Listening tests
Listening tests are inevitably subjective, but really there are few other ways to evaluate a sound card's performance with the equipment available to me. If you're looking for fancy response curves and double-blind tests done in soundproof chambers, sorry.

All music playback tests were done with a set of Klipsch 2.1 Promedia PC speakers, with volume levels for each card normalized to within a decibel of each other and the software equalizers turned off. I enlisted the help of Carl and Ed from Hardcoreware.net to help with the music testing. I played each music track back several times on each card, and only I knew which card was being used at any given time. The impressions you'll find below refer to our collective opinions of each sound card since there was general agreement about the characteristics of each card.

3D audio tests were conducted alone with a set of Philips MMS305 4.1 channel speakers. Here, additional listeners weren't necessary, because our 3D audio tests were meant to evaluate a card's ability to accurately reproduce and fade positional audio across multiple speakers rather than its ability to produce a sounds that were pleasing to the ear. After playing with each card extensively, I found that each card's gaming sound characteristics closely matched its music playback characteristics.

Hercules Muse LT and 5.1 DVD
Music playback - Our panel was a little shocked by the performance of both Muse cards; the cards sounded much better than what was expected given their price point. The Muses were particularly good at the high end of the spectrum where their output was clear, bright, and lively. This is a happy sound card. In songs with a lot of treble, the Muses excelled, background instruments came through nicely, and there was plenty of range.

Unfortunately, the Muse's preference for highs came at the expense of its performance at the low end of the spectrum. Drums didn't really hit hard; in fact, nothing at the low end hit particularly hard or clearly. The bass lacked depth and sounded a little muffled. Whatever range the Muses have they use up on the highs rather than the lows.

3D audio - There was nothing glaringly wrong with either Muse's reproduction of 3D audio. Moving sounds faded in and out of each speaker clearly, though there tended to be a little more distortion when a sound source moved behind an obstruction.

Hercules Gamesurround Fortissimo III and Digifire 7.1
Music playback - The Fortissimo III and Digifire's music playback performance was almost exactly the opposite of Hercules' Muses. While the Muses' strengths lay with bright, lively highs, the Fortissimo III and Digifire excelled at producing deep, loud lows. At times, our panel felt that there was almost too much bass, but that may have been because the highs were more muffled than on other cards.

The low end range on the Fortissimo III and Digifire wasn't as striking as the Muses' high end range, but the Fortissimo III and Digifire didn't suffer as much with highs as the Muses do with lows. If you're looking for something to get your speakers thumping, the Fortissimo III and Digifire are it.

3D audio - With my 4.1 speaker setup, the Gamesurround Fortissimo III and Digifire both produced great positional audio results. Transitions between speakers were smoother than on the Muse, but I really didn't have a good way to test the cards' 7.1 channel 3D audio capabilities. Mixing and matching different speaker systems to bodge a 7.1 speaker arrangement didn't produce consistent results across all speakers because, well, I don't have seven identical speakers.

Creative Audigy
Music playback - Overall, our panel found that the Audigy sounded better than every other card except Terratec's DMX 6fire 24/96. While some of the other cards we tested were particularly good at either highs or lows, the Audigy managed to sound good throughout its range. The other cards felt like they sacrificed one end of the spectrum for the other, but the Audigy was clear and consistent throughout.

Honestly, our panel expected the Audigy to distinguish itself more during the listening tests, but that didn't happen. The Audigy's performance was consistent, but it didn't sound exceptional playing any one of the songs we used. On tracks with a lot of bass, the Fortissimo III and Digifire sounded better, and on tracks with more treble, the Muses had a more pleasing, lively feel. In the end, the Audigy had a well balanced sound across all tracks, but its consistency was the bright spot, not its particularly exceptional performance.

3D audio - As you might expect, the Audigy's EAX performance was good, but not by a margin that really set it out from the rest of the pack. Overall, the Audigy's speaker transitions were smooth and its handling of obstructions effective, but it's hard to say the Audigy's overall positional audio performance was much better than the Fortissimo III or Digifire.

Terratec DMX 6fire 24/96
Music playback - Summing up the DMX 6fire 24/96's music playback performance is actually quite easy; it's sound quality was simply an order of magnitude better than everyone else's. It doesn't matter what end of the spectrum we were at, the DMX 6fire 24/96 produced clear, crisp, rich sound that was easily distinguishable from every other card we tested. From the highs to the lows, treble to bass, it wasn't even close. In fact, using the DMX 6fire 24/96 right after any other card immediately exposed the previous card's weaknesses.

The DMX 6fire 24/96 sounded as close to perfect as anything this panel had ever heard from PC audio, and it easily dominated our music playback tests. Even seconds into a track, it became clear that the DMX 6fire 24/96's sound quality was far superior to the others. Quite simply, we were spoiled.

3D audio - The DMX 6fire 24/96's positional audio sounded better than any other card in the test, but it's really hard to separate the card's sound quality from its ability to fade sounds correctly between speakers. Most striking was the Dolby Surround tests, where the card's ability to fade in sounds from behind obstructions was particularly impressive.

VT8235/ALC650 integrated audio
Music playback - When we listened to the Albatron KX400+ Pro's VT8235/ALC650 audio on its own, without any comparative reference, it sounded all right. The integrated audio didn't seem to favor the high or low end of the spectrum. In fact, it didn't seem to really favor anything. When compared with the other cards, the integrated audio sounded a little flat and was distinctly lacking in range. The lack of range was especially apparent when we had a number of different low, high, or even mid-range instruments all going at once. When different sounds were forced to share the VT8235/ALC650's limited range, they tended to blend together and were more difficult to distinguish from each other.

The worst part about the VT8235/ALC650 was its tendency to mute background subtleties that came across much clearer on the discrete audio solutions we've tested. Music played back with this integrated audio setup always sounded like it was missing something, especially when played after the other cards.

3D audio - The VT8235/ALC650's positional audio was a little rough, but it still worked. Fading is the real issue here, with transitions between speakers lacking the smoothness present in the other cards. Even the Muse's transitions weren't this rough.