Physical Setup

Locals Room

The locals room (Boondock) will involve four pieces of equipment:

Sound Pressure Level (SPL) meter
One silverback Toshiba laptop (Poe)
Loudspeaker: Subwoofer box plus the Right-side speaker (i.e. the left-side speaker not used.)
Texai

Figure 1 (below): Conceptual Setup of Locals Room:

See Photo 1 for an overview of the physical items.

SPL meter: Screw onto tripod. Place as close to edge of table as possible so that foam ball is more or less above velcro dot.
- Attach power cable (hiding under black rubber flap on the left side of the housing).
- Attach USB cable to SPL meter (same place as power). Don't attach computer side of USB cable yet.
Silverback laptop: Attach power, boot up. PWD is 'willow' (the only user account is 'paepcke')
Loudspeaker:
- Place subwoofer on table, speaker cone facing the Texai and SPL meter, such that the face of the subwoofer is above the velcro (~4ft from both the Texai mike and the SPL meter).
- Attach power to subwoofer
- Attach just the Right-side speaker to the subwoofer. The left-side speaker is not used.
- Set bass knob in back of the subwoofer to the forth dot from the left.
- Attach loudspeaker to headset output of silverback (front)
Texai:
- Place Texai across the table from the SPL meter. Have the metal 'torso' of the Texai touch the table. (distance from Texai speakers to SPL meter will thereby be roughly 3ft.)

Pilots Room

For the Pilots Room, please refer to Figures 2 and 3. Figure 2 shows the conceptual setup of the room. Figure 3 shows the audio mixer connections. In the pilots room the following equipment is used:

Sound Pressure Level (SPL) meter.
One silverback Toshiba laptop (Kipling).
Loudspeaker: the speaker underneath the large office computer display.
The Eurorack audio mixer.
Pilot's headset with boom microphone.
The microphone adapter box (Photo 2).
The Zoom digital recorder (Photo 3).

Figure 2 (below): Conceptual Setup of Pilot Room:

Figure 3 (below): Eurorack Audio Mixer Connections in Pilot Room:

Photo 2 (below): The microphone adapter box:

You best follow this sequence of steps for setup, without turning anything on till the end.

Place mixer, microphone adapter box, Zoom Digital Recorder, and the Kipling silverback on the table.
Run wires from mixer to their destination
Attach camera to Kipling silverback.
Adjust all the buttons on the mixer
Fire up Kipling
Establish a Skype connection on Kipling and check that sound works back and forth.
Place SPL sound meter on desk, and follow procedure below for setting up storage of the readings.

About the Eurorack Mixer
Here is some terminology and placement information regarding the Eurorack mixer that we are using.

Power switch: The Eurorack's switch is on the rear right, immediately next to the power cord input.
Phantom power: Special voltage required for some microphones. The phantom power switch is to next to the power switch. Please keep that power off until all microphone connections have been made. Microphones don't like to be plugged in while phantom power is on. Speakers do not like the resulting loud pop either. I'll remind you of turning the switch on in the instructions below.
Channel Strip: a vertical set of controls for one input channel. The strips are numbered from left to right. For the experiment only three of the strip controls are relevant; all others should be left in their default positions.
- Microphone and line inputs are the top-most two jacks, respectively.
- Microphone pre-amp control is the first black knob from the top. On Strip-1 the microphone this knob should be at the last tick below maximum (marked 60db; all the way clockwise).
- Aux send level (pre-fader) is the fourth of the gray knobs from the top in each of the strips. We use it send the full microphone volume to Skype. The setting on Strip-1 should be one tick below vertical.
- Channel level is the bottom-most gray knob in each strip.

About the Zoom Digital Recorder
Relevant controls on the Zoom digital recorder are:
Photo 3 (below): The Zoom digital recorder:

Power switch
Sound input (from Mixer CTRL R Out)
Power input (wall wart)
Play/Pause switch (push up to toggle between play and pause)
Record button (push once to check level; push again to record; push again to stop recording.)
Jog wheel (only needed to browse and select files on menu)
SD card removal (door on back of housing)

Setting up Sound Meter Data Recording
The following soundlevel meter instructions are true for both the Pilot Room and the Locals Room.
See photo 3

The instructions look worse than they are! I'm just spelling it all out. Nonetheless, the connection between the sound meter and its laptop is a bit finicky during setup (though not once the connection is established). See Troubleshooting below.

Attach the power adapter to the sound meter. The socket in the sound meter hides underneath the black rubber flap on the left side of the housing.
Start up a silverback: Toshiba laptop (Kipling or Poe). Wait until the laptop is fully booted.
Turn on the sound meter. Notice a little one-handed clock face on the lower left of the sound meter display.
On the sound level meter:

Press the Max/Min button until neither the word Min nor the word Max appears on the sound level meter display. (Probably doesn't to begin with. Just keep pushing).
Press on the button labeled 'Level' until the scale on the sound level meter display shows '30...130'.
Press the Fast/Slow button until the sound level meter display shows the word 'Slow.'

