Hercules Fortissimo III 7.1 and Digifire 7.1 – THG.RU

Introduction

The Fortissimo range has been the delight of gamers ever since its first version in 1999. But so far Hercules had only ventured into the field of home cinema for PC with Game Theater XP and, more recently, Muse 5.1 DVD. To give the latest Fortissimo the versatility it lacked while maintaining the performance and quality/price ratio the range is noted for, Hercules has kept the Cirrus Logic CS4624 chipset but given the Fortissimo III Dolby Digital EX decoding in 7.1. So this really is a new feature and an important innovation in home cinema for PC.

The Digifire 7.1 is even more versatile in that it has greater connectivity in addition to Dolby Digital EX decoding. This addition comes in the shape two IEEE1394 ports for plugging in a digital camcorder or any other device, such as an external hard drive or CD burner. Hercules drives the video side home by adding to the card PowerDirector Pro 2.5 PM, a video editing program. Apart from this difference, Fortissimo III 7.1 and Digifire 7.1 are exactly the same with an architecture built round the Cirrus Logic CS4624 chipset.

Before going into detail on the technical features and performances of the cards, we must give an exact rundown on the sound standards of home cinema in general and Dolby Digital EX in particular.

The 5.1, 6.1 and 7.1: A Speaker Multiplication Table

In movie or DVD sound, 5.1 means the recording has been made on five main channels – right, left, center, right surround and left surround – plus one for LFE (Low Frequency Effects) represented by the .1 in “5.1”. When it comes to speakers, the terms 5.1, 6.1 and 7.1 represent the number of elements in the sound system. The difference between them is easy: it just depends on the number of surrounds – two for 5.1, three for 6.1 and four for 7.1.

Some sound tracks use a variation of Dolby Digital called Dolby Digital EX. This format uses a matrix system which includes a third surround channel based on the left and right surround channels of the conventional 5.1. This matrix system means Dolby Digital EX is still considered a 5.1 system. Especially since Dolby Digital 5.1 decoders can read these sound tracks, the only difference being that sounds encoded for the third surround channel are retranscribed on the surround channels of the conventional 5.1.

So a Dolby Digital EX sound track can be read in 5.1 by a Dolby Digital 5.1 decoder. But the reverse is also true. You can get a 6.1 or 7.1 from a 5.1 audio track. The signals on the two surround channels are mixed and redistributed through all three or four loudspeakers. This distribution can be done either with a Dolby Digital EX decoder or a THX Surround EX decoder.

So you can see that the figure describing the recording is not the same as the figure meaning the number of loudspeakers in a sound system. With Dolby Pro Logic II you can even play a stereo sound track on a multi-channel system.

Dolby Digital

In 1965, an American physicist and engineer called Ray Dolby founded the Dolby Laboratories in London. His idea was to develop noise reduction systems to improve sound quality for professionals and general public alike. The name of Dolby is now known throughout the world and the surround sound standards he created are used both in movie theaters and the private home. First of all a description of the two Dolby Digital ancestors:

• Dolby Surround: this has three channels, two for the front and one for the rear with a bandwidth of 100 Hz to 7 kHz.
• Dolby Pro Logic: this is an enhancement of Dolby Surround with 4 channels, including a center one and two elements sharing a channel for the rear sound.

As for Dolby Digital 5.1, also called AC-3 (for Audio Code-3), this has 6 channels – two front, two rear, one center and one for the subwoofer. When a movie is shot, the sound is generally recorded with at least five microphones (a boom for the voices and four mikes for background sound effects). Unlike Dolby Surround and Pro Logic, the bandwidth here ranges from 20 Hz to 20 kHz. The term AC-3 refers to a coding technology which eliminates sound data the user cannot hear and produces a Dolby Digital sound track coded on six channels. An absolute prerequisite for Dolby Digital sound is a decoder, such as the one on the Creative Labs Extigy, or else a sound card like Fortissimo III.

