Gamer's Guide to 3D sound and reverb APIs

Mikael Hagén and Mark Muschett - Last updated January 8, 2002

IAS

IAS stands for Interactive Around-Sound and is developed by Extreme Audio Reality. It was quite sometime since the last game using IAS shipped and in most cases the IAS has been an unofficial patch for the game, the most famous being for Quake2.

Games using IAS are unlike the other APIs not using your soundcards 3D sound engine but instead Extreme Audio Reality’s 3D sound engine which, in the case of 2-speakers, is just stereo panning. For 4-speaker soundcards they have instead developed specific IAS components that will take advantage of the rear speakers. As far as I know 4-speaker IAS components are only available for Diamond’s Monstersound cards, Vortex2 cards and the Live. IAS is also only working in Win9x/ME not Windows XP/2000.

As mentioned it was sometime ago since we saw any new game using IAS or IAS components for new soundcards, but EAR’s website was recently updated with info saying they will soon release new IAS components that will work in Windows XP/2000. They also say they hope to create a solution that will work with all games “even if they weren't authored with the IAS audio engine” and most recently there was an announcement that they and Advent Innovations have entered into a partnership agreement for the purpose of licensing the IAS solutions to the various computer game audio industry designers, programmers and users. Advent Innovation’s role in the partnership will be to monetize EAR’s intellectual property patents via licensing agreements and other business transactions with various industry users. For more details you can check out the full press release.

You can download the IAS components and patches for Battlezone and Quake II from EAR’s website. 

ZoomFX

ZoomFX is an extension to DirectSound 3D that allows developers specify the volume of the sound source. The only cards that support it are cards which includes later versions of Sensaura’s engine. The one we know for certain already offer this is CS4630/CS4624 based cards and SoundMax 3.0. VXD drivers for the CS4630 (GameTheater XP, SonicFury and Santa Cruz) and CS4624 (Terratec’s DMX Xfire and Hoontech's SoundTrack Digital CS) and recent WDM drivers for ADI SoundMAX. Future drivers for other Sensaura based cards will most likely also offer support for ZoomFX. We currently only know of one game that supports ZoomFX (Hasbro’s Pacman - Adventures in time) and one upcoming game (Rage Software’s Incoming Forces). For more details about ZoomFX check out our Sensaura article.

RSX

A software 3D engine that was developed by Intel. RAD Games tools later bought the technology and included it in its SDK Miles Sound Systems. Games that use Miles Sound System and take advantage of 3D sound often let the gamers that don’t have a soundcard which supports DS3D or A3D 1.0 choose between selecting RSX or Microsoft’s DS3D engine.

QSound’s QMixer

QMixer allow game developers to use QSound’s 3D sound technology on any soundcard. If it detects that the soundcard supports DS3D it will instead take advantage of the 3D sound engine of your soundcard.

Dolby Digital, DTS, Dolby Pro Logic II and Dolby Pro Logic/Surround

Long before games started to use 3D sound movies featured multichannel soundtracks using Dolby Surround/Pro Logic and later also Dolby Digital and DTS. Games using Dolby Surround/Pro Logic also appeared before the first A3D games were available. It’s quite clear that an A3D or DS3D game when played back on a 4-speaker system has a clear advantage over Dolby Surround/Pro Logic since you then have full frequency stereo surround channels compared to the Dolby Surround/Pro Logic format which use a frequency limited (100Hz to 7000 Hz) mono surround channel. Many realized this but then wondered why not use Dolby Digital or DTS for games instead of this new A3D or DS3D APIs. What they then miss is that Dolby Digital and DTS is not really a competitor to 3D sound APIs but rather another multi-channel compressed music format. That is a competitor to other forms of compressed audio (e.g. MP3).

When it comes to interactive games that claim  support for Dolby Surround/Pro Logic and especially Dolby Digital and DTS you should know that most are still just featuring a pre-rendered Dolby Pro Logic/Digital or DTS encoded soundtrack as part of a movie clip or in some cases the music is in Dolby Surround/Pro Logic (and perhaps in the future we will see music soundtracks in Dolby Digital and other multi-channel formats).

Having said that we recently started to see more console games featuring interactive use of one of the above formats but this is just another way to output the multi-channel sound than the in the PC market more common form of a front and rear stereo jack on your soundcard. The two most well known products doing this is MS Xbox and nVidia’s nForce which use the Dolby Digital 5.1 format to take advantage of the surround channels of your speaker system for any game that supports DS3D. This is not offering any better quality or positioning than if it used 3 separate stereo jacks on your soundcard it’s just a more convenient way to output it for those that have Dolby Digital receivers (common in living rooms which is the Xbox primary target). This is also why it has been more common on console games to use Dolby Pro Logic/Surround for interactive multi-channel gaming than on PCs. For more details about the advantage and disadvantage of using Dolby Pro Logic, Dolby Digital, DTS and even the new Dolby Pro Logic II read “A Gamer’s Guide to Interactive Multi-Channel Audio” (not availabe yet).

Related Information:

• A Gamer's Guide to 3D Sound and Reverb Engines - January 8, 2002
• QSound vs Aureal Debate - June 22 to July 8, 98
• A Gamer's Guide to Direct Sound 3D and A3D 1.x - April 4, 1999
• A Gamer's Guide to EAX - October 14, 1999
• QSound 3D Audio - May 4, 1999
• Sensaura 3D Audio - February 5, 1999
• Audigy Tour Report - September 1, 2001
• Philips European Press Event Report - November 14, 2001
• Visit to the Creative EMU Technology Center - April 28, 1999
• Sensaura Site Visit - February 20, 1999

Have comments or questions on this feature?
Why not post them in our forum?

All content, design and work is © 2001 - 3D Sound Surge Please respect the copyrights of the articles and writers herein. All copyrights are enforced by 3DSS.  
View the 3DsoundSurge Privacy Statement