HTPC The Home Entertainment PC – Part 3 Audio

The HEPC (Home Entertainment PC)

The computer is finding its way into the living room. This invasion brings
about horrifying visions of trailing cables as the PC crawls out of the primordial
soup of the home office. How can the fledgling PC compete against a world otherwise
dominated by components that are chameleons hiding behind names like home theatre
and game boxes?

The PC is itself becoming more of a chameleon whether it hides behind the disguise
of office productivity or of home entertainment center. Can the powerful PC,
supreme in its native office environment, survive in the jungle of your living
room? Does it have to be an eyesore shooting off cables like vines growing wild?

Home Theatre PC or HTPC is a popular term. Home Theatre implies that the PC
will be used to play back DVD movie content with a PC rather than a stand alone
consumer grade player. The HTPC isn’t a “set-top box” either. A set-top
box is a device which enables a viewer to become interactive with the television
set. Set-top boxes may appear to be similar to PCs but they aren’t.

Why a PC in the living room?

We wouldn’t be recommending dragging the tower out of the home office to stand
it beside the TV. We wouldn’t want to scar the decor either with a bland, beige
box noisily whirring away. The thought of cables trailing across the floor gives
us hives.

PCs are more affordable these days. There used to be a time when it was one
TV per household. Now two or three is common. The same can be said for the PC
and with the sheer amount of digital content some are accumulating it only makes
sense to incorporate that into the home entertainment center for music, games
and movies.

The HEPC (He-PC…no pun intended) combines Home Theatre quality DVD playback,
high quality audio, gaming, Internet and all the creature comforts of a traditional
PC into a unit that blends in with the living room or family room environment.
The HEPC offers the ability and advantage of storing large volumes of digital
video and audio. It has the benefit of connecting with other PCs in the household.
There also need not be cables strung everywhere ready to snag limbs as you pass
by like catch wires on the deck of an aircraft carrier.

Assembling the HEPC isn’t complicated or expensive and the technology is surprisingly
good. In some cases it may be even better than what is presently sitting in
the home entertainment cabinet.

Short-Media delves into the world of audio for Section three of the HEPC guide.
Audio is one of the most overlooked areas for PCs yet it is the cornerstone
of the HEPC. What formats need to be addressed now and what matters for the
future? Is an audio card as good as it says it is on paper?

These questions and more will be answered.

Section 3: Making it all sound good

Choosing any piece of audio equipment is mostly based on the choice of features,
aesthetic appeal and price point. Hardly anyone looks at specifications and
rarely do they understand what specifications really mean and what they could
be hiding.

A buyer may be impressed when a home theatre amplifier is listed as 400 watts.
The reality is a completely different story. That 400 watts may be measured
when the amplifier was tested in near freezing conditions and only one channel.
At room temperature the actual performance may only be 50 watts per channel
and the distortion is so bad that even at ¼ volume the sound is terrible.
That 400-watt amplifier could be outperformed by a $10 transistor radio.

Audio component specifications are a game that marketing spin-doctors play
listing what makes the product look good on paper. As in the previous example
a manufacturer may list the specifications as 400 watts but fail to include
the 400 watts was achieved by cooling the amplifier down to freezing levels
and driving only one channel. At room temperature and with all channels driven
each channel may only be able to deliver 30 watts of undistorted sound.

Choosing a PCI audio card opens up the same can of worms. What ISN’T
listed is equally as important as what is.

There are too many who post in our forums “I want to buy a sound card.
Which one is good?” Hands-on opinion is crucial as user impressions go
beyond the paper specifications to how the product sounded in reality and the
dislikes and likes of the features. This question should be asked last.

Everyone should ask themselves a few questions before asking questions of others.
Properly assessing needs, desires and present equipment can save a sound card
buyer from a wasted and useless expenditure.

The goal for the HEPC is to utilize a PCI sound card that would deliver the
highest quality sound to a home theatre amplifier for playback of digital music
files by way of a digital interface. Secondary to that was DVD and game sound.

There exists a home theatre amplifier that can accept either optical or coaxial
digital inputs and has onboard Dolby, Digital Dolby 5.1 and DTS surround decoding.

The desirable sound card must have future worth by providing 24-bit 96 kHz
support on all channels and a software interface that could be programmed for
favorite settings when switched from DVD to music to game mode. The home theatre
amplifier would provide any necessary equalization.

It’s that simple.

If everyone would take five minutes to asses what they want and what they have
or plan to have in the very near future then the shopping choices would become
many times easier.

The second floor of the learning tower deals with formats both present and
future possible.

DOLBY DIGITAL

Dolby Digital is now an intrinsic part of our lives. We often
associate Dolby Digital with DVD movies and 5.1 sound but Dolby Digital, formerly
known as AC-3, is a digital audio coding technique that reduces the amount of
data needed to produce high quality sound.

Dolby Digital can be 2-channel stereo or up to 5.1 speakers such as home theatre.

DOLBY PRO LOGIC II

Dolby Pro Logic II is the next level of Dolby Pro Logic and
the effects that Dolby Pro Logic provides are now hardware based instead of
synthesized. It just does a better job of those room effects added to audio
sources such as CDs and VHS tapes. Dolby Pro Logic and Pro Logic II give a simulated
room effect by use of two or more speakers to traditional two channel sources.

DOLBY EX

Dolby Digital EX is 7.1 sound but provides the additional
speaker signals by “creating” them from the left and right surround
signals. This is commonly known as matrix sound.

DTS

DTS is the competition to Dolby Digital sound and uses less
compression in the audio thus audiophiles feel that DTS is the superior sound
format to Dolby Digital.

DTS NEO:6

DTS NEO:6 is provides the extra rear speakers from a stereo
signal through matrix decoding.

DTS ES

DTS ES is the same as Dolby Digital EX and DTS NEO:6 but up
to 7.1 channels of sound are discretely provided instead of through matrix processing.

DTS 96/24

DTS 96/24 joins the “better than CD” fight with
the DTS 96/24 format which provides:

– Sound quality equivalent to the original 96/24 master.
– Full backward compatibility with all existing decoders. (Existing decoders
will output a 48kHz signal.)
– No new player required: DTS 96/24 can be carried on DVD-Video, or in the video
zone of DVD-Audio discs that is accessible to all DVD players.
– High resolution 96/24 5.1-channel sound with full-quality full-motion video
for music programs and motion picture soundtracks on DVD-Video.
– Digital 96/24 output through the S/P DIF port. DTS 96/24 allows the use of
external, very high quality D/A converters and associated analog electronics.

