Dynamic Range

Introduction

Welcome to my week 4 assignment for the Music Production course. Today I am going to look at Dynamic Range and some methods a producer can use to manipulate it.

Dynamic Range

This is simply the difference between the loudest and the quietest sounds in a recording.

The musicians give a natural dynamic range by following their score and playing louder or softer during their performance. The post-production work adjusts the dynamic range to give more feel to the music.

There are a number of areas where dynamic range can be adjusted:

• Macro Scale>
• Transients
• Compression
• Expansion
• Dynamic Processors

The Macro Scale

The producer will look at the overall performance, and will see the relative levels between sections of the recording. They will ride the fader and automate the volume levels to strengthen the difference between verses and the chorus.

Transients

A transient is where the amplitude changes a lot during a short timescale. Examples of transient sounds include snare hits.

Compression

Compression reduces the dynamic range and brings volume levels to all the parts of the music into a similar level.

Expansion

Expansion increases the dynamic range, and gives more emphasis to sections of the music, either by bringing the perceived volume level up or down.

Dynamic Processors

A producer will use a dynamic processor to adjust the level of the audio following rules. Expanders, gates, compressors and limiters are types of dynamic processors.

Threshold

The point that a dynamic processor starts taking effect is known as the threshold. This is measured in dB, and a lower threshold (eg -30dB) means a large portion of the signal will be affected compared to a higher threshold of -5dB.

Ratio

The ratio is how much the processor changes the level once the threshold has been passed. The higher the ratio, the more the signal will change.

A ration of 6:1 means that if the input level is 6dB over the threshold, the output signal will be 1dB over threshold. The gain in this case has been reduced by 5dB.

Attack and Release

Attack and release provide a measure of control over how quickly a compressor acts.

The attack phase is the time when the compressor is decreasing gain to match the level that is set by the ratio. The release phase is when the compressor is increasing gain once the level has fallen below the threshold.

A compressor's attack and release are measured in mS, the time that it takes the gain to change a set amound of dB.

Soft and Hard Knees

The knee is how quickly the effect takes place. A soft knee slowly increases the compression ratio as the level increases and eventually reaches the compression ratio set by the user. The softer knee's reduces the audible change from uncompressed to compressed, especially for higher ratios.

Compression

A downward compressor reduces loud sounds over a certain threshold while quiet sounds remain unaffected.

An upward compressor will increase the loudness of sounds below the threshold while leaving louder sections unchanged.

Both downward and upward compression reduce the dynamic range of an audio signal.

Expanders

An expander increases the dynamic range of an audio signal, and typically are used to make quiet sounds even quieter by reducing the level of the signals that fall below a set threshold level.

A noise gate is a type of expander.

Reflection

I have given a brief introduction to Dynamic Range and the ways that a producer can change the level of a song.
The one thing the producer must consider about above all else is that the essential character of the music is not changed.

I would like to thank you for taking the time to read my discussion on Dynamic Range. There is so much to learn about the topic, and it will take a lifetime to fully understand the practical aspects.

Mixing Desks - The Channel Strip

Introduction

Alto ZMX164FX USB Mixing Desk

Today I am going to show you how signals move through a mixer, using the Alto ZMX164FX USB analogue mixing board pictured to the right to demonstrate.

Mixing boards look really complicated, but they are modular devices and contain a number of repeated sections.

This board has 12 channel strips, four subgroups, a special effects section, the monitor section, and the main mix fader.

The sections of the board are shown in the diagram to the right.

This lesson is going to focus on the signal flow through the channel strip. I am also going to briefly discuss where the signals go after leaving the channel strips - the sub and main mixes.

The Channel Strip

As a rule, signals flow from the top to the bottom of the channel strip, although there are a couple of exception to this rule, they will be described later.

I am going to describe the mono input channels 1-8, on this mixer channels 9-16 are stereo inputs and are have slightly different operation.

Although the inputs are mono, the output after the fader are a stereo signal.

The Input

Inputs

The signal starts with the microphone or line input at the top. The line inputs are TRS balanced/unbalanced inputs.

The insert is to allow connecting an external effects rack into the mix using a TRS connector.

