The Internet Monthly is a podcast dedicated to the latest news and developments in the internet, produced for Zen Internet by myself, and subsequently syndicated on my blog. However, things don’t always go according to plan!

Recording podcasts is just like anything else in life; there are good days and bad. During our monthly recording sessions for the podcast, mistakes are invariably made, some of which I kept for posterity. As such, I have put together a short collection of these out-takes and bloopers for your seasonal amusement…

Podcast Bloopers 2009

The Internet Monthly – Podcast Bloopers 2009:

Download audio file (bloopers_09.mp3)

Or, download: bloopers_09.mp3 [3’ 14”, 1.5MB]

Thanks

As the final days of 2009 fade away, I’d like to take this opportunity to say thanks very much to you all for following my blog over the last year.

Hopefully the New Year will provide me with further inspiration for new and interesting posts in the month’s to come… we can at least hope!

Merry Christmas and Happy New Year!

Album or cover artwork can easily be embedded within MP3 files via ID3 tags. However, the ID3 specification caters for over 20 different image categories. So which is the best image category to choose, and is it ever worth embedding more than one image into your MP3 files?

Since the release of version 2 of the ID3 tag specification over ten years ago it’s been possible to add album artwork to your collection of MP3 files. This feature of the ID3 specification is now pretty well supported. Most MP3 players with a screen capable of displaying graphics (be they software or hardware  based), now support this feature.

However, as usual with these sort of things, MP3 player manufacturers tend to implement the ID3 tag standard in subtly different ways. This inevitably leads to unpredictable results for the user, particularly when displaying album art.

Embedding Images into MP3s

If all this talk of ID3 tags leaves you a bit cold, then it may be worth pausing for a moment to read my previous post on ID3 tags in MP3 files before proceeding, as they are fundamental to our further discussions.

Embedding images into MP3 files is fairly straightforward and indeed might be accomplished automatically for you by your CD ripping software. If this is not the case, then you will need a special piece of software called a tag editor to help with the task. There are lots of tag  editors available for a host of operating systems, with some good free ones available. My personal favourite is Mp3Tag.

If you want to know more about adding cover art to your MP3 files, the best image format to use and what image size you should consider using, then check out my previous post on embedding album art in MP3 files.

ID3 Artwork Options

The present ID3 standard (version 2.3.0) lists 21 different images that can be embedded within an MP3 file. In practice only one image is ever usually embedded, although an MP3 track could technically have 20 images (only one of the icons #2 or #3 can be embedded at a time). However, the space taken up by the images in such a file would become quite significant compared to the audio data.

The images available to choose from are:

1. Other
2. 32×32 pixel icon (PNG only)
3. Other file icon
4. Front Cover
5. Rear Cover
6. Leaflet page
7. Media (e.g. label side of CD)
8. Lead artist, Lead performer or Soloist
9. Artist or Performer
10. Conductor
11. Band or Orchestra
12. Composer
13. Lyricist or Text writer
14. Recording Location
15. During Recording
16. During Performance
17. Movie or Video screen capture
18. A Bright coloured fish
19. Illustration
20. Band or Artist Logo
21. Publisher or Studio Logo

There are two notable exceptions in the above list that are a little different from the others:

• The second option (#2) only allows images in the PNG format and images which are sized 32 by 32 pixels for use as a small icon.
• The eighteenth option (#18) in the list; a bright coloured fish! Some loony tune obviously decided that this was a good idea for a formal specification. Need I say more?

So, for all essential practical purposes, the list really has 20 options (ignoring the brightly coloured fish), or if you are just considering images of unrestricted size, then it has 19 options.

Support for ID3 Images

MP3 Players

Not all MP3 players are created equal when it comes to displaying ID3 images. For example, the Creative Zen Vision: M, while having a large colour screen capable of displaying pictures, does not seem to display any of the ID3 images as far as I can tell; no matter which image tag is used.

The basic Creative Zen displays the ID3 image from the last track in a folder, but insists on using this same image for all tracks in the folder, no matter whether they have different artwork embedded within them or not.

Software Players

Windows media player seems to display any ID3 image correctly, but providing there’s only one image in a track. If a track contains more than one image, it will default to the Front Cover image. Quite how you’re supposed to see the other images, I really don’t know, but at least this seems a sensible fall back position.

Podcasts

A lot of podcasts seem to use the Other image tag (#1 from the above list) for their artwork instead of the Front Cover option. I’m not really sure why this is, other than that their software defaults to this option. My preference would be for the Front Cover tag in this circumstance, but I’d be interested to see what the general consensus is on this.

Test your Player

Having tried a few players and found them to be wanting in their handling of ID3 images, I decided to do a structured test on those I had available to me.