This means that DTS 96/24 can be experienced now including a digital connection
but the decoder unit must be able to decode 96 kHz 24-bit sound.

THX

THX (named after Steven Spielberg’s first film THX-1138)
is not a sound format but a certification process. THX encompasses the whole
nine yards of the movie experience. In order to be completely THX the video,
the audio, the equipment and even the construction of the room must be THX certified.

For example if a person watches a movie with the THX certification on it on
a non-THX DVD player it isn’t truly THX. If the movie, player and amplifier
are THX certified but not the cables then it’s too bad. The same goes
for the room in which the pricey THX certified equipment sits in.

“Up to” the old tricks with “better
than CD”

In all of the specs and chatter bantered about the phrase “up to”
comes into play most often. Remember that UP TO does not mean that it will necessarily
be as specified. It just means that it has the capability of that specification.

Audiophiles have a whole new area to debate and that is about two new formats
that are now part of a niche market. DVD-Audio and SACD are two competing formats
that bring the promise of “better than CD” audio.

DVD AUDIO

DVD-Audio raises the bar for audio by providing up to 24-bit
data sampled at a rate of up to 192 kHz. The key words are “up to”.
The actual sampling rate is 24-bit 96 kHz for multi-channel sound and 24-bit
192 kHz for traditional two-channel or stereo sound. CDs are presently 16-bit
data sampled at 44.1 kHz.

There are two important definitions to add to your vocabulary at this moment;
lossy and lossless audio compression.

Lossless Audio Compression is a digital file that has been more efficiently
“packed”. No information has been discarded but the data has been
reorganized to a greater efficiency and can result in a smaller file size than
the original. Of course an equally as good decoder must be used to “unpack”
the file for playback. Remember that there is still a very smart compression
algorithms applied.

Lossy Audio Compression removes certain characteristics of the file thus making
it manageably smaller. Lossy Audio Compression is achieved by an algorithm that
determines which frequencies in the waveform wouldn’t normally be heard or distinguishable
by the listener and removes these “redundancies” of the waveform,
resulting in a smaller file size. The harder the compression, the harsher the
“decisions”. MP3’s have lossy compression algorithms applied
during compression but the greater the compression means the greater the reduction
in quality.

Another equally important point to remember is that a high quality copy of
an inferior source results in a high quality playback of bad audio. If that
old, worn out cassette tape that has been rattling around the trunk of the car
since the mid-80’s is encoded at 24-bit 192kHz using the best audio equipment
then the result will be a high quality digital file that sounds like a worn
out cassette tape that has been rattling around the trunk since the mid-80s.
Higher bit and sample rate will not improve sound quality of a poor source.

DVD-Audio will also include extras such as video, web content, limited interactivity
and other such features that are designed to lure the consumer to purchase.
It is the hybrid between DVD video and high quality audio.

The problem is that it isn’t compatible with anything at this moment
save a DVD player with the DVD-A logo on it. DVD-Audio discs will come with
additional tracks that will allow a listener to enjoy two-channel (stereo) or
even multi-channel sound with current PC DVD-ROMS or a stand alone DVD player.
This is just the same as present CDs. DVD-Audio discs need, of course, a DVD-Audio
compatible DVD player and if you don’t have that little symbol on the
DVD player then you are out of luck for the full DVD-A experience.

Forget about that really expensive digital coaxial cable or Toslink (Optical)
cable as neither will be able to handle the amount of data that DVD-A spews
out. For that a FIREWIRE (1394) connection is needed. At present only the top
end (expensive) home theatre amplifiers have 1394 connections and 24-bit 192
kHz built in DACs. The bottleneck is with the S/P DIF interface and not the
cable itself.

This leaves the audiophile reduced to an analog connection between home theatre
receiver/amplifier and the DVD-A playback unit. Where there were 6 cables for
discrete 5.1 sound came one in the form of a digital cable and where there was
one digital cable now there shall be up to 6 for 5.1 amplifiers and up to 8
for 7.1 amplifiers and they shall be analog. From analog to digital to analog
the cycle repeats.

PC enthusiasts are out of luck at this moment. There aren’t any DVD-ROM
drives that will play the 24-bit, 96 or 192 kHz tracks of a DVD-A disc. There
may be when market demand encourages profit for a manufacturer but until then
the PC audiophile who wants DVD-A will have to buy a stand alone DVD player
with DVD-A approval. Present PC DVD-ROM players will read a DVD-A disc but audio
only. Audio cards that are not DVD-capable meaning the ability to process up
to 24-bit 192 kHz audio on ALL channels will not play DVD-A discs. Sound cards
that are 24-bit 96 kHz capable on all channels will also play DVD-A discs but
if the DVD-A disc exceeds 24-bit 96 kHz then it is “no go”.

Third party software is also needed to play DVD-A discs and at the time of
this article there isn’t any software on the market that has true DVD-A support.
Any software that claims to be will only play audio. The other DVD content such
as timed lyrics, extra content, multimedia, etc. is not available to the PC.

DVD-ROM drives can “see” the tracks but without a minimum of a 24-bit
192 kHz all channel capable audio card and third party software…there is no
DVD-A joy for the HEPC. Since DVD-A discs can either be 24-bit 96 kHz for multi-channel
and 24-bit 192 kHz for two channel (stereo) the best recommendation would be
a 24-bit 192 kHz all channel audio card to provide the ultimate in flexibility.

Be aware that “DVD-A capable” is totally different from DVD-A “now”.

SUPER AUDIO CD

Super Audio CD or SACD utilizes the same media as DVD. That
is both are “pressed” on a 4.7 GB single layer data disc. SACD boasts
an incredible 2.8 MHz per channel frequency that is very much higher than DVD-A.
The specifications say 1-bit but that is not a data rate but a name for Sony’s
digital to audio conversion.

SACD does not contain content other than audio and like DVD-A, for the moment,
will contain normal 16-bit 44.1 audio tracks and 1-bit 2.8MHz audio tracks stereo
or multi-channel tracks. SACD is thought to be more of the “audiophiles”
choice for listening perfection. A high end audio retailer we spoke with agrees.

SACD puts people in the same boat as DVD-A; no logo – no play and no
1394 FIREWIRE connections from the playback unit to the amplifier – no
digital audio.

As I look at my year old $7000 investment in home theatre equipment I realize
that it may not live up to the formats that lurk in the future. This “buy
now and regret it later” syndrome haunts all of us and the question is
what to do about it now?

