How Does Cubase Handle MIDI and Audio?

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How Does Cubase Handle MIDI and Audio?

Unlike a tape recorder, Cubase records not only audio information but MIDI as well. Cubase SX/SL handles MIDI through MIDI ports, MIDI channels, and MIDI tracks and handles audio through audio inputs, audio tracks, mixer channels, and audio outputs (see Figure 1.7).

Figure 1.7. How the MIDI and audio data flows from inputs to outputs in Cubase.

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MIDI Port

A MIDI port is a hardware (physical) or software (virtual) point of entry or point of exit for your MIDI data. The number of physical MIDI ports is determined by your computer's MIDI interface. This can be a stand-alone MIDI interface or MIDI connectors found on your sound card. If you have a sound card that has four MIDI inputs and four MIDI outputs, you will have four MIDI ports available for this interface in Cubase. On the other hand, if you are using Cubase to send or receive MIDI information to and from another application inside your computer, you will also be using virtual MIDI ports.

Why virtual? Because they do not require additional hardware. This is the case when you are using a VST virtual instrument (this will be discussed in Chapter 5) or when working with third-party software such as Propellerhead's Reason, Tascam's GigaStudio, Ableton's Live, or others. Whenever you load virtual instruments, they create virtual ports that are available in Cubase for you to use as if they were plugged in to your computer through an actual MIDI port. The virtual ports will, in other words, allow you to receive MIDI from these applications or send MIDI to them.

The MIDI port determines which physical or virtual MIDI socket information is coming from and going to (see Figure 1.8). Each MIDI port can carry up to 16 MIDI channels.

Figure 1.8. Example of a MIDI input port selection menu.

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How To

To view a track's MIDI input and output port setting:

  • Click on the Show Inspector button in the project window's toolbar (Figure 1.9).

    Figure 1.9. The Show/Hide Inspector button found in the project window's toolbar.

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Each MIDI track has its own MIDI input port setting and output port setting. This way, you can choose to record MIDI from different MIDI sources directly in your project, just as long as you have a MIDI input device, such as a keyboard, connected to these input ports.

Which MIDI input port appears in your track input port selection field depends on the ports that were set as active in Cubase's MIDI device setup window. This will be discussed later in this chapter.

MIDI Channel

Each MIDI port will support up to 16 simultaneous MIDI channels. In Cubase, the channel used by the MIDI device connected to the MIDI input has little effect over the result. It is the MIDI output channel of a track that determines how the incoming MIDI data is interpreted. For example, if your MIDI keyboard is connected to the MIDI input of your computer's MIDI interface, you need to tell Cubase where the MIDI is coming from through the MIDI input port selection mentioned above. Let's suppose you have connected a multitimbral instrument to the MIDI output port of this track. A multitimbral instrument can play one sound per MIDI channel. So you might have a piano on channel 1, a guitar on channel 2, and a bass on channel 3. If you change the channel on the track, you actually change which instrument will play the MIDI data that was recorded on it, or the MIDI data going through it as it is being played .

You have to select a MIDI channel in order to send information to a particular patch or preset in your MIDI instrument. Once your MIDI channel is selected, you can assign a patch to it, like a bass, for example. A MIDI channel can play only the assigned patch for the instrument you wish to play or record MIDI with. You can change the patch or preset along the way, but you can have only one patch or preset assigned to that channel at a time. In other words, you can have up to 16 sounds/patches/MIDI devices playing simultaneously on one MIDI port.

If you run out of MIDI channels for one MIDI port, you will need to use another MIDI port to play the MIDI events. Each virtual instrument loaded into Cubase's memory will create its own virtual MIDI port, so running out of MIDI channels is unlikely inside Cubase.

In Figure 1.10, you can see that the MIDI in port is set to All MIDI Inputs, which implies that any device sending MIDI to Cubase will be recorded. However, the MIDI out port is set to a1 MIDI out, which also implies that whatever comes in or whatever is already present on this MIDI track will be sent out to this MIDI port. Selecting the MIDI channel will cause all MIDI events on this track to be sent to this MIDI channel. In this case, the pointer displays channel 4 as the new selected MIDI channel. Letting go of the mouse while this channel is selected will cause the check mark appearing next to the number 1 in this list to move to number 4. When you play or record events from this point on, all events will be heard through this MIDI port (the a1 virtual instrument) and MIDI channel 4.