Test Images

In order to test the various ID3 image tags on a range of players, I produced 21 different images corresponding to each of the image tags. Each image is a 300 x 300 pixel jpeg (except the 32 x 32 pixel PNG icon):

If you’d like to use these images yourself for your own experiments, you can download all 21 as a zip file. Each individual image is approximately 25kB in size:

• ID3-Images.zip (246kB)

Test MP3 Tracks

In order to test these images on an MP3 player, they each needed to be embedded into an MP3 file with the appropriate ID3 image tag associated with the image.

My tag editing software doesn’t support the 32×32 icon image tag or the nonsensical fish tag, so I ended up creating 20 separate MP3 files: the 19 basic image tags plus one MP3 containing all 19 images in the one track.

The MP3 track including the 19 separate images in the one file ended up with a resultant file size of 911kB for a 26 second 128kbps MP3!

• 21 – ID3 Image – All Images.mp3 (911kB)

If you’d like to use these MP3 files for yourself to test your own MP3 player’s performance in this respect, you can download all 20 as a zip file:

• ID3-Image-Test-MP3s.zip (2.5MB)

Report Back

If you’ve found these files useful and end up discovering some quirks with your particular player, please leave a comment so that others can benefit from your findings.  You never know, it may spur a manufacturer into updating their firmware to fix the problems and make their players fully compliant for future users.

Whenever you play a podcast on your portable MP3 player or PC, you will invariably see a host of information about the track on the player’s screen. This information typically includes the cover art for the track, the album, artist and track name, its genre and track number.

Such information is stored in the MP3 file itself using ID3 tags. However, in addition to the tag information in the example above, the ID3 tag standard can support over 80  different tags. So, out of this vast array of tags what are the key tags that you should consider using in your podcasts?

What are ID3 Tags?

ID3 tags are a simple and convenient way of embedding descriptive data about an MP3 track within the track itself. This descriptive data is sometimes referred to as metadata, which is data describing other data. The ID3 tag data describes the audio data of the MP3, e.g. the track title, artist name etc..

For a fuller and more in-depth description of ID3 tags, check out my previous post: What are ID3 Tags in MP3 Files?

Essential Tags

Downloaded podcasts will already have ID3 tag data buried within them, but if you produce your own podcasts, you have free reign to add whatever ID3 tags you wish. However, you could fill up your tracks with 50 different tags or more, but who is this really going to benefit? Not you for certain; it’ll probably take you longer to add all of these superfluous tags than it did to record the podcast in the first place.

Brevity is the key. Just include the bare minimum that users are likely to need, any more and you’re wasting your own time and wasting space in the MP3 file storing useless junk.

The tags serve two purposes. The first is to provide general information about the podcast that the user is likely to want to know, while the second is to enable the user to search through a large collection of tracks at a later date and hopefully filter out your podcast via its tags.

Track Title

This is undoubtedly the most important tag, being the title of your podcast episode and is a fundamental tag that should not be missed.

By way of example, the title I use for my monthly podcast, is the generic title of the podcast with the month and year appended:

The Internet Monthly – June 2009

Cover Art

Another important tag to consider is the cover art tag. As the saying goes; a picture speaks a  thousand words, and this tag gives you the option to brand your podcast in glorious colour, forever etching it in the user’s memory.

However, while this tag will help to connect the user with your podcast, it’s unlikely to serve much use when trying to search for the podcast later on.

If you’d like to learn more about embedding images into your podcasts and what image types and sizes to use, then check out my previous post on: Embedding Album Art in MP3 Files.

Artist

This is the producer of the podcast. For example, I record a monthly podcast for Zen Internet to a script that they provide, so I add their name as the artist, as it’s essentially their creative work:

Zen Internet Limited

Album

While this tag is designed for use with music albums, where it refers to the album which an individual track belongs to, in podcast terms it is commonly used to refer to the series name of the podcast (assuming the podcast is not a one off, in which case this field would be left blank). For my monthly version of the Zen Internet podcast, I use the following album tag:

The Internet Monthly

Track

This isn’t often used in podcasts unless you have a concurrently running sequence of episodes, in which case you could use this field to denote the episode number.

Year

This is the year in which the podcast episode was first published. This field is probably not of much interest to the user under normal circumstances, but can prove useful later on when searching through an archive of tracks to narrow down the search:

2009

Genre

Again, this tag is not of much use other than for categorising the track for archiving and searching purposes. For podcasts, the de facto standard entry for this tag is unsurprisingly podcast, although sometimes you may come across alternatives of speech or vocal.

Interestingly podcast is not defined in the list of genres in the official ID3 tag specification, even though it is common practice to use this as the genre name for podcasts. Both speech and vocal are officially recognised as legitimate genres however.