There is a technological push and a marketing push for change that meets and
equal and opposite push back from the consumer. Technology progresses and just
because it can be done doesn’t mean that it will be done for the mass
market. Marketing likes to hang “bigger, better, more” on products
to entice buyers. The consumer may be enticed by lofty numbers but, in truth,
they can’t enjoy a lot of it.

In short, SACD, may not be available to the HEPC market at all.

The future of DVD-A and SACD

DVD-A and SACD discs are not as plentiful compared to regular audio CDs and
neither is the equipment that can support it.

Multi-format DVD players are entering the marketplace in a variety of price
points but how will the public react to being forced to step back to analog
connections after years of digital persuasion? There is the thought that entire
CD collections will have to be replaced with SACD or DVD-A versions. Some of
us already went through this investment transitioning from LPs to CDs. DVD-A
and SACD in the home doesn’t mean DVD-A and SACD in the car or in the personal
stereo. A lot will have to be replaced and that is why both formats are including
16-bit 44.1 tracks to ease the transition over time as equipment is upgraded/replaced.

Instinct tells me that it will be DVD-A which gains a foothold before SACD.
DVD-A offers the added features to attract buyers. DVD-A has a perceived value
where SACD only offers an allegedly superior audio signal. If a consumer can
live with analog connections then a current DVD player will suffice as long
as it has the DVD-A logo on it. A major influence to which format “wins”
lies in the ability for it to travel from home theatre to car audio to personal
players.

The HEPC could at least provide the DVD-A experience for audio and that depends
on 3rd. party software which isn’t fully developed yet.

Making the right choice means assessing what you have now and if you plan to
upgrade it within the next year and how much you want to spend if that upgrade
should occur. Presently 1394 equipped home theatre amplifiers are at the top
end of the price scale in the thousands of dollars. Since DVD-A and SACD require
a FIREWIRE connection for true digital 24-bit 96 kHz, 192 kHz or 2.8 MHz sound
then an audio card with a FIREWIRE port may be rather useless for playback.
Keep in mind that the port has to be true DVD-A and SACD capable for the digital
experience.

PC DVD-ROM drives support all Dolby, Dolby Digital and DTS multi-channel discs
with the proper software and the audio is still 16-bit 44.1. Therefore an audio
card with optical or coaxial digital out is a must if the amplifier has a better
audio processor and decoder than the PC sound card This is provided that the
amplifier has optical or digital in. Make sure that a sound card’s digital
out matches the digital in connection to the amplifier.

But there is where it ends. Multi-channel sound from a game or an audio disc
that an amplifier doesn’t natively decode is best handled by the sound card
which does. Analog connections now come into play turning the home theatre applier
which processes and decodes into “just and amplifier”.

Another important possibility to consider is that the amplifier may not have
an audio processor and decoder equivalent to the sound card The sound card may
be better and in that case, regardless if the amplifier has DTS or Dolby Digital
decoding, it may be better to use the sound card to process and decode the audio
and feed it to the amplifier. Sound cards today can be better better at this
task of making the audio sound good compared to that year old or 10 year old
amplifier.

Analog connections are always offered on a sound card but make sure a minimum
of 5.1 is supported by discrete connections. The ability to have discrete audio
is superior to “virtual” signals for the center and LFE (sub-woofer.)
Discrete audio means a dedicated channel for each of the 6 surround speakers;
left, right, center, left surround, right surround and LFE (Low Frequency Effects
otherwise known as the sub.).

Looks good on paper…sounds terrible

Now that those choices have been narrowed down to a few products then how to
tell which one is the best choice? The next step is to delve into the specifications
to further thin out the pack.

Audio cards can have some pretty impressive specifications on paper. To the
novice those specifications may look good but the card sounds terrible after
it comes home. What do specifications really mean and are manufacturers being
100% truthful with their claims? Let’s examine a hypothetical list of
specifications and discover this.

Short-Media DigAudio 9000*

Dynamic Range	100 dB (a-weighted)
Signal-to-Noise Ratio	100 dB (a-weighted)
THD	0.001%
Frequency response	20 Hz to 20 kHz
Crosstalk	100 dB

*an imaginary piece of equipment for illustrative purposes
only

Those specifications may look comprehensive but they aren’t. It’s
important to know what isn’t included in the specifications along with
what is. For example a claim may be made that a Ford Pinto’s top end speed
is Mach 1 which is pretty impressive but the fact that the Pinto was strapped
to the Concorde was omitted. The same goes for audio equipment specifications.

Incredible as it may seem there are manufacturers who don’t tell the
truth. Most present partial information that makes the product look good on
paper when it truly isn’t.

The first step to demystifying audio specifications is knowing a bit about
typical human hearing. The “typical” human ear is sensitive to sound
from 0 dB to 120 dB. Anything below 0 dB is too quiet to hear and anything above
120 dB can cause pain and potentially hearing damage. Long term exposure to
sounds above 85 dB will cause hearing damage and exposure to a 140 dB will cause
immediate damage. It is said that sounds above 130 dB aren’t “heard”
because they overload the human ear.

Decibel or dB is a measurement of sound level. It is not how a measurement
of high or low the pitch of a sound is (frequency) but the strength of that
sound. In electronics and signals dB can also represent a ratio of power, or
voltage or intensity or several other things.

Humans talk about sound in loud or quiet terms and high or low pitched. Sounds
can be loud and low pitched and quiet and high pitched or vice versa. Just because
a sound may become too high a frequency that the human ear can’t distinguish
doesn’t mean that it has become quiet. Your dog who hears much higher
frequencies than you and I may be frantically telling you to turn it down even
if you can’t hear it.

Frequency and dB have a scale but don’t have the same “middle”
in the case of human hearing. On the 0-120 dB scale there is an approximate
middle of 40-70 dB. 40 dB is equivalent to that of a very quiet neighborhood
or inside a library and 70 dB is a noisy restaurant, vacuum cleaner, a party
with a lot of people talking or roadside traffic. On the frequency scale of
human hearing from 20 Hz to 20 kHz the “middle” where the average
person is most sensitive to sound is approximately 2-4 kHz which is in the upper
third quarter of the scale. Sensitivity to frequency changes with age and exposure.

Individually everyone’s hearing is different. A person may be able to
hear a large range of frequencies at 60 dB but the same person may have a very
small range of sensitivity to that range at 30 dB.

Perfect hearing would be the ability to distinguish all frequencies from 20
Hz to 20 kHz from 0 dB to 120 dB. Nobody has perfect hearing.

This can be applied to any piece of audio equipment. The “perfect”
piece of equipment would be able to “hear” the entire spectrum of
frequency from 20 Hz to 20 kHz at any given dB level from 0 to 120 dB then reproduce
it equally as well perfectly free from distortion or other added information
that wasn’t in the source.

