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CCRMA Studio E

Studio E (Knoll 320, behind the Stage - “Epstairs”) is a small (about 15x10.5 foot, with ceilings ~9.6 feet) general-purpose computer music studio suitable for a variety of activities, primarily designed for composition, mixing and mastering in 22.2-channel surround-sound. It features a custom metal framing structure, filling almost the entire room volume, that holds the loudspeakers in place, with five of them mounted on trolley systems to be able to move between full-surround and out-of-the-way locations.

How-to links:

Studio E Contents

The front of Studio E with three computers (laptop, Mac, and Linux machine) in use simultaneously.

In this space you should see:

Photo of Studio E Audio Rack. See bullet list above for an explanation of the contents.
Studio E Connection Diagram from before the upgrade from 8.2 to 22.2. This is all still correct but now incomplete.

Don’t touch

Studio E users are expected to leave all of the following alone:

If you see any problems with any of the above please contact CCRMA staff.

To Reset Studio E

Audio System

Studio E contains a 22.2 channel sound system able to surround a listener:

There are two ways to get sound into the system:

  1. Eight channels (speakers 1-8 of the main ring) via the mixer (namely the 8 routing busses), with automatic bass management: plug into the mixer and turn up the desired channels
  2. All 22.2 channels direct from your laptop’s multichannel audio software: connect your laptop to the MOTU 1248 and output to channels 9-32.

These both always work simultaneously; in other words, the 8 signals from the mixer + crossovers are mixed with the 8 signals from your laptop’s outputs 11-18 to the MOTU.

Of the 10 speakers in the main ring, six are mounted on trollies that allow each speaker to move between its position in the 10-channel ring and an “out of the way” position that may be more convenient sometimes.

Loudspeaker positions

This table shows the numbering and positions of the 22 loudspeakers (when all 6 trolley-moveable speakers are in their ring/dome position). These are in spherical coordinates (wikipedia), with distance in inches and angles in degrees, where azimuth 0=forward, azimuth 90=left, elevation 0=“ear level”, and elevation 90=up.

num azi elev distance
1 -18 0 60”
2 18 0 60”
3 -54 0 58”
4 54 0 58”
5 -90 0 56” (?)
6 90 0 56” (?)
7 -126 0 58”
8 126 0 58”
9 -162 0 60”
10 162 0 60”
11 -22.5 33 69.25”
12 22.5 33 69.25”
13 -62 33 69.25”
14 62 33 69.25”
15 -118 33 69.25”
16 118 33 69.25”
17 -157.5 33 69.25”
18 157.5 33 69.25”
19 -45 66 64.5”
20 45 66 64.5”
21 -135 66 64.5”
22 135 66 64.5”

A few notes:

  1. The azimuths of speakers 13, 14, 15, and 16 are approximately 2.5 degrees off from 8 perfect subdivisions of the circle. (Ideally they should be +/- 67.5 and +/- 115.5 degrees.) This is because otherwise the closet door would hit speaker 15. Then for symmetry we mirrored 15’s wrong position along two axes so as to infect 13, 14, and 16 with equal wrongness.

  2. Speakers 1-10 form more of an ellipse than circle (with distances 56, 58, and 60 inches), so as to fill more of the room’s footprint compared to the circle that could be inscribed within the room’s width.

  3. For the middle ring at elevation 33 degrees, we “rotated” the loudspeakers:

Loudspeaker Spatial Definitions

We define the infinitesimal “point” that is “the position” of the entire loudspeaker as being on the front surface, on the circumference of the grille over the woofer, on the “highest” point closest to the tweeter.

The room is quasi-cuboiodal with three Cartesian axes:

The “center” of the room’s floor plan is where the midlines of the interior left/right and front/back directions meet.

The “sweet spot” is above that point at “ear level”, defined as 46” above the floor. (Determined empirically by sitting in a chair with “good posture.”)

Mixer Wiring and Channel Numbering

The rear of Studio E’s DM1000 mixing board, showing the many audio connections described in this section.

The Yamaha DM1000 digital mixer connects pretty much every audio device in the studio. It has several built-in analog inputs and outputs, plus two expansion slots. It is the audio sample clock source for both the Mac and the Linux machine.

