Tag: audio recording

Audio and AV articles that may be of interest

Naim NDS network audio player

The Naim NDX and NDS network media players are an example of what high-end network-based audio is about

I have purchased tickets to the Australian Audio and AV Show 2016 that will be held at the Intercontinental Melbourne The Rialto hotel and am running this list of articles regarding audio and AV content in the context of the connected lifestyle.

Some of these are about using Windows 10 with its inherent support for the FLAC file; bring legacy audio media like vinyl to today’s technology; or simply to highlight some AV trends. There is also a few relevant buyer’s guides which relate to buying for online or network-based audio or simply buying your next set of headphones for your smartphone or laptop.

Windows 10 and the FLAC file

Those of you who have upgraded your computers to Windows 10 will realise that it can handle the high-quality FLAC audio file format. This covers both playback and ripping audio content from CD to files, although when you rip from CDs the sound will be regular CD quality.

FLAC studio-grade audio files to be supported by Windows 10

You can rip CDs to FLAC using Windows 10’s Media Player

FLAC – now the audio filetype for archival use

Legacy audio formats and today’s needs

Linn Sondek LP12

You may want to get those old familiar records on to your computer to play on your home network

This article is about how you can set up your equipment to play vinyl and other older media to your network-enabled multiroom system or for digitally salvaging old recordings with your computer.

Legacy analogue audio to today’s needs–can this be done?

Using audio-editor software to salvage recordings on legacy media

Equipment trends worth highlighting

There are some trends that are affecting the high-end audio and AV market that I will be calling out here.

Network media players that serve as control amplifiers – Some manufacturers are running network media players that can connect to any power amplifier or active speaker and work as a control amplifier in their own right.

Why do I give space to the network-capable CD receiver – An article about the network-capable CD receivers, especially those that are being offered by the respected hi-fi names, and the fact that these are continuing on the idea of the high-quality integrated music system.

Relevant Buyer’s Guides

Buyer’s Guide – Component Network Media Adaptors – How to go about buying devices that can add network or online media playback to your existing audio or AV system

Buying an Internet radio – What to look for when you buy an Internet radio or network-capable sound system.

Buyer’s Guide – Network Attached Storage – How to choose the right network-attached storage for your home network especially if you are “ripping” your CDs to your computer hard disk and wanting them available around the network.Denon UrbanRaver AH-D320 headset

Buyer’s Guide – Headphones and earphones – Understanding the kind of headphones or earphones you can get for your laptop, smartphone or tablet and how to go about purchasing them.

Buyer’s Guide – Giving your portable computer equipment better sound – How to go about using the right speakers, sound modules and similar equipment to enhance the sound that your laptop, tablet, smartphone or other equipment provides.

Should I buy a soundbar rather than a surround-sound system to improve my TV’s sound – Considering a soundbar rather than a fully-fledged surround-sound system as a way to improve your flat-panel TV’s sound

Your DLNA Home Media Network

This series of articles will be important to you whenever you buy that Smart TV or network-capable home audio system because most of these devices offered by most manufacturers provide this kind of functionality.

Getting Started With DLNA Media Sharing – How you can use your computer with media-server software to share your music, photos and video to your DLNA-capable AV equipment. Also have a look at this Assistance Journal about making some travel pictures available to a Smart TV so they are shown to a mother-in-law – this can be done out of the box with Windows XP onwards.

Setting Up PC-Less Network AV – How to go about using a dedicated media-server device like a NAS to share your media without the need to have your computer on and available to your network all the time. This is very important for those of you who have a laptop computer and want to move that computer around the house, pack it away when not needed or take it with you to work or when you travel.

The Three-Box DLNA Network Model – How you can use another device like a smartphone, tablet or computer to have content held on a DLNA server appear on a DLNA media player. This is more of a reality with tablets and smartphones appealing as a control surface for network-based media.

