Audigy2 Question

[Fizzycapola]

A2 Mod
RightMark Audio Analyzer test

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

Summary
Frequency response (from 40 Hz to 15 kHz), dB: +0.10, -0.26 Very good
Noise level, dB (A): -96.8 Excellent
Dynamic range, dB (A): 95.2 Excellent
THD, %: 0.0025 Excellent
IMD + Noise, %: 0.0059 Excellent
Stereo crosstalk, dB: -99.7 Excellent
IMD at 10 kHz, %: 4.140 Very poor

General performance: Excellent


Could someone tell me what this is "IMD at 10 kHz" ?

I've re-capped the card, and most of the results are great, except for the above which is rated "Very poor"

Any ideas why?

Thanks!

[zandrax]

Re: Audigy2 Question

Could someone tell me what this is "IMD at 10 kHz" ?

I've re-capped the card, and most of the results are great, except for the above which is rated "Very poor"

Any ideas why?

Thanks!

IMD means Intermodulation Distortion: in practice, any unwanted sound due to an union between sounds. I think it's the sound counterpart of optical interference: the result (e.g. moire patterns) is something caused by original waves, but correlated to them in a not-linear way.
Did you analyze your Audigy before recapping? If you did, you can state if recapping caused a jump in IMD or if the card was already a poor performing.

Zandrax

[Fizzycapola]

Re: Audigy2 Question

I have recorded different stages, but they're on computer in storage at the moment.

I'm quite sure the value should be more like approximately 0.00XXXetc

It should be more like the IMD + Noise, %: 0.0059 Excellent

I wonder if using Panasonic ECA 105 degree's ( sold as general high temp) was right or whether I should have used the Panasonic ECA 85 degree ones (sold as high fidelity audio). Do you think using inappropriate capacitors could cause this?

[zandrax]

Re: Audigy2 Question

Quite strange: I found some reviews of Audigy 2 cards which show high IMD at 10 KHz values at 16 bit and very low ones at 24 bit. So I think is more a driver / audio chip issue (bad hardware resampling?) than a bad recapping or a wrong cap choice. Try analysing at 24 bit to see if something changes.

Reviews:
- http://www.extremetech.com/article2/...1684445,00.asp
- http://www.futurelooks.com/184-DFI-I...ew.html?page=8 (half page)
- http://forum.rightmark.org/topic.cgi?id=4:868#11
- http://www.csie.ntu.edu.tw/~r89004/rmaa52/sbd-24-96.htm (no IMD at 10 KHz, just for values comparison)

Zandrax

[Fizzycapola]

Re: Audigy2 Question

Ok thanks for the reply. I guess it's just a quirk of the card rather than a real serious issue. I will be doing further testing in the next few months and post back any definitive conclusions on this later if relevant.

[zandrax]

Re: Audigy2 Question

Ok Fizzy, keep us updated.

Zandrax