Now let's start measurements of the digital-analog and analog-digital tracks of the card, but before let me cite claims presented for our articles on sound cards and measurements of their characteristics:

1. Usually a line-in of sound cards have much worse characteristics than a line-out. That is why parameters "line out - line in" are not precious, since a user is mostly interested in D-A track. At the same time, parameters of the circuit A-D are worse by 10-15 dB, it is also shown on the manufacturers' sites (Sigmatel, Wolfson, CS). What curious things will appear, for example, when measuring AFC for 3 different cards, are indicated in the article on Creative SB Live! Platinum sound card.
2. Measuring parameters are greatly dependent on a position of faders for recording and reproduction. It is clear that it is necessary to even out input and output levels for 0 dB. But how much positions of Master, Wave and Line-In correspond to it? It may strongly influence the measuring parameters. That is why you should be up to some tricks. You should choose regulator positions which correspond to 0 dB of amplification, in order to avoid outstepping the limits in digital mode. You can get this information in the specs of codecs. Usually, level regulators are set to 0 dB right after installation of drivers (on a blank system).
3. It is difficult to repeat our measurement with the SpectraLAB even if you are technician.

To overcome the latter drawback and widen the range of tests we used a program Sound Card Analyser v 1.0 developed by Aleksei Lukin. The reference sound card EgoSys WaveTerminal 2496 (professional) was used to generate a signal and read measurements.

EgoSys WaveTerminal 2496: 16 bit 48 kHz Line Out - Line In

EgoSys WaveTerminal 2496: 16 bit 44.1 kHz Line Out - Line In

To prove the first thesis here are some tests of the Creative SB Live! Live! Player 5.1 sound card (Sigmatel STAC 9708 codec) for 'Line-In - Line Out', line-in, line-out:

Creative SB Live! Player 5.1: 16 bit 48 kHz, Line Out - Line In

Creative SB Live! Player 5.1: 16 bit 48 kHz, Line In

Creative SB Live! Player 5.1: 16 bit 48 kHz, Line Out

You can see that Line Out - Line In results are much closer to the characteristics of the Line-In and too far from that of the Line-Out. And a user listens to music in 99% cases and only in 1% cases it uses a Line-In.

Now up the thorough testing of the Hercules Game Theater XP.

Front Line Out, 48 kHz

Calibration

Frequency response

Noise and pickups

Dynamic range

Noise and Distortions with 1000 Hz @ -3 dB signal

Channels crosstalk

Summary table

Front Line Out, 44.1 kHz

Calibration

Frequency response

Noise and pickups

Dynamic range

Noise and Distortions with 1000 Hz @ -3 dB signal

Channels crosstalk

Summary table

Note that the figures obtained are referred to the definite sample of the card, they were received with the definite program in use, and do not pretend to be taken as absolute values. But the results can be used for comparison with other cards tested in analog conditions - after the Hercules Game Theater XP we inserted the Creative SB Live! Player 5.1 card (SB0060 model) and conducted the same tests.

It is interesting to compare characteristics of two cards of the same class (the same model is used in the Creative SB Live! Platinum 5.1):

Creative SB Live! Player 5.1 16 bit 48 kHz Line Out

Creative SB Live! Player 5.1 16 bit 44.1 kHz Line Out

Line Out of the Hercules Game Theater XP vs. Creative SB Live! Player 5.1, comparison table:

The both cards show quite good scores. In the 44.1 kHz mode the frequency after the filter is less than 20 kHz, that is why the measuring program has registered a small gap in characteristics. It can be neglected, though, since AFC is an ideal straight line in the range of audible frequencies. A bit lower DR of the Helcules is accounted for by the dithering in mixing algorithms. Analog characteristics are shown by the Live! 4830 in Digital Output Only mode from a front output (see the detailed information in the Santa Cruz review). The only drawback of the Game Theater XP is a channels crosstalk what worsens localization of sound images. But this drawback can be heard only on the expensive equipment or in headphones. And looking at the 2-meter cable connecting the card's codecs with the external module, it is amazing that the Hercules engineers managed to protect the signal coming from the card from pickups and heavy losses in quality.

Line-In tests

Those who are going to use Line-In, for example, for sampling music in order to compress it into MP3, may be interested in the quality of the Line-In of the card. Since the 2-meter cable from the external module doesn't improve the quality, we have chosen Aux- In located on the rear panel of the sound card.

Here are the results:

Hercules Game Theater XP Aux In 48 kHz

Hercules Game Theater XP Aux In 44.1 kHz

Below are the competitor's characteristics:

Creative SB Live! Player 5.1 16 bit 48 kHz Line In

Creative SB Live! Player 5.1 16 bit 44.1 kHz Line In

And the final table:

Line-In of the Hercules Game Theater XP vs. Creative SB Live! Player 5.1:

The Line-In of the Hercules card (more exactly, work of the ACD codec CS4294-JQ) has traditionally good results. It doesn't yield to the Creative card. And if you listen it recorded from an external tuner using files from the Santa Cruz review, you can feel more transparent highs. Apparently it is caused by usage of the CrystalClear technology from Crystal Semiconductor.

SB Live! line-in demo (WAV, 1.05 Mbytes)

Santa Cruz line-in demo (WAV, 0.92 Mbytes)

However, one may prefer timbre sounding of the Live! on the middle frequencies... But if you don't feel all these nuances, then you'd better choose a card according to the handling convenience or useful features.

And at last there are characteristics of the headphones output:

Hercules Game Theater XP Headphones Out 48 kHz

Hercules Game Theater XP Headphones Out 44.1 kHz