Slot 1 is an ADAT lightpipe expansion card with 2 lightpipe inputs and 2 lightpipe outputs giving 16 channels each way.

Slot 2 is an analog input expansion card taking 8 analog inputs from the MOTU 1248 for drop-in laptops

Mixer inputs

The most popular mixer inputs are analog 1+2 carrying a stereo signal from your phone’s or laptop’s headphone jack via the LTI-1 direct box. Note the 1/8” stereo male plugged into the laptop, the white and red 2-channel XLR snake running from LTI-1 to mixer, the green “signal” LEDs lit on channels 1+2, layer 1-16 selected on the mixer and the two leftmost faders being up.

This information about the 48 input channels also appears on some 4-line-tall printed labels below the faders.

The labeled faders of the DM1000 in Studio E, each with 4 possibilities

DM1000 Input Patch lets you decide which physical inputs appear on each of the mixer’s 48 input channels. You should never need to change this. The default input patch is number one CCRMA DEFAULT.

Mixer outputs

The 8 bus outputs of the DM1000 correspond to the first 8 speaker channels; they come out in analog via “Omni Outs” 1-8 and connect to the bass management.

Also Slot 1 has an ADAT card that digitally sends and receives 8 channels to and from both both permanent computers:

DM1000 Output Patch lets you decide which mixer signal (such as an aux send) goes out each of these 16 ADAT output channels on Slot 1. The default output patch is number one CCRMA DEFAULT.

Selecting Your Laptop or the CCRMA Mac

XXX need photo of new KVM 2023

Studio E KVM Switch. Note the two LEDs on the left show you which of the two computers have USB “online”, while the two LEDs on the right show you which one is currently selected.

There’s a KVM switch labeled “Linux” (1), “Mac Studio” (2), or “Laptop” (3). Press the button corresponding to the computer you wish to use.

This switch controls access to:

  1. The USB keyboard (Apple Keyboard with Numeric Keypad: “A1243”)
  2. The USB mouse (Logitech)
  3. The LG E2341TX monitor (1920x1080, 60 Hz)

Using Your Own Laptop

Connecting Your laptop

Studio E with a USB-C laptop connected to keyboard, video monitor, mouse, and MOTU audio interface

A “combo” USB and HDMI cable sits unplugged on the left of the main desk. All the dongles you might need (accommodating Mini DisplayPort and USB-C) are in the drawer under the mixer (or check the Adapter Closet if you have special needs).

You can follow any subset of these steps in any order:

Plugging in a USB-C laptop might look like this

MOTU I/O channels

The MOTU 1248 is configured as an “Audio interface” for you to plug into your computer via USB.

Input channels your computer sees:

Output channels your computer sees:

Note that if you choose the MOTU as your operating system’s selected audio interface, then all the “normal” computer sounds like audio from web browsers will come out channels 1+2 (so you can hear them in speakers 1+2 and/or headphone 1).

Seek staff assistance if you want to use the MOTU’s digital audio I/O (ADAT, S/PDIF, or AVB).

(XXX: re-do this with new dual MOTU setup.) Max’s I/O Mappings window when your laptop connects to the Studio E MOTU 1248. Note that Max can “see” the names of the MOTU inputs corresponding to ADC input channels 1-14 as well as the names of the MOTU outputs corresponding to DAC output channels 1-12. Outputs 1-4 appear as “Multiple Outputs” because they are routed both to the corresponding Analog output and also to the headphones.

Using the Mac

CCRMA maintains a Mac studio (wikipedia) named for any CCRMA user to use.

First select “Mac studio” with the KVM switch. You should see the OSX login screen; use your usual CCRMA username and password and when you log in you will see the same home directory as on the CCRMA Linux workstations

The machine is currently on MacOS 12 (“Monterey”).

Installed software includes Adobe Creative Cloud (including Illustrator, InDesign, Photoshop, Premiere, etc.), Ardour 3.5.403 (not working), Audacity 2.0.6, GarageBand 10.3.4 (but it can’t talk to the correct channels of the Apollo), iMovie 10.1.14, JACK, Logic Pro X 10.4.8, Max 8, miniAudicle, Octave, Pd-extended, Soundflower (not working), Sublime Text, SuperCollider, TeXShop, and VLC 3.0.8.

