2
Exactly what it says on the tin.
I have a Sound Blaster X-Fi Xtreme Audio Notebook sound card and I was measuring its output frequency using frequency counter connected to the card's output. Frequency was generated using a program called FrequencyGenerator. I've noticed that it can't provide frequencies higher than 16 kHz (upper limit of audible range is at 20 kHz) and I found that strange.
Is there any info on common maximum frequencies provided by sound cards? I know that for example Realtek ALC 268 can provide as much as 19500 Hz (which is pretty close to the needed 20 kHz), but since X-Fi is supposed to be better than average integrated sound card, is are ALC 268's capabilities an exception or is the X-Fi just really bad card (as in has low output spectrum)?
Are you talking about the sound card only or also about the speakers or headphones you're using? – slhck – 2011-01-26T22:27:55.367
@slhck Meter was connected directly to sound card's output, so just sound card. I expect that speakers/headphones and similar devices do have their own limitations. – AndrejaKo – 2011-01-26T22:29:47.673
It's going to depend on the chips that the card uses, so you'd have to do a search for each cards specs. However, I would expect the upper range to be < 20 kHz. – ChrisF – 2011-01-26T22:32:06.977
2What is your sound source? Please don't say MP3, which are limited to 16khz. – mtone – 2011-01-26T22:34:14.743
@ChrisF I know that, but is there any info how close average card should be? I know that it should be <20 kHz, but is it ≈20 kHz or is it more like ≈15 kHz? – AndrejaKo – 2011-01-26T22:34:40.710
1I would have thought ≈20 kHz (as per the Realtek spec), but I've no evidence for this. – ChrisF – 2011-01-26T22:36:20.200
@mtone It's a program (called FrequencyGenerator) which generates sine wave signal at specific frequency. It works fine up to 16 kHz on X-Fi and up to 19.5 kHz on ALC 268, so I doubt the program is the problem. – AndrejaKo – 2011-01-26T22:36:39.537
@ChrisF That's what I expected too. Now I'm going to measure maximum output frequency on every computer I get my hands on :) ! – AndrejaKo – 2011-01-26T22:39:49.690
Make sure you are testing on a digital output, not over a hedphone jack etc – nathanchere – 2011-01-26T22:41:33.140
@FerretallicA Why would that be important? Also, I'd have to decode digital signal tom get output frequency and then I'd be measuring my DAC's capabilities instead of the capabilities on card's DAC. Furthermore, I connect speakers to the output jack, so I'm measuring the signal which card sends to the speakers. Meter is close to the card's output, so there should be little interference, especially on a dedicated card which isn't too close to noisy devices such as network cards and the like. – AndrejaKo – 2011-01-26T22:45:27.530
@AndrejaKo - because with an analog signal path you aren't as reliably measuring the sound card's output. A digital signal has no interference or degradation and isn't artificially limited by the transport media at all. – nathanchere – 2011-01-27T10:50:04.763