The recording kit

This is a short introduction on how to use the recording kit. Reading thru this document will save you valuable time and reduce problem potential greatly! Even experienced technicians may find it helpful to spend a few minutes reading this manual.  

First of all: Please, be careful! This is fragile equipment!

Content
Use this list to ensure that the recording kit is complete when you pick up and deliver it.

  • Two microphones
    • sE4 with two cardoide and omni capsules OR
    • Shure KSM141 microphones with popfilters
  • Two microphone adapters
  • Stereo bar
  • Two microphone cables, 15 m
  • NI Komplete Audio 6 Audio Interface
  • USB cable
  • Shure SRH440 Headset
  • Cabel reel, 5 m

A successful installation and setup will provide you with the following recording system:

1. Driver

The audio interface works with Windows, OS X and iOS (iPad). The communication between the audio interface and the computer/tablet is taken care of by an application called a driver.

If you´re using Windows or OS X 10.7 or older you may download the driver from here . Double click the downloaded file to start the installation. Read the instructions on the computer screen while installing the driver and do a restart if the computer tells you so.

If you´re using OS X 10.8 or never or an iPad theres is already a driver available in your system.

Windows users: Remember to unzip the downloaded files before installing: Right-click the downloaded file and choose Unzip all…/Pakk ut alle….

Mac users: If the computer hesitate to install the driver because its downloaded from internet, hold down the Ctrl key while clicking the downloaded file, choose Open and choose Open again.

After you´ve installed the driver, connect the interface to the computer with the USB cable.

2. Prepare your computer

Prepare your computer for audio recording:

  1. Connect the external power supply. The CPU frequency of the computer is usually reduced when a computer is running on batteries, reducing the performance of the computer.
  2. Do a complete restart (if you didn’t while installing the driver)
  3. Disable Wi-Fi and all other networks to avoid interrupts
  4. Close all programs except your audio recording program. Remember to close programs running in background such as Skype and DropBox, GoogleDrive.

3. Mounting and connecting the microphones

  1. Mount the microphone bar with the microphone adapters on a microphone stand.
  2. Place the microphones into the microphone adapters. SE4: Squeeze the handles of the shock-mount together and slide the microphone into the shock-mount.
  3. Use the microphone cables and connect the microphones to the inputs of the audio interface.
  4. The microphones in the recording kit are condenser type and needs 48 volt (phantom power) from the audio interface. Be aware that phantom power can cause serious damage to ribbon microphones. If you´re using other microphones than those included in the recording kit, check your microphone’s manual to see whether it is safe to use phantom power on them.
  5. Switch on 48 V on the rear panel of the audio interface.
  6. Remember to switch off 48 V before disconnecting the microphones.

4. Choosing Komplete Audio 6 in your Digital Audio Workstation

Start your audio recording program. Such a program is also called a DAW (Digital Audio Workstation).

OS X/Mac: Ableton Live

  1. Choose Live – Preferences…
  2. Choose Audio in left column
  3. Click right of Driver type and choose CoreAudio
  4. For Output Device, choose Komplete Audio 6
  5. For Audio Input, choose Komplete Audio 6
  6.  Close the Preference window

Windows: Ableton Live

  1. Choose Options – Preferences…
  2. Choose Audio in left column
  3. Click right of Driver type and choose ASIO.
  4. Click right of Audio Device and choose Komplete Audio 6
  5. Close the Preference window

If you are using none of the above programs, look for Preferences, Audio Input or similar, then look for Driver, Audio Connection or similar and choose Komplete Audio 6. You may also check the operation manual for the program and look for Driver.

5. Setting the recording level

  1. Create a new stereo audio track in your DAW
  2. Ensure that INPUT 1 & 2 of the audio interface are the input source of the audio track
  3. Record enable the track so that the input indicator of the track shows the level of the input signal from the microphones.
  4. Start the sound source that are to be recorded (ask the musician to play some music…)
  5. Observe the input indicator of the audio track while adjusting the recording level with the Gain controls of the audio interface. Be careful to adjust both Gain controls of Input 1 and 2 to the same level to capture a correct stereo image.

6. Monitoring

  1. Ensure the Volume control for the Phones is turned all the way down.
  2. Ensure that the audio track in your DAW are record enabled (Ableton: Button at bottom end of track turns red) and Monitor activated (Ableton: Auto) on the tracks so that the signal from the microphones are routed thru the audio track and to the output of the DAW.
  3. Connect the headphones to the PHONES socket on the right side of the front panel of the audio interface.
  4. Turn up the Volume control on the front panel of the audio interface (not the big knob on top).

