DC to 24000

[Viesturs Balodis]

Hello,

I am new to this forum and maybe this has been already discussed. I have REW made measurement txt export compatibility problem. When making measurement its window states DC to chosen frequency, but when exported (depending on smoothing or no smoothing 1.8hz to approximate 1.8hz as a start frequency) there is no 0 (DC) and there is no 24000 Hz in exported coefficients. So eventually I cannot use it with my xover program. It states logical issue - "non-linearly spaced frequency vector" .

Could anyone could comment on this issue?

 

[John Mulcahy]

That message doesn't sound like it would result from a need for DC or Nyquist data values, more likely to be due to exporting data at log rather than linear spacing. There may be an option in your crossover program to accept log spaced data, or you need to export at 'Resolution of measurement' from REW. If 'Resolution of measurement' does not show a frequency figure but instead shows 96 PPO go to the Analysis preferences, uncheck the 'Allow 96 PPO log spacing' box in the frequency response calculation section and use the IR windows dialog to re-apply the window, that will recalculate the response with linear frequency spacing.

 

[Viesturs Balodis]

Thank you for response. I have unchecked the Allow 96 PPO. My xover software does not suppot log spaced data and it needs a frequency starting with 0Hz linearly spaced in frequency. Please explain what means "Resolution of measurement" , I do not see this in any REW windows?

 

[John Mulcahy]

It is in this dialog, which is the export dialog in the 5.19 beta versions:

 

[Viesturs Balodis]

Ok. Thank you! Will check it out and reply

 

[Viesturs Balodis]

Hello John,

Now the only problem for my xover program is stated as - Number of samples needs to be 2^N+1. Maybe you have comment on that? Other thing is why still no possibility from 0Hz? There is a 2Hz instead of DC?

 

[John Mulcahy]

REW doesn't retain data below 2 Hz in the measurement so it isn't available to export. You could create some additional entries in the exported data to make the crossover program happy.

 

[Viesturs Balodis]

John, I made it to work by adding values down to and including DC from the REW lowest exported FR. And added up to 24k including so my xover software now is happy and shows correct sample rate. This would be very useful to make this available in REW,