Logic Pro X: Aggregate Device

When I first started out recording myself on cello, I would end up having to find creative ways to increase the volume of my recordings without noticeably distorting the sound.  I had two different types of microphones that I wanted to use simultaneously which eventually led me down the path of creating an aggregate after a friend sent me this article https://support.apple.com/en-us/HT202000 that discusses combining multiple audio interfaces through the use of an aggregate device.  This article got me going in the right direction, but I had to do a lot of experimenting to find the custom solution for my specific set up which consisted of:
(1) an iMac computer with Logic Pro X
(2) the Apogee USB MiC
(3) a CAD C9 mini condenser mic that hooks up to my Behringer X1204USB audio interface

Below are the steps that worked for me:

Step 1:  Create the aggregate device using the three ‘Audio Devices’ that pertain to my setup.  For the purposes of this example, the aggregate device that I created is called ‘My Aggregate’.  Navigate to Finder > Go > Utilities > Audio MIDI Setup.  Click on the ‘plus’ button in the bottom left hand corner of the ‘Audio Devices’ window and select the ‘Create Aggregate Device’ option.  You can double click on the defaulted aggregate name to type in the name of your choice.  The Apple support article mentioned above goes into more detailed steps on creating the aggregate and is worth a read.  In my case, I selected the USB Audio CODEC device that had the 2 Ins, the USB Audio CODEC device that had the 2 outs, and the MiC device that had the 1 In.

My Aggregate 1

Step 2:  Open up a Logic Pro project and go to the global settings on the ‘Devices’ tab to select ‘My Aggregate’ as the audio ‘Input Device’ and ‘Output Device’.  To get to the global settings:  Navigate to Logic Pro X > Preferences > Audio > Devices

Logic Global Settings

Step 3:  Create at least 2 audio regions in your project and double check that the ‘Input device’ and ‘Output device’ settings point to ‘My Aggregate’ before clicking on the ‘Create’ button.

Create Audio Region

Step 4:  The ‘Input’ setting on each of the 2 channel strips will have to be changed to reflect the ‘Input Channels’ settings in the aggregate device settings window.  In my case, since I selected my Behringer audio interface first when I created the aggregate, the first 2 input channels are being utilized by that audio device.  I selected the MiC second when creating the aggregate, so input channel 3 was assigned to that audio device.  In my Logic project, I need to make sure that one of the audio regions has ‘Input 3’ selected on the channel strip while the other audio region can remain at the defaulted value of ‘Input 1’ on its channel strip.


Using a Digital Piano To Record Audio Tracks

Sometimes I practice on and use an 88-key Casio Celviano digital piano that also doubles as my MIDI controller.  I occasionally use this digital piano to create piano audio tracks in Logic Pro by using the headphones jack to send the signal to my x1204usb interface in stereo.

Step #1:  Plug the single end of an 1/4 inch cable into the ‘Phones’ input on the digital piano.  See the photo below.

Pic 1. - Phones input jack on digital piano
Pic 1. – Phones input jack on digital piano

Step #2:  Connect the 1/4 inch dual ends of the cable to channel 5/6 on the x1204usb interface.  (You can also use channel 7/8.)  See the photo below.

Pic 2. - Dual end into Channel 5/6
Pic 2. – Dual end into Channel 5/6

Step #3:  Make sure that the ‘2-TR/USB TO MAIN’ red button is NOT pressed down.

Step #4:  To adjust the volume of the recording, you can play around with turning the volume knob on the digital piano and/or adjusting the ‘MAIN MIX’  R/L faders on the x1204usb.  See the photo below.


Pic 3. - Main Mix faders
Pic 3. – Main Mix faders

Step #5:  Make sure that the audio interface is connected to the DAW.  In this specific scenario, I’m using Logic Pro 9 on an iMac.

Step #6:  In Logic Pro, follow the navigation in the photo below to change your audio preferences.

  Logic Pro —> Preferences —> Audio

Pic 4. - Audio preferences navigation
Pic 4. – Audio preferences navigation

Step #7:  Select the ‘USB Audio CODEC’ option for the ‘Input Device’ field.  (I have this same CODEC option selected for the output device since I like to listen to my tracks through my Yamaha HS8 monitors which are also connected to my audio interface.)

audio CODEC
Pic 5. – Input Device CODEC option


Turning Studio Equipment into a PA System

I try to avoid having to set up my own sound amplification system whenever I have to perform live on acoustic cello, but as an independent musician, it’s inevitable that the day will come when you will need to have some understanding of how to do this.

Below is the specific list of equipment in my home studio that I use to create a miniature PA system that works nicely for a small to medium sized crowd.  Any studio monitors that you have should work.  Also, make sure that the audio interface that you use has ‘Phantom Power’ capability.

  • 2 Yamaha HS8 powered studio monitors
  • 2 speaker cables
  • Behringer X1204USB interface
  • miniature condenser microphone
  • kick drum mic stand
  • microphone cable
  • 2 studio speaker stands
  • power strip(s)

My Setup Using The Behringer X1204USB

Step 1:  Make sure that everything is powered off.

Step 2:  Arrange the speaker stands and monitors so that one set is on the left side of the room and the other is on the right side of the room.  Keep in mind that the musician needs to be positioned behind the monitors to avoid unwanted feedback coming through the microphone.

Step 3:  Connect one end of each speaker cable to its designated monitor, and then connect the other loose end of the cable to the audio interface.  On the back of my x1204,  I use the L ‘Control Room Out’ port for the monitor on the left side of the room and the R ‘Control Room Out’ port for the monitor on the right side of the room.  See the photo below.

Pic 1. Control Room L/R
Pic 1. – Control Room Out L/R Ports

Step 4:  Set up the condenser mic and microphone stand in the vicinity of where the musician will be performing.

Step 5:  Connect one end of the microphone cable to the condenser mic and the other end to the interface.  I use the mic preamp port on channel 1.  See the photo below.

Pic 2. Connect mic cable to channel 1
Pic 2. – Connect mic cable to channel 1

Step 6:  Press the ‘Solo’ button on channel 1 and make sure that the ‘Mode’ button is depressed so that the volume can be controlled by the control room volume adjusting knob.  See photos below.

Step 7:  Turn the ‘Phantom Power’ switch on.  See photo.

Phantom on
Pic 5. – Phantom turned on

Step 8:  Power on the interface.

Step 9:  Power on the monitors.  (The monitors are the last thing that you power on when you’re setting up and the first thing that you power down when you’re packing up so that you don’t have to hear all of the clicks and pops as you attach and detach equipment.)

Step 10:  Do a sound check to determine what adjustments you have to make to the mic placement and the volume level on the mic channel.

Step 11:  Turn the white ‘Control Room’ (CTRL RM) knob on the x1204 to adjust the mic volume up or down.  See photo below.

mode n room knob
Pic. 6 – White CNTRL RM knob