I decided to go with the flow and hopefully the specifications will catch up with conventional wisdom:

Podcast

Comment

This field is often used for show notes and additional information pertaining to the podcast. Some people use this field for copyright notices, although if this is your intention, their is a specific copyright tag field dedicated to the purpose.

As my company (Silicon Bay Limited) produces the monthly podcast for Zen Internet, I use this field as a slight promotional opportunity:

Produced by Silicon Bay Limited

Copyright

Instead of using the comment field for your copyright information, this is the correct tag for the purpose:

Copyright (c) 2009 Zen Internet Limited

WWW

Invariably your podcast will be associated to your website, so why not embed your website’s URL into your podcast? This way if the podcast gets distributed via other means than your own website, you’ll have a way of driving traffic from interested listeners back to your site:

http://www.richardfarrar.com/

In Summary

The key ID3 tags that you should consider using in your podcasts, that will give the most benefits to your listeners without overloading them with information are:

• Title – The podcast title
• Cover Art – Thumbnail of the podcast art
• Artist – The artist that recorded the podcast
• Album – Which series the podcast belongs to (if applicable)
• Track – The track number from the podcast series (if applicable)
• Year – The year the podcast was published
• Genre – The type of track, e.g. podcast, speech, vocal
• Comment – General comments
• Copyright – Copyright notice by the copyright holder
• www – The website address for the podcast

Manufacturers like to develop and retain technologies that gives them a commercial and technological advantage over their competitors. To this end we as consumers have ended up with a collection of competing, but unfortunately technically incompatible, solutions to the same problem; that of storing large amounts of audio on portable audio players.

Thankfully the majority of manufacturers (but by no means all) of these portable audio players have eased our potential incompatibility problems by making sure that their players can play the majority of compressed audio formats that are in common usage today.

So what are these common compressed audio formats, why do we need them and what are the associated problems with having so many different formats?

Why Compress?

Back in the dark ages of computing, not so long ago, computer memory was not so plentiful, or cheap as it is today. As such, storing large amounts of data, such as audio files, was very costly.

As necessity is the mother of invention, the limited quantities of computer memory available prompted the white coated technical boffins to develop fiendishly cunning ways of throwing away most of the audio data from these files, while still retaining a high level of perceived audio quality.

How they do this is rather complicated, but they essentially save space by not storing the bits of the music that we can’t hear. During compression of a 128 kbits/s MP3 file, typically 90% of the audio data is discarded, leaving a file size of one tenth of the original size. This in turn means that your MP3 player is able to store ten times the amount of songs compared to if it had to store the original uncompressed CD data.

MP3

MP3 (MPEG-1 Audio Layer 3) is by far the most well known out of all of the audio compression systems available today, and while it may not be as technologically advanced as some of the newer systems, it is the most widely used and provides perfectly adequate results for moderate bit rates for the majority of people’s requirements.

The major benefit of encoding your audio files in MP3 format is that you are pretty much guaranteed you’ll be able to play your resultant files on almost any modern media player or device. It is for this reason that most podcasts choose to adopt the MP3 format as their preferred compression system.

While most people think that MP3 is a free and open source format, it’s not! There are numerous patents owned by a host of different organisations that are applicable to the MP3 technology. This can make official licensing of MP3 technology for use in encoding software or playback devices quite tortuous. Out of all of the organisations that lay claim to the technology underlying MP3s, the German Fraunhofer Society is probably the most notable.

AAC

AAC (Advanced Audio Coding) is actually part of the MPEG-2 and MPEG-4 specifications and is designed to be a superior technological replacement for the older MP3 format. AAC is designed to provide improved sonic quality and transparency compared to MP3 files encoded at the same bit rate, although this advantage only becomes dominant for lower bit rates (below 128 kbits/s).

AAC is the default format that Apple have adopted for their iPods, iPhone and iTunes and for their iTunes online music store.  Sony has also adopted AAC as the standard audio encoding system for their PlayStation 3 and has been incorporated into their PlayStation Portable and recent Sony Walkman systems. Other companies adopting this format include Nokia and Nintendo (Wii and DSi).

WMA

WMA (Windows Media Audio) is Microsoft’s proprietary audio compression system built into its Windows operating system and is the default compression option used for ripping CDs to your computer using Windows Media Player.

Whilst WMA is a proprietary Microsoft system, the technology has been licensed by numerous third parties meaning that if you’ve ripped your entire CD collection onto your computer’s hard drive in WMA format (as I have), then you have a good chance of being able to play these WMA encoded audio files on a host of compatible devices.

I have a Creative Zen MP3 player, which plays WMA files without any problems and I also have two Netgear MP101 media players at home linked to my home network that can stream music from my server in WMA format.