Integrating Classical Music Into Your Digital Music Collection – How to integrate serious classical music in to your digital music collection so you can find and play particular complete multiple-movement works easily. This is important when you buy and rip classical-music CDs that come with two or more multiple-movement works like concerti, quartets or sonatas on them.

Making Cloud-Based File-Share Solutions Work With Your DLNA-capable NAS – How you could use a DLNA-capable NAS to show content held on selected folders in Dropbox or similar services on your DLNA-capable media players. This is important when you, for example, use these services as a media pool for special occasions.

General Articles

Why do I buy and rip CDs for my online music library – An article that allows you to justify your position in buying your music on CD in this day and age of file-based audio, Spotify and “back to vinyl”. This includes “ripping” your CDs to a NAS or your computer’s hard disk for an online music library.

FLAC–now the audio filetype for archival use

Naim NDS network audio player

This high-end Naim NDS network audio player is an example of equipment that can handle the lossless FLAC file type

If you work with audio content, whether to “rip” CDs to the hard disk or home network, or record speech or music content for audio projects, you may have been dealing with various compressed filetypes like MP3 or AAC as your main recording format.

But most of these filetypes work on a lossy principle where data is effectively lost and when the file is played back, the software reconstitutes that file to make it something to listen to. Now an open-source file format has been released to allow for lossless compression of audio content.

This recently-issued format, known as FLAC or Free Lossless Audio Codec, has answered many audio technicians’ prayers because the sound is encoded in a manner as to prevent the loss of audio content through recording or playback. This is in a similar manner to how a ZIP or RAR “file-of-files” is prepared in order to conserve disk space or bandwidth. You still have the advantage of a compressed file not taking up too much storage space or transmission bandwidth. Being an open-source free codec, it means that audio applications can implement this codec without the need to pay royalties to particular organisations and there are very few other encumbrances on that codec.

FLAC re-rip of CD

FLAC – a better archival format

One of the best analogies that I came across for using FLAC in the audio-archival context is that it is like if you are a wine collector and you purchase a premium wine-cellar to keep your collection. Here, the wine-cellar is keeping the wine collection at an ideal temperature and humidity for long-term storage. But when you want to serve that drop at the dinner party, you have the bottle sitting on the sideboard and resting until it is at the ideal serving temperature.

Previously this required a user to download and install a FLAC codec on their computer to be able to record, play or edit these files. Then the Linux and Android operating systems had native support for this filetype built in to tie operating system and various audio applications provided application-level support for working with these files. Similarly, high-end sound cards and USB DACs furnished this codec as part of their software. Now Windows 10 has provided native support for FLAC files including ripping CDs to these files.

How can I use FLAC in my audio workflow

Creating your digital-audio content

If you use a computer or a file-based digital-audio recorder (including some digital mixers) to record audio content, make sure that you record as a PCM form like a WAV or AIFF file; or as a FLAC file. You may find that some equipment like a lot of the digital mixers with integrated USB recording abilities may only work with USB hard disks or solid-state drives that use high-speed data transfer if you have them record to WAV or similar files.

Then you use an audio editor like Audacity, NCH WavePad, or Rogue Amoeba’s Fission; or an audio converter program like NCH Switch, dbPowerAmp or Foobar2000 to convert the WAV or AIFF file in to a FLAC file. You may find that some video converters may offer audio-to-audio conversion for the FLAC file.

dbPoweramp Music Converter - one of the audio converters worth using out there

dbPoweramp Music Converter – one of the audio converters worth using out there

You could do this to your audio file once you have that file in “master-ready” condition – you have edited it and applied any audio transformations to that file to get it sounding right and it is ready to distribute. On the other hand, you could also create a “raw” FLAC file from the WAV or AIFF you have recorded before you perform any of the editing and audio transformation work. In this situation, you then use this “raw” file as your reference file if you needed to approach the editing in another way.