Dolby Digital uses a fixed sound compression method of about 1:12. This means that however much sound there is to encode, compression will always be the same, so we have a compression algorithm with a constant output. The practical side of this is in the disk space, but the downside is that sound quality decreases as its volume increases. But to set against this is that the less space used on a DVD, the more space is available for different languages or bonuses, and this can compensate for a loss of quality. In general, AC-3 sound is coded in 18 bits, so the standard output of an AC-3 flow is 384 Kbps (6 channels x 18 x 48 kHz). On restitution, the Dolby Digital decoder transmits with a delay of one millisecond on the front channels because the listening position is usually closer to the rear speakers than the front or center ones. This optimizes simultaneous sound reception. With some decoders you can adjust this delay to give the best listening configuration.

The main advantage of the Dolby Digital standard is that it is the digital audio surround standard for DVD. In the rules defining the DVD standard, no other kind of digital sound track can be inserted on a DVD unless there is also a Dolby Digital sound track. So you’ll never find, say, a DTS sound track on its own, and most DVDs only have the one digital sound track, the Dolby. This leads to the second advantage of the standard – it is virtually universal. The first movie with a Dolby Digital 5.1 sound track was “Batman returns” in 1992. Since then, practically all DVDs have extended the standard.

Dolby Digital EX is an enhanced version of Dolby Digital 5.1 in that it has a support for an extra surround speaker or two behind the listening position. This means you can put your side speakers in the right position and gain in sound effects and immersion from the back. Remember though that Dolby Digital EX is not a “true” 6.1 or 7.1 sound standard because the surround channel is matrix encoded from the conventional 5.1 surround speakers. The sound is recorded as in Dolby Digital and the sixth channel is added when the initial encoding is done. The sound engineers view the film and decide which sounds should be moved to the rear, so the EX is definite progress. As for the argument over whether 6.1 or 7.1 is better, this is rather pointless. In 6.1, the rear center speaker produces mono sound. In 7.1 the two rear center speakers produce the same mono sound. The advantage of Fortissimo III 7.1 and Digifire 7.1 is that you can have either 6.1 or 7.1 depending on whether you want more or less. The choice between the two modes is a purely technical one: if you have a large room with lots of widely-spaced listening positions, the 7.1 is best, otherwise the 6.1 is perfectly adequate.

DTS

DTS, for Digital Theater System, was introduced by Steven Spielberg with the release of “Jurassic Park” in 1993. So far, this standard applies more to the big screen and is only just beginning to be used in the private home. It too is 5.1, with sound is coded over 6 channels like it is in Dolby Digital. There are now many DTS-compatible systems around like the sound cards which can decode the standard by software. However, while DTS quality is undeniable, and even a bit better than Dolby, remember no movie comes out in DTS alone and Dolby is considered as a digital sound standard and DTS is not.

The main feature of DTS is that its coding system favors sound quality over disk space. So a DTS sound track codes in 24 bits instead of the 18 bits with Dolby. Compression uses a dynamic process where the compression rate varies with the amount of sound to encode. This rate ranges from 1:1 to 40:1 and generally results in better sound quality than Dolby Digital with an average rate of 1.5 Mb/s. The main drawback is obviously that the sound track takes up much more space (about three times as much) than a Dolby one. So DVDs coded in DTS can only have one language and a limited number of bonuses. Until recently, very few DVDs had a DTS band, but there are a lot more around now owing to the quality advantage this system has over Dolby Digital.

This quality advantage is due mainly to the way DTS encodes dynamically, but also to other factors, such as the fact that Dolby Digital mixes the channels above 15 kHz at 448 Kb/s and above 10 kHz at 384 Kb/s. This means Dolby Digital can reduce the space needed for the sound track on a DVD and retain a maximum of bandwidth at high output, but to the detriment of overall quality. DTS encoding never mixes the channels. This remark is not intended to kindle an argument over Dolby and DTS, just to show that each format has opted for different encoding systems. Dolby Digital goes for disk space and bandwidth while DTS prefers quality above all.

The DTS quality advantage also applies in 6.1 and 7.1 because only the DTS ES standard has discrete encoding on the sixth channel, meaning independent of the other surround channels and integrated during recording (on at least five sound effects mikes). But be warned: movies encoded in DTS ES Discrete are as yet few and far between and what you mostly find is a DTS ES Matrix track which has a rear center channel matrixed into the left and right surrounds as in Dolby Digital EX. So for the time being, there is only one true 6.1 sound system standard and it is not exactly mainstream.

