In our next stop in the making of Sacred 2 we get to hear about the sounds inside the game….
Lars Hammer (37) is the lead audio designer and audio/network programmer on Sacred 2 – Fallen Angel. Today he will shed some light on the special aspects of Sacred 2‘s 5.1 music – and prick up your ears too!
At demonstrations and press events I always point out that Sacred 2 is one of the few games featuring an actual 5.1 soundtrack. Usually, people reply “Well, that’s not really that new a feature. When I play xyz I always hear something on the back speakers, too…”
Therefore, I’d like to tell you a bit more about this subject:
Admittedly, 5.1 sound effects have been around for a while, and, basically, they have become a standard feature of current games. But, technically speaking, what exactly is a 5.1 effect? It is a mono sound, which is arranged in the space around the listener using a surround setup (i.e. with a minimum of four, usually six to eight speakers). A bird flying past behind the listener’s back is an often used and realistic example.
And how is music played back in computer games? Usually, you put a piece of stereo music on the two front speakers (or spread the signal on all speakers – still, it’s nothing but a stereo track with left and right channel information). In the 1970’s several musicians and bands found out that four speakers instead of two will give you an entirely new listening experience – quadraphonic sound was born. While multi channel music was forgotten again shortly afterwards, the success of 5.1 home theater systems lead to its eventual revival and use on audio DVD’s and SACD’s.
There are several ways of using the additional speakers in 5.1 mixes. From placing individual instruments between the front speakers (using the back speakers only for spatial effects, e.g. Mark Knopfler – “Sailing To Philadelphia 5.1”) to choosing extreme positions for individual instruments “in” the speakers (e.g.The Eagles – “Hell Freezes Over DTS”). A very “spaced out” example is the “carousal effect”, thanks to which all instruments spin around the listener symmetrically (e.g. Mike Oldfield – “Tubular Bells 2003 5.1”). The last example in particular is very exhausting to listen to and definitely unsuitable for a computer game, in which the music should add to the atmosphere. 🙂
In Sacred 2 we decided to use a blend of all approaches: on some tracks the instruments are separated clearly on different channels, on some other tracks the sound moves through space, not around the listener as on the Oldfield mix. In any case, you hear the difference at once: while the sound used to stay in the front speakers as if it were locked in there, it suddenly becomes “3D” through 5.1 and gains a depth it never had before.
Something like that is hard to describe, you really have to hear it for real, which is why we have two examples right here. The tracks use the 5.1 WMA format, which any modern player can play (e.g. Windows Media Player, WinAmp etc.). Note: You will have a hard time hearing any difference at all on stereo systems or with headphones. Usually, the player will downmix tracks to stereo when no multi channel system is detected.
The first piece is a portion of one of the desert area’s tracks. From 0:00 till about 0:54 you hear the stereo version, then we fade over to the 5.1 version, and the sequence is repeated. You can clearly hear how those small effects are spread all over the different speakers:
Sacred2_stereo_51_Demo1.wma (5.9 MB)
The second example was taken from a background track of the orc region. Again, from 0:00 till about 0:28 we hear the stereo version, then the same sequence again in 5.1. This track shows particularly well, how the sound floats through the air.
Sacred2_stereo_51_Demo2.wma (3.1 MB)
Thus, “5.1 soundtrack” does not just mean that you may also hear something on the rear speakers, but actually something different than of the other speakers. 🙂
In the final version of the game the music tracks won’t be stored as WMA, but rather as OGG Vorbis files, and there will be separate 5.1 and stereo versions. That way we can save resources on systems with stereo speakers (or headphones) and make sure the downmix sounds exactly as we had in mind.
See you next time!
Last Updated: April 1, 2008