Even if you are salvaging audio content from legacy media like LPs, open-reel tapes or cassettes, you can still use FLAC as your audio filetype for these efforts. Here, you can use theses FLAC files simply as the digital archive for this media.

As you create or edit a FLAC file, you can add metadata about the content you recorded to that file and, like with MP3 files, that data which describes the song title, performer, genre, album and other attributes stays with that file. This will work properly with smartphones or media players that play these files; along with DLNA media servers that distribute these files across small networks – these servers can index them and have them found according to the metadata that describes the content.

Distributing your FLAC-based audio content

When you distribute your content, you can then use the FLAC file as your source file – you could simply copy that file if you are targeting newer FLAC-compatible  “open-frame” equipment like Android or Windows 10 smartphones or Windows computers, or convert to MP3, AAC or Apple Lossless for Apple and other equipment that doesn’t support FLAC. Similarly, most current-issue DLNA-capable NAS units can work from FLAC files especially if you have FLAC-capable playback equipment on the network.

The FLAC file is also useful as a “master” audio file if you are creating an Audio CD because it is a compressed audio file that has has the same audio qualities as a PCM WAV or AIFF file. Similarly, you may have to convert the FLAC to a WAV or AIFF if you are importing it in to a video editing program for use as part of your video project’s soundtrack.

Conclusion

Once you use FLAC as your main file type for audio recording and editing or simply convert legacy audio files to FLAC, you are then ending up with a digital-audio file that can be used as an archival or distribution-master form.

Using audio-editor software to salvage legacy media

Linn Sondek LP12

You may want to get those old familiar records on to your computer to play on your home network

A task that you will want to do is to record content held on vinyl, cassettes and other legacy media to your computer. This may be to copy it to a CD or have as audio files that you can play on a computer, mobile device or through your home network. It is a task you will end up doing either for family-memory recordings or recorded material where there isn’t a chance of it being reissued on modern audio formats.

What do you need?

Here, you will need to use an audio-interface device such as a sound card or sound module to connect the turntable or tape player to the computer; along with an audio-editing program which records the sound and allows you to edit these recordings.

Creative Labs Sound Blaster Digital Music Premium USB sound module press image courtesy of Creative Labs

Creative Labs Sound Blaster Digital Music Premium USB sound module – useful for copying old media to your home network

Audio-interface devices need to be equipped with line-level input connections so you can connect them to an amplifier’s tape-recorder connections or to a source device like a tape deck that has these kind of connections. On the device’s side you will typically have a 3.5mm stereo audio phone jack that is typically highlighted in green or marked LINE IN or some better sound modules may be equipped with a pair of RCA sockets that are similarly marked.

If you are using a laptop computer, an “all-in-one” computer or a small desktop computer, it is a good idea to purchase a sound module that connects via USB, Thunderbolt or similar connectivity technology and use that as your audio-interface device because most of these computers don’t implement line-level input connections on their integrated sound hardware. Similarly, a dedicated sound card may work wonders for sound quality and computer stability if you are using a traditional desktop computer that can be outfitted with standard expansion cards.

Audacity audio-editor software recording

Audacity – a typical and common audio-editor program

One common software tool is the open-source Audacity program which is highly capable advanced tool but may take a bit of time learning. On the other hand, there is NCH’s Wavepad which comes across as a “free-for-personal-use” program for basic tasks or you can buy a fully-function program for under $100. This one does provide an interface that you can easily get a grip of for most editing tasks. It is also worth noting that you may have ended up with an audio-editor program if you bought an audio-interface device for your computer like a USB sound module; or it may have been bundled with a comprehensive multimedia package or perhaps your computer.

How do I go about this?

Create a software monitor path using your audio-editing software

Here, you create a “confidence monitoring” path to be sure that the sound that you want to record is getting from the source device to the software. This can be useful if you want to hear the source coming through that software or as a troubleshooting tool.