ATRAC

ATRAC (Adaptive Transform Acoustic Coding) is another proprietary audio compression format, this time developed by Sony, originally for their MiniDisc systems in the early 1990s, but has since been used in the company’s range of portable audio players.

Since its inception, ATRAC’s compression algorithm has been improved over the intervening years, with the newer versions offering improved perceived audio quality over earlier versions for similar bit rates.

Unfortunately, ATRAC encoded files are not widely supported by other manufacturers and as such, if you have a Sony branded audio player and have ripped all of your CD selection into ATRAC files, you’ll be extremely limited as to where else you can play your audio files.

Licence Free

Ogg Vorbis

While the Ogg Vorbis audio compression format is not hugely popular outside of the geeky computer nerd circles, it is worth a brief mention as a number of commercial “MP3  players” support the format. More importantly though is the Ogg Vorbis system is FREE!

There are no patents or licence issues to worry about if you choose to adopt this system, although compatibility with other media playback devices may prove to be an issue.

FLAC

FLAC (Free Lossless Audio Codec) is another audio compression system worth a mention, partly because it’s free (as its name suggests) and partly because it’s lossless.

All of the above compression systems loose some audio quality in their compression process. FLAC does not, but the downside is that the same sort of compression levels are not achievable.

FLAC files tend to be between 40 to 50% the size of the original audio file, which is not that impressive compared to a typical 10% figure of an MP3 file.

Like anything in life, it’s a balancing act. If you can afford the additional storage space required and want original quality audio, then FLAC is the way to go. For the majority of people however, these tiny improvements in audio quality compared to the space saving benefits of any of the above compression formats will not be worth the penalty of compatibility issues.

Summary

While MP3 is the most common and well known of all the audio compression systems, it’s by no means the best. There are a multitude of different audio compression systems available, with just a handful of the most common ones mentioned above.

The choice of compression system can depend on many factors, but for most people, providing the audio quality is reasonably good and the file sizes acceptably small the overriding issue will probably be compatibility.

Thanks to the advent of digital audio and the power of modern PCs, it’s now well within the capabilities of virtually anyone to produce and publish their own radio play using the same technologies as used in podcasting.

As a small kid I remember producing plays with my toys, an upturned stool for a theatre, a few torches and the tales of Peter Rabbit by Beatrix Potter as a script. Since then my interests graduated to music production; I played in numerous bands and have always been keen on recording bands as a hobby.

However, my recent visit to an audio post production film editing suite at Pinewood Studios, re-sparked my interest in plays (I’ve always been a fan of the BBC’s radio series: The Hitchhiker’s Guide to the Galaxy) and got me to thinking about using the same equipment that I use for podcasting, but pushing it’s use a bit further.

All I needed was some creative inspiration, but in it’s absence, I did the next best thing and borrowed it from someone else…

Inspiration not Perspiration

In the beginning was the word and the word was written by John Davison; the word was Bananas.

John has grandchildren, five in fact, but it’s his two youngest grandchildren that were the catalyst for this radio play.

John would often tell his grandchildren bedtime stories, which he usually made up as he went along. However, after a while, John began to formalise his bedtime stories around a young gorilla named Bananas as the central character.

Having developed a few adventures of Bananas, test driving them on his grandchildren first, John published some of his stories on his personal blog, with the first story published being Just Another Happy Day At The Farm!

To accompany the stories on his blog, John flexed his creative muscles even further, drawing the main characters of his stories for visual enhancement.

Some of the themes for his stories were actually suggested by his grandchildren, giving him a creative head start. The story that I used as the basis for my radio play was one of these; George Helps Bananas and Farmer Jones.

Story to Script

Having the story of Bananas was the starting point for the radio play. However, it was only after a few glasses of wine on a dark and damp winter’s day at John’s house that the reality of turning this story into a radio play began to take shape.

A few glasses of wine later and the story of Bananas and George had been turned into a script for our fledgling radio play.

Recording

The recording of the radio play was done in stages, depending on people’s availability, with the recording setup being essentially the same as I use for recording Zen Internet’s podcast every month.

Character Voices

The first voice to be recorded was Winnie’s. Winnie recorded the narration, but also recorded the voices of Bananas and Mrs Jones.

The second voice to be recorded a few weeks later was that of John himself, who played Farmer Jones. During this recording session, John and his wife Connie also assisted in recording a few sound effects for the play, namely the stirring and the drinking of the hot chocolate featured in the play and the pouring of the bird seed.

The final character voice for the play was provided by my son James, who played George.

The only other voice for the play was that of the announcer, provided by myself.

