Game Audio Recording

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The following are details of the history of game audio recordings conducted by Yog-Sothoth.com from 2003 to the present.

The original recordings used the following setup.


Original Recording Equipment

Sony Portable MiniDisc recorder

Sony ECM F-8 microphone

Minijack cable to link MiniDisc to computer sound card

Computer

Audio software: Cool Edit Pro


Method I

The recorder and the mic would be placed in the middle of the table, raised up and insulated a little from inevitable table movements (e.g. in the case of the CoC recording for The Haunting the equipment was placed on top of a handy copy of a Call of Cthulhu 20th Anniversary edition rulebook). The MiniDisc recorder (Sony MZR 91) would be set to record mono to give twice the normal recording time.

The recording would then be transferred as an analogue source digitised into the computer as a mono 128 KBPS 44MHz 32 bit sound file, with input levels adjusted through software so the audio 'highs' didn't top out the digital recording levels (>0 dB).

The raw source would be saved as a mono 128 KBPS 44 MHz 16 bit sound file which is sufficient for later MP3 re-editing of voice-only audio.

If the input recording level is too low the waveforms would be normalised to 90%. Little can be done where the input source was too high as the missing digital data cannot be recovered.

The final waveform would be saved as low bit rate MP3 for audio streaming using the MP3pro standard at the lowest setting (32 KBPS, 22 KHz). MP3Pro files still sound normal through any MP3 player, but those that can decode the additional frequencies encoded in MP3Pro will hear much superior audio quality (essentially 32 KPBS 44 KHz).

A 32 KBPS file should be streamable over most dial-up (56K) connections (as long as the listener is not doing too much else).

Lessons learned from recordings:

1) Place your mic on a good insulator e.g. a sponge foam block. This will insulate from shocks that can be picked up loudly by the mic, and then...

2) Once you're recording, don't move the mic!

3) Recording to a laptop is more efficient by way of length of available recording time and direct digitization.

4) Make sure your laptop is plugged into a power socket and that energy saving is off.

4) Put the loud people further away from the mic, and the quieter people nearer. Also make sure the mic is near the GM (i.e. softly spoken people should sit near the GM).

5) Try to get a sample of recording levels from your players before starting the recording so you can set a suitable input level.

Most people were no more than 2-3 feet away from the mic, but the Sony ECM F-8 is good at picking up noise from a distance as well. Hence the background hub-bub heard in many of the field recordings.

Older portable MiniDisc recorders can be picked up pretty cheaply on eBay. Audio minijack connection cable c. £2 (UK). The microphone ECM boundary mic about £20 (UK), computer and software - as necessary (some good shareware and trial programs available). It's always worth testing a mic to make sure it works with your equipment.

Audio can be compressed as far down as 24 KBPS/22 KHz and still produce acceptable results, as long as the original audio source is of sufficient quality.

Newer Recording Equipment

iRiver iFP 790 MP3 Player/Recorder

Computer

Audio software: Adobe Audition


Method II

In the case of the World's Largest Dungeon recordings they were recorded direct to the iRiver which is suspended from above the table on the Dining room light fitting. The recording rate set at 64KBPS/44KHz mono MP3 (Auto Gain Control off), which means several hours of audio in one sitting, a single AA rechargable battery can lasting up to 20 hours.

Files are transferred directly from the iRiver to computer via a USB 2 link. A sample of the ambient background 'room noise' was recorded and subtracted from the rest of the audio for increased clarity. The resultant waveform then normalised to 90% and saved as before as an MP3Pro file at 32KBPS/22(44)KHz.

Newer Recording Equipment

Marantz PMD 670

Audio Technica AT841A Boundary Mic

Audio software: Adobe Audition

Method III

The Boundary mic is placed in the centre of the table connected by an XLR cable to the PMD 670 (portable digital audio recorder) located a little distance away. The sensitivity of the mic is such that low recording levels can be used which helps eliminate digital blow-outs with loud sounds such as laughing or screaming. Due to the typical length of recording (2-3 hours) the recording format set as 128KBPS 44KHz mono MP3. Which allows sufficient storage on the Compact Flash memory card.

The resultant file is processed with Adobe Audition using a similar methodology to that described above with background noise reduction as well as DC offset correction, an 80Hz low cut, a compression filter and final normalisation to -0.2dB.

The waveform is saved as a 48KBPS/44KHz MP3 file for general online distribution, along with 64KBPS Masters for archive.

Examples of these types of files can be found on YSDC and also under the Wiki entry for Masks of Nyarlathotep Game Audio Recording.