There isn’t a perfect piece of audio equipment.

Dynamic range is the measurement of
the ratio between the lowest frequency sound and the highest and is typically
expressed in dB. Dynamic range can be at the input level and the output level.
In human terms a person who hears very low frequencies, very high frequencies
and everything in between has a large dynamic range of hearing. A singer who
can sing very low notes, very high notes and everything in between has a large
dynamic range to their voice.

Let’s deal with output level first. In order to measure the dynamic range
of a piece of equipment it must be fed a sweep of 20 Hz to 20 kHz frequency
spectrum and then the reproduction of that spectrum is analyzed. Now if the
“average” range of hearing is from 0 dB to 120 dB then the best
measurement would be 120 measurements; the 20 Hz to 20 kHz spectrum at 0 dB
then 1 dB etc.

Nobody wants to look at 120 graphs so an average “middle” dB level
is chosen. There is no hard and fast rule that says choose 40 dB or 50 dB or
60 dB. Some choose 60 dB because it is smack dab in the middle of the range
of human hearing and what has been labeled on the dB scale as “background
music” level.

There isn’t a room full of people that sit and listen and write down
the results. It would be too much work so a filter is used to synthesize the
response of the human ear. It isn’t a microphone. It is an algorithm that
is applied to the results to simulate what a human ear would be sensitive too
across the spectrum of frequencies given. This is a “weighting”
filter and “A-weighted” is the name given to the algorithm that
is thought to best simulate the reaction of the average human ear over the 20
Hz to 20 kHz frequency spectrum.

Dynamic range is expressed in decibels and is the range between where noise
(contamination) enters at the low end and distortion happens at the high end.
So if a piece of equipment specifies that it has 100 dB of dynamic range at
60 dB a-weighted that means that the 20 Hz to 20 kHz signal was fed to the device
at 60 dB and the a-weighted filter was used to analyze the results.

The perfect result would be 120 dB of dynamic range.

So in the case of 100 dB of range the piece of equipment was able to reproduce
a 100 dB window between the quietest sound and the loudest sound. (50 dB above
and below the 60 dB base signal)

Did you ever wonder why some speakers don’t sound as good at a low volume
level as they do at a higher volume level? That is because the speaker has an
increasingly smaller dynamic range as the dB (volume) lessens. They may have
70 dB of dynamic range at 70 dB but only 30 dB of dynamic range at 40 dB. You
can now see why it’s important to keep your “dB’s” straight.

Dynamic range ties right into Frequency Response. Frequency response is the
lowest and highest parts on the frequency spectrum, which can be reproduced
by an audio component, within specific limits. If a specification says that
the frequency response is 20 Hz to 20 kHz but does not include a +/- dB number
it is useless.

This is why.

Frequency response, In very simple
terms, is measured by feeding a device a 1 kHz tone to establish a 0 dB reference
point. The tone is then continuously changed in steps and measurements are taken
at specific frequencies. The perfect result would be a peak for that frequency
in exactly the same place on every variation. Audio equipment isn’t perfect
so there will be some variations and it is those variations that are measured
and then given a dB number which is usually +/-. The lower the number the better
and higher than 3 dB means you should begin to be cautious of the product.

An important note about the human perception of continuous sound is that an
increase or decrease in sound pressure level by 3 dB or less is barely perceptible;
an increase or decrease of 5 dB is clearly perceptible; and an increase or decrease
of 10 dB is perceived as a doubling or halving of noise level. Some argue that
sound doubles or decreases by half in as little as 5 dB increments. It all depends
on the acuity of hearing of that particular person.

Therefore a number that is less than 3 dB is acceptable. When those numbers
are getting to be tenths of a percentage different from each other below 1 dB
as in 0.8 versus 0.3 the difference is negligible and no one is going to be
able to say that, based on those specifications alone, one single piece of equipment
will perform better than the other. It’s when the sound travels through
several pieces of equipment that it begins to add up.

Signal to noise ratio is the strength
of the audio signal in comparison to that of the background noise. All electronic
equipment has noise and there is no getting away from it. A lower number means
that more noise can be heard in comparison to the original signal. For example
when listening to a CD and a lot of electronic hum, hiss or crackling is heard
then the signal to noise ratio is low but the less the hum, hiss and crackle
gets then the signal to noise ratio number, expressed in dB, increases. An SNR
of 40 dB is audible noise easily heard by most everyone. An SNR of 60 dB will
result in noise heard only during quiet passages. An SNR of approximately 95
dB will mean someone will have to listen extremely carefully in an extremely
quiet room to be able to detect the faintest unwanted noise. Above 100 dB and
unwanted noise is more or less inaudible.

THD or Total Harmonic Distortion basically
is the original signal plus any distortion from the equipment the signal is
passing through. All equipment distorts a signal and the rule of thumb is the
smaller the percentage the better. Some say that 1% THD is the threshold between
audible and inaudible distortion so when dealing with two pieces of equipment
that have a THD of 0.01% and 0.001% respectively then based upon that sole specification
neither will sound better than the other. The THD is so insignificant in either
case. THD+N (Total Harmonic Distortion plus Noise) is the preferred rating as
that is the composite picture of the entire signal instead of the harmonic distortion.
An electronic signal, video or audio, can pick up a lot of noise or “crap”
in the journey through a sound card, amplifier or cables.

Crosstalk is one channel affected by
another channel. If a lot of people were confined to one room and some of them
wandered to another then those wanderers would be crosstalk. They are supposed
to be kept to one room (channel) but some of them spill over to the other room
(channel) which is unwanted.

The wool over our eyes

Manufacturers include specifications that are designed to impress but it is
what is not included that becomes important. Everything isn’t what it
seems in audio specifications and manufacturers will include what makes their
product look good but in reality it may be a different story.

As an example a product may state that it has a dynamic range of 100 dB and
may also include the fact that the test was conducted with a 60 dB input using
an a-weighted filter. What wasn’t included was the bandwidth range because
the dynamic range can change depending on the frequency tested and manufacturers
may use the optimum result but may be inappropriate for actual listening range.

An absolutely must read explanation of specification mistakes that are quite
common in every product spec sheet can be found
here. This includes complete explanations of the topics already covered
including correct and incorrect examples.

Digital or Analog?

For the longest time consumers have been beaten over the head about the benefits
of a digital connection between devices. This was our misconception when it
came to an audio device for the HEPC. “Digital is best, digital is best.”
is what we kept telling ourselves. And this is what threw us.

