Why is USB audio way louder than other channels in my mixer?

mistercharlie

I use a USB mixer to hook things up, so I can play guitar and some other gear standalone, but also to integrate with an iPad or Mac.

With the guitar etc, I can set input gain, so my mixer’s volume knobs and faders can all stay around 0db.

But when I send audio into the mixer over USB, it’s super-loud. I can only turn the USB channel knob a fraction of the way up before it’s louder than everything else.

Why is Mixer is a SoundCraft Notepad 12, if that has anything to do with it.

Processaurus

A lot of digital sources are “normalized”, meaning they are meant to get close to 0dB, the absolute limit before clipping digitally. Your mixer might have been designed to anticipate more headroom left in the usb source.

I know when I record with my mixer into the daw, I leave 10db of headroom as a rule of thumb, and playback of the recorded tracks is pretty moderate. If I play back some mastered/commercial music, like out of iTunes, it is BLASTING. My solution is just to turn down the volume control in the program, if I don’t want to turn down the playback channel on the mixer.

Ideally there would be a gain/trim control on the usb return channel, but you only get that on bigger mixers. They had to make sure there was enough gain to be able to play quiet, un-normalized stuff off the computer and not run out of volume.

Processaurus

If you aren’t lighting up the channel peak meters with your guitar etc. you can crank up the gain on their channels, and turn down the master, to try to match your usb source. Or turn down your speakers volume controls. I have my monitors turned way down so I can get a better level out of the computer, same with my PA system. You want at least half of the green meter lights on the mixer output lighting up when you get rocking.

RUST( i )K

Gain stage

mistercharlie

Thanks for these answers. @RUST( i )K I’m gain-staging all the other inputs. That’s the problem. I had it set up so that the guitar etc were much hotter, by cranking their gain to match the usb. That meant having the channel and master faders too low.

I’ll live with the loud USB input, and just keep its knob turned down low. I just wondered if I might be missing something.

mistercharlie

Update: I got around to doing some recording, and realized that the input gain needs to be up high on the soundcraft mixer to get any decent signal into Logic/GarageBand.

So, that dictates the current setup: a good, high input gain, channel volume knobs set too low, and the main fader set too low.

However, I can also control the overall volume by setting my powered monitors a little lower. The problem, here is the lack of click stops on the speakers’ knobs. This makes it hard to match left and right. But it should let me crank the channel and output faders closer to 0db.

Any problems doing it this way?

Dr_M

Reduce the usb audio output at the source, in the digital realm. K

0 on a standard mixer is low like -24 in the digital realm, & the opposite is true, 0 in digital can be up to +24 analog, depending in or out, brand, balanced or not etc . The 0 mark on your channel faders doesnt matter if its going to digital, only point that matters is when that channel distorts. You could use direct boxes to boost your signal upto +4 if you have XLR inputs. Your aiming for -6 on the digital meter digial meter so Adjust your trim accordingly.
If you only have 1/4 jacks you’ll only have gain to boost the channel volume and that will raise the overall noise floor of you audio source as well. If you wait to boost till after the mixdown you will be raising the noise floor of every stem in the recording when you boost the final mix.