Fortissimo III 7.1 and Digifire 7.1: Technical Data

Fortissimo III 7.1 and Digifire 7.1 architecture is built round the Cirrus Logic CS4624 chipset, the same as the Fortissimo II Digital Edition. Its technical specs are as follows:

• AC `97 2.1 Link CODEC, PC `99 and PCI 2.1 interface
• DSP 255 MIPS SLIMD architecture
• Supports DirectSound 3D, EAX, A3D 1.x and echo cancellation
• Wavetable synthesis with unlimited number of channels, DLS and 10-band graphic equalizer
• Supports 4 output channels
• SRC hardware and SNR 90 dB
• 96 hardware-managed 3D sound channels
• Secondary AC `97 1.0/2.1 Link CODEC for multi-channel sound and digital connection
• Asynchronous digital serial interface
• Optical S/PDIF input/output interface (PCM, AC3 5.1)
• MPU-401 MIDI Interface
• 3.3V power supply

The first thing that these specifications show is that CS4624 is supposed to be a chipset for managing 4.1, and not 7.1. To cope with two extra analog outputs and Dolby Digital EX decoding, Hercules has had to bring two parameters into play. The two cards each use two CS4294 AC97 codecs – a main and a secondary. In the first place the secondary AC97 codec is put in action. For this Hercules has opted for a “crossover” function, given that each codec manages 4 channels, so there are two stereo outputs: the main one manages outputs 1 (front speakers) and 3 (center channel + subwoofer) and the secondary one manages outputs 2 (surround) and 4 (center surrounds). In the second place, decoding is done by software not hardware, as is usual for 5.1 sound cards. So it is the main processor and not the sound card which provides the CPU time for decoding. The optical digital input found on the Fortissimo II Digital Edition has gone. This is due to lack of space on the card itself and the cost of moving it to the bracket with the MIDI/game port.

So by pushing the CS4624 to the hilt, Hercules can claim to offer cards with high performance in 3D sound for games and which can also decode Dolby Digital EX sound tracks on DVD. The full technical data for this card is as follows:

• PCI 2.1 interface
• Cirrus Logic CS4624 chipset
• 16-bit 44.1 kHz sound quality
• 4.1, 5.1, 6.1 and 7.1 sound for games and DVD
• 96 hardware-managed DirectSound channels
• CD in and Aux in internal inputs
• Mike, Stereo Line in external inputs and MIDI/Game port on internal bracket
• 4 stereo analog outputs for 7.1 sound
• Optical S/PDIF output
• Sensaura 3D sound engine
• Supports DS3D, EAX 1.0, 2.0, A3D 1.x, Sensaura Virtual Ear/Macro FX/Multidrive
• 52 hardware-managed DS3D channels
• General Midi and Yamaha XG compatibility
• 8 MB Wavetable software
• 64 hardware-managed polyphony channels
• Dolby Digital and DTS pass-through compatibility
• DLS and DOS real-mode compatibility

Fortissimo III 7.1 costs $49.99. It is delivered with Power DVD Pro EX, Hercules Media Station and Acid eXpress.

Digifire 7.1 is more powerful than Fortissimo III 7.1 in, that it has two IEEE1394 (FireWire) ports and its software includes PowerDirector Pro 2.5 PM. So it is designed for video but any IEEE1394 device can be connected to it. If you look at both cards, you’ll see that apart from the odd capacitor they are identical except for the two extra chipsets dedicated to management of the IEEE1394 ports. The first is the Agere FW323-05 which is an IEEE1394 controller compatible with outputs of 400, 200 and 100 Mb/s. Note that this controller can be used to create an IEEE1394 network between two PCs, like the Creative Labs Audigy. The second is the HINT HB1-SE33, a PCI-PCI bridge for integrating and managing a PCI element (the FW323-05 chipset here) on the sound card. The PCI bus created by the card works at 33 MHz like a standard PCI bus. We tested the output performance of one of the IEEE1394 ports on the Digifire 7.1 using a LaCie external disk and the result was more than convincing because it reached a rate of 10 MB/s. Compatibility should be no problem since the FW323-05 is one of the most commonly used components for dedicated IEEE1394 cards. The card also has an internal IEEE1394 connector.