Technical Setup

To record all of the voices I used a Rode NT1-A low noise, wide diaphragm condenser studio microphone (shown left) with a pop shield to stop the microphone “popping” with loud sounds beginning with Ps and Bs.

The microphone was also mounted on a “cat’s cradle” shock mount to help prevent vibrations from the microphone stand passing to the microphone.

The voices were recorded into the PC via a Focusrite Saffire firewire interface. During this process a little gentle compression and equalisation was added to the voices via the Saffire’s on-board DSP.

For those of you NOT interested in the nerdy technical details, then please skip the next geeky bit:

Compression: A compression ratio of 2.5:1 was used with a 10ms attack time and 350ms release time. The threshold was set to -30dB to give a compression of up to 6dB during peaks.

Equalisation: A high-pass filter set to 90Hz was used to filter out low end bumps and pops. A –4dB high frequency shelf filter was used, set at 16kHz to take a slight harsh edge off the sound. 6dB of boost was added at 200Hz with a Q of 1.7 and 6dB of boost at 4kHz with a Q of 1.2.

All recordings were done at a sample rate of 44.1kHz (CD sample rate) and were recorded as uncompressed WAV files to retain their maximum quality.

Editing and Production

Recording the voices was only a small piece of the puzzle. Now the rest of the pieces had to be assembled; only they didn’t come with instructions!

To assemble all of the recorded pieces, a computer based Digital Audio Workstation (DAW) was used. My weapon of choice was Steinberg’s Cubase 4 LE that came bundled with my Focusrite Saffire audio interface; an amazingly powerful bit of software considering it was effectively given away free.

The picture below shows a screen shot of the main editing window in Cubase. Using this window I assembled the various audio pieces into their correct order and colour coded different groups of tracks for easy navigation. The intro and outro music pieces were coloured orange, voices were yellow, foley effects were pink, ambient and animal noises were purple and all other sound effects were in green.

With all of the tracks in place, additional audio processing was performed with some compression, equalisation, de-essing and noise gating.

The final mix was then created using the software’s powerful mix automation features to remember the fader (volume) positions, pan (left and right stereo positions) and reverb settings throughout the mix.

With the final mix completed, the resultant WAV file was converted into an MP3 file encoded at 128kbps, joint stereo to produce a fairly compact file for downloading, while retaining a reasonable level of quality.

The final tweaks to the MP3 file were the addition of various ID3 tags to include the track title, artist etc. and the embedding of the cover art of Bananas into the file itself.

The Play Itself

So, you’ve heard how it was produced, but what about the final result?

Well, judge for yourself, here it is:

Bananas Helps George:

Download audio file (bananas-helps-george.mp3)

Or, download: bananas-helps-george.mp3 [5’ 21”, 5MB]

By now you’ve probably heard of the term “bit rate” used in connection with MP3 tracks and podcasts, you may even know that higher bit rates give better quality audio. However, like most things in life, nothing is simple and we can further complicate the whole bit rate discussion with variable and constant bit rates. So, what are the pros and cons of these constant and variable bit rates?

Choosing a bit rate for a podcast, or an MP3 track, is a bit of a balancing act at the best of times. On the one hand, higher bit rates (variable or constant) give improved audio quality, whilst on the other they lead to bigger file sizes.

Introducing yet another variable into the equation, that of constant or variable bit rates, only serves to confuse the situation even further. What then are the relative pros and cons that may affect your choice of type of bit rate to use?

Balancing Bit Rates

If you’re not familiar with bit rates, then my previous post on What are bit rates? should point you in the right general direction and help to get you started.

In essence, higher bit rates give improved audio quality, no matter whether variable or constant bit rates are used. However, higher bit rates will always lead to larger file sizes, which in turn lead directly to longer download times and require more storage space.

When choosing which bit rate to use for your podcast or MP3 track, you really need to go for the highest bit rate possible, while retaining reasonable file sizes and practical download times.

Accepting the fact that you need to choose the highest practical bit rate you can, which option should you go for next (assuming your encoding software gives you the option) constant or variable bit rates?

Constant Bit Rates

Constant Bit Rates (CBR) are pretty much as their name suggests, where one fixed, or constant bit rate is used for the entire file or track.

However, constant bit rates are not optimal as they waste valuable data bits encoding simple sections of audio, and conversely may not use sufficient data bits on more complex audio passages, resulting in poorer audio quality during these sections.

The more complex audio sections of tracks encoded with a constant bit rate will be of a lower audio quality compared to the more simple sections of audio within the same track, so a suitable bit rate must be chosen that provides sufficient audio quality for the most demanding sections of the audio being encoded.

Constant bit rates are easier and therefore faster to encode compared to variable bit rates and lead to consistent and predictable file sizes. Being an older format, constant bit rates are more compatible with older MP3 players.