Attach the DT-8851 sound meter to the laptop via USB. On the sound meter, the USB port hides underneath the black rubber flap on the left side of the housing (next to the power socket).
On the laptop, double-click the icon that looks like a recycling symbol. It's labeled: SoundLevelMeter8851. The data gathering application starts.
On the laptop: pull down menu Com Port(C) and ensure that entry Com4(4) has a little black dot to its left.
On the sound level meter, press the button labeled 'Setup.' You should now notice that the one-handed clock face on the lower edge of the sound level meter display has disappeared. You should also see on the laptop that the picture of the sound level meter shows sound numbers. If these changes do not occur, press the Setup button on the sound level meter again, this time more slowly (thinking loving thoughts.)

One-time Texai Volume Calibration
We need to ensure that the pilot's microphone input level, and the Texai's loudspeaker volume setting are matched and consistent across all experiments. We also need to know how loud the background noise that we generate in the locals room comes across in the Pilot room. The following calibration process is therefore required once whenever the experimental setup has been torn down and resurrected, or when knobs have been messed with.

Set Texai volume to a standard setting:

Pilot room: click on the silverback's desktop icon called "PinkNoise." A media player will start. Click its 'loop clip' button. Set the mixer's Main volume level until the sound meter reads 94db.
In the Locals Room, without background noise, adjust the Texai volume to generate a 94db reading on the Locals Room sound meter.
Return to the Pilots room, and close the media player.

Determine base sound level in Pilot room:

For each Background Noise level: measure and record sound level with pilot silent. (This level will later be subtracted from compute speaker level to determine the pilot's voice volume.)

Conducting an Experiment Run
You will perform the following operations with both sound level meters (i.e. in both rooms). All these operations are executed within the sound level meter application on the laptop:

Start the Skype session.
Double-click the PartyNoise icon on the Locals Room silverback desktop and set the background noise level to the experimental condition.
Note the time; write it down.
Start monitoring

In both rooms, click on the lightning bolt in the SPL sound meter application, or Real Time-->Run. The lighting bolt turns gray, the 'forbidden' sign turns red, and you'll see a red line graph developing on the application graph 'paper.' You may need to scroll to see the line.
In Pilot room, turn on the Zoom digital recorder.

Have the pilot run through the speaking routines.
Stop monitoring

Click on the red 'forbidden' sign, or Real Time-->Stop

Save data

As txt file: File-->Save As
As .xls file: Click the spreadsheet icon Place all log files into: C:\Users\paepcke\WillowGarageData\Sidetone

Clear log from memory and the graph

Real Time-->Clean Data

Note: Each logging session can last for 10,000 seconds: 2hrs 45mins. If you need more, modify the 20000 in the setup above.
Note: The exported spreadsheet or csv files do not come with their 'Time' column filled in. You will find only a Date, Value, and Unit column populated. This deficiency is sad, but not fatal: a reading is taken every 1/2 seconds. So, if you followed instructions and noted down the starting time...(you forgot that part didn't you?).
Troubleshooting

Sound Level Meter Data Collection Problems
If the connection between the sound level meter and the silverback laptop is not establishing properly, there are several steps to attempt. All need to be performed with hope in your heart, and positive energy directed towards the devices:

Press the sound level meter Setup button again; slowly.
Exit the sound meter application on the laptop. Unplug the USB cable. Power cycle the sound level meter. Plug the USB cable back in. Start the sound meter application on the laptop. Press the Setup button on the sound level meter again; slowly. But not too slowly.
Combinations of the above.
In the sound meter application on the laptop, select menu: Com Port-->Com4(4) This menu item should have a little dot in its left margin.
If Windows crashes, it's the sound meter driver's fault! Just reboot and start over. It seems like unplugging/replugging the USB tends to cause crashes.
Make sure that everything has power.
Ensure that the following is true (these are the defaults):

Real-Time data.no to be recorded is set to 20000
Real-Time Sampling Rate is set to 0.5
Recording Period ... To: is set far enough in the future to reach beyond the end of your experiment session.
Cancel out of this dialog.

Windows Crashing (Blue Screen of Death)
I have observed the silverbacks crashing with the famous blue screen of death. While this almost never happens any more with Vista, the soundlevel meter data collection driver is capable of causing this sad event. I have seen the event occur when I unplugged the USB cable that connects the computer and the sound level meter.
If this happens, just allow the machine to 'Start Windows Normally,' decline to have Windows look for a solution, and dismiss any other missives of silverback sadness.
Mixer Not Mixing

Make sure that the mixer has power: the power switch is in the back. You should see a green LED on the mixer's surface.
If the headphone mike is not working, make sure that you also turned on the mixer's phantom power. That switch is also in the back of the mixer. You should see a red LED next to the green one.

No Sound from the Pilot Room Speaker (Attached to Pilot Display)

Make sure the display is turned on.
Make sure that the loudspeaker is turned on. The loudspeaker casing has a black knob on the right, which controls power to the speaker, and volume. You should see a bluish vertical light in the middle of the speaker.

Trouble with the Zoom Digital Recorder

Removing the SD card is a bit intricate. To open the SD card access door, pull the grated plastic tab away from the housing, then lift the door, then fold it away from the housing. To remove the SD Card, you best turn the device upside down, push down on the (spring loaded) card, and let go.
For other matters, try to refer to the manual. We are using 'Input 1' with mp3 recording.