Another difference is that Digifire 7.1 has a combined line-in/ mike input which are separate on the Fortissimo III 7.1. You select which one you want via the General tab in the control panel. It also has a 20-pin port called “Feature” where all the card inputs and outputs are connected. In future, this port should allow you to connect an internal or external rack (via bracket), a bit like the Game Theater XP. There is as yet no definite information on when this rack will be released.

So the difference between Digifire 7.1 and Fortissimo III 7.1 boils down to the software, combined inputs and two IEEE1394 ports. The Digifire does not have an IEEE1394 cable. It costs $79.99.

Fortissimo III 7.1: Drivers

As usual with Hercules, great care has been taken with the card driver interface. It is good-looking, complete and very well organized. Among its good points is the “Small Speaker” checkbox in the General tab. You should know there are two ways of managing low frequencies in 5.1, depending on the size and type of speakers connected to the sound card.

In theory, the Cirrus Logic 4624 chipset only manages one mode: Large Speaker Mode. This means that the output device sends a full-frequency signal to all the elements without redirecting or filtering low frequencies to the subwoofer alone. So sounds logically dedicated to the LFE channel by the DVD software are dispatched to all the elements. In Small Speaker mode the card can redirect low frequencies specifically to the subwoofer, making for clearer and better positioned sound. So Hercules had a good idea in adding this configuration mode to the drivers. You can use amplified multimedia or hi-fi speakers, but also non-amplified ones like the ones in mural systems.

Digifire 7.1: Drivers

The Digifire 7.1 drivers have the same interface as Fortissimo III 7.1 with the five General, Mixer, Midi, EQ and Others tabs.

Test Setup and Methods

The Fortissimo III 7.1 and Digifire 7.1 sound cards were tested objectively and subjectively. The following software and DVDs were used:

• Right Mark Audio Analyser 4.1
• Audio Winbench
• Dungeon Siege
• DVD Test Platinum Series
• DVDs encoded in Dolby Digital 5.1 and EX

Fortissimo III 7.1 and Digifire 7.1: Dolby Digital EX decoding

The drivers and four analog outputs give Fortissimo III 7.1 and Digifire 7.1 the capacity to decode DVD sound tracks encoded in Dolby Digital EX. To do so, you have to use the Power DVD Pro EX provided with the cards. Hercules has done things neatly so that the card driver and software sound configuration dovetail and activate 5.1, 6.1 or 7.1 decoding depending on what you choose. This means you don’t have to configure the same thing twice in two different places.

Fortissimo III 7.1 and Digifire 7.1 were tested subjectively with DVDs encoded in Dolby Digital EX like Star Wars Episode One, Phantom Menace and Lord of the Rings, and with DVDs encoded in Dolby Digital like Alien Resurrection and Saving Private Ryan. Nothing in particular to say about decoding itself – the job was done more than adequately, even though you don’t get quite the quality and clear positioning results of a dedicated decoder. The advantage of 7.1 and 6.1 over 5.1 is patent – the rear surround speaker(s) envelope you in sound much better. An appreciable point is that music and background noise are on these speakers and so free up the main surrounds for sound effects.

However, the gain in the sound effects themselves is negligible because 90% of them are still on the standard 5.1 channels. They are hardly to be heard on the rear surround channels. This is as true for 7.1 as for 6.1, especially since in 7.1 the Dolby Digital EX matrix system means the same sounds are heard on the two rear center speakers, so 7.1 is only better if you have a large room and a lot of people, otherwise 6.1 is quite adequate. Note that the Fortissimo III 7.1 and Digifire 7.1 analog outputs give a lower sound level than the Creative Labs Audigy. This is a good thing in a way because it limits distortion but it does also limit the maximum reachable volume. Overall, we can say both cards do a good job of Dolby Digital EX decoding.

As we already said, a system which can decode sound in 6.1 or 7.1 is also good for playing DVDs encoded in Dolby Digital 5.1. Positioning is not as good as with EX sound tracks but still effective. The surround sounds are spread over the four speakers so listeners are better enveloped in sound. This should be avoided though in some movies because it reduces the power of the sound effects. Another thing to remember is that 7.1 emulation from a DVD encoded in 5.1 substantially impairs the quality of the sound on the rear surround speakers (see explanation below).