Variable Bit Rates

Variable Bit Rates (VBR) are likewise pretty much as their name suggests, where the bit rate may change throughout the file or track being encoded.

Variable bit rate encoding analyses the audio file, adapting the bit rate as it goes to match the complexity of the audio it encounters.

For simple audio passages, the system automatically turn its bit rate down, saving valuable data bits, while retaining the perceived audio quality. Conversely, during more complex passages, the system automatically turns its bit rate up, using more data bits to retain the same level of audio quality.

Using this method, the average audio quality of a file can be increased as the available data bits are used more flexibly to encode the sound data with increased overall accuracy.

When encoding an MP3 track or podcast with the VBR method, the encoding software usually allows you to decide on the overall quality of the resulting track that you desire, after which the system encoder uses the bits required to achieve this defined quality level. Higher quality levels will require more bits.

Compared to constant bit rates, variable bit rates produce smaller file sizes for a given audio quality. However, as the bit rates are variable, it’s difficult to predict the size off these files in advance.

Variable bit rates are harder and therefore slower to encode compared to constant bit rates, as the adaptive encoding process is more complex an processor intensive.

Being a more recent encoding method, some older MP3 players or computer software may not be compatible with variable bit rate encoded MP3 tracks or podcasts.

Constrained Variable Bit Rates

A Constrained Variable Bit Rate (CVBR) is a flavour of variable bit rate, where the maximum bit rate allowed, or the Average Bit Rate (ABR) are predefined.

For example, encoding an audio track with the bit rate set to be an average of 128kbps should produce a resultant audio file of higher perceived quality than the same track of encoded at 128kbps CBR, as the ABR file can use data bits it saved during the simpler passages to add extra data bits (above the 128kbps average) to the more complex passages to improve the overall audio quality.

Which to Use and When

Compatibility

Generally speaking, encoding an MP3 track or podcast using a constant bit rate will be better for the sake of compatibility compared to using a variable bit rate, as some older MP3 players don’t support variable bit rates.

By way of example, in their guidelines for broadcast media, the BBC recommends the use of constant bit rates for their all of their podcasts and downloadable audio files.

Quality

If compatibility isn’t a significant issue for you, then you will probably be better off using a form of variable bit rate of encoding to squeeze the best audio quality that you can out of the available bits.

Whether you choose to use a constrained variable bit rate, so that you can keep a handle on the size of file you’re likely to get, or go for a fully variable bit rate, is entirely up to you.

However, before fixing which method you’re going to use, it may be best to do a few test recordings using different bit rates and bit rate types, before deciding on which suits your purposes best.

In Summary

Attaching speakers to your Hi-Fi system usually only requires a few cables. You wouldn’t think that getting these cables mixed up would present much of a problem would you, providing your music plays back OK and no smoke comes out of the system?

Well, under most circumstances you’d be right, with a simple channel mix up being the most likely probable outcome, but if you have a real knack for getting things back to front, then you could have your speakers wired out-of-phase, which while it won’t do any damage, certainly won’t help you to get the best out of your system.

These potential problems are easy to spot with a few simple tests and luckily the corresponding remedies are equally simple.

Left and Right Tests

In the grand scale of things, getting your left and right speakers mixed up is not a major problem. If your left and right speakers are mixed up, your music will still come out in wonderful stereo (providing of course that you’re listening to a stereo track) it’s just that what should be coming out of the left-hand speaker is actually coming out of the right-hand speaker and vice versa.

Record producers and mix engineers spend weeks mixing and producing an album and as part of the process they will decide where in the mix to place certain instruments. So if you have a favourite track that has an instrument panned (music speak for stereo positioning of sounds) to one side, wouldn’t you prefer to listen to it as the artist intended rather than topsy turvey?

You would? Good.

Then try the following two fairly self explanatory tests on your music system. Listening to the left speaker test, you should hear Winnie’s voice coming out of the left hand speaker (or headphone) only and vice versa for the right speaker test.

Left Speaker Test:

Download audio file (left.mp3)

Right Speaker Test:

Download audio file (right.mp3)

If things don’t go according to plan, then you have either got your speakers wires mixed up (or headphones on the wrong way round), or the audio cabling (shown right) from your playback device to the amplifier crossed over.

Normally audio signal cables (as opposed to speaker cables)  are colour coded with the red plug going to the red socket and white to white at each end of the cable.

You will need to check the wiring of your system, rewiring where necessary and then repeat the two tests to make sure that both channels are working and in the correct order.

The following diagram shows how to wire your speakers to your amplifier:

Balance Test

Now that you’re happy that you have your left and rights sorted out, the next thing to check is your speaker balance.