The machine also has hundreds of plugins installed, so when you first launch a plugin-hosting program such as Audacity, GarageBand, or Logic, it will spend about 5 minutes scanning plugins. (CCRMA no longer supports Pro Tools (not even in the Recording Studio).)

Also the machine has software installed by both MacPorts and Homebrew, which might not be a good idea.

Talk to Matt about installing additional software.


The Studio E Mac Studio shares the MOTU 1248 via the KVM switch.

Also for now (remainder of 2023?) it’s connected to a Universal Audio “Apollo” interface connected via Thunderbolt. (What kind of “Apollo”? The sticker on the front says “QUAD”. The UAD Control Panel’s System Info tab calls it “Apollo QUAD” and indicates it has 4 DSPs. In the website it’s called “Apollo x4 Thunderbolt”. To select the device from software such as Logic or Max the name is “Universal Audio Thunderbolt”.) The Apollo has four high-quality mic preamps as well as powerful onboard DSP that can run many useful plugins.

In the Sound part of System Preferences you can select Universal Audio Apollo as the operating system’s default sound output (or input) device. Then web browsers and other “normal” audio programs will output via the Apollo.

The Apollo should sync its sampling rate to word clock coming from the DM1000. When this is properly configured you will see two green LEDs on the front panel just to the right of the UA logo: EXT CLOCK (successful external clock synchroniation) and UAD LINK (successful Thunderbolt connection to the Mac). EXT CLOCK being red can mean that some software on the Mac has set the Apollo to a different sampling rate than the one it is currently from the DM1000; try explicitly setting the Apollo sample rate in your software.

There is an OSX application named Console (inside the Universal Audio subfolder of the /Applications folder) that controls the Apollo hardware; you will need this to access the plugins and might find it useful for debugging. Console is a virtual mixing console that controls the UA hardware and runs simultaneously with whichever audio software you use. It allows channels to be routed into your software from all the Apollo’s inputs, potentially via plugins. Unfortunately Console doesn’t show signals that you are generating inside the computer, only the signals coming into the Apollo’s physical audio inputs, so it’s not good for monitoring or troubleshooting sound problems, only for seeing and applying effects to the input signals. This system is a bit complicated, so attention to the routing features of Console and whichever recording program you use is necessary.

Console has a Console Settings window with tabs for HARDWARE, CORE AUDIO, DISPLAY, PLUG-INS, and MIDI.

You might want to read the Apollo Software Manual (pdf in /Applications/Universal Audio/Documentation).

Apollo I/O channels

If you set your OSX Sound Preferences Output to Universal Audio Thunderbolt (PCI card) then the stereo sound from normal OSX applications (such as web browsers, but annoyingly not GarageBand) comes out of the Apollo’s ADAT 1+2 outputs, which is exactly what we want, because the Apollo connects via ADAT to the DM1000 and hence the loudspeakers. This is set in the Audio MIDI Setup application, Audio Devices window, after selecting Universal Audio Thunderbolt and clicking the Configure Speakers... button.

Otherwise output channel numbering is confusing because we only use the Apollo’s digital outputs to the mixer, so the audio output channel numbers you need to use start at 11 instead of 1.

There’s a better way to configure this using their “Core Audio Panel” and “Flex Driver Overview”: Talk to staff if you would like to work on this or if this would help you.

The Console Settings window’s CORE AUDIO tab shows the channel mappings listed in the rest of this section.

Input channels the Mac sees:

Output channels the Mac sees on the Apollo:

These channel mappings have sometimes changed in weird ways, for example one time outputs 43-50 were mapped to ADAT (instead of 11-18). If you get weird behavior try power-cycling both the Mac and the Apollo.

So for example, in Logic Pro X you would go to Preferences > Audio... (under the Logic Pro X menu), then the I/O Assignments tab, then the Output sub-tab, and under Stereo set Output: to Output 11-12 using the drop-down menu.

