"Clock rate adjustment is too large" when importing sweep data

[3ll3d00d]

I'm recording the output of a system to a multichannel wav file then importing into REW (latest beta) using the "import Sweep" option. The system does have some inherent delay because it's a multiway setup with a matched delay subtractive crossover, I think the total system delay is in the 20ms range. The sweep is a 256k sweep so thats ~12s long, the recording of the system is the same.

When I import this into REW I get the "Clock rate adjustment is too large" message and the reported adjustment is ~126k ppm, the FR of the tweeter is also abruptly truncated for no obvious reason as per the below.

If I apply a simple crossover (i.e. something like a BW2), the measurement loads without any issues.

Given that I'm using REW to determine the response of this system, I don't have another obvious way to verify if the problem is in my filters or is some problem in REW.

Any idea?

 

[3ll3d00d]

I was about to post the recorded data but had pruned some unnecessary channels to reduce the size, I had also amplified the signal somewhat (as I was trimming it in audacity and wanted to see the waveform). I imported that back into REW to check it was ok and saw the channel was imported normally.

Hence the issue here is with misinterpretation of a signal that must be too low level to be considered a sweep?

I'm not sure how this results in a truncated FR but I wonder if it's possible to detect this case? perhaps even amplify the signal for me if I want to?

e.g.could it (optionally) account for the sweep level? aka if my sweep is -30 then add -30 before parsing it

 

[3ll3d00d]

actually it's not a gain issue, I ramped up the gain in the playback system all the way so that the captured trace peaks at 0dBFS

I then imported this into audacity and exported it straight back out as a wav, this version is read fine by REW so it's some file format issue perhaps?

attached back files, recorded.wav is the one out of audacity

here's what mediainfo says about them

 ~      mediainfo /media/home-media/junk/Disk\ Writer\ -\ 3\ Nov\ 20_50_58.wav                                                                                                                                                        
General
Complete name                            : /media/home-media/junk/Disk Writer - 3 Nov 20_50_58.wav
Format                                   : Wave
Format settings                          : PcmWaveformat
File size                                : 20.3 MiB
Duration                                 : 12 s 288 ms
Overall bit rate mode                    : Constant
Overall bit rate                         : 13.8 Mb/s

Audio
Format                                   : PCM
Format profile                           : Float
Codec ID                                 : 3
Codec ID/Hint                            : IEEE
Duration                                 : 12 s 288 ms
Bit rate mode                            : Constant
Bit rate                                 : 13.8 Mb/s
Channel(s)                               : 9 channels
Sampling rate                            : 48.0 kHz
Bit depth                                : 32 bits
Stream size                              : 20.2 MiB (100%)


 ~      mediainfo /media/home-media/junk/recorded.wav                                                                                                                                                                                 
General
Complete name                            : /media/home-media/junk/recorded.wav
Format                                   : Wave
Format settings                          : PcmWaveformat
File size                                : 15.2 MiB
Duration                                 : 12 s 288 ms
Overall bit rate mode                    : Constant
Overall bit rate                         : 10.4 Mb/s

Audio
Format                                   : PCM
Format settings                          : Little / Signed
Codec ID                                 : 1
Duration                                 : 12 s 288 ms
Bit rate mode                            : Constant
Bit rate                                 : 10.4 Mb/s
Channel(s)                               : 9 channels
Sampling rate                            : 48.0 kHz
Bit depth                                : 24 bits
Stream size                              : 15.2 MiB (100%)

 

[3ll3d00d]

another oddity, I can't upload the file, it uploads and gets stuck at 100% but won't actually accept it (but doesn't error).

file can be downloaded via this link

 

[John Mulcahy]

Likely to be problematic since the crossover will be removing or altering the acoustic timing reference. Why not just make a normal measurement with a loopback timing ref?

 

[3ll3d00d]

Why not just make a normal measurement with a loopback timing ref?

my usual audio device is out of action so have fallen back to my RME Fireface 800 which I've never been able to get working in a REW -> RME -> JRiver -> RME multiclient chain

I don't see how it can be the timing ref causing an issue when simply opening it in audacity and saving to a new wav means it can be imported without issue, it seems to imply there is something specific to the format of the 1st wav that is causing a problem for REW.

 

[John Mulcahy]

The channels cannot be processed properly if the first input channel doesn't have the timing reference signals. Those look to be on channel 5 of your file. You didn't attach the sweep file so I can't try importing them as sweeps, but the file loads without issue as imported audio data.

 

[3ll3d00d]

the measurement signal is attached

The channels cannot be processed properly if the first input channel doesn't have the timing reference signals.

ok I didn't know that but it still doesn't explain how simply opening in audacity and exporting as a wav with the same channel mapping makes it import ok. The only apparent difference is the original is 32bit float while the exported is 24bit pcm.