NVIDIA’s NFORCE2 motherboard platform offers the ability for a motherboard
manufacturer to send audio to an external source via an S/P DIF connector. Everything
that the NVIDIA SOUNDSTORM package can do it delivers out the S/P DIF port.

This is good isn’t it?

Not exactly. M-Audio explains why.

Full S/P DIF advantages:

• Convenience: only one cable is required to output 5.1.

Full S/P DIF disadvantages:

• You’re not sending pure Dolby Digital from games or music to the external
  decoder. The chip takes an audio output from a game or media player (for example),
  converts it to Dolby Digital, outputs it to a decoder, and it’s converted
  back to separate channels.
• Requires a costly external Dolby decoder or more expensive Dolby-decoding
  speakers.
• You get the D-A converters on your external converter. These can be decent
  on better surround receivers, but most are inferior to those on Revolution.
• Audio is compressed to 16-bit when going into Dolby Digital mode. If you’re
  playing DTS or Windows Media 9 content it has to be re-encoded as a Dolby
  signal. This degrades quality. This applies to music, games, or anything.
  An extra level of compression is never good for audio.
• Forget 24/96 and 24/192 kHz audio. These can’t be handled by standard Dolby
  streams.
• Dolby Digital assumes stereo or 5.1. Other configs (quadraphonic, stereo
  with discrete subwoofer, etc.) may not work with this. User may be stuck with
  a 5.1 set.
• User STILL has to adjust settings. Do you choose Dolby Digital, Dolby Digital
  Stereo, Dolby Pro Logic, Dolby Surround, Dolby Pro Logic 2? Most users don’t
  understand the difference and often choose the wrong one, neutering their
  sound.
• You won’t get DVD-A or any other high-resolution audio advantages with this
  setup.
• Don’t forget input. Having pro-quality 24/96 input capability makes a huge
  difference in what you can do with audio. Video editing, home music recording,
  vinyl-to-digital conversion all benefit from high-quality recording capability.
• No ability to do bass management or any other high-end processing on audio
  unless built into decoder (and it’s not on most under $500.00 receivers/speakers
  with decode).

Full analog disadvantages:

• You have to run “all those cables.” For most people this is not
  a big deal. Most multimedia speaker sets ship with a “three headed”
  analog cable that’s a single cable with three (or now four) mini-jacks.

Full analog advantages:

• Compatible with ANY kind of surround audio: gaming, music, cinema, etc.
  Play a game, movie, music in surround or stereo and it works.
• Supports all the way to 7.1
• Supports all speaker configs from stereo through 2.1, 4.0, 4.1, 5.1, 6.1,
  and (of course) 7.1.
• Windows Media Audio 9 Compatible (without recompression or conversion)
• Compatible with any multimedia speakers.
• Compatible with any surround receiver with analog input.
• Use high-definition A-D and D-A converters on the Revolution card.
• Can be recorded by an external source (of interest to many users).
• Supports up to 24-bit/192kHz audio output.
• DVD-A capable.
• Supports high-quality bass management for real home theater experience.
• Virtual surround sound on stereo speakers (not present in DD stereo mode).
• TruBass and Dialog Clarity features allow you to increase perceived bass
  output of speakers and increase dialog clarity.
• Of course, we can send pure Dolby Digital or DTS (including EX/ES) to an
  external receiver and decode it.

Taking the “spin” off this boils down to this. It is a no brainer
that if the home theatre amplifier has superior audio quality for DACs, ADCs
and decoding then the DTS or Dolby Digital signal should be sent to the amplifier
digitally. The optimum situation is to feed best quality to best quality. It’s
that simple.

S/P DIF offers the convenience of a single cable but here’s what we didn’t
fully comprehend. For two channel or DTS or Dolby Digital 5.1 signals it is
one of the best delivery forms providing the home theatre amplifier has high
quality decoding on board. The disadvantage is best exemplified when a NON-DTS
or Dolby Digital 5.1 signal is used. The signal is first decoded from a game
by the audio card providing it supports the game audio formats. It is then RE-ENCODED
as a Dolby Digital signal to then be RE-DECODED by the home theatre amplifier/receiver.

It is like going from German to English to Chinese to English. Something HAS
to be lost in the translation.

And something is.

There are the subtleties of upsampling, upconversion and oversampling to contend
with. In other words the conversion from one bit rate and sampling rate to another.
The pros and cons of bit and sample rates could take up many more pages of explanation
in itself but, using a wide brush, converting sound to a higher bit and sample
rate does not mean it will sound better. It may, in fact, add more noise to
the signal thus making it sound worse.

Bass management is another term widely used in the pros and cons discussion
of audio. Bass management, in the most basic of explanations, is directing the
bass information in a multi-channel system. If, for example, a user has a 4.1
system consisting of 4 satellite speakers and a subwoofer then the satellite
speakers may not be responsive enough to produce the proper bass sounds. Bass
management allows the user to properly direct the bass audio signal to the subwoofer
thus providing a fuller spectrum of sound. Bass management is more or less a
crossover device splitting the audio frequency thus providing the ability to
properly direct it.

Often in home theatre equipment the settings for “large”, “medium”
and “small” are used. The assumption is made on the part of the manufacturer
that the physically larger speakers should be able to handle more bass. For
argument’s sake this is true but it really depends on the specifications of
the speaker if the proper setting is to be used. Sometimes bigger doesn’t mean
better.

If an onboard audio processor takes a non Dolby Digital signal and encodes
it for S/P DIF output then bass management may be lost due to the fact the signal
was encoded and then decoded by a Dolby Digital bass management system which
may be different from the original bass management signal. Again…something
will be lost in the translation.

It is now clear that the best route is to output a signal to an external amplifier
in it’s true form. Encoding the processed signal into another form to then be
decoded and processed again by an external device will only degrade the final
output. In some cases analog connections to the amplifier are superior to digital.

Now the kicker

Audio, be it analog or digital, has to bounce through a few devices in order
to get to the speakers. If the source is on a CD or as a digital file on the
hard drive it begins the journey picking up unwanted noise and distortion from
the hard drive, the cables, the circuits, etc. The signal may pass through components
that restrict or change the dynamic range or have a different frequency response.
This digital “lint” accumulates. The sound card adds its “lint”
to the signal and fires it out the door to the home theatre amplifier which
in turn adds its “lint” and finally the speakers have their own
“lint”

By the time the sound gets to your ears it may be a far cry from the alleged
impressive specifications that were listed on the sound card itself.

So now what?

The ideal home theatre setup is a topic of endless debate but there are smart
choices that can be made. Achieving good specification numbers across all components
has been already briefly been discussed.

