05-11-2018, 01:51 AM
OK, I've just started the process of testing but this is my method:
Created WAV test files in Sound Forge (all at -6 dB FS):
20 Hz - 48 kHz tone sweep @ 24 bit 96 kHz;
20 Hz - 44.1 kHz tone sweep @ 24 bit 88.2 kHz;
100 Hz sawtooth wave @ 24-96;
pink noise @ 24-96.
Chose some test music (all in WAV @ 16 bit 44.1 kHz):
Toto - Rosanna (musical equivalent of pink noise)
Alan Parsons - Prime Time (hi-hat sounds and other instruments are staggered and well mixed)
Stravinsky - L'oiseau De Feu - Xiii. Danse Infernale De Tous Les Sujets De Kachtcheï by Boulez/CSO (dynamic orchestral)
Jordi Savall - Turquie, mss. de Kantemiroglu - Makam Rast Murass'a usul Düyek - from the album Orient Occident (good room and instrument sound)
David Sylvian - When Poets Dreamed of Angels - from remaster of Secrets of the Beehive (problematic treble on some systems)
I loaded these onto a USB stick for replay in an RPi3 running moOde 3.8.4 and 4.1. I am using a good SMPS with plenty of amps for power.
DACs:
HifiBerry DAC+ Pro IIS (I don't have an ALLO Boss, sorry, but this does use the PCM5122 chip)
Topping D10 USB
Topping D30 USB
I am recording the output of these DACs with an RME Fireface UFX and Sound Forge Pro software at 24 bit 96 kHz.
I will switch between LL, RT and Standard kernels in moOde 3.8.4 and record the output of the test files. I will do the same for moOde 4.1 with its standard kernel. I will then use FFT analysis to find differences or anomalies. I hope that this will show any convolutional changes between the kernels.
I will also spend a bit of time listening to music, both normal and hi-res. I will be listening on Genelec 8260A speakers and Beyerdynamic DT-880 Pro headphones. The connections are pseudo-balanced from the DACs to an Allen & Heath mixer (RCA -> TRS) and fully balanced from the mixer to the Genelecs (XLR -> XLR). The listening room is acoustically treated with a very short RT60 and quiescent noise level of 25 dBA. The speakers have been calibrated for the listening position with the Genelec SAM system.
Caveats:
This will take a little bit of time . . .
This is not a laboratory-standard test. I don't have an Audio Precision but if something interesting pops up I can look at using an analyzer.
I am hoping the RME Fireface and other equipment are of sufficient quality to show audible differences.
I suspect some of the perceived differences are psychoacoustic and I can't measure for those, but I am going into this with an open mind.
If you have any suggestions about kernel settings or testing methods, etc, I am very happy to try them out. For example, I'm thinking that a square wave (odd harmonics) might be better than a sawtooth (all harmonics).
-Richard
Created WAV test files in Sound Forge (all at -6 dB FS):
20 Hz - 48 kHz tone sweep @ 24 bit 96 kHz;
20 Hz - 44.1 kHz tone sweep @ 24 bit 88.2 kHz;
100 Hz sawtooth wave @ 24-96;
pink noise @ 24-96.
Chose some test music (all in WAV @ 16 bit 44.1 kHz):
Toto - Rosanna (musical equivalent of pink noise)
Alan Parsons - Prime Time (hi-hat sounds and other instruments are staggered and well mixed)
Stravinsky - L'oiseau De Feu - Xiii. Danse Infernale De Tous Les Sujets De Kachtcheï by Boulez/CSO (dynamic orchestral)
Jordi Savall - Turquie, mss. de Kantemiroglu - Makam Rast Murass'a usul Düyek - from the album Orient Occident (good room and instrument sound)
David Sylvian - When Poets Dreamed of Angels - from remaster of Secrets of the Beehive (problematic treble on some systems)
I loaded these onto a USB stick for replay in an RPi3 running moOde 3.8.4 and 4.1. I am using a good SMPS with plenty of amps for power.
DACs:
HifiBerry DAC+ Pro IIS (I don't have an ALLO Boss, sorry, but this does use the PCM5122 chip)
Topping D10 USB
Topping D30 USB
I am recording the output of these DACs with an RME Fireface UFX and Sound Forge Pro software at 24 bit 96 kHz.
I will switch between LL, RT and Standard kernels in moOde 3.8.4 and record the output of the test files. I will do the same for moOde 4.1 with its standard kernel. I will then use FFT analysis to find differences or anomalies. I hope that this will show any convolutional changes between the kernels.
I will also spend a bit of time listening to music, both normal and hi-res. I will be listening on Genelec 8260A speakers and Beyerdynamic DT-880 Pro headphones. The connections are pseudo-balanced from the DACs to an Allen & Heath mixer (RCA -> TRS) and fully balanced from the mixer to the Genelecs (XLR -> XLR). The listening room is acoustically treated with a very short RT60 and quiescent noise level of 25 dBA. The speakers have been calibrated for the listening position with the Genelec SAM system.
Caveats:
This will take a little bit of time . . .
This is not a laboratory-standard test. I don't have an Audio Precision but if something interesting pops up I can look at using an analyzer.
I am hoping the RME Fireface and other equipment are of sufficient quality to show audible differences.
I suspect some of the perceived differences are psychoacoustic and I can't measure for those, but I am going into this with an open mind.
If you have any suggestions about kernel settings or testing methods, etc, I am very happy to try them out. For example, I'm thinking that a square wave (odd harmonics) might be better than a sawtooth (all harmonics).
-Richard