Audacity - audio inputs

Audio inputs on Audacity

Select the “recording device” or “source input” that your source device or amplifier is connected to directly on the audio-editor software. Typically this refers to the actual jack on the sound-card or sound-module that your source device is connected to. Then you select the “playback output” or “playback device” directly on audio-editor software if the software allows you to do so.

Audacity - audio outputs

Audacity – audio outputs

If you use a hi-fi amplifier with a “tape-monitor” switch, connect the sound module’s audio input and output to the amplifier’s tape input and output connections. Then you select the source you want to record using the input selector and enable the tape-monitor function on the amplifier if you want the monitoring ability.

Some highly-sophisticated amplifiers have the ability to select which audio source is recorded by a connected tape deck such as through a “record select” switch, or there are amplifiers and receivers that have two tape loops but have a “dubbing” switch that determines how the sound flows between those connections. In the former situation, you may have to set the “record select” switch to the appropriate input and in the latter situation, you may have to select “Source” on the tape-dubbing switch unless you are recording from a tape deck connected to the other tape loop, where you would select that recording device using the tape-dubbing switch.

For the software, you would have to select the sound-module audio input connected to the tape output as the recording device and the sound-module audio output connected to the amp’s tape input as the playback device. Then you would have to enable software monitoring, also known as “software playthrough” in the audio-editing software to verify that the sound is coming through. On the other hand, modern Windows operating systems have the “Listen” tab in the Recording Devices Properties dialog box to allow you to “listen” to the source through your computer’s default audio-output device or an audio output device of your choosing, again useful for verifying your setup.

Setting recording level and parameters

Most of the software will have a level meter but this may require you to enable a “monitor” function on the software to see the meter in action. It is also the time where you can troubleshoot any connection problems.

VU meters on Philips DCC-900 in play mode

VU meters that indicate playback output level

If you are playing a a recording on a playback device equipped with VU meters that show the output level during play, check these meters for audio output coming from that recording. As well, if the equipment uses an adjustable level for its line-level outputs, adjust this control to at least 75% or 80% of its maximum level. Then you use the software’s level meters to determine the recording level, making sure you allow a bit of headroom on the meters. On the other hand, you may try adjusting the software’s recording level to maximum and winding back the source equipment’s output-level control to achieve the right signal level if the source equipment is connected directly to the audio-capture device.

As well, you set the digital-recording parameters to 16 bit quantisation and 44.1 kHz sampling rate for all legacy recording media if you use an analogue signal path. Also set up the recording parameters to record in stereo unless the recording was recording from a mono source or recorded with mono equipment, whereupon you set the parameters for mono recording. Using 44.1 kHz sampling rate works properly for burning to CD, or you could use 48 kHz if you are working towards using the material in a video project, but you can use either

You may find that using one of the audio filter functions on your amplifier like a “subsonic filter” may come in handy when recording vinyl for example. Similarly, using the Dolby noise-reduction function on your cassette deck may benefit the transfer process for a suitably-recorded tape.

Assuring proper computer performance

It may be a good idea to make sure that as few applications and tasks are running on your computer before you commence recording. This is because you need to dedicate your computer’s processor and RAM resources to the recording task and make sure that it will record reliably and properly.

This may involve closing email clients, games, office applications and Web sessions before you commence the recording session. Then, while you are recording, you make sure you aren’t using any other app on the computer that is doing the recording.

For laptops, it may be better to have them connected to AC power so that the recording session isn’t destroyed due to the battery dying. Sometimes, you may have to set your computer’s power-usage behaviour to “full-on” or “high-performance” for your recording job so that it doesn’t go to sleep during recording.

Recording

When you are ready to record, start the software recording then start your legacy media playing. Once the recording is complete, make sure that you save the sound file or project depending on the software so you don’t lose the recorded sound.