“Must haves”:

• Over 100 dB of dynamic range with a wide frequency response that isn’t “marketing
  cloak and dagger”.
• S/P DIF out if the home theatre amplifier has a better audio processor and
  decoder. Most of us on a budget may be surprised that some of today’s PC Sound
  cards have better audio processors than the stereo. The choice will be a matter
  of the user’s listening experience but having S/P DIF out along with analog
  gives that choice. S/P DIF out also allows for a CD, for example, to be digitally
  heard without any processing.
• The S/P DIF interface should not upsample, upconvert or oversample the digital
  source.
• The sound card should be able provide 24-bit 192 kHz as a minimum on all
  channels. This takes a step towards preventing obsolescence.
• 5.1 discrete channel are a must and 7.1 is a luxury but also is a step towards
  preventing obsolescence. If that 5.1 home theatre amplifier is replaced with
  a 7.1 capable unit it will be nice to know the PC sound card doesn’t have
  to be replaced as well.
• Support for game audio formats only makes the game experience that much
  better.
• A simple yet flexible GUI (Graphic User Interface) is a must. A GUI that
  is complicated and hard to understand or set could mean the full capabilities
  of the sound card are not utilized.
• Bass management on all speakers will make audiophiles ecstatic. Novice users
  can also greatly benefit from bass management.
• The audio card should be flexible for speaker configuration. Some users
  may only have two speakers, some may have four and others may have up to eight.
  The audio card should have the ability to properly direct audio signals dependent
  on user configuration. There is not point sending 5.1 sound to a two speaker
  system. Much of the audio won’t be heard.

Considerations:

• If true digital DVD-Audio is the eventual goal then a sound card with FIREWIRE
  output is desirable providing the home theatre amplifier has a FIREWIRE input.
  FIREWIRE equipped home theatre amplifiers are relatively expensive and not
  as common.
• If the desire is for playback only then S/P DIF IN is an unnecessary luxury
  unless the goal is to encode from another digital external source that has
  a matching S/P DIF interface. If the desire is to digitize those scratchy
  LPs in the back closet then a LINE IN connection is sufficient. Just make
  sure the device that is between the record player and the sound card doesn’t
  add noise, hum, distortion or other unwanted interference.
• A GUI EQ may not be necessary. It’s a 50/50 affair but if there is to be
  one…it had better be good. A home theatre amplifier can provide the necessary
  treble and bass and is preferable to a software EQ at this level.

The M-Audio Revolution 7.1

Who knew that choosing a sound card could become so labor intensive. There
was a lot to be learned and un-learned. It was CDMEDIAWORKS
that provided the proper direction. (Incidentally CDMEDIAWORKS has, to our knowledge,
the best Canadian price on the M-Audio Revolution.)

Specifications

• PCI solution for high-quality surround sound up to 7.1
• also supports DTS output and Dolby Digital 5.1/EX (6.1 DVD) decoding
• high-resolution audio output up to 24-bit/192kHz
• true professional 24-bit/96kHz recording
• Incredible 107dB signal-to-noise ratio
• real-time stereo-to-surround conversion
• SRS Circle Surround II technology delivers realistic surround sound from
  any stereo source
• simple control panel for Bass Management and other features
• supports all popular media players including Windows Media 9
• includes software bundle worth over $200

Technical

• 24-bit/192kHz audio playback on all output channels.
• Supports all speaker configurations from stereo (or headphones) up to 7.1
• Analog line in supports recording up to 24-bit/96kHz
• Analog mic in supports recording up to 24-bit/96kHz
• Coaxial digital output
• S/N Ratio A->D: 100dB
• S/N Ratio D->A: 107 dB (eight channel/two channel)
• Driver-Level Bass Management
• Windows Media 9 Compatibility
• Very low CPU utilization
• Dolby Digital Decode (Windows)
• Supports both CircleSurround II and TruSurround XT

Audio Performance

Line Outs

• Dynamic Range: 106 dB (typical, -60 dB input, a-weighted)
• Signal-to-Noise Ratio: 107 dB (typical, a-weighted)
• THD: 0.003% (i.e., -90dB)
• Max. Line Output Level: 1.26 Vrms (+2 dBV)
• Frequency Response: +0.8/-0.0 dB, 20 Hz to 20 kHz +0.8/-3.0 dB 20 Hz to
  80 kHz
• Crosstalk: – 120 dB

Mic In

• Dynamic Range: 90 dB (a-weighted)
• Signal-to-Noise Ratio: 90 dB (a-weighted)
• THD: 0.003% (i.e., -90dB)
• Max. Line Output Level: 1.26 Vrms (+2 dBV)
• Frequency Response: +0.0/-3.0 dB, 80 Hz to 17 kHz

Line In

• Dynamic Range: 105 dB (a-weighted)
• Signal-to-Noise Ratio: 100 dB (a-weighted)
• THD+N: 0.003% (i.e., -90dB)
• Max. Line Output Level: 1.26 Vrms (+2 dBV)
• Maximum Input Level 1.45 Vrms (+3.2 dBV)

Sampling Frequencies (KHz)

• No sample rate conversion: 32, 44.1, 48, 88.2, 96, 172.4, 192
• With MME rate conversion: all sample rates up to 200kHz

Package contents

Revolution 7.1 comes with over $200 of high-quality software including:

• Tony Hawk Pro Skater 3 (full version)
• VJ Lite (full version)
• WinDVD 4 (Dolby Digital EX version)
• Propellerhead Reason (trial version)
• Ableton Live (trial version)
• Over 100 sounds and loops
• Free M-Powered Artists CD sampler

System Requirements Windows ME / 2000 / XP

• W/O CSII , P 200 MMX, 64 megs RAM
• W/ CSII (5.1), PIII 500, 64 Megs RAM
• W/CSII (7.1), PIII 700, 128 Megs RAM

System Requirements MAC

• OS 9.2.2 or Higher (OS X compatible)
• W/O CSII , G3 350 (native), 64 Megs RAM
• W/CSII (5.1), G4 350(Native), 64 Megs RAM
• W/CSII (7.1), G4 500, 128 Megs RAM

Picking a sound card was relatively easily once we understood what we had to
work with and what we needed. The M-Audio Revolution does look similar to every
other sound card. So do the specifications compared to the competition. Spec
for spec the Revolution does a “nose ahead” and a “miss by an
inch” game with its rivals. Specifications are the first step of weeding
out the contenders and the next step determines a winner.

