QSound's Q3D

QSound is one of the true pioneers in the 3D sound engine market being included as part of Soundblaster ISA card several years before the 3D sound card market took off. In more recent years QSound’s engine has mostly appeared on soundcards using ForteMedia’s FM801 chip and most recently several of Philips chips and soundcards including the top of the line Acoustic Edge.

As we mentioned in the introduction, QSound only uses HRTFs for headphones and have taken a different approach to their 2, 4 and 5.1 speaker solutions. Instead of using HRTF + cross-talk cancellation for 2-speakers, QSound decided to develop audio filters specifically for the 2 speakers and they performed more than 550 000 listening tests before they finally were happy with the filters. The approach for 4 and 5.1 solution are similar.

QSound's doesn’t claim their method to be superior to HRTF and cross-talk cancellation for sound placement but point out several benefits. The two most important are that their 2 speaker solution played back with headphones will to most users still be perceived as an improvement compared to stereo, even though you will lose most of the 3D sound experience. This isn't important with computer games where the user can choose if he wants to use speakers or headphones, but for canned content like music it's a significant benefit. Another benefit, and much more interesting for PC gamers, is that QSound's method is more efficient.

Just like Creative Labs’ Live/Audigy engines and Sensaura’s S-3DPA engine, QSound’s Q3D engine supports A3D 1.0 in addition to DS3D by converting the A3D 1.0 calls to DS3D. Some of the WDM drivers (required in Windows XP/2000) unfortunately seem to lack this A3D 1.0 support. The Q3D, just like all other non Sensaura cards, lacks support for ZoomFX (for details see our API article).

The reverb engine, named QEM, supports EAX 1.0 and in later versions also EAX 2.0. So far only the Acoustic Edge, newer Seismic and Rhythmic Edge and ForteMedia FM801 WDM drivers use the version that supports EAX 2.0. It currently lacks support for I3DL2 and EAX Advanced HD. As described in our API article the support for I3DL2 is currently not an issue and may never become one. It would also be easy for QSound to add support for it since it’s almost identical to EAX 2.0 in functionality. In the case of EAX Advanced HD only the Audigy will support it and with no games yet released it’s impossible to tell if lack of this will become a major issue or not. More details on I3DL2 and EAX Advanced HD can be found in our API article.

The 3D positioning of the QSound Q3D engine is great for 2, 4 and 5.1 speakers. We think it’s noticeable better than Creative’s Live engine for 2-speakers and not far behind Sensaura’s engine for 2-speakers except for elevation cues where we find the QSound engine weak. It’s worth noting that the other engines including Aureal’s A3D and Sensaura’s S-3DPA are weak when it comes to elevation cues too and the difference in actual game play is minor but it’s clearly noticeable in blind tests. When it comes to both 4 and 5.1-speakers we think it’s similar to Creative Labs’ Live and Audigy engines if you ignore the QMSS feature. That is on QSound cards where QMSS is not present (all cards not using Philips/VLSI ThunderbirdQ3D or Avenger chips). If you take the QMSS feature into account we find both the 4 and especially 5.1 version to be slightly but clearly ahead of the Live and Audigy.   That comes thanks to QMSS resulting in effective center channel and even surround channel usage for stereo source material (present in most if not all current games).

Our impression of the reverb engine is similar to our impression of Sensaura’s reverb engine. That is the quality is good but the lack of tweaking the reverb levels and consistency puts it overall clearly behind the Live and Audigy. While both the levels and consistency are clearly behind the Live/Audigy, they are ahead of the Sensaura engine. 

Where the QSound engine shines is the additions of some stereo expansion algorithms. It varies between cards what they offer but the ones that are available are QXpander, 2D-3D, QSurround and QMSS. QXpander and 2D-3D are both 2-speaker stereo expansion algorithms we find to offer a nice effect. QSurround is even more impressive offering virtual surround sound for DVD movies. QMSS is a stereo expansion algorithm for 4 and 5.1 speakers that offer an amazing good ability to put the sound effects that should be behind you to the rear speakers in games that only support stereo or Dolby Surround. It’s also useful for the stereo sound effects you find in 3D sound supporting games, this is especially useful if you use a 5.1 speaker system as described in our 5.1 gaming article (not available yet).

To judge for yourself how effective the QSound Q3D 2-speaker and headphone algorithms are you can download QSound’s Q3D demo.

On to Sensaura's S-3DPA