The line gain allows the level to be adjusted to line level. This is different to a DAW, as the DAW expects the signals to already be at line level.

The peak led illuminates if the signal should rarely, if ever, light otherwise you will have distorted signals from the very start.

The low-cut button switches in a 75Hz low frequency filter to reduce hum from a mains power supply or stage rumbles.

The Equaliser

Signal Routing

The blue knobs are a 3-band EQ with a sweepable MID range.

Aux Sends

The Aux Sends can be thought of as a separate mix

The yellow knobs are the auxiliary sends level controls. These control the signal levels to the two auxiliary bus.

AUX1 and AUX2 can be switched to pre or post fader and can be used for monitor or inputs to an effects and sound processor.

AUX 3 and AUX4 are configured as post faders. AUX4 can be assigned to the onboard effects module.

The PAN control is used to position the signal to the left or right side. In the central position the audio will appear in the centre of the stage. This is also an out of order signal flow.

The Fader Section

Channel Fader
and Options

At the top of the fader section is a peak warning led. Ignore this at your peril, it flashes to warn you when you are reaching signal saturation and possible distortion.

The mute button is equivalent to pulling the fader down, and causes the mute led to illuminate.

The channel can route to sub 1-2, sub 3-4, and the Main LR busses.

The solo button routes the signal from the channel to the control room.

Finally, the fader controls the overall level of the signal sent out to the main and sub busses. On this board, the unity gain is marked with a 0. The fader allows from -∞ to +15 db. The ∞ means that effectively no signal will be heard from the channel.

Ideally you want to keep signals around unity as much as possible, this gives the least risk of distortion occurring in your work.

The DSP

DSP Options

The mixer has a 24 bit digital special effects unit that can add flangers, reverb, chorus, delay and combinations of these. There are 16 preset options for each effect selected.

The effects out control is the signal sent to DFX OUT and can be set between -∞ to +10 db.

The AUX1 and AUX2 controls are used to set the signal level from AUX Return 4 on the channel strip to the AUX Send1 and 2. The range is between -∞ to +15 db.

The Peak LED illuminates if the input signal is too strong. The DSP can be muted, and this causes the peak LED to illuminate.

The board power and phantom power indicators can also be seen on this picture.

The Equaliser

Graphic Equaliser

The board has a nine-band graphic equaliser, and a bypass button.

This allows the fine-tuning of the overall output audio levels. 

Sub groups and Main Mix

Subgroups and Main Mix Faders

This is where the output from all of the channels appears.

The four white sub faders control the levels for each of the sub channels.

The red fader is the main mix, the output that your audience are listening to. This board controls the overall level, unlike some that can control the individual left and right levels.

The channel that each of the sub groups appears on the main mix is controlled by the assign to main mix buttons.

Subgroup assignment

Pressing the LEFT button will assign the subgroup to the left main mix, the RIGHT sends to the right  main mix, and having both selected will send to both channels.

Reflection

I have focussed on the parts of the board that I have used, the only section I haven't discussed are the auxiliary sends and returns. Apart from the built in DSP, I don't have any equipment to connect and experiment with (donations gratefully accepted!)

Creating the lesson has helped me understand the operation of my board in more detail, in particular how the special effects unit operates.

I would like to thank you for your time in reading my lesson on the Channel Strip, and I hope you have gained as much as I have (so much so, that I'm tempted to create lessons on some of the other options for this assignment).

Now I want to go and put theory into practice - apologies to my neighbours!

Preparing a Project in a DAW

Introduction

This is my second assignment for the Introduction to Music Production course. I am going to look at setting up a project in a Digital Audio Workstation for recording.

I am going to use Audacity and Reaper for this demonstration.

Audacity is a free and open source application that is available for Windows, Linux and the OSX environments. I am using the OSX version of Audacity, the other versions look almost the same.

Reaper is a commercial product for OSX, I am currently using the evaluation version of the software.

I was hoping that version 3.0 of Ardour would have been released for OSX in time to do a comparison over three packages, however currently only the Linux version was available.