Features

Most may comment on the “missing” S/P DIF IN connection but that
has already been explained. Unless the digital signal is coming from another
external digital hardware device then S/P DIF IN isn’t necessary for the HEPC.
LPs can be encoded through the LINE IN port as there is no sense converting
the LP signal to a digital signal inside a home theatre amplifier/receiver.
It will not result in a direct capture of the LP/analog source.

The Revolution 7.1 is a 24-bit 192 kHz card. It is capable of delivering up
to 24-bit 192 kHz audio on all 8 channels. The competition may be able to deliver
24-bit 192kHz audio on only 2 channels and 24-bit 96 kHz on only 6. The Revolution
does the job of staving off obsolescence by including the capability of full
7.1 24-bit 192kHz audio.

The E-N-V-Y chip is the workhorse and rumor has it that Chaintech will be looking
at including it on future motherboards in some capacity.

The card appears to look fairly simplistic but don’t be fooled. The software
GUI is equally as simplistic but look carefully. We were amazed at how simple
yet powerful the GUI is. It continues to leave us shaking our heads. It seems
in poor taste to lead with a fault but one of our dislikes was the lack of a
desktop ICON pathway to the GUI. The Revolution control panel has to be opened
by double clicking on the taskbar icon or right clicking to open the menu.

The main GUI interface appears simple enough and a consumer may feel like there
should be more for such a high end product. The eye candy isn’t there and for
good reason. It isn’t needed and it only clutters up the GUI.

First off the GUI comes pre-configured with 5 click-able buttons across the
top. These aren’t hard coded. They are programmable and it is very easy to set
up favorite settings. The trick is to right click on one of the five setting
icons and remove it. Any setting made thereafter can be saved by dragging the
CURRENT SET icon to that top bar. Just remember there cannot be five icons in
the top toolbar before saving a CURRENT SET icon to the toolbar. Remove at least
one.

The speaker setup tab is immensely powerful. It still leaves me giddy for the
control it has. First the size of the speaker is not limited to “large”
and “small”. It has size settings of small, medium, large, flat panel
and cube. That’s 2 more than my expensive home theatre amplifier.

Next is the crossover setting which is defaulted at 80Hz but a user can customize
it to 40, 60, 80, 90, 100 or 120 Hz. Why is this such a benefit? Everyone has
different speakers and the ability to adjust the bass management, to fine tune
it, to a particular speaker is paramount in the task of sweetening the overall
sound.

Next each channel can be individually controlled for output or controlled by
link pairs.

The distance the speaker is from the listener sitting in the preferred location
can be set. Revolution’s intelligent software utilizes this to provide for better
audio enjoyment. It “times” the audio to “hit” you at the
same time from each of the speakers. Rarely do we sit in the exact center of
an audio room in the sweet spot. The Revolution allows for that sweet spot to
be moved.

Now here is the giddy part. The precise control over the speaker size, crossover,
output level and distance can be done for each of the channels; all eight of
them. Most audio cards assume the user has identical speakers on each channel
the exact same distance from the 5.1 optimum center.

This isn’t always true as we sit in different spot and some have matching mains
and a different center and surrounds.

The Revolution allows for independent control of both LFE bass (the DVD bass
track/dedicated bass channel) and redirected bass. This is key for fine-tuning
bass configuration on a home theater. It also provides for the ability to boost
or lower both of the previous from the control panel which means there’s no
need to crawl behind the subwoofer to tune it. Lastly the Revolution provides
for the ability to invert phase on the subwoofer in the control panel. Again,
no need to crawl behind the subwoofer when tuning.

And bass management is extensive. Pull bass off a 2.0 signal to create a true
2.1 config (discrete subwoofer). Same goes for 4.0 to 4.1.

So where to begin?

Get familiar with the Revolution control panel and what it offers then why
not remove every QUICKSWITCH SETTING icon to start with a clean slate. The CURRENT
SET has a pull down menu that has all the basic default settings for headphones
through to full 7.1 settings. It also has many of the PC speaker systems from
Altec Lansing, Cambridge Soundworks, Creative Labs, Harmon Kardon, Klipsch,
Logitech, Monsoon and S4 Midland that are pre-optimized for the best sound for
those speakers.

If the Revolution is feeding a home theatre amplifier the user can then select
from generic settings, such as stereo, then fine tune bass management, dB levels
and crossover until totally satisfied. An absolutely necessary step is to choose
SAVE CURRENT SET from the pull down menu then drag the icon to taskbar. The
CURRENT SET icon can then be dragged to the QUICKSWITCH SETTINGS toolbar and
it is there for the next time. If the option SAVE CURRENT SET is not chosen
from the pull down menu it will not saved even if dragged to the taskbar.

This can be done for a multitude of speaker configurations. Now if a user wants
to play a game in 5.1 surround then they can choose their custom setting for
that function. The same goes for a music setting. The downfall is that the QUICKSWITCH
SETTINGS icons cannot be given custom names. A user can add an icon setting
for 5.1 surround up to five times in the QUICKSWITCH SETTINGS toolbar and each
one can have a different speaker setup but there is no means of labeling which
is which.

The QUICKSWITCH SETTTINGS are easy and handy. Once a preference has been set
up it is just a matter of one click to get to that favorite.

The output mixer tab displays as many channels that are active. It’s the same
as the output levels on the SPEAKER SETUP tab but all on one tab for an “all
in one” glance. Both tabs have solo and mute.

Surround effects are almost impossible to describe in words. They have to be
heard. The settings do not produce “cheesy” effects either. There
is no other way to describe the multitude of audio settings except to say that
you won’t be disappointed.

SRS TruSurround XT is available for speaker configurations less than four.
This feature allows for multi-channel playback on a 2 or 2.1 speaker system
without missing any of the audio. The setting “virtually” places the
surround speakers therefore allowing the user to hear the multi-channel DTS
or Dolby Digital sound track. The virtual speakers do not mean that a user can
have 5.1 or 7.1 surround without the additional speaker expense. It, more or
less, redistributes the sound from those tracks that don’t have speakers to
the mains. A bit of audio “trickery” is used to create virtual speakers
giving an illusion of extra speakers. Remember that this cannot replace the
sound quality from a true 5.1 or 7.1 surround system…it allows for a “smoke
and mirrors” illusion of it.

Four speakers and above atomically makes SRS Circle Surround II available which
is “just fun” to play with. It has to be heard and will become one
favorite of mine. Basically it turns two channel sources into multi-channel
surround.

Both SRS TruSurround XT and SRS Circle Surround II have the ability to boost
bass and enhance the dialog clarity. It can, amongst other things, compensate
for “tinny” or “muddy” speaker systems.

