Signal Passing Through Audio Interface When Knobs Are At Zero

i’m new, so please forgive my ignorance.

i purchased an M-Audio 192/6 and via USB-C it plugs in to my Macbook Pro M1 Max / macOS 13.

any sound source i plug into it (Microphone, Line, Instrument inputs) comes thru even when the volume/gain/knobs are all the way down/off.

i’ve tried it using GarageBand as well as Audacity… same issue with both.
yes, i can still turn up the knobs, and it does boost the signal, but still, shouldn’t there be NO sound coming thru with those knobs down?

i spent 2 hours with M-Audio tek support via chat yesterday and they said the device must be defective. i purchased it on Amazon last week, so i did a return and re-purchased it (from a different seller on Amazon). i received it today, plugged it in, & it’s doing the same thing!

am i missing something?

thanks - i appreciate any wisdom on this.

Im not familiar with this unit, but looked at video and google online.
The input control knobs are called “Gain” and the VU level meter goes down to -20 db
Zero ( 0 ) db is gain of 1 …what is input will be same as output
-20 db is gain of 0.1 … output will be 0.1 times input.
There is also a balance pot between USB sound out and direct sound…does changing this make any difference.
Did M-Audio say the sound should go down to “off” when the pots were at minimum…??

Do you have a problem with clipping? What are you plugging in?

If you don’t have clipping you can reduce the level or mute after recording. (It’s a recording interface, not a mixer.)

Somebody had a similar problem with a different interface and a guitar. When they turned it fully-down they were still getting clipping. (I think it was a Focusrite but I’m not sure.)

Of course a guitar has a volume knob, but the guitar player didn’t want to use it.

And a lot of studio condenser mics have “pad” switch to reduce the signal by -10 or -20dB.

I’d be asking that question right after “Hello.”

Volume controls are a very special hardware device. They work like your ear does where a volume change isn’t where you think it’s supposed to be (half-way isn’t half volume). But unlike your ear, everybody is expecting a volume control to go off when you turn it off. That’s a special purpose device.

Conspiracy Theory would have it they used a non-volume control to save a few pennies. That change would, in fact not go off when you turn it off, but very few people record performances with the control off. Further Conspiracy would have it the servicing people know this and are skilled in talking around it.

A different idea has your computer recording your voice from two diffent pathways and you’re not turning off both of them. That one is a little “out there” and I’m much more likely to go with the “save a few pennies” theory.


my apologies for my delayed responses…

THANK YOU for your reply!

when i say that i’m a noob, i really mean it (LOL). i don’t understand that DB math. all i really grasp of DB (at this point) is to make sure the level meter is between -3 to -6 DB for optimal sound.

BUT, i ‘think’ what i gather from what you’re saying is that this interface does in fact pass the signal thru even with no gain. tho it’s weak. so adding the gain gives it the boost you need for the levels to be optimal AND it somehow helps it sound better (more full).

so i should tell my OCD to take a back seat & let go of the idea that it should cut the signal completely if the gain is all the way down.

i think i was also confusing “Gain” with “Volume”. i did some reading to discover how they are different (tho i still don’t grasp it fully, i think i get the general idea now).

and to answer your questions,
i’ve not been using the interface “outputs” except for the USB-C to the computer. i’ve been monitoring the sound via the computer speakers. so both the main out & headphone out knobs have been all the way down too.

and yes, the M-Audio tek support did say the sound should be “off” when the pots are at minimum. but they were clearly wrong.

THANK YOU for your reply also!

i’ve been careful to not let the meters (both on the interface & in Audacity) to get into the yellow or red - so there’s no clipping.

as far as what i have plugged in, my first goal with this is to digitize some old cassettes, so i’m coming out of a boombox headphone out port with a TSR that splits into dual TS plugs into the interface.

i do want to start trying to record some music at some point (acoustic guitar & vocals), but i’m holding off on that until i learn more & get more comfortable with all this. that said, i did plug in a microphone to test this also, and the signal passed thru as well (tho weak).

as you said, it’s an interface, not a mixer - i may have been thinking of it as both for some reason. but, i’m learning.

THANK YOU also for your reply!

i mentioned just above that i mistook the gain knob for a volume knob, and that i’m just learning about the differences etc.

not sure i understand what you’re saying about conspiracy theories, but i’m just trying to understand/learn & use this new piece of hardware in conjunction with my computer.

.peace. :v:

That’s only the belief that a non-fatal, but odd behavior isn’t broken, but just the manufacturer trying to save a few pennies. It may not be true, but it’s fun to think about.

Decibels (dB) are a little wacky. But then your ear works a little strangely.

“Half Volume” or 50% is a 6dB dip in volume. Please note the bouncing sound meter goes down to -60dB on the left.

Screen Shot 2023-06-05 at 19.32.47

Also note that the digital system doesn’t run out of steam until -96dB. So trying to describe sound in percents doesn’t work very well.

Your background noise is -60dB, or your background noise is 0.0001%?