Setting up a DAW Project

Preproduction Checklist

Before we start our project, we need to consider the following things:

• Where and What
• Digital Audio Preferences
• File Type
• Hardware Settings
• Buffer Size

Saving your files in suitable locations  and choosing appropriate filenames makes it much easier to locate, edit and backup your work. You do back it up, don't you?

Audacity

Audacity has a friendly feel to the interface and is very easy and simple to use.

Saving Work

Folders

You can see I am keeping materials for this course organised into folders by assignment.

Audio Preferences

Sample Rate and Size

I have set the sample rate to 44.1kHz and the sample size to 24-bit.

This is a higher rate and larger word size than used in CD quality recordings.

File Type

Audacity uses it's own default file type that keeps all data about the recording in a project file and folder.  It is possible to name individual tracks on the recording.

Hardware Settings

Recording hardware selected

I am recording from my mixing desk, it shows as USB Audio CODEC in the lists.

Buffer Size

Buffer Size

Audacity gives a buffer size in mS, not the number of samples and I am leaving at the default 100mS.

Reaper

Reaper has far more options than Audacity, and provides a more professional seeming interface, although not all of the options match up with the descriptions given in the lectures.

Saving Work

I have selected a 'ReaperRecordings' folder for saving the files produced by Reaper.

Audio Preferences

I have selected a 44.1 kHz sample rate with a 24 bit sample size for the recordings.

 

File Type

Project Save Settings

I have set Reaper to use a WAF format for saving, there are several other options available.

Hardware Settings

Hardware Settings

I am using the USB CODEC for my mixing desk.

Reaper has an option to request a sample rate, the default was 48,000.

Buffer Size

Buffering Options

Reaper does not seem to have an option for the buffer size in the same way as the lectures suggest. 

Reflections

As with everything involved with computers, there are many different ways of describing and doing the same tasks. Using a DAW is much the same with the two packages looked at having a different look and feel.

I'd like to thank the reviewers for taking the time to read through my resources, I hope you gain as much from the tasks as I have while preparing this.

Songwriting Week 2

This week has been looking at number of lines to create a feel within a song.

The assignment was on having a stable chorus with an unstable verse. I'm not going to post my efforts here until after the assignment has been graded, and depending on the reviews I might not even then! The title is "The Runaway" and is further explorations on the theme.

I started looking at the idea of the song a few months ago (I was at the Ketton Ox in Yarm near Middlesbrough at an open acoustic night when the idea struck me), and have had two or three attempts at putting words together for it

I'm still finding the unit interesting, but really need to organise my time better; especially as I have another course starting in April.

Coming up with ideas for lyrics may be something that I'm capable of, but learning enough musical theory and practice to create the accompanying melody is going to be a little more challenging. I also need to make more time to continue learning the guitar, I feel that I've barely picked it up in the last month or so.

Now to look at my assignment for the Music Production course that is also due soon...

Music Production week 2

I've decided that I'm not a fan of working Saturdays with a day off mid-week.

It probably wasn't helped that this last few days have been particularly busy for me, with going to an event in Newcastle after the Cub Scout meeting on Friday, followed by working Saturday then going to a party on Saturday night.

I have caught up with the Music Production videos early this week, and have completed the quizzes on a sensible day for a change. I just have to do the reviews for the week 1 assignment and prepare my assignment for week 2.

This weeks lectures have been about making edits using a DAW and how the midi controllers send messages. Although again there were lots of videos to watch, they were only a minute or so each and worked very well in the small bites. It gives time to have a try at the ideas and techniques using the software that you have on your own machine.

I am planning on leaving the assignment until Wednesday before starting, I seem to have a free evening and intend to make good use of it to so more preparation for the second assignment. Although I might also make good use of it by seeing Lynn for a couple of hours.

• Prepare a project in your DAW using the project checklist from the material as your guidelines.
• Record audio in your DAW including preparing the project, creating the track(s), setting the click and countoff, and recording efficiently.
• Perform the important editing tasks in your DAW including: trim, separate, crossfade, merge, grid, cycle, markers, zoom, name and color.
• Add a software instrument and record MIDI and quantize in your DAW. Including preparing the track(s), adding the instrument, setting the click and countoff, and recording efficiently.
• Efficiently create a compile from multiple audio recordings in your DAW.
• The Analog to Digital conversion process.
• Editing an imperfect audio performance to correct the timing.

