Detail the process of effectively using send and return channels for effects processing in a hip hop mix and give multiple reasons for doing so.

Send and return channels, also known as aux sends and aux returns, are an efficient method for processing multiple tracks with the same effect in a mix. This technique is very common in hip hop production and is great for adding a sense of cohesion and depth to a track while also reducing CPU usage.

The Process of Using Send and Return Channels:

1. Creating an Auxiliary Track:
- Create an auxiliary (aux) track or return track in your DAW. This is a separate channel that is solely dedicated to processing an effect. The audio signal won't be played directly in this channel.
- Label the aux track clearly. For example, "Reverb," "Delay," or "Chorus," to make sure that it's clear what this channel is for.

2. Inserting the Effect Plugin:
- Insert the desired effect plugin on the aux track. This could be a reverb, delay, chorus, flanger, or any other effect you want to use.
- Ensure that the effect plugin is set to 100% wet (no dry signal), as the original dry signal is still present on the source track. Only the effect output is needed.

3. Sending Audio to the Auxiliary Track:
- On the track or tracks you want to apply the effect to, find the aux send controls. These are often marked "send," "aux send," or by a number or letter. Each DAW has a different approach to this, but they all share the same principles.
- Increase the send level to send a copy of the audio signal from the original track to the auxiliary track where the effect is applied. The amount of the send determines the amount of the effect added to the dry signal.
- Adjust send levels individually for each track to control the amount of effect applied to that element. Each track will have its own unique send amount.
- For example: If you want to apply a reverb effect to several different elements, set the amount of reverb on each track by adjusting the send knob. The higher the send, the more the reverb.

4. Mixing the Effect Return:
- The output of the auxiliary track, which contains only the effect, is then mixed back into the main mix using the auxiliary track fader.
- Adjust the fader of the aux track to control the overall level of the effect in the mix. This allows the user to balance the affected and unaffected signals.
- For example, a reverb aux channel may require a lower volume to balance it with the rest of the mix.

Multiple Reasons for Using Send and Return Channels:

1. Cohesion and Consistency:
- Shared Space: Using a single reverb or delay effect on multiple elements creates a sense of shared space and cohesion. This will make all the elements feel more like they belong to the same song, because of the shared effects.
- Consistency: Consistent use of the same effect on different elements creates a more uniform and professional mix. A single reverb unit will create a consistent spatial environment for the different elements, giving the sense they are sharing the same space.
- Example: Using one shared reverb on all vocals can make them feel like they are all in the same room, creating a more cohesive mix. Using the same delay unit on a couple different instruments will make it sound more balanced because they are all in the same sonic space.

2. Reduced CPU Usage:
- Single Instance: Instead of inserting the same effect plugin on multiple tracks, you use only one instance of the plugin on the aux track, saving CPU resources. This makes it easier to create more complex mixes without over stressing the CPU.
- Better Performance: Using send effects is a lot more efficient for using the same effects on many tracks because the plugin is not loaded in every instance, and the same processing power is being used.
- Example: Instead of adding 5 separate reverb plugins on 5 different tracks, you can add one single reverb plugin on the auxiliary track.

3. Flexibility and Control:
- Independent Mixing: You have independent control over the effect level, as the effect is on its own fader. This makes it easy to mix, and control the amount of effect that is being used in the song.
- Adjustable Send Levels: Each track can have an individually adjusted send amount, which controls how much of the effect is applied to that track. This gives a lot more control than adding the same effect to all the tracks.
- Example: You can use a lot of reverb on the snare but very little on the kick drum, because they both have individually adjustable send levels to the reverb.

4. Parallel Processing:
- Blending Dry and Wet: Send and return channels are essential for parallel processing. By sending a signal to an aux track with an effect and then blending the aux channel output back in, you can create a mix with both the dry and wet signals blended together.
- Dynamic Effects: Parallel processing allows for more dynamic effects while retaining the original qualities of the track.
- Example: Parallel compression using a send and return is very common, where a heavily compressed track is blended in with the original track. A heavily distorted guitar signal can also be blended with the original, providing a much wider sound.

5. Consistent Effect Parameters:
- Shared Settings: If you make a change to the parameters of the effect on the auxiliary track, all the tracks being sent to that effect will be affected, providing a very consistent sound.
- Example: If you make changes to the reverb, the reverb amount, or time, all the instruments using that reverb will share the same settings.

6. Creative Sound Design:
- Experimentation: Send and return channels allow for experimentation with different types of effects and combinations. This provides a lot of space for using effects in a more unique and creative way.
- Unique FX Combinations: By combining effects on different aux channels, and sending the same audio to multiple aux channels, very unique effects can be created, opening up many more options.
- Example: By sending a vocal track to both a reverb and a delay, a much more spacious and textural feel can be created.

Practical Examples in Hip-Hop Mixing:

1. Shared Reverb:
- Use a single reverb on a return track and send different amounts of your vocals, snares, claps, and other instruments to it. This will create a sense of depth and space.
- For example, the snare can be sent a lot more than the kick to make it sound more spacious.

2. Delay Throw:
- Use a delay on a send track and create specific delay throws on certain words or phrases in your vocals to add movement and interest. A delay throw is an instance of a delay effect, often a quick and short delay applied to a specific part of a vocal.
- For example, a delay can be sent to the last word of each line, creating a unique rhythmic effect.

3. Parallel Compression:
- Send your drums or the entire mix to a heavily compressed return track, then blend it with the original to add punch and loudness.
- For example, a compressor on an aux channel with a very low threshold and high ratio can be mixed with the original dry drums to create a much larger and fuller feel.

4. Chorus on Synths:
- Use a single chorus effect on an aux channel, and send multiple synth tracks to it, to create a more full and cohesive sound with the chorus effect, and to save resources and CPU power.

In summary, send and return channels are crucial for effective effects processing in hip hop production, allowing for a clean, cohesive, and efficient workflow while also freeing up CPU power. They create a shared sense of space for different elements, provide a dynamic way of controlling and adjusting effects, and are also crucial for a number of creative sound design possibilities. The proper use of send and return effects is the key for a modern professional mix.