3D Sound and Digital Output

3D Sound

A few years ago, three-dimensional sound would have entailed talking about fancy reverb and phase modulation of an audio signal sent to two speakers to create an additional sense of ambience or depth. The evolution of technology and the industry has redefined 3D audio as the real time manipulation of audio streams coming from front and rear speakers. In addition to panning around the various speakers and HRTFs, 3D audio also includes the movement of sound around the listener. Sounds are no longer just in front and back, but also now closer, farther, to the side and above and below the listener.

In choosing the Yamaha YMF744, Guillemot has also chosen to support Sensaura's 3D audio technologies. As you probably already know, Sensaura is not an API, but rather an implementation of DirectSound3D. This means that programs written for DirectSound3D will be able to take advantage of Sensaura's unique technologies. The highlights of Sensaura's technologies include MacroFX and Multidrive technology.

Multidrive extends the HRTF (head related transfer functions) to the rear speakers as well as the front; this provides for a more immersive sound field that Sensaura likes to call a sphere of sound around the listener. This four-speaker HRTF is actually a feature that the Sound Blaster Live did not support until LiveWare 2.and a feature that Aureal has yet to implement. You may have heard that the 4-speaker support on the Fortissimo is just a Stereo X 2 configuration, however that is completely false. The Fortissimo's 4 speaker support is 4-speaker positional HRTF - you just have to make sure you set the sound properly in the control panel.

MacroFX allows for sounds to be imaged closer to the listener. The original DirectSound3D implementations only allowed for sounds to get within a meter of the listener, anything closer would still sound the same. One limitation of MacroFX is that it requires that your internal mixer volume levels be set to no more than 60% to provide the additional volume headroom needed.

In regard to 3D quality, it really just boils down to software support. Here, the Guillemot also succeeds. By using Sensaura technology, the Fortissimo supports the DirectSound3D, A3D 1.0, and EAX 1.0 APIs which utilize all of the card's hardware features. A3D 2.0+ and EAX 2.0+ are not supported, however the Yamaha YMF744 chip is incapable of the occlusion and reflection offered by those APIs.

Digital Output

Like the MonsterSound MX400 or Sound Blaster Live Platinum, the Guillemot Maxi Sound Fortissimo will let you hook up your sound card to a Dolby Digital/DTS receiver or a DAT recorder. However, the Sound Blaster Live! and the MX400 only offer coaxial digital outputs and so owners of portable MiniDisc recorders are out of luck. The Yamaha YMF744 chip is based on the AC '97 standard as defined by Intel, and so the internal sample rate is a fixed 48kHz. So, if you are interested in doing digital recordings with a MiniDisc recorder you should make sure that your recorder has sample rate conversion. With the exception of AC-3 encoded DVDs, S/PDIF output will be limited to the front two channels.

I used the Fortissimo's digital output with my Hoontech DAC II external D/A converter based on the world famous Burr-Brown PCM1704 DAC as well as a Sharp 821 MiniDisc recorder and it worked flawlessly with both. If you're looking for a low-cost soundcard with digital output for your MiniDisc recorder, this is definitely a good match for you. A digital connection between a MiniDisc player and a soundcard will not result in "faster" recording, however. Recording an hour of music onto MiniDisc will take an hour of your time unless you have a special Sony MD Recorder and Sony CD player which allows for faster dubbing.