Use your turntable's cueing lever or button to lower the arm when you start playing that record

Use your turntable’s cueing lever or button to lower the arm when you start playing that record

If you are recording from vinyl using a manual or semi-automatic turntable, use the cueing function if it has one to lower the stylus to the record rather than actually lifting the arm on. It is typically represented by a lever at or near the arm’s pivot or some turntables have a button on the front of the base or near the front edge. This will protect the stylus from being chipped and avoids unnecessary loud clicks.

What you will end up with is a large WAV or AIFF uncompressed PCM file for the whole recording or a side of the recording if you record different files for each side or program.

Changing the media during recording

If you have to attend to the medium such as to change sides on a record or tape, you could pause the software’s recording function before you turn the record or tape over. This has all of the album recorded as one file and may be found to reduce glitches.

On the other hand, you may want to stop and save the recording before you attend to the medium then start recording the other side to a new file. This can work well with most studio recordings which are centred around individual tracks or where each side represents a logical part in the recording.

Some audio-editing programs support a silence-based automatic pause or stop function so as to have the recording stop when the source material hits the end of the side.

Editing

Most such software offers the ability to edit a recording that you have made. This can range from simple “cut-and-splice” editing such as to split a recording in to multiple files, combine two recordings in to one recording or remove unwanted noise from a recording.  Anyone who has worked with open-reel tapes or MiniDisc will be familiar with these editing techniques. Your first recording will be a time to become familiar with how your software implements these editing techniques and the way you perform them.

Audacity and some other audio-editing tools allow you also to “mark up” a recording file with index markers kept as a separate file or as part of a logical “project” file. This may be used to facilitate exporting of the file as individual tracks, but allow you to use the effects to adjust the sound across the whole of the audio recording. On the other hand, you may use the cut-and-splice editing techniques to break up the audio files in to individual tracks.

These audio-editor programs also offer the ability to adjust the sound of the recordings courtesy of built-in “effects” or audio-processing routines. There are the elementary effects like equalisation (tone adjustment) or dynamic-range compression but a lot of the programs offer routines geared towards this activity like audio-level normalising, noise-removal and speed adjustment (handy for tapes that have been recorded on portable equipment with half-dead batteries, using a turntable that is only capable of working at 33rpm and 45rpm to work with 78s or salvaging open-reel tapes recorded at speeds not supported by the deck you are playing them on).

A good practice is to save your recording when you get your editing perfect. Sometimes you may want to save the recording as a copy if you are trying an edit or effect out so you don’t ruin your original recording or a successful edit or effect treatment. This may be an important practice as you become familiar with your editing software and will be of value if you are trying to “bring out” poorly-recorded material like cassette recordings made using portable recorders with their integrated microphones.

Editing techniques for legacy media transfer

A good editing technique would be to trim off silence at the start and end of the whole recording and excess silence that has existed between sides or programs of that recording.  For example, some recordings especially those that are on a tape have a longer silent period before the end of the side to preserve a logical program break but have extra space available on the medium for that side.

You could also be removing unnecessary clicks and pops, especially those that are loud and are typically of equipment being started or stopped.

As well, you use the normalising function to bring the tracks’ peak volumes louder but preserve any dynamic range that exists in the recordings. You may have to set up channel-independent normalisation if you have recorded form most consumer-focused equipment because there is a tendency to make one of the stereo channels stronger than the other.

Similarly, the amplify function can come in handy for those recordings that have come through very weak but this is simply about multiplying the volume in that recording and can lead to clipping and distortion if you aren’t careful.

Various filter and equalisation function can be of use to remove unwanted noise such as tape hiss or vinyl rumble. Here, you may have to save a “reference” version of your file and toy around with these filters if you are trying to remove the noise.

Exporting

Most audio-editing software allows you to export the audio content in to different file formats like MP3, FLAC, WMA or AAC compressed forms or a WAV or AIFF uncompressed form. Some of the programs even allow you to “burn” an audio CD from the files you create thanks to an integral CD-burning software engine.