I am looking at three DAW's at the moment, and will need to choose one to focus on. More decisions!

How To: Recording an Electric Guitar or Bass without an Amplifier.

Introduction

I'm Neil Stoker, from Washington in the North East of England.

This lesson is for week 1 of Introduction To Music Production at Coursera.org. I am going to do a brief How To on recording an Electric Guitar without an amplifier.

I am going to describe recording a traditional guitar track, House of the Rising Sun, using my electro-acoustic guitar and include some audio clips during the process. For the examples, please focus on the quality of the audio and try to ignore the quality of the playing.

Lesson

Before you can record an electric guitar, you need to be able to convert the signals from the guitar or bass into signals that the computer understands. I have an instrument to USB adaptor that performs this conversion, and also have the use of a mixing desk with a built in USB interface.

You also need some audio recording software. I use a program called Audacity for the recording, this has the advantage of being free software and is available on PC, Linux and OSX machines.

A nieve solution using a built in microphone

It is possible to record audio using a built in microphone on a computer, but there are several problems with the audio. You can clearly hear additional noise in the background of the playing. Clip 1 

Using a USB Interface

An Instrument - USB Interface

In these examples I am using a USB interface to connect between the guitar and the computer. I am still using Audacity to carry out the recordings.

The adaptor is simple to set up, and converts the analog guitar signal into the digital signals that a computer understands.

This is a cheap and effective method for a solo guitarist to create a recording, however a significant amount of work will be required for a multi-instrument version to be created.

This is the recording of the track using the USB interface, the audio levels are similar but without the background noise.

It is possible to create a multi-track recording by laying down additional tracks, in Some Folks Do I recorded two guitar tracks using the USB interface and the two singers were each recorded in separate sessions. I don't remember the number of takes, but it did take several hours of recording and re-recording until we were satisfied - or just possibly we'd had enough!

Forlorn intentions

Alto ZMX164 FX USB Mixing desk

I had planned on using a mixing desk to produce a version and talk through the steps taking to record the guitar track, however I had some technical difficulties with getting the audio to record at a reasonable level from Audacity over the USB interface.

What I didn't think about in time for completing the main part of the assignment was to use the phono (RCA) tape mix outputs to feed into the microphone socket on the laptop. I am hoping that I will get some time on Monday evening to finish this off before the deadline.

The general steps I would be taken would have been:

• Make sure all connections are made with all equipment powered off. This is to prevent sudden noises from potentially damaging your speakers and amplifiers.
• Turn all gain and level controls down, and mute all channels if possible
• Power equipment up in the following order
• Instruments
• Mixers
• Amplifiers
• Adjust the gain for the input to get to the +4 line level. Don't rely on gauges, use your ears. You can hear transient distortion long before it will appear on a meter.
• Adjust the studio and main mix outputs to get the desired listening levels.

Reflection

What have I learned?

• You need a really good quality signal to get a decent recording
• It's hard to do a solo recording session
• I can see why good sound engineers are highly sought after, and the most important single skill that they have is their listening
• Batteries fail at the most inopportune time (as if I didn't already know that from my photography)
• Learn at least the basics of how to equipment before wanting to use it for real

Oh, yes: the most important thing would be not to leave important work until almost the last minute.

Thank you's

I have spent a lot of time on reviewing, rewriting and rerecording the sections of this work, the hardest part was cutting out unnecessary sections. The finishing was done in a rush, I had given myself a set of challenging and interesting scheduling conflicts by taking on a new job and signing up for new courses all around the same time.

I'd like to thank everybody that has reviewed my work, and receiving feedback is the best way to learn and develop new skills.

Music Production Week 1

The second of the courses I've signed up for.

This one was a little more intense than the Songwriting one, and the nineteen lectures in the first week cover topics ranging from propagation of sound to how to connect microphones and instruments into a system.

There were seven quizzes too, covering propagation, amplitude, frequency, visualising sound, microphones, cables and signals. I have managed to get what I class as a satisfactory mark for the quizzes, so I'm feeling pleased about that.