When you listen to the following test, place your head as centrally as you can between your two speakers; you should hear Winnie coming from the dead centre of your speakers. In this case you are hearing equal amounts of Winnie from both speakers.

Centre Balance Test:

Download audio file (centre.mp3)

If Winnie sounds to be coming either to the left or right of the centre position, you may need to check to see if your amplifier or system has a balance control. If it does, ensure that the balance control is in the centre position.

If after checking the balance control, things still sounds one sided, you may have a more fundamental problem with your system that requires investigation or professional attention. This could be as simple as a dirty connection or a dodgy interconnecting cable, or if things are worse it could be a more ingrained electronic or speaker problem.

Alternatively, if you can’t pin point the sound as definitely coming from the centre, you may have a phasing problem…

Phasing Test

A phasing problem with speakers is very simple to fix, but can significantly degrade your system’s sonic performance.

Trying to describe how out of phase speakers sound is a little difficult unless you’ve experienced it first hand. You’re likely to hear significantly less bass and instead of producing a strong centre image, the sound appears to stay within the speakers, making things sound rather disconnected.

Listen to the following and you should be able to hear the difference for yourself:

Speaker Phase Test:

Download audio file (out-of-phase.mp3)

If the above test sounds perfectly fine, but the previous centre channel test sounded really odd, then your speakers are out of phase.

Fixing the Problem

Thankfully, while the effect can be quite strange, the fix is really simple.

Pick a speaker, but not both, this must only be done on one speaker. Now swap the two wires on the back of the speaker around. Usually the speaker will have two connections; one black (the negative or – connector) and one red (positive or + connector).

That should  be it, job done. Now listen to the centre/balance test and phase test again to confirm that you have everything working hunky dory.

Sit Back and Relax

Now that you have your speakers wired up correctly with your lefts and rights where they should be and no strange out of phase effects, you can lie back, put your feet up and listen to my latest podcast in knowledge of a job well done.

You had no problems; excellent, so there’s no reason not to listen to my latest podcast either! 

In today’s  society our senses are being continually bombarded with an overwhelming and virtually limitless stream of information. How do we cope with it all? Podcasts are yet another potential drain on our valuable time resources. So, if you choose to satisfy your information cravings with this modern medium, when do you say enough is enough?

If you listen to podcasts, what is the ideal length of a podcast to fit in with your busy schedule? When do they become too long, and when are they too short to be worth bothering with?

Conventional Media

If you look through a typical TV guide, you will see that television and radio shows are often either half an hour or an hour in length, although after removing the “dead time” between them, the actual shows themselves are more likely to be 25 minutes and 55 minutes in length respectively.

However, podcasts don’t have to be as regimented in their length as broadcast shows, as they can be listened to at anytime; they don’t have to fit in to an existing schedule with predefined time slots. They can be as long, or as short as they need to be to get their message across.

Can a Podcast be too Sort?

If you’re at your computer and you want to listen to a short podcast for example, then it’s probably not too much of a problem to do so. Just click the button in your web browser and listen to it there and then.

Practicalities

However, if there are a few short podcasts that you want to listen to in your car, is it really worth the bother of downloading them all individually onto your MP3 player? Notwithstanding the hassle you’ll have later on in the car; fiddling around with your MP3 player every few minutes to select the next track!

Furthermore, to get over any real information that may be either useful or entertaining, the podcast obviously can’t be too short.

So what is too short? Would it be fair to say that for a podcast to be of any significant value, you should be looking at a minimum length of at least 5 minutes?

Over Cooked

While there may, or may not be such a thing as a podcast that is too short, the converse is not the case. A podcast can definitely be too long.

Attention Spans

Our attention spans don’t seem to be what they used to be, so there will invariably be a point at which you switch off and stop concentrating. Any podcast longer than your personal attention span, is therefore too long.

The average attention span of an adult listening to a lecture is between 15 to 20 minutes. Perhaps a good guideline for the length of a podcast!

Environmental Circumstances

Podcasts are designed to be listened to at your convenience, wherever and whenever that may be.

If you typically listen to your podcasts in your car on the way to work and your daily commute takes 25 minutes, then podcasts lasting 30 minutes or more will probably be too long for you in the given circumstances.

Clearly then, how and when you listen to podcasts will have a significant bearing on what you think is an optimum length for a podcast.

Time is Relative

According to Einstein’s theory of relativity, time is relative.

While this may be true for the physicists, it is also true for all of us, but from a more subjective viewpoint, depending on how busy our lives are.

Those with busier lives will undoubtedly have less time to listen to podcasts and will probably prefer their podcasts to be shorter and more concise; easily digestible bite sized chunks.