In Max you might want to go to the Audio Status window (available under the Options menu), click Open I/O Mappings, and set Max’s outputs 1-8 to go to Apollo outputs 11-18, as shown in this screenshot:

If you use Max you might want to use these I/O Mappings so that when your patch outputs to DAC channels 1-8 it comes out the proper Apollo outputs into the DM1000 and the speakers.

Using the CCRMA Linux Machine

cmn56 has its own separate desk, monitor, keyboard, mouse, and audio interface (RME Hammerfall DSP Digiface).

You should be able to use your usual CCRMA username and password, and once you log in you should be able to see all your files, like with any CCRMA Linux Machine.

Linux Audio

It may require troubleshooting to get sound on Linux through the RME Hammerfall DSP Digiface audio interface. The RME’s sample rate should be set to synchronize to its word clock input, which comes from the DM1000. The RME’s first ADAT output, corresponding to output channels 1-8, goes to DM1000 input channels 33-40, and its first ADAT input, corresponding to input channels 1-8, comes from the DM1000.

The RME interface has no front-panel meters. You want to see two LEDs lit on the front panel, both in the “INPUT STATE” area:

  1. WC lock (telling you the RME is properly locked to wordclock coming from the DM1000)
  2. ADAT 1 (telling you the RME sees one 8-channel ADAT light pipe connection from the DM1000)

The “host” LED might be red - that means a bad connection between the Linux machine and the RME. (If the connection is OK there will be no light.)

“ADAT” might be blinking green - that might or might not be a problem.

You probably want/need the hdspmixer and hdspconf Linux command-line programs. hdspmixer presents a quasi-mixing-board-like interface that’s mainly useful for metering (though one time Matt was getting no sound through JACK and after launching hdspmixer it immediately started working, though that may have been coincidence…) hdspconf lets you configure the RME’s settings; make them look like this photo:

hdspconf should look like this in Studio E

In general for RME issues you can try logging out and back in, or rebooting cmn56

General Linux Audio Software / ALSA / Pulse audio

Doesn’t work. So forget getting sound from Firefox, VLC, etc.

By default sound will go through PortAudio and ALSA but ALSA can’t see the RME audio interface.

Sound Preferences doesn’t see the RME as a “Device”, offering only Dummy Output which does nothing.

Audacity under Linux

Audacity should see Hammerfall DSP: RME Hammerfall DSP + Digiface (hw:0,0) and offer it as an input and/or output audio device. If you explicitly select the device then Audacity will output (only) to the first and second outputs, which is probably what you want. (The default other Playback Device options may do nothing.)

JACK under Linux

You will probably need JACK to use Ardour, Pd, JackTrip and other software.

The main issue is that you have to make sure JACK is talking to the proper audio device, in this case either RME Hammerfall DSP + Digiface aka hw:DSP,0 or Hammerfall DSP (hw:0) aka hw:DSP.

JACK sees 26 output signals (playback_1 through playback_26) under system, but only the first 8 connect to anything (namely mixer inputs 33-40). Likewise JACK sees 26 input signals (capture_1 through capture_26) but only the first 8 are connected (via ADAT coming from DM1000 slot 1 outputs 9-16, which you can access using the DM1000 Output Patch.

More info about running JACK on CCRMA Linux Workstations

Sound system and bass management

The 8 bus outputs of the DM1000 come out in analog via “Omni Outs” 1-8. These go into a pair of Xilica XP-4080 DSP Processors that are each configured as a 4.1 crossover. The front left speakers (1,3,5,7) go through the top unit, with the 4 crossover high-frequency outputs each going to the appropriate speaker and the 4 crossover low-frequency outputs being mixed and sent to the front left subwoofer. In other words, any bass frequencies you send to any of the left 4 speakers will “automatically” come out the left subwoofer. Likewise with the four right speakers (2,4,6,8) and one right subwoofer through the bottom unit.


Recall the good preset on the DM1000

Are all 8 loudspeakers powered on?

Is everything still plugged into the KVM? Should be 2 computers (Mac Pro and your laptop), shared keyboard, mouse, video monitor

Are all of the Xilica input and output channels unmuted?

This page of CCRMA documentation last committed on Tue Oct 17 09:56:07 2023 -0700 by Matthew James Wright. Stanford has a page for Digital Accessibility.