Performance in Games

The theoretical and practical tests of the capacities of Fortissimo III 7.1 and Digifire 7.1 were all run on both cards. Their drivers and components being virtually identical, some of the results are too, so in this case we shall only publish one set, as with the results for Audio Winbench 99. These are not bad at all, though slightly higher than for Fortissimo II, which is a bit surprising.

Dungeon Siege results are very conclusive and also virtually identical to the odd tenth of an FPS. We should point out though that this game is compatible with EAX 2.0 and EAX Advanced HD, so in theory, if you activate EAX with these cards Hercules should run the game in EAX 2.0. Yet, while the bench tests show a significant drop in performance, the quality results are rather odd: when EAX is active, 3D positioning is practically non-existent and sound effects not very marked, whereas when it is deactivated, positioning is excellent and you are totally enveloped in sound. What’s more, the 7.1 mode is amazingly efficient in this game and in Soldier Of Fortune II. Directional effects are focused on the loudspeakers in conventional 4.1 but background and music are on all the surround speakers. It has to be said though that the quality of restitution is sometimes defective on the rear surrounds. More on this later.

Digifire 7.1: Input and Output Quality

Here are the results given by Right Mark Audio Analyser for front stereo output quality with Digifire 7.1 using the following test line: Digifire 7.1 Stereo Out 1 – DMX 6Fire 24/96 Line In.

So results are very good, with a signal-to-noise ratio of 82 dB. Here are the corresponding graphs:

The card’s bandwidth curve shows whether its frequency reproduction over the entire sound spectrum is balanced. The test is measured from 20 Hz to 20 kHz, the usually accepted limits of human hearing.

The second test is of noise and interference levels, and measures in particular where the card’s background noise is located and its sensitivity to interference from the computing environment: power supply, transformers and monitors.

Related to the above test, the dynamic range test gauges the level of noise generated in the presence of a sound signal, in this instance a sine wave (1 kHz at -60dB) at card input.

The next test measures harmonic distortion or THD. It assesses the card’s sound fidelity, noting the appearance of harmonics when a single but high (-3 dB) sine wave is sent to the card.

Digifire 7.1: Input and Output Quality, Continued

The following results show the quality of Digifire 7.1 recording via the line-in/Mike-in stereo input. The input was of course configured in line-in. The test line was: DMX 6Fire 24/96 Stereo Out – Digifire 7.1 line in.

Digifire 7.1 also comes out pretty well at all levels in recording via the analog stereo input. The signal-to-noise ratio is not top rate but average at -79.6 dB.

Fortissimo III 7.1: Input and Output Quality

Here are the results given by Right Mark Audio Analyser for front stereo output quality with Fortissimo III 7.1 using the following test line: Fortissimo III 7.1 Stereo 1 out – DMX 6Fire 24/96 Line In.

Like Digifire 7.1, Fortissimo III 7.1 gives good quality output which bodes well for playback. Bandwidth compliance is more than adequate and the signal-to-noise quite good enough for a card in this range. There are a few differences compared to the Digifire 7.1, notably with regard to the THD which is lower (so better) on the Fortissimo III 7.1.

Fortissimo III 7.1: Input and Output Quality, Continued

The following results show the quality of Fortissimo III 7.1 recording via the line-in stereo input. The test line was: DMX 6Fire 24/96 Stereo Out – Fortissimo III 7.1 line in.

Once more Fortissimo III comes off very well with excellent bandwidth compliance and a very good signal-to-noise ratio, even though it comes nowhere near the 95 dB and more of more music-focused cards.

Fortissimo III 7.1 and Digifire 7.1: Input and Output Quality

Fortissimo III 7.1 and Digifire 7.1 have four separate analog outputs, so these each need to be tested to see if they do all have the same quality. Given that outputs 1 and 2 (front and surround) are on the main codec and that 3 and 4 (center channel/subwoofer and center surround) are on the secondary one, there may be some differences to notice.