Figure 1.10. Selecting a MIDI channel for a MIDI track.

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MIDI Track

A MIDI track usually contains MIDI information for one channel at a time. When you play on a keyboard, it sends out MIDI events on a MIDI channel that is recorded on a MIDI track. You then assign a MIDI channel to that track to get the appropriate sound at the output as mentioned previously.

Cubase doesn't replace the original MIDI channel information that you record. It simply puts a filter at the output of the track in order to hear the MIDI events played on the MIDI port and channel you decide. This makes the MIDI recording process much simpler because, otherwise , you would have to change the MIDI channel of your MIDI input device and inside Cubase.

Each track has its own MIDI input and output port setting as well as its channel setting. You can also record from multiple input sources and multiple channels simultaneously on a single track by selecting the appropriate settings for this track; however, it is recommended that you keep each musical part on a separate track for easier editing later. Since you can create as many MIDI tracks as you need in Cubase, you don't really need to worry about running out of them.

Audio Connections

New to Cubase SX/SL 2.0 is the concept of audio connections. An audio connection is a way to create a link between your sound card's audio connectors and an audio track. The link provides you with a way to configure these physical inputs and outputs into mono, stereo, or surround connections (with SX only). That way, when you decide to record an audio track in mono, all you need to do is use your mono connection, which is configured appropriately. These links or connections are called buses, and there are two types of buses: input buses and output buses.

So why this additional layer? By doing so, you can use the same physical connection in different configurations; for example, if you have an ADAT connection on your sound card, you can configure the same inputs in different bus configurations. If you look at Figure 1.11, you can notice that the ADAT 1 is configured as a mono bus as well as part of a stereo bus. Similarly, the ADAT 5 is used both as a mono bus and as part of a surround bus.

Figure 1.11. How audio inputs become input buses through the audio connections in Cubase.

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You can save the bus configurations as a template or with your project file. If you intend to always use the same connection setup throughout your projects, then using a template file will most likely suit your needs. If you find yourself using different configurations each time you begin a new project, then you can simply set the connections once at the beginning of a project. Cubase will save these connection configurations along with the project file so that you don't need to repeat the configuration every time.

After the bus configurations are created, you don't really need to worry about them since whenever you want to select an audio input or output in Cubase, you will see and choose from the bus configurations you made earlier.

Input Buses

An input bus is a bridge between the physical inputs of your sound card and the source for the audio that you want to record onto an audio track. By selecting an input bus, you simultaneously decide if the audio track will record mono, stereo, or surround content, depending on how you configured this input bus in the first place.

Each physical connection on your sound card can be routed to one or more input buses. However, if you choose to record on several tracks simultaneously using different input buses that share one of the sound card's input, you will end up recording the same material on all the tracks that share this input. For example, let's say you create two audio tracks, hook up a pair of microphones to record a stereo guitar feed and another mike to record vocals. In this case, you probably want the guitar track to be stereo and the vocal track mono. If you've configured a stereo input bus to use the physical inputs 1 and 2 and a mono input bus to use the physical input 1, then you'll be recording a stereo guitar on one track and a mono guitar on the other track. But if you've hooked up your vocal mike in input 3 and configured an additional mono input bus to use that connector, you'll be able to record all three audio inputs simultaneously.

If you are using Cubase SL, you won't have control over the level of a signal coming into an input bus, but Cubase SX will allow you to adjust this level in order to prevent clipping or undermodulation (low input level). Cubase SL users will need to adjust the input level of a signal by using the controls available on their sound card's control panel or on the output level of the device being recorded in order to make changes to the input level of their sound card.

In Figure 1.12 you can see how Cubase associates input buses with your ASIO device physical inputs (known as ports). In this case, there are three stereo input buses and three mono input buses that can be used whenever you want to record digital audio. You may also create new ones. The Bus Name column displays the names of the inputs as they will appear when you need to select which input bus to use in a recording situation.

Figure 1.12. The VST Connections panel looking at the input buses.

