found something

[url]

I've been doing tests comparing mixing platforms, analogue, daw, daw through desk. I was testing the later with a kick through the desk and testing compressors, one internal sonalksis and one external dbx160xt recording them individually to dat then back to computer to a/b sounds. so the digital one sounds brighter, infact i'd say its even sounds pitched up, but not bad, has a different character to the dbx, the dbx is darker. I run a tuner over them both, the dbx kick sways b1 to c1 and a flurry of other notes on the transients and snare spill, really moves around a lot on the meter. then I find the digital one stays unmoved and fixed on b1, doesn't move a nanometer. so i guess this is mathematical rounding then. wow. says a lot abot the two forms.

[chris p]

I dunno, URL. There's a lot of difficult factors to take into account.

The dynamics in kicks (and indeed all drums) are highly velocity sensitive (thwacking creates different sounds to tapping it) so unless you played it exactly the same way, there may have been more dynamics to be compressed in the dbx take.

Futher, its more likely precision than rounding with the Sonalkiss compressor. A tuner will pick up the fundamental frequency of the tone fed to it, but doesn't tell you anything about harmonics per se (harmonics just cause little spikes and dips on the fundamental waveform without changing its frequency).

Like any accoustic vibrating surface, I would expect the kick to have a slightly sharp attack (but nowhere near a full semitone) before settling down to its tuned note. If you're getting such a large swing, I'd be looking for extraneous noise in the take.

Anyone else got any thoughts?

[Chris H]

Well i think he could be onto something. There are ways to see if this is a frequent result,eg splitting the signal so it is the same one that gets the two signal paths. Or repeat the test on several takes and different drums.

[mfdu]

regarding testing different elements of singal path, issue 50 of tape op has a review of a number of pre's from the house of old school audio.

multiple 57's evenly spaced around circumference of a guitar speaker cone. used white noise, checked to ensure mics all have same tone. compared preamps by capturing multiple in-phase signals.

there's sure to be something about it on the tape op forums.

chris.

[url]

missed that article somehow, will give it a shot since i'm in testing mode.

[mfdu]

where you based, URL? your reg details dont indicate. . .

i got a GSSL clone, a twin 1176 clone and a twin what? opto compressor clone and i want to set them up for some similar testing.

i'd like to try with guitar as per the tape op gear review i mentioned, but also i'd like to test with drums.

chris.

[url]

we've actually met. you came and jammed with my band once at la trobe, by the name of lung. look out for me in the next issue of a.t cause i won the prize ... dancing, clicking heels.

[mfdu]

oh my lordy - yes yes yes i remember

i was out at la trobe earlier in the week in my local goverment suit - web accessibility conference. sigh. good conference, but soooo far from st.kilda.

congratulations on winning the AT prize. i look forward to seeing the issue arrive.

if you get into some multiple source testing, let me know the results.

chris.