Still using the Right Mark Audio Analyser and subjective tests with Sennheiser HD570 Symphony headphones, we did indeed notice substantial quality discrepancies between outputs 1-2 and 3-4. We discovered when we listened that the sound from outputs 3 and 4 was really poor, while from 1 and 2 it was very good. So you have good quality sound on the front and surround speakers while the rest are inadequate. Contrast this with cards like the Terratec DMX 6Fire LT or the Creative Labs Audigy Player where the sound quality is identical on all outputs.

In the objective RMAA tests, this quality difference of Fortissimo III 7.1 and Digifire 7.1 was blatantly obvious. It was definitely noticeable in the bandwidth and appalling when it came to stereo crosstalk. This, by the way, is a measure of the isolation between the card’s left and right sound channels, in other words the highest level of sound that can be heard on a channel before it starts to be heard on the other as well. This is an important factor in multi-channel environments.

To see what we mean, here is an example of results obtained with RMAA 4.1 for Digifire 7.1, the Fortissimo III results being virtually identical and with the same symptoms. We have just used output 2 as reference to make the charts simpler.

Basically, these results prove that bandwidth compliance is appalling and crosstalk more than inadequate on outputs 3 and 4 while they are excellent on 2 (and therefore 1).

Fortissimo III 7.1 and Digifire 7.1: Input and Output Quality, Continued

The reason for this quality difference is quite easy to explain for output 3, which handles the center channel and subwoofer. Hercules has added a filter to it to cut out low frequencies on the center-dedicated channel. This results in a 300 kHz crossover on the output which explains the crosstalk results because the two channels are not getting the same sound information. The reason for the filter on output 3 is to allow Fortissimo III 7.1 and Digifire 7.1 to be easily connected to a subwoofer with no integrated cutout system. It is a technical compromise which is detrimental to sound quality but advantageous for compatibility with speaker systems. This is a pity for those who do have an integrated cutout system (like MegaWorks 510D) and it may be that Hercules will include an option for deactivating the filter in its future drivers. Let’s hope so.

For output 4, the explanation is similar in that it has a software-applied filter for when the eight elements are used from a source not encoded in 6.1 or 7.1. So if you play a DS3D game, watch a movie encoded in 2.1 or 5.1, or listen to a CD Audio with all the loudspeakers running, Fortissimo III 7.1 and Digifire 7.1 “virtualize” the sound into 7.1 instead of stereo panning it over the four surrounds. The result is convincing with regard to background sound, but it has negative effects on the “virtual” sound on the rear surrounds.

Hercules is aware that this technical arrangement can sometimes impair the quality of the sound and so has decided to develop new drivers which will have an option for deactivating virtualization to reproduce the same sounds on the four surround outputs. Users will then be able to choose according to taste. The filter on output 3 could also be deactivated to optimize use of speakers with electronic crossover.

Conclusion

The Fortissimo III 7.1 is meant to be a multi-purpose card for games and DVD. With Digifire 7.1, it’s the same, but with more advanced connectivity and software focusing on acquisition and editing of digital video. Their two main new features (7.1 sound and Dolby Digital EX decoding) are certainly not negligible, but we do rather wonder what their real advantage is. 7.1 sound can only be a deciding factor for movies if the PC (or DVD/DivX box) are located in a good-sized room and not in an office or other room of ordinary size, but it is unlikely that users with a room like that would hesitate to invest a bit more in a card or decoder of home cinema quality. That said, you can always stick with 6.1 which will give you truly better sound immersion for Dolby Digital EX movies. In fact, Fortissimo III 7.1 and Digifire 7.1 are cards in a very low price range ($49.99 and $79.99) which makes them very affordable. This economy choice obviously does not place them in the music or top-of-the-range cards for sound fidelity. But we reckon their quality is quite adequate for leisure purposes like DVD and games. Moreover, within a few weeks Hercules should have overcome the quality problems caused by the filters on outputs 3 and 4 by releasing optimized drivers enabling users to choose the way the sound is restored.

After all, if you discount this quality problem, there is no denying the attraction of Dolby Digital EX in movies and the sometimes significant advantage of 6.1 and 7.1 in games. The quality/price ratio of Fortissimo III 7.1 and Digifire 7.1 is a definite and deciding advantage compared with other solutions for games and Dolby Digital decoding. Performance in games is really good and the driver interface is a model of its kind for appearance and simplicity.