If you use another program to burn audio CDs, make sure that you export your audio content to WAV or AIFF uncompressed PCM files with one file per track. These are the best-quality audio files you can work with when you are targeting these CDs.

Most exporting procedures also allow you to add metadata to CDs as CD-Text data or to files as integral ID3 data. Here, fill in as much metadata as you can about the recording and assign genres particular to the recording’s content. It is important when you copy the files to your DLNA media server or smartphone, or make use of CD-Text when you burn CDs.

Then, you can get away with exporting your legacy-media salvage effort to FLAC files which are a lossless file being handled by most good-quality audio equipment. Similarly, you could export the recording to a 320kbps MP3 file if you want widest compatibility with older MP3-playing equipment.

Conclusion

Once you use a suitably-capable audio interface device connected to your hi-fi equipment along with audio-editing software, you can use your computer as a tool for recording LPs that won’t ever be released anymore or salvaging family memories thus having them on your home network.

Microsoft researches a way to consolidate recordings from multiple recording devices

Article – From the horse’s mouth

Microsoft Research

Abstract

Detailed article – PDF

My Comments

Sports scoreboard app

Microsoft is working on a way to create better recordings from many smartphones and audio recorders recording the same event

Microsoft has completed some research on how to amalgamate audio recordings of a meeting that were captured by different recording devices to turn out a higher-grade recording that captures the whole of a meeting. It is seen as being the audio equivalent of experiments and projects that aggregate multiple camera views of the same object, or could be seen as a way to create a “Claytons microphone array” using multiple recording devices with their own microphones.

The technique involves the creation of audio fingerprints of each of the recordings in a similar vein to what Shazam and its allies do to “name that song”. But these fingerprints are used to match the timing of each of the recordings to identify what was commonly recorded, allowing for the fact that one could start or stop a recording device earlier or later than another person.

This can lead to TV-grade multi-camera video recordings from a combination of DSLRs, high-end cameras and camcorders used by different users

This can lead to TV-grade multi-camera video recordings from a combination of DSLRs, high-end cameras like this one…

The technology that is assumed to be used in this context are standalone file-based digital notetaker recorders or the audio-recording function incorporated in many a smartphone or tablet typically by virtue of an app. Typically these recorders are recording the same event with integrated microphones and implementing automatic gain control and, in some cases, picking up their “own” background noise.

But you could extend this concept to integrating audio recordings made on legacy media like audio tape using standalone devices, or the soundtracks of video recordings recorded during the same event but are subsequently “dubbed” to audio files to be used in the recording. A good example could be someone who uses a “shoebox” or handheld cassette recorder to make a reliable recording of the meeting using something they are familiar with; or someone videoing the meeting using that trusty old camcorder.

Sony FRD-AX33 4K HandyCam camcorder press picture courtesy of Sony America

… and camcorders like this one of special events.

There are plans to create further research in to this topic to cater for recording music such as when the same concert performance or religious service is recorded by two or more people with equipment of different capabilities.

A good question to raise from the research is how to “time-align” or synchronise a combination of audio and video recordings of the same event that were recorded at the same time with equipment that has different recording capabilities. This is without the need to record synchronisation data on each recording device during production, and allowing for the use of equipment commonly used by consumers, hobbyists / prosumers and small organisations.

The reality that can surface is someone records the event using top-shelf gear yielding excellent audio while others film from different angles using camcorders, digital cameras and smartphones that record not-so-good sound thanks to automatic gain control and average integrated mics, while the good digital cameras and camcorders still implement their excellent optics and sensors to capture good-quality vision.

Once this is worked out, it could then allow a small-time video producer or a business’s or church’s inhouse video team to move towards “big-time” quality by using top-shelf audio gear to catch sound and the use of one or two camcorders operated by different operators to create “TV-studio-grade” multi-camera video.

Who knows whether the idea of post-production audio-level synchronising and “blending” for both conference recordings and small-time video producers.