Digital Audio Recording – Choose Your Devices Carefully

Author Dragan Berak 20.9.2007. | 17:41

Recording Digital Audio – Considering Your Options and Choosing Products

 

Remember when dictaphones and answerphones had mini cassettes, and you recorded radio onto your tape deck? Thanks to advances in technology, it is now easier to record audio, in higher quality, more portably, in shareable file formats, with cheaper devices, for longer periods of recording time.

 

Benefits of Recording Digitally

  • Digital recording devices typically have few or no moving parts, eliminating machine hiss and other noise.
  • Easy choice of compression, so you can store huge amounts of audio on small, portable recording media.
  • Digital recording devices, due to the lack of moving parts, are typically smaller and more durable than tape recorders, and have lower power consumption.
  • Digitally recorded audio in standard formats is easy to edit, share, store, manage, search, and overwrite – especially when working with computers.
  • Digital recordings can be stored on a wide range of digital media, giving you better options for backup and long term data fidelity.

 

 

Considering Quality

When you are considering different electronics to record sound digitally, you need to start by deciding what audio quality you require:

  • Mono, compressed audio: good for storing voicemail, voice memos, or informal recordings.
  • Stereo, less compressed audio: good for shared audio such as podcasts and records of speeches.
  • High quality lossless audio: suitable for music recordings or recording "clean" tracks for mixing later.

If you want to record audio to go along with video, e.g. the soundtrack for a movie you’re shooting, it’s advisable to use specialist equipment to make sure your audio channels are synched with the video stream.

 

Audio Quality

Apart from the recording device, and recording medium  / storage format, there are two main factors affecting the quality of your recorded audio:

1) The quality of the sound signal recorded in the first place. Obviously a recording in a padded room in a studio is going to sound much better from the very beginning, than something you shot on a windy day by a busy road.

2) The quality of the microphone and its connection to the audio device. You can buy a cheap karaoke microphone for under $20, but professional studio mics go into the thousand dollar range, so when it comes to getting higher quality sound pickup, you get what you pay for. Professional sound recording is a highly technical profession, so beware of asking sound engineers open ended questions.

A microphone is of course just an audio input device, from the point of view of the recording device. Digital recorders that can record from an external microphone will also accept line-in audio recording from any audio device. You could record radio, record from an electric musical instrument, or input sound data from a computer or even a telephone.

 

How Long Is A Piece Of Audio?

  •  Digital audio can be stored in any number of different formats. Most formats involve some kind of data compression.
  • Most formats have different "minutes per kilobyte" if you change the sampling rate, compression ratio, and number of channels (e.g. stereo or not)
  • With 1GB of storage space you can comfortably record over 4 hours of audio at very acceptable quality. The same amount of storage could hold only half an hour of the best studio quality audio, or over 10 hours of phone-quality audio.

 

 

 

Considering Devices

Let’s take a look at some of the latest Made in China gadgets that will help you with your digital recording needs, and assess what applications they would be useful for.

 

Device Recording Method Application
Flash-based personal media player.

E.g.

Chinavasion Music Lovers Edition MP4 Player
[click to check out live prices]

 

Recording is via a small built-in microphone. Recording is in mono, and stored in either WAV or VOX format in variable compression on the player’s flash memory storage.

Suitable for informal voice recording. Microphone will only pick up close speaking or loud noises.

 

Device Recording Method Application
Flash-based personal media player with line-in recording.

E.g.

Chinavasion Special Recording RF MP3 Watch
[click to check out live prices]

 

Recording is via audio jack line-in. A converting cable (2.5mm long format male – to – 3.5mm male) is provided allowing you to connect the device to an audio output on, say, a radio or computer. With the right cable converter, this could also be used with an external microphone.

Highly portable recording gadget. Suitable for ad-hoc and even covert recording. Lack of visual interface means reviewing recordings on the device will be difficult. Suitable for recording higher quality audio using a good microphone.

 

Device Recording Method Application
Standalone Personal Digital Recorder

E.g.

Chinavasion Spy Telephone Recorder
[click to check out live prices]

Recording is via audio jack line-in meaning you can record from a microphone, audio line output, or telephone using the supplied adapter. Storage is in WAV (higher quality, bigger filesize) or ACT (much more compressed). For basic voice recording this also features a built-in microphone.

Click to see more recording pens from Chinavasion.

Basic LCD readout and built-in speaker makes review of recordings quite easy with this device. Versatile, portable, and easy to change the batteries, which is an advantage ‘in the field’, compared to the watch and mp4 player above, which require recharging of the internal batteries from a computer or power outlet. Audio recording quality could be quite high provided the input is good, so this could be used for higher-end recording situations. The only drawback is that it only features 128MB of storage, non-expandable.

