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Old 29 October 2016, 12:48   #126
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Join Date: Jun 2010
Location: PL
Posts: 1,653
Originally Posted by jarp View Post
Btw. tried your RMAA files and results were extremely... wild. Frequency response was a roller coaster etc. Files do sound different also than mine when I listen them. We must have different versions of the RMAA or something.
They may sound different as frequencies will be correct (Amiga is not capable to play 44100 or 48000 as such frequency can't be set in Paula), other issues may be related to dithering and noiseshaping (but there is no way to play level -60dBFS on 8 bit sample).
I've downloaded latest RMAA and saved wav's, later wav's was converted with SoX to something more suitable for Amiga.

SoX script (PC commandline) bellow:

@rem 58146 57208 56300 55420 54568 53741 52939 52160 51404 50670 49956 49262 48588 47931 47292 46670 46064 45473 44897 44336 43789

@set sr=47931
@set /A pre=%sr%/4
@echo %sr%
@echo %pre%
@rem lipshitz, f-weighted, modified-e-weighted, improved-e-weighted, gesemann, shibata, low-shibata, high-shibata

@set noiseshp=improved-e-weighted

@echo %noiseshp% 

@sox --multi-threaded --buffer 131072 -S -V -D "%1" "%~n1.sox" rate -v -s -a -I %sr% stats -b 8
@sox --multi-threaded --buffer 131072 -S -V -D "%~n1.sox" "%~n1_ECS_%sr%.8svx" dither -f %noiseshp% -p 8 stats -b 8

@set xx=640
@set yy=294

@set /a w=%xx%-144
@set /a h=%yy%-78

@sox --multi-threaded --buffer 131072 -S -V -D "%~n1.sox" -n spectrogram -z 86 -q 12 -x %w% -y %h% -o "%~n1_sox.png"
@sox --multi-threaded --buffer 131072 -S -V -D "%~n1_ECS_%sr%.8svx" -n spectrogram -z 86 -q 12 -x %w% -y %h% -o "%~n1_ECS_%sr%.8svx.png"

@del -q "%~n1.sox"
Originally Posted by jarp View Post
I also "upgraded" my test gear from my Asus Xonar STX to an old E-MU 0404 USB. Mainly due to it's excellent integrated pre-amp (STX has better specs otherwise) - Amiga puts out quite a low voltage without a preamp and the one I used in my earlier measurements was not the best (~90dB noise floor). Repeated the tests but pretty much nothing changed (which was expected of course since my preamp was better than Amiga's outputs in any case).
I think about buying Behringer UMC202HD - it support sample rate up to 192kHz@24 bit so should be sufficient for this task.
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