Abit iDome and AirPace Music

Analog vs. Digital

Abit's Personal Digital Theater is built around the concept of a digital speaker system. Traditional speaker systems are analog and rather simple in comparison. An analog signal representing the sound to be played is passed to the speakers where it drives the speaker's cones, which in turn creates sound waves that our ears perceive as sound. While this is the basic concept of a speaker, an actual sound system is much more complicated. Additional steps must be considered, such as the generation of the analog signal being passed to the speakers as well as amplification and processing of the signal to control various aspects of the sound like intensity and the amount of bass present.

In a computer, the task of signal generation and processing is handled by a sound card / chip and the process is digital since your computer is a digital device and the sound that is to be played begins as a digital file or stream on the computer. However your ears, and sound for that matter, are fundamentally analog. So at some point the sound signal must be converted from a digital signal to an analog signal. Unfortunately, this conversion is never perfect and a certain amount of information is always lost in the process. This also means that the more you convert the signal between analog and digital, the more it's degraded. In a computer, this conversion is usually handled by the sound card, which has one or more built-in digital-to-analog converters (DACs). The quality of a sound card's DACs is one of the main determinants of the sound card's quality.

Analog Speaker System

The transmission of analog signals also has many problems which all sound systems must deal with. The inherent problem is that it is extremely difficult to perfectly transmit an analog signal through a wire without signal degradation due to interference or signal loss. The severity of these problems depends on many factors such as the length of the wire that is transmitting the signal, the level of electromagnetic interference the wire is exposed to, the conductivity of the material that the wire is made of and the purity of the material. While a digital signal cannot completely escape from these problems, resulting in misreading and data loss, it is significantly more resilient than analog signals. It's also possible to correct most data lost during transmission with the use of error correction algorithms and except in extreme cases, digital transmission can be thought as being relatively immune to signal degradation.

After being converted from digital to analog form by the sound card's DACs, a sound signal inside of a computer must contend with a great deal of interference generated by the other components in the system. Then it must survive the journey through a wire to the speaker, all the while being subjected to interference from external sources and signal degradation due to impurities in the wires and connections. Sometimes the signal might also be converted back to digital form again to allow for further processing before being converted back to analog form. Ultimately what this means is that a significant amount of information is lost on the way from the signal source to your ears and a certain amount of extra junk is added to the signal. So the sound you end up hearing isn't quite the same as the original recording.

Abit's Digital Speaker System

Abit attempts to minimize these problems with their digital speaker technology by decreasing the number of times the signal is converted and by reducing the distance the signal must travel once it's been converted to analog. To accomplish this, the iDome speakers take advantage of the digital S/P DIF optical output found on most modern sound cards and many onboard solutions. The signal passed through the S/P DIF output has skipped the sound card's DAC and is in its pure digital form. It is also relatively safe from further degradation on its journey to the speaker since one of the primary advantages of optical fiber technology is that the signal is transmitted via light and is totally immune to electromagnetic interference. Amplification and extra processing is done locally by the iDome while the signal is still in digital form, and then when the signal is ready to be converted into sound waves, the signal is passed through a DAC and then immediately transferred a very short distance to the speaker cones. Theoretically, these precautions should ensure that there is minimum signal degradation and you hear the sound "the way it was meant to be heard".

Although abit has gone to great lengths to ensure that the sound signal that arrives at the speaker is as true to its original form as possible, that isn't the only factor that affects sound quality. The quality of the DACs and speaker cones also greatly affect the sound quality, not to mention various environmental effects once the signal actually gets converted to sound waves.
Read on to find out if abit's strategy has succeeded in creating a superior set of speakers.

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