 

 

Device Recording Method Application
HDD Enclosure Media Player with Recording Function

E.g.

Chinavasion Video Recorder HDD Media Player
[click to check out live prices]

 

An HDD Media player is basically an enclosure for a standard formatted PC IDE hard disk – the same you use in your computer. This means enormous storage space, and because it’s not inside a computer, you can take it anywhere and plug it into your TV or any other monitor to watch your videos or review photos.

With this particular model, you can record video to the hard disk directly from an analog video input. The video clips are stored in AVI format. Video is recorded via RCA AV-in cable (that Red, White, Yellow connector you use for your TV) and where there’s video, there’s audio.

Click to see more HDD Media Players / Recorders from Chinavasion

An HDD media player requires an external power source. That is going to limit your roam-ability, but if that is not important, recording direct to mobile HDD means enormous storage. And enormous storage means you can go wild with audio quality.

The drawback of this method is that most microphones will not give you an RCA output, meaning some fiddling with converters. And of course this article is about recording audio only, so to get just the audio you’ll need to strip it out of the video data file using video editing software.

The MP4 Player below also features AV line-in recording so could be used as a more portable solution to recording higher quality audio with or without video:


AV Recording Wireless Receiver MP4 Player

 

 

Device Recording Method Application
Bluetooth To Wired Audio Adapter

E.g.

Chinavasion Stereo Bridge For Bluetooth Devices
[click to check out live prices]

 

This new gadget is a receiver for Bluetooth audio signals, which relays the signal to a standard (RCA or audio jack) wired audio signal. This means you can use better speakers for audio signals from, say, a bluetooth mobile phone.

 

The reason for including this here is that if you need a solution for recording wirelessly, or for recording mobile phone conversations, you can pair this with a compatible Bluetooth microphone, earpiece, or mobile phone, and use your normal digital recording equipment (as above, or a computer) to record in fairly good quality.

 

 

Device Recording Method Application
Spy Cameras with Audio

E.g.

Chinavasion Wireless Mini Spy Camera with Audio
[click to check out live prices]

A discussion of audio recording would not be complete without dipping into the realms of surveillance. Whilst this is not exactly an invisible bug, it is a discreet mini security camera, transmitting color video and audio wirelessly to a remote receiver.

If you want a way to record the video and audio of day to day events, from a fixed vantage point (indoors), then this is a cheap and unobtrusive way of doing it. However this is just an AV pickup device and you will need a DVR solution for actually monitoring, recording, and storing the video and audio!

 

 

More Ideas

One other solution for recording audio is, paradoxically, to record video.
Many camcorders have excellent quality built-in, directional microphones and you will find that for portability, battery life, ease of use, and sound quality, they are hard to beat.
In addition, most digital camcorders incorporate a voice-record-only function too.

Click to check out some Chinese Digital Camcorders

 

For a little audio novelty, check out this distance-listening device:

Chinavasion Spy Listening Device

 

 

 

Conclusion

Before purchasing kit for recording audio, "Begin with the end in mind". Ask yourself these key questions:

  1. What quality do I need the audio in?
  2. How many hours of audio am I going to record in one session?
  3. What is my budget?
  4. Do I need my recording kit to be portable? (Do I need the equipment to be discreet?)
  5. In what situations will I be recording? (What special aspects, e.g. for the mic, power, weatherproofing – will be required?)
  6. What kind of microphone will I be using?
  7. Where/how am I going to be storing and editing the audio? (What is the easiest way to transfer my audio to my storage or editing equipment? What starting format is going to make it easiest to store and edit the audio? )
  8. What solutions have I tried in the past, that were not good enough, and how will my new hardware overcome these problems?

This article is from original advice courtesy of the Customer Support Department of Chinavasion Wholesale Ltd. – http://www.chinavasion.com – You may redistribute this article online provided the text and "follow" links are left intact.

Author Dragan Berak 20.9.2007. | 17:41
Write a comment

1 Comment

  1. matthias j gautreaux October 21, 21:46

    I need a portable recorder that I can use to record my voice, record through a board (XlR, or the usual input, what is it called 8″ ??)…

    and I need this recorder to be able to record my songs live.

    Meaning, record me & my acoustic guitar. (So maybe this recorder should have a mic input , or at least have a built in recorder that can p/up a deceint sound of my live songs (i.e. Me singing & my acoustic guitar).

    What should I do? Get a mini disc recorder or a recorder that I can plug into my computer (USB ,etc) ??

    I also need to stay in the 100.00 – 150.00 $$ range. please help.
    kind regards, Matthias

View comments

Write a comment

Leave a Reply

Watch latest gadget videos

Chinavasion Video


action cam

Add Chinavasion on Google+

Add Chinavasion on Facebook

Archive