January 26, 1999

The listening test

The listening test of this soundcard has revealed a very pleasant soundcard but without any great surprises. All the instruments have a very good sound quality but not more. The listening of MiDi files is very pleasant and very interesting, the video games sound reproduction is accurate and reproachless and the WAVE files playback is excellent and of a very good quality. However, with a great astonishment, we noticed the presence of residual noises when listening to MiDi files. Even if these noises are very weak we were very surprised of them and we were seriously wondering where the could come from. These noises, mostly audible on solo instruments playing short notes, sounded like cracking sounds. We couldn't tell for sure if these noises were coming from the files themselves or were computing noises generated by the card itself. There was some music files were there was no noises but we don't remember their presence on any other soundcard we've tested before as we always use the same MiDi music files for each card we test.

By the way, the users can choose from 3 wavetables format. So, they can get, depending of the wavetables chosen, 64, 128 or even 320 voices. Furthermore, it is possible to download new wavetables and use them instead of the wavetables included with the installation.

In short, the MX300 is a soundcard that limit itself to do its work without bringing any special dimension to the music but may be it is exactly what it has been designed for!

The Frequency Spectrum Analysis

The frequency spectrum analysis performed on this soundcard is using the Fast Fourier Transform method which is a mathematical tool developed and named after Jean Baptiste Fourier (1768 - 1830) commonly used to convert a signal from the time domain (amplitude-vs-time) to the frequency domain (amplitude-vs-frequency) .

The below table is summarizing the measurments performed on this soundcard using SpectraLAB 4.32 with the courtesy of Sound Technology inc.

		FFT Measurements Summary Full Duplex configuration The Diamond MX300 Vortex 2 AU8830
	Frequency response		30hz to 15khz = to be determined
	1 khz Total Harmonic Distortion		.01% @ -.25db
	I9 khz and 20 khz Intermodulation distortion		.0075% @ -18.09db
	Signal To noise Ratio		74db
	Dymanic Range		82db

Full Duplex Frequency Response

A very weird accident is appearing when reading the above graphic. As a fact, we can observe a deep notch around 16Khz indicating a drop of about 30db. Is this important drop followed by a light raise in the frequency response is an indication that we were testing a defective card or is this flaw affecting all the soundcards of this model was the question we were wondering when we did this measure. To make sure that we were not in presence of a defective board we contacted Diamond in order to get another evaluation unit of this soundcard and we will do this test again as soon as we will get a new testing unit. Let's hope that Diamond will be cooperative on this mater and for the moment, we suggest that you ignore this flaw at least for as long as we do not conduct any additional test or we don't come back to you on this matter.

Full Duplex 1 khz Total Harmonic Distortion

Full Duplex Intermodulation Distortion

Full Duplex Dynamic Range

All the above measurements have been performed by feeding the soundcard with reference WAVE samples then looping back the output of the soundcard to the input of the soundcard.

As these measurements have been performed in a Full Duplex configuration, the results are much worse than the actual use of the soundcard in a simple playback or record configuration. So, the above results displayed, can't be compared to those obtainned in a standard configuration but just with soundcards tested with the same configuration. Note that the own limitations of the test engine used should also be taken into account as well as the purity of the test signal.

Conclusions

In conclusion, we are pretty perplexed by the flaws we've discovered on this soundcard and we can only hope that they are only present on the unit we were testing and not on all of them. It would be very sad if these problems would be noticeable on all this model of soundcard because even if they are very minor they still are there. However, even with this in mind we really liked this soundcard and if we were not to take them into account we would have recommended this soundcard. So, the best advice we can give to you it to verify by yourself by listening closely to the music especially when you are playing MiDi files because you are the final decision taker.

Click here for more information about the Diamond MX300 Vortex 2 AU8830, clic here.

Test Setup Used.

Motherboard: IWILL BD100 Chipset: Intel 440BX CPU: Intel Pentium II 350mhz Memory: 128mb PC100 SDram (LGS) Primary IDE port: Disque dur Quantum Fireball EIDE ST 3.2A Secondary IDE port: AOpen CD-936E 36X CD-ROM drive AGP slot: Matrox Mystique G200 16Mb AGP PCI slot no: 2 : Diamond MX300 Aureal Vortex 2 AU8830 PCI slot no: 1 : Modem US Robotic 56k X2 OS: Win95 OSR2 4.00.950B DirectX 6.0

Product Specifications:

Audio Processing Chipset: Aureal Vortex 2 PCI Controller (AU8830) Quad AC97 codec 320 Voice DLS - 4MB (64 Voices Hardware) Bus Type: PCI 2.1 Signal to Noise Ratio: >96 dB Sample Rates: Up to 48 kHz Audio Output: 2-Buffered Stereo Line-level Outputs Audio Input: Microphone Input Stereo Line Input Internal CD/Modem/Aux. Input

Connectors: MPU-401 MIDI/Game Port Wavetable Header MPC (CD, Modem, Aux) API Support: Aureal A3D 1.0, 2.0 Microsoft DirectSound3D Microsoft DirectSound Microsoft DirectInput® Operating System Support: Microsoft Windows 95/98 Microsoft Windows NT 4.0 Microsoft DOS Minimum System Configuration: Windows 95/98 or Windows NT 4.0 One available PCI 2.1 compliant slot Pentium 90MHz or higher 8 MB system memory (16MB or higher recomended) 16MB free hard disk space Powered speakers or headphones