errors in my writing, since English is not my native tongue :))
Here we go: 
 
I am hobbyist and a beginner at best when it comes to producing, so I bought cheap Line6 UX2 and use it in my home recording purposes with Sonar X3 and everything ran out smoothly no noise, no latency, equals to one very happy hobbyist. :)
Well, after this my friend asks me to come and record some early demo to his rehearsal room near by.
 
I have been there before doing some recording with very basic n-track studio. Now, my friend has audio interface in his mixer. It is Behringer (don`t remember the model now) mixer desk with built-in USB audio interface. When I plugin the USB to my computer something weird happens. Background hiss (whitenoise) becomes intolerable. When recording it seems to grow louder the more tracks you record. When you click "stop audio engine" button, hissing stops, and when you push p for preferences window, otherwise it doesn`t go away and is recorded on the tracks aswell. I thought it could have been Behringer preamp issue  of some sort, but when I close Sonar and start n-track, hissing disappears and everything seems to be in order. This is very frustrating since I have no idea how to fix this issue.

Im hoping someone could help me with this issue, so we can move on with the recordings. Thank you very much already!

I have a Behringer 1204USB mixer that works surprisingly well, so I know they can.
 
As sx suggested, the first place I would look is configuration.  Could also be some gain knobs on full blast - I always start with everything at min and go from there.

Hay FoxxOne...You have read the forums but do not post much on it...So welcome...And I quess you are up to speed with HDMI turned off.?..if it is on...Could help big time with noise issues, and clicks and pops, mouse issues and such...((Noted here)) as helping with solving.
 
So, if I got you right in thoughts?
 
You have moved to a new location, ((never using his new mixing desk before?))...
Note sure of your setup, and are you using the ASIO drivers for the devices you are now needing to use.... What is windows default audio device set to in control panel ?
 
have you turned off redundant devices to try to solve for the issues you are having?.
How are you disabling the devices in device manager, ...have you done the power management tweaks?, and usb power set to always on in device manager?...Is the system setup correctly needs to be addressed first.
 
So more input gets better output.
You can also put a description of you system in your profile..and what windows version.
 
Windows, Msconfig, and turn off auto updates, and other things you need not be loaded up at boot up...to reduce services, and apps from being run.
 
Also noted that turning off redundant devices in the BIOS of the motherboard, helps stop some services from being loaded at boot up, or IRQ held for, which could also help stop issues if found running, when disabling in control panel, device manager....So it might be better to turn off wi fi, blue tooth, on board audio, and nic in the bios....depending on what you want the system to do...
 
Once more is known about the setup you have, more directions open up for a solution.
 
Sonar can be made to settle down, once the base is working....and the right gear is put to use there on .
 
Some gear does not always behave with other gear...some drivers may over write other drivers or ties to OS reg.
 
Just to say...it takes time to get it all righted, and knighted as blissful.
 
Might just want to make a new system for the Friends place/make a new boot drive with just his setup and sonar...and swap out the drives for X, via selecting the boot drive for Y...Set that up and see if it makes a difference?
 
Your English is better than mine....Wink!
Regards.

oh noise on pro channel, when loading up, as all channels were set to default on/ and had a bug... was one of the problems with one version of x3...I think X3e solved.

I googled some and a few people had Xenyx USB devices with noise issues. They went away after installing the latest drivers and setting their DAW to ASIO.