Lengths of Example Podcasts

By way of example it may be helpful to look at a few example podcasts to see what sort of typical lengths podcasts are:

Looking at the above table we can see that podcasts come in a range of different lengths from 10 minutes to almost an hour.

The average length of the above podcasts is 27 minutes, by coincidence the same length as your average TV or radio show.

I’ve been producing a regular monthly podcast for Zen Internet for almost two years now. The shortest podcast that I have recorded was just over 13 minutes, while the longest I did was 23 minutes in length.

The average length of the Zen Internet podcast is 16 minutes.

Have Your Say

For my own personal preference, I would have to say that my ideal length of podcast would be around 15 minutes. Interestingly, approximately the same length of your average adult’s attention span.

So, what’s your preferred length of podcast, if you have one?

Once you have submitted your answer below, you will get to see the results of the poll so far.

Podcasts, by their very nature, are designed to be listened to on portable media players such as the ubiquitous iPod. However, podcasts are merely computer audio files that can be played back on a variety of media devices, be they portable or not, which opens up a host of possible listening opportunities.

A podcast at its simplest level is nothing special. In essence a podcast is a simple computer audio file (usually in an MP3 format), that can be played back on a range of equipment from desktop PCs to mobile phones and MP3 players.

The vast array of modern devices that now support the playback of MP3 files, and consequently podcasts, is bewildering. This in part has been instrumental in the success of podcasts, because they can be listened to practically anywhere, making them an extremely accessible media format.

Wherever you Want

Due to the wide variety of portable media devices capable of playing MP3 files, you can listen to your favourite podcasts virtually wherever and whenever you want. Some of the most common places being:

• Home
• Work
• Walking / Jogging
• Gym / Exercising
• Commuting / Travelling

Where and How

Where Defines How

Where you chose to listen to your podcasts may have an impact on how you listen to your podcasts. For example, if you want to listen to your podcasts in the car on the way to work, a desktop PC will clearly not be your best option.

How Defines Where

Conversely, if you want to listen to your podcasts in high quality on your Hi-Fi system, then listening to your podcasts anywhere on the move is likewise not a practical proposition.

Quality Issues

Podcasts are usually recorded as MP3 files, and can be recorded at a variety of bit rates, that directly affect the quality of the resultant podcasts. Higher bit rates give better quality audio.

Unfortunately, when you download a podcast, the bit rate has been fixed by the podcast’s producer and there’s nothing further that you can do to improve its quality. However, the type of system that you choose to listen to your podcasts on may enable you to get the best out of the quality available.

For example, listening to a podcast on a tiny pair of speakers built in to your average laptop will never give the same quality as listening to the same podcast via an iPod linked in to your Hi-Fi system.

Does this matter? Probably not, unless it’s a music based podcast, as the primary choice in how you listen to a podcast is most likely not that you want it in absolute fidelity, but rather where and when you are able to, or want to listen to the podcast.

The choices of how you listen to your podcasts can include:

• In-ear, mini headphones
• Conventional headphones
• On the car stereo system via an FM radio transmitter
• On the car stereo system via a direct jack connection
• On a laptop with the built in speakers
• On a PC via desktop speakers
• On your Hi-Fi system’s speakers

Have Your Say

How, where and when you listen to your podcasts may be dependent on many factors from what equipment you have available to listen to them, whether you’re fussy on the audio quality of the podcasts and on your lifestyle (where you can afford the time to listen to podcasts).

I listen to all of my podcasts at home via my desktop PC using a pair of external speakers through a Hi-Fi amplifier. How do you listen to yours?

Select as many answers from the list below that are applicable to how you listen to your podcasts. Once you have submitted your answers, you will get to see the results of the poll so far. If the categories don’t fit perfectly,  pick the closest that you feel apply.

If you’d like to leave any comments in the section below on your podcast listening habits such as how, where and when you listen to your podcasts, I’d be really interested to hear. Thanks!

The Internet Monthly is a monthly podcast dedicated to the latest news and developments in the internet that I produce for Zen Internet and syndicate on my blog. However, things don’t always go according to plan!

Everyone has their good days and bad, and recording podcasts is certainly no exception to the rule. So, I have put together a short collection of out-takes and bloopers made during the recording sessions of the monthly podcast for your seasonal amusement. Enjoy…

Podcast Bloopers 2008

The Internet Monthly – Podcast Bloopers 2008:

Download audio file (bloopers.mp3)

Or, download: bloopers.mp3 [2’ 44”, 1.3MB]

Thanks

Before the final days of 2008 draw to a close, I’d just like to take this opportunity to say a big thank you to all of you that have followed my blog over the last year. Hopefully I haven’t peaked and I’ll have plenty of interesting things to talk about in the new year…

Merry Christmas!