Messages in this thread | | | Date | Mon, 29 Aug 2005 08:52:35 -0400 | Subject | Re: Surround via SPDIF with ALSA/emu10k1? | From | (Lennart Sorensen) |
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On Sat, Aug 27, 2005 at 05:47:08PM -0400, Lee Revell wrote: > For the best S/N ratio and dynamic range all mixer controls SHOULD be at > 100%, assuming the volume control in your driver only attenuates > signals. This is the case for the emu10k1 which implements all mixer > controls via DSP programs that run on the soundcard anyway, and handles > overflow itself.
Well I don't want them all at 100% since I do want to be able to have even levels between the cd, midi and wave, which isn't always the case at 100%. They sure sounded worse.
I certainly know some simpler sound cards would have more distrosion when you ran the amplifiers on the card at 100%.
> Think about it, if you lower the mixer controls to 75%, you're not > getting the full 16 bits of dynamic range, it's probably more like 14 or > 15. 16 bits is barely enough headroom anyway, so you really don't want > this.
Bit 16 is used as soon as the signal passes 50%. After all it is required when the signal goes past 32767 and is on all the way to 65535.
So at 75% depending on how things are done internally I will be either using the full range just not amplified to the same amount, or if truly done entirely digitally, then I will be using 75% of the range, which is still more than even 15bit could handle (since 15 bit has half the range of 16bit).
> Anyway the problem here is a bug in the emu10k1 driver, see alsa-devel > for the resolution.
Well that probably helps.
Len Sorensen - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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