Aureal’s A3D

Aureal’s A3D engine is probably still the most well known 3D sound engine. In the early days of 3D sound in the PC market it was available for licensing by any chip maker but Aureal later decided to only offer it as part of their Vortex 1 (AU8820), Vortex 2 (AU8830) and Vortex Advantage (AU8810) chips. The most famous non Vortex card using the Aureal A3D engine is Diamond’s original Monstersound card.

The A3D engine that was used by the original Monstersound card offered 3D sound using HRTF for 2-speakers and headphones with the 4-speaker solution only using 4-speaker panning with no HRTFs. When Aureal introduced the Vortex2 they also introduced a slightly improved 3D sound engine with the most important addition being HRTFs for the front speakers even when using 4-speakers. The rear was still just panning. This 3D sound engine can be accessed through DS3D and all versions of A3D. Cards using the A3D engine lack support for ZooomFX (for details see our API article) just like all other non Sensaura cards. However a similar feature is part of A3D 3.0 (again for details see our API article).

The early versions of the A3D engine had no reverb but the last VXD (Win9x/ME) driver release for the Vortex2 cards added a reverb engine including support for EAX 1.0, I3DL2 and the reverb part of A3D 3.0. It lacks support for both EAX 2.0 and EAX Advanced HD. Turtle Beach drivers for its Vortex2 series even lack EAX 1.0/I3DL2 support. If you use the Aureal reference drivers on Turtle Beach’s 4 speaker Vortex 2 boards you won’t be able to use the rear speakers or the S/PDIF in/out.

The 3D positioning offered by the A3D engine is excellent both for 2-speaker and headphones. We still think it’s the best 3D sound for headphones while the 2-speaker solution is about on par with Sensaura’s. The 4-speaker solution offered with the Vortex2 cards is also very good even though we consider it slightly behind the competition. The older version offered by the original Monstersound is a bit further behind but again still quite good, definitely delivering better front-rear positioning than using the 2-speaker algorithms.

When it comes to reverb the quality is very good when it works, almost on par with the Live to our ears. You’ll also have the option to tweak the strength, which is very nice. Unfortunately the consistency is not very good with several EAX 1.0 games not working or offering a vastly different reverb than they do with other cards. Another major issue is the lack of EAX 2.0 support.

In addition to reverb the Vortex2 cards offer first order reflections in A3D 2.0 and 3.0 games that use wavetracing. In the few games that support it we find it to be very impressive but it also results in a significant performance hit in most games. You can find more details about A3D 2/3 and wavetracing in our API article.

As pointed out earlier, Creative Technology is now the owner of the A3D engine and we are unlikely to ever see it used again, at least not under the A3D name. Also worth noting if you use the WDM drivers (required in Windows XP/2000) the A3D 2/3 support is slightly lacking and the reverb engine is not available. That is, no support for EAX 1.0 or I3DL2 at all.

On to Creative Labs 3D Sound Engines