Convolution using Rephase Filters

[DuckSoup (Mike)]

Core Machine (Operating system/System info/Roon build number)

Mac Mini, OSX, 256Gb SSD for OS, 16Gb RAM, External 4Tb for Music Files, Roon 1.6 Build 416

Network Details (Including networking gear model/manufacturer and if on WiFi/Ethernet)

BT Router, Ethernet

Audio Devices (Specify what device you’re using and its connection type - USB/HDMI/etc.)

Benchmark DAC3 HGC, USB connection to Roon Core

Description Of Issue

Created room correction filters using REW. Exported filters .WAV impulse, compressed files to ZIP, loaded into DSP and works fine.

Used RePhase. Imported REW measurement, Imported REW Filters. Corrected Phase using RePhase Filters. Exported impulse filters from RePhase as ‘64 bits IEEE-754’ (.dbl) format. Created configuration file as per instructions in Roon Knowledge-base. Created ZIP file with configuration file and .dbl files. Loaded into DSP convolution filter. Got message saying “Unexpected Error Communicating with Device” “Too Many Failures. Stopping Playback”.

So, my question is why the filters exported from REW work but the same filters exported from RePhase do not?

Also, noticed that the .wav files exported from REW are larger filesize and vary according to sample rate (from 524Kb to 2.1Mb) whereas the .dbl files exported from RePhase are all 131Kb. Is this what would be expected?

Text of .cfg file I created is below.

44100 2 2 0
0 0
0 0
ASW_RP_L_44.dbl
0
0.0
0.0
ASW_RP_R_44.dbl
0
1.0
1.0
88200 2 2 0
0 0
0 0
ASW_RP_L_88.dbl
0
0.0
0.0
ASW_RP_R_88.dbl
0
1.0
1.0
88200 2 2 0
0 0
0 0
ASW_RP_L_88.dbl
0
0.0
0.0
ASW_RP_R_88.dbl
0
1.0
1.0
48000 2 2 0
0 0
0 0
ASW_RP_L_48.dbl
0
0.0
0.0
ASW_RP_R_48.dbl
0
1.0
1.0
96000 2 2 0
0 0
0 0
ASW_RP_L_96.dbl
0
0.0
0.0
ASW_RP_R_96.dbl
0
1.0
1.0
19200 2 2 0
0 0
0 0
ASW_RP_L_192.dbl
0
0.0
0.0
ASW_RP_R_192.dbl
0
1.0
1.0

[DuckSoup (Mike)]

Solved it.

Problem was with .cfg file - I had created one .cfg file which contained references to filters for all 6 sample rates I had created. Tried again using separate .cfg file for each sample rate and creating .zip file with 18 files (6 .cfg files, 6 .dbl files for L channel, 6 .dbl files for R channel) and this works.

Interesting to note that, when played in Roon, the .wav impulse files created by exporting from REW show (in the signal path) as 131K taps whereas both .wav and .dbl created from rePhase show as 16K taps.

rePhase allows you to set the number of taps when exporting impulse responses - the default is 16384 (which fits with what is seen when used in Roon). As far as I can see REW doesn’t allow you to set the number of taps when exporting filters.

Wonder if the difference is because REW exports IIR impulse files whereas rePhase exports FIR filters?

[DuckSoup (Mike)]

Figured out why the difference in filesize and number of taps. rePhase has default of 16,384 taps. REW doesn’t seem to have option to change this so must be set to 131K (probably 131,072 which is 8 x 16,384).

As might be obvious I’m just getting used to learning what rePhase can do. My reasons for using it (instead of just using convolution filters exported from REW) is that rePhase allows for correction of phase as well as amplitude so that you can create minimum phase filters.

It anyone else out there is using rePhase with REW to create filters for Roon then I’d be interested in comparing notes …