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Output Buses

Output buses enable you to monitor the content of an audio track through a set of audio outputs on your sound card. As with input buses, you can create several output bus connections, depending on your needs. Essentially, you will need to have at least one mono output bus if you have mono content, a stereo output bus if you have stereo content on an audio track, and a surround output bus if you need it as well.

You may also decide to record a signal using a pair of inputslet's say 1-2and monitor through another pair of outputs, like 3-4, for example.

Figure 1.13 is similar to Figure 1.12, with the exception that this figure represents the output buses with their respective ASIO device port settings.

Figure 1.13. The VST Connections panellooking at the output buses.

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Audio Track

An audio track in Cubase is similar to an audio track in an audio multitrack recorder. It has, however, the advantage of being either mono, stereo, or multichanneled to support surround sound (Cubase SX version only), depending on the audio bus configuration you choose. You can create as many audio tracks as you need in Cubase. This said, you will probably be limited by your computer's speed, disk access, or memory capacity at one point, so working within these limits will be your only concern.

Your project's settings will determine the audio bit depth and sample rate recorded in an audio track; however, the bus selection and the number of audio channels it supports are determined at the time you create an audio track. When you create an audio track, Cubase will ask you which configuration you wish to use: mono, stereo, or one of many multichannel configurations. This will ultimately influence your choice in input and output buses later on. For example, if you want to create a vocal track, you could create a mono track and then select a mono input bus. But you can also use one of the channels in a stereo bus or one of the channels in a surround bus as its input source as well.

As logic would have it, however, to monitor or record stereo content, you will need to have a stereo or multichannel track. Placing a stereo audio event on a mono audio track will still allow you to hear the content, but, as you would imagine, in mono only. As for surround or multichannel events, you will need an equivalent or higher number of channels in the bus assigned to this track. For example, you could record an LCRS (Left, Center, Right, Surround) mix in a 5.1 surround audio track. Playing a multichannel audio source through a mono or stereo track will not allow you to monitor the audio as it was intended. For example, monitoring a 5.1 audio event in a stereo track using a surround output bus will cause all the information to play over the center channel, thus creating distortion on this track.

As a rule of thumb, you should:

  1. Record mono signals on mono tracks using a mono input bus or one of the channels on a stereo or multichannel bus and monitor through a mono bus.

  2. Record stereo signals on stereo tracks using a stereo input bus and monitor through a stereo bus.

  3. (Cubase SX only) Record multichannel signals on equivalent multichannel audio tracks using the same type of input bus and monitor through the same type of multichannel output bus.

Mixer Channel

Whenever you create a track in Cubase, you create a Channel. Channels appear in the Mixer panel as shown in Figure 1.14, as well as in the Inspector area of a selected track (project window) under the Channel section as shown in Figure 1.15.

Figure 1.14. The Mixer panel mirrors all the channels (and their settings) found in your project.

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Figure 1.15. The channel section displays the channel settings for a selected track in the Inspector area of the project window. Making a change in the mixer will be reflected here and vice versa.

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A channel in Cubase is similar to a mixer channel on a hardware mixer with some exceptions:

  • If you set a track to record or play stereo or multichannel events, the mixer channel will display information for all channels. On hardware mixers, stereo channels would take two channel strips .

  • If you use a virtual instrument such as a software synthesizer, it will create a MIDI channel that will allow you to control the MIDI automation for this virtual instrument and a special type of audio channel to add audio effects or equalizer parameters. If your virtual instrument supports multiple channels, there will be as many channels created in the channel mixer as there are output channels for this instrument. For example, loading the LM4-Mark II drum machine will create a set of three stereo channels and six mono channels in your mixer.

  • When you want to add an effect, a reverb for example, you create an effect (FX) track, which in return creates a special channel in the mixer.

  • Because this is a virtual mixer environment, it is a dynamic mixer too. In other words, you can create group channels when you need them and add audio channels as well as MIDI channels as you create audio or MIDI tracks in your project.

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Cubase SX. SL 2 Power.
Cubase SX/SL 2 Power!
ISBN: 1592002358
EAN: 2147483647
Year: 2003
Pages: 154
Authors: Robert Guerin

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