[LAU] digital volume sounds better at 0 dB?

Bearcat M. Sandor hometheater at feline-soul.com
Fri Jun 18 19:32:59 UTC 2010


Mark Knecht wrote:
> 2010/6/18 Bearcat M. <hometheater at feline-soul.com>:
>   
>> Folks,
>>
>> My system is set up as follows: computer with Asus Essence ST sound card
>> out to Trends Audio ta-10.1 amp to anthony gallo acoustics speakers.
>>
>> In the alsamixer console program i note that the meters turn red as you
>> get towards the top but i think that's just a pre-set color band and
>> isn't really telling me anything about clipping or over-driving the
>> card. More important is the 'dB gain' indicator. Correct?
>>
>> I seem to hear that when the dB gain is at 0 (volume at 100%) and i've
>> adjusted my integrated amp to the same (as far as i can tell) volume
>> that i would have listed to with the alsamixer control at 70 (dB gain
>> -18.00)  that the sound is much fuller with better bass.  My mate seems
>> to hear that as well.
>>
>> Does this sound right?  Could  it really be that dB 0 sounds better on
>> this card in a noticeable way or is it just a psycho acoustic trick? Are
>> digital volume controls a "bad thing"? I think i've read that before
>> somewhere so again, i may just be psyching myself out.
>>
>> Getting up to change the volume is a pain, but i might just invest (or
>> learn how to make) an outboard volume control if it really is that much
>> better at dB 0.
>>
>> Bearcat M. Sandor
>>     
>
> The alsamixer colors are, as you suspected, simply preprogrammed and
> don't in themselves say anything about how the sound would sound or
> whether the card is being overdriven. Whether a given card experiences
> clipping or power supply related issues is based on how much headroom
> the design has.
>
> In your tests have you accounted for Fletcher-Munson? If not please do
> and then re-report your results.
>
> http://en.wikipedia.org/wiki/Fletcher-Munson
>
> If you have accounted for Fletcher-Munson then possibly there's
> something in the card design that makes a difference but I suspect
> that until you get sound volume levels up to around 80db  (measured
> with a good db SPL meter) that you may be 'hearing the human ear'...
> Just a guess. (NOTE: an 80 db SPL is considerably louder than I
> normally listen but I can attest that it does sound noticeably
> better.)
>
> Good luck,
> Mark
>   
Mark,
I think that may be another matter. I'm not speaking of the dB/spl that 
is coming out of the speakers. What i'm doing is adjusting the sound 
levels on the left/right channels of my sound card and then adjusting 
the volume control on my integrated amp to keep the spl coming out of my 
speakers the same (or at least close to it). For instance if i had the 
sound card volume at 50% and the amp volume control knob at 50% for 80 
dB, then to do the experiment i would put the soudn card volume at 100% 
and reduce the amp volume control by 50% to attain the same volume (i 
know it would not work that way given a number of factors but it's just 
an example). I'm wondering about the adverse effect of using the digital 
volume control of the card, rather then just leaving the card at full 
volume (0 dB) and adjusting the volume on the amplifier (analog volume 
control) instead. 

Is it worth it get out of my chair after every other track to re-adjust 
the volume manually or is the difference i am hearing just in my head

Thanks for the link. That was interesting.

Bearcat


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