Some of the theory I was familiar with, could be something to do with the training I received as a telecommunications engineer when I was with BT (although it was known as "Post Office Telecommunications" when I first joined).

The peer review assessment is to select a topic and prepare materials to help teach the topic. The lesson can be in a variety of formats including a pdf document, a video, a screen movie with voice-over, text with diagrams, a blog post, a powerpoint...  Basically almost any method that you want to.

The topics that can be chosen are:

• Audio Basics: Propagation, Amplitude, Frequency, and Timbre. (you can do a broad overview or focus on a single parameter of sound)
• Microphone Basics: Type, Frequency Response, and Polar Pattern. (you can do a broad overview or focus on a single aspect of microphones)
• Visualizing Sound
• Type and Usage of Important Studio Cables. 
• Typical Recording Signal Flow Using Your Own Equipment. 
• How To: Recording Spoken Word. 
• How To: Recording an Acoustic Instrument. 
• How To: Recording an Electronic Instrument. 
• How To: Recording an Electric Guitar or Bass without an Amplifier. 
• How To: Recording an Electric Guitar or Bass with an Amplifier. 

I don't know which one I would choose yet, I'm going to have to think fairly hard about it. I'm quite tempted by recording an Electric Guitar without an amp - I have an electro-acoustic guitar and a 1/4" to USB adaptor and some free recording software, and also have a small mixing desk I can throw into the mix. Decisions, decisions!

I think I know what I'm going to be doing on Sunday, there is no chance of me doing any tomorrow or Saturday because I'm thinking about going to the Epic Powwow after the Cub Scout meeting tomorrow night and I'm working on Saturday and have a party to go to that night too.

I think it's time I should be heading to bed, I've an 6am alarm for work tomorrow.

Songwriting Course Week 1

I have signed up for a couple of online courses recently, and for a change ones that are totally out of my normal field of study (ie not computing ones!).

You won't be too surprised to find out that Songwriting is one of these courses, although I suspect the title of this post might have given it away!

Today was my day off (because I'm working Saturday), and apart from getting a replacement oven and a mooch around Dalton Park, I have spent some time in watching the lectures for the course.

The course is structured around video's, with quizzes to back up the ideas in the lecture followed by an assessed piece of coursework.

There are several songs that the quizzes refer to, and YouTube is a big help as I didn't have any of the songs quoted in my collection!

The lectures looked at the structure of songs, how to develop ideas in songs and different points of views. You mustn't forget the six best friends of songwriting: Who What Where When Why and How - these are probably best friends of authors too.

I'm sitting writing this while Lynn is cooking tea, and I intend on starting on the other course I signed up for this evening. I might have to push myself fairly hard to try and get it completed tonight too, especially as I haven't checked the deadlines for it out yet!

The songs

There were only two of the songs that I recognised Eleanor Rigby and The Great Pretender, although it was the Freddy Mercury version I had heard before.

One or two I though might be doable as a guitar soloist, and when I get my skills up enough I intend to give a try - open acoustic events beware!

• "Eleanor Rigby" (John Lennon/Paul McCartney) performed by The Beatles


• "One More Dollar" (Gillian Welch) performed by Gillian Welch


• "Still Crazy After All These Years" (Paul Simon) performed by Paul Simon


• "In Front of the Alamo" (Gary Burr) performed by Hal Ketchum


• "It Was a Very Good Year" (Ervin Drake) performed by Frank Sinatra)


• "For No One" (John Lennon/Paul McCartney) performed by The Beatles


• "What’ll I do?" (Irving Berlin) performed by Linda Ronstadt


• "Can’t Be Really Gone" (Gary Burr) performed by Tim McGraw


• "Judgement of the Moon and Stars (Ludwig's Tune)" (Joni Mitchell) performed by Joni Mitchell


• "I Can’t Make You Love Me" (Mike Reid/Allen Shamblin) performed by Bonnie Raitt


• "The Great Pretender" (Buck Ram) performed by The Platters


• "Strawberry Wine" (Matraca Berg/Gary Harrison) performed by Deana Carter


• "Why Can't I Have You?" (Ric Ocasek) performed by The Cars