7. Latency, distortion and crackles

The signal in the headphones may be delayed compared with the direct sound from the sound source. In some circumstances there may also be distortion and crackles. The delay is called latency and is caused by the processing time of the recording system (audio interface, driver and computer). Reduce the Buffer Size, like explained below, to minimize the latency. Distortion and crackle are usually caused by CPU overload. Increase the Buffer size, as explained below, to avoid distortion and crackles.

Ableton Live:

  1. Choose Live/Options – Preferences
  2. Choose Audio
  3. Decrease Buffer Size to reduce latency.
  4. Increase Buffer Size to value to avoid distortion and crackles.

8. Direct monitor

If the signal in headphones are still delayed, even though you´ve adjusted the Buffer Size as explained above, disable Monitor in your DAW (Ableton, Monitor: Off) and push the MONITOR ON button at Komplete 6 Audio Interface.

This routes the incoming signal from the microphones directly to the headphones without delay. Unfortunately, this setup won´t provide the opportunity to control monitoring with your DAW software.

Turn up the MONITOR VOLUME.

9. ORTF Stereo technique

Two microphones may be configured in several ways for stereo recording. We recommend the ORTF stereo technique. http://en.wikipedia.org/wiki/ORTF_stereo_technique:

ORTF combines both the volume difference provided as sound arrives on- and off-axis at two cardioid microphones spread to a 110° angle, as well as the timing difference as sound arrives at the two microphone membranes spaced 17 cm apart.

The result is a realistic stereo field that has reasonable compatibility with mono playback. Since the cardioid polar pattern rejects off-axis sound, less of the ambient room characteristics are picked up. This means that the mics can be placed farther away from the sound sources, resulting in a blend that may be more appealing.

As with all microphone arrangements, the spacing and angle can be manually adjusted slightly by ear for the best sound, which may vary depending on room acoustics, source characteristics, and other factors. The angle between the microphones can be reduced to enhance the centre of the sound image, or increased for more width. Larger distance between microphone membranes creates a broader stereo perspective but, be aware that to large distance may create a “hole” in the middle of the sound image.

This arrangement is defined as it is because it was the result of considerable research and experimentation, and its results are predictable and repeatable.

10. Distance between sound source and microphones

Position the microphones far enough from the sound source to pick up the complete sound of the instrument or ensemble.

Adjust distance between sound source and microphones to balance direct sound (from sound source) and room reverb. Larger distance lower the sound level og the direct sound and yields more reverb on the recording.

11. Microphone switches

The microphones has two switches:

Pad switch. Reduce the signal level with -10/15 dB or -20/25 dB. Should only be used when the microphone is being used to record exceptionally loud sound sources that may overload the microphone preamplifier. Use if the signal is distorted even if the recording level are correct.

Low Cut. Activates a high-pass filter that reduces the amount of low frequencies. Low Cut may be used to reduce the amount of bass boost caused by the proximity effect when working very close to the microphone or to exclude low frequency signals, such as traffic and floor vibrations where the signal being recorded has little or no deep bass content.

Shure KSM141 Microphones. Twist the ring to choose between cardoid or omni pattern.

SE4 microphones. Switch mic.capsules to choose between cardoid or omni pattern.

More on microphone patterns and characteristics here.

12. Disassembly

  1. Ensure that PHANTOM POWER 48 V or POWER ofthe audio interface is OFF before disconnecting the microphones.
  2. Dismantle the microphones from the shock-mounts and put them into the small bag before they are put back into the carrying case.
  3. Leave the shock-mounts mounted on the microphone stereo bar.
  4. Fold the headphones before you put them in the case.
  5. Use the list at the top of this document to ensure that the recording kit is complete when you pick up and deliver it.

13. Help

If you need help; read this manual carefully one more time. If you still need help; ask a friend. Still got a problem? Ask another friend. If you still need help; try Google, then write a polite email to av@nmh.no explain your problem and beg for a solution.

14. Faults and irregularities

All faults and irregularities on the equipment are to be reported to av@nmh.no immediately. 

15. Booking the recording kit

Students at the Norwegian academy of music mey book teh recording kit here.

16. Troubleshooting

Crackles and distortion?
Increase Buffer Size, as explained under paragraph Latency, distortion and crackles

Delayed sound in headphones?
Reduce Buffer Size, as explained under paragraph Latency, distortion and crackles

No signal from microphones?
Ensure PHANTOM POWER 48 V on rear panel of audio interface is enabled.

Google “Komplete Audio 6” and a description of the problem.

Legg igjen en kommentar

Din e-postadresse vil ikke bli publisert. Obligatoriske felt er merket med *