The INPUT/OTHER tab allows for stereo recording at a user setting sample rate.
AISO buffer size will compensate for stutter during the recording process or
playback process due to processor lag.

RightMark
Audio Analyzer test

Rightmark audio analyzer is a quick an easy way to assess an audio card. It
isn’t the laboratory route but does provide some information that’s right for
the price. (free). Before the assessment is made that one audio card is better
than the other it is absolutely crucial to not base a final decision on numbers
from different reviews unless they are extremely far apart. Different reviews
used different power supplies, different cables and connections and different
setups. Comparisons using Rightmark are better when as many of the components
are the same therefore we provided a comparison against the NVIDIA Soundstorm
package on the ASUS A7N8X.

The only way of truly assessing sound card performance is in controlled environments
using professional audio measurement tools. Rightmark provides and obvious comparison
platform and catches the big differences. Tests such as these should be used
to narrow down the field as the final test comes with the user’s listening experience
and getting the features they looked for.

Rightmark Audio Analyzer in loop back mode uses on the card itself and while
a card may have a high rating on the output the input may be lacking thus the
total score lacks too. Use RightMark in comparison to other Rightmark scores
using the same cables and testing procedures.

• Testing chain: External loopback (line-out – line-in)
• Sampling mode: 16-bit, 44 kHz

M-Audio Revolution 7.1 Sampling mode: 16-bit, 44.1 kHz
Frequency response (from 40 Hz to 15 kHz), dB:	+0.14, -0.06	Very good
Noise level, dB (A):	-79.3	Average
Dynamic range, dB (A):	79.1	Average
THD, %:	0.0025	Excellent
IMD, %:	0.059	Good
Stereo crosstalk, dB:	-79.9	Very good

Asus A7N8X NVIDIA Soundstorm Sampling mode: 16-bit, 44.1 kHz
Frequency response (from 40 Hz to 15 kHz), dB:	+0.33, -0.90	Average
Noise level, dB (A):	-59.6	Poor
Dynamic range, dB (A):	59.6	Poor
THD, %:	0.048	Good
IMD, %:	5.622	Very poor
Stereo crosstalk, dB:	-57.5	Average

M-Audio Revolution 7.1 Sampling mode: 24-bit, 44.1 kHz
Frequency response (from 40 Hz to 15 kHz), dB:	+0.13, -0.06	Very good
Noise level, dB (A):	-79.4	Average
Dynamic range, dB (A):	79.1	Average
THD, %:	0.0024	Excellent
IMD, %:	0.060	Good
Stereo crosstalk, dB:	-80.1	Very good

Asus A7N8X NVIDIA Soundstorm Sampling mode: 24-bit, 44.1 kHz
Frequency response (from 40 Hz to 15 kHz), dB:	+0.34, -0.88	Average
Noise level, dB (A):	-59.8	Poor
Dynamic range, dB (A):	59.4	Poor
THD, %:	0.046	Good
IMD, %:	4.400	Very poor
Stereo crosstalk, dB:	-59.4	Average

The comparison tests show that the Revolution leaves NVIDIA’s Soundstorm behind
by a very large margin. NVIDIA Soundstorm is about as good as it gets for integrated
motherboard sound.

Listening Feedback

How the Revolution sounded is almost impossible to describe in words. What
wasn’t heard is very easy to describe. There was no distortion. There was not
crackling or popping. There was no circuitry or line hum even when the volume
was cranked to “10”. Playback of a CD sounded like playback of a CD
from a stand alone CD player on a digital connection.

To comment that the Revolution sounded better than my own personal DVD player/home
theatre amplifier combination would be a lie. It sounded just the same. It is
important to note that I have a high end setup worth many thousands of dollars.
If the Revolution produces sound quality equivalent to the expensive system
by way of a person sitting in the room listening…then it can be safe to say
that it will deliver very high quality audio to any lesser amplifier. From there
it will be the amplifier’s or speaker’s fault if noise or signal degradation
occurs.

The Revolution does bring some interest surround effects to the table that
expensive surround receivers don’t particularly do a good job of. My expensive
home theatre amplifier doesn’t, for example, do a good job of surround music.
It produces the cheesy hall effect whereas the Revolution can produce sound
from “everywhere”.

The HEPC was also hoofed around to other stereo and speaker systems including
a JVC RX551 “pre-surround days” amplifier driving two bookshelf speakers.
The SRS TruSurround XT setting was chosen and after experimentation with the
Front Speaker and Crossover settings the audio was found to be rich and full.
Initially there was thought to be some distortion but Revolution’s aforementioned
settings rectified this with fine tuning. That fine tuning isn’t available in
a lot of other audio cards.

Those of you with low to medium end 5.1 amplifiers can benefit from the Revolution.
Use the amp as just an amp and let the Revolution handle Dolby Pro Logic, DTS
and Dolby Digital 5.1 decoding. The sound quality may even be better than what
the amp can do. Only listening tests will help in the decision but it’s nice
to have the option.

Lastly there is the lure of DVD-A. It’s 2/3 of the way complete. DVD-A discs
can be purchased. The discs can be read in a PC DVD-ROM drive. The Revolution
is one of the only cards, if not the only card, that can support 24-bit 192
kHz audio on all channels. The missing element is the software for the full
DVD-A multimedia experience in a PC. M-Audio assures us that they are currently
working on this.

A “hot key” programmable option to the QUICKSWITCH SETTINGS icons
would be convenient to assign the audio pre-configured settings to a USB remote
or keyboard.

Lastly is the M-Audio Revolution 7.1 “better” than the nearest competition?

It can’t be said at this stage because we haven’t worked with the high end
cards from manufacturers like Creative, Terratec and AudioTrak. We do know that
on some fronts the Revolution surpasses all of the aforementioned and given
our lack of really expensive testing rooms and hardware our own tests are admittedly
far from laboratory conditions.

We are immensely pleased with the sound quality of the M-Audio Revolution.
It is a top choice for audiophiles and places well for gaming though M-Audio’s
expertise lies in audio recording and production. The HEPC’s primary goal is
to deliver the high quality audio first and foremost. The M-Audio Revolution
7.1 was a good choice for a sub-$100 USD audio card. It has longevity and the
ability to control bass management on all speakers surpasses even higher end
audio amplifiers.

Reference sources

Our thanks to Chris Coey of CDMEDIAWORKS
for his support in both hardware and knowledge. We began our search for the
HEPC audio card some time ago at CDMEDIAWORKS had the best price we found in
Canada and a lot of the US. Our thanks also goes to M-Audio for their invaluable
assistance with putting the reams of information we had assembled into perspective.

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