[sdiy] DACs on-board 12 vs external 16 vs 24 bit

[cheater00 .]

On Wed, Nov 6, 2013 at 11:20 AM, cheater00 . <cheater00 at gmail.com> wrote:
> On Wed, Nov 6, 2013 at 11:14 AM, Justin Owen <juzowen at gmail.com> wrote:
>> Hello,
>>
>> For a digital, micro-based oscillator (being used in a modular environment if that makes a difference) outputting the standard one waveform at a time sine, triangle, saw, pulse waveforms between e.g. 0.1 Hz and 20KHz (probably closer to a max of 10KHz) with the regular features of hard sync, FM, PWM, Unison etc.
>>
>> ...how much difference is the average human going to hear between 12, 16 and 24 bit DACs?
>>
>> For extra reference - I'm looking specifically at the 12-bit DACs on the STM32F407xx vs. the option of an external DAC of some sort.
>>
>> Thanks.
>>
>> J
>
> Generate a sinewave at 0dBFS in soundforge, decimate to 16 bit, then
> make a copy and decimate to 12 bit and then upsample to 16 bit again.
> Flip that and add it to the original - you're left with the difference
> only. Look at that in the spectrum analyzer. You'll see some
> sidebands. If they are under -90 dBFS you're very unlikely to hear
> anything. Report when you've learnt more.
>
> D.

BTW, by saying "add to the original" I meant add the 16-12-16-flip
soundwave to the 16-bit soundwave (the "original").

Cheers,
D.