Hoontech SoundTrack Digital XG

Digital For All

Digital Input

Before I take a closer look at the XG DB I, the digital I/O daughter board for the Digital XG sound card, let me again repeat that those of you who only need a digital connection from your CD-ROM to the sound card need not the extra daughter board, as a 2-pin SPDIF connector is already built in. In fact, Hoontech goes so far to even offer this freeware CD player which allows you to digitally transfer the audio data from the compact disc to the sound card on any CD-ROM supporting Digital Audio Extraction.

However, for the digital recording enthusiast, Hoontech's daughter board offers the best digital daughter board I have ever seen. Not only are coax SPDIF, and TOSLINK connectors available, but also AES/EBU inputs and outputs which you'll only find on high-end audio equipment (although the AES/EBU cable is an extra $12).

Massively Digital I/O

AES/EBU adapter

The digital inputs allow for editing and manipulation of digital masters, from DAT for example. Although the Digital XG can accept all standard digital frequencies (32kHz, 44.1 kHz, and 48kHz), because the sound card is based on the AC '97 standard defined by Intel, the internal sample rate is a fixed 48kHz. So all incoming digital signals are converted to 48kHz in hardware using a high-quality algorithm that does not affect the dynamic range of the signal. According to Hoontech, other digital cards such as the SB Live have a poorer algorithm and an incoming signal with 96dB dynamic range can be reduced to 78 dB.

This means that the digital signal is not bit-identical because it's always resampled to 48kHz, but it's still very good. The TerraTec DMX, on the other hand, can accept 32kHz and 44.1 kHz data directly without conversion, but the DMX does cost more than three times the Digital XG. Another advantage of the DMX is the ability to "bypass" the SCMS copy protection bit.

Since the Digital XG is a consumer product, only one digital input can be active at any given time. Fortunately, the card automatically selects the digital inputs with the following priority:

So, while you won't be able to input more than one stream at any given time, you don't have to worry about "losing" your CD Digital when you are temporarily using the daughter board. If you do need multiple digital inputs or bit-perfect digital recording, Hoontech does offer a complete line of non-gaming (no DirectSound 3D support) Digital Audio cards and kits which do bit-perfect 24-bit, 96kHz digital I/O which range from $300 to $1100.