Input issues on Mac High Sierra 10.13.6 using Numark M101 USB


I’ve got 2 record decks and a Numark M101 USB 2 channel mixer which you can connect to PC/Mac via a USB cable. I’ve tried everything I can find on wiki for setting it up but I’m still having issues.

Ive got USB codec set to input default on the Audio Midi set up and and it’s also selected at the input on sound preferences. I was just getting flat line with no sound recording and now all I’m getting is an error message “error opening recording device” Error code -9986 internal port audio error.

Any help would be greatly appreciated as I feel I’ve tried everything.


2 record decks

Can we assume players, not recorders?

Your kit also has to appear in Apple (upper left) > Preferences > Sound > Input and it has to be able to make the sound meter jump.

If you get it that far, restart Audacity with the mixer plugged in. Set Audacity for stereo, 44100 sample rate. Does the mixer show up in Audacity > Preferences > Devices?

Where do you lose it? Which step doesn’t work?


Hi Koz,

Thanks for the reply. It’s not making the sound meter jump, what can I try to fix this?

Technology isn’t my strong point if i’m honest, yes two pioneer plx500 record players connected to the mix via phono cables.



what can I try to fix this?

Missed a step. Does it appear?


For device selction options it’s got USB Audio Codec as an option to choose in sound preference, does that count as it appearing?

does that count as it appearing

Yes. Some manufacturers burn the maker’s name or model name into the USB connection. If they don’t, USB Audio CODEC is the generic name. If it vanishes when you unplug your mixer, then you got the right one.

If the sound meter never bounces when you play music, then the mixer isn’t sending sound to the Mac. Audacity gets the sound from the Mac, not the mixer.

Chances are good there’s something wrong with the mixer.


Make sure USB Audio CODEC is selected in that Systems Preferences panel.

It’s pretty unusual for the audio service to die at this step. Did you buy the mixer new? Do the headphones work?


Do you get the bouncing sound meter on the mixer?


Yeh mixer was bought brand new in July last year. The bouncing sound meter only goes up and down when you first turn it on then nothing when the music is playing, headphones work too. It’s definitely recognising the USB connection as it disappears when I unplug it.

The bouncing sound meter only goes up and down when you first turn it on then nothing when the music is playing

The mixer bouncing sound meter is the indication that there’s sound going down the USB cable.

If you’re hearing music when the meter is silent, that’s the cue system you use to set up the next record while the current one is playing.

Let’s say the music is playing on the left-hand system. Make sure the left slider is up, the left GAIN (near the top ) is up, the cross-fader at the bottom is to the left and the Mixer Master (upper right) is up. Do you get the mixer sound meter?


I’ve just tried what you suggested and the bouncing meter works. I guess it’s bot been working when I’ve had my speakers on because at that level it would blow my speakers but the test proved the meter works.

I’m connect from an amp, into a pre amp, then pre amp into the mixer, then the decks are running into the line inputs.

Update - so when I have the gain and master up at their top level I’m now able to record in audacity, however the sound is so distorted even with my amp on low volume it’s completely unlistenable.

Is this a set up issue between mixer - pre amp - amp ?



then the decks are running into the line inputs.

Which decks? We only know what you tell us. We can’t see your setup.

When this system is installed using actual turntables such as the Techniques 1200 MKII, there is no phono preamp and you have to use the Phono-Ins of the mixer. You also have to use the two ground straps. That’s what that GND screw is doing. I have no idea what your decks are or how to connect them.

an amp, into a pre amp, then pre amp into the mixer,

What’s that doing? The only other thing you should need is a 1/4" type microphone for announcements. This should be right out of a club band kit. That’s their vocal microphone such as the Shure SM58 and a special mic cable.

Turn the speakers off until you resolve the regular recording sound pathway. The mixer sound meter should bounce in the green region with maybe occasional flashes of yellow. The Mac System meter should bounce about 2/3 up, or so. Not go all the way up. If you run Audacity, the bouncing meters should bounce somewhere between -20dB and-3dB. If they go all the way up, you will get distortion.

On the mixer, I expect the two channel GAIN knobs to be at noon or 3:00 o’clock. The channel faders should be about 3/4 up. That’s why those markings are a little thicker right there. The sideways channel fader on the bottom should be all the way left or right depending on which turntable you’re using. Or if you’re really adventurous and good at this, in the middle and run two songs at the same time. That’s why music has a beats per minute rating.

I don’t know where the master volume upper right is supposed to be. I would guess at Noon to 3 o’clock.

Once you get a good Audacity recording, we can worry about the house amps and speakers. Judge the Audacity recording by listening to the computer, not the mixer.



Thanks for all your help on this, I’ve now got it all working and recording into Audacity. Seems like this issues were with the connections between the amp/mixer/decks. I’ve now gone amp to mixer then decks into the phono on the mixer which seems to be doing the trick.