Forum Replies Created
14 July 2022 at 6:13 pm #518
>> Doesn’t the latency increase if I create only the Magnitude
No. On the Auto Mag tab you have selected a minimum phase filter response. This puts the FIR filter peak at time=0, which you can see on the Export tab and provides essentially no latency. Can I suggest you research FIR filter basics? We have a white-paper at
while you may find helpful. Also take a look at the tutorials on
>> I use 8 measuring microphones to average the response of the room.
The averaged measurement on the Import tab still looks too detailed to be useful. I’d suggest applying some smoothing, either on the Import tab or on the Auto Mag tab.
EA Support14 July 2022 at 4:50 pm #516
I’ve taken a look at your FIR Designer project file. It generates a minimum-phase FIR filter so the approximate delay through the filter is 0ms and is why you’re seeing no roughly the same latency with the FIR on & off.
Also, it’s generating a FIR filtering using the Auto Mag process with no smoothing. This is generally not a good idea. Fine resolution filtering like this may make the measurement position sound better, but will sound a lot worse in all other locations. We recommend some measurement averaging and Auto Mag smoothing.
EA Support4 July 2022 at 10:41 am #507
It looks like FIR Designer matches REW in mag and phase. The measurement clearly has very high phase slope and thus significant bulk delay. This bulk delay should be removed in the measurement process if phase is to be used in any subsequent filter design. FIR Designer does its best to create an IR from the freq/mag/phase TXT format but using freq/mag/phase looses information when the measurement has very high phase slope. Better to export the measurement IR directly and load this into FIR Designer.
BTW, from a display perspective, in Preferences you can uncheck “Show phase plot wrapping” to remove the vertical lines between when the phase wraps.
EA Support25 June 2022 at 7:57 am #490
Thanks, we’ll add a comma to line ends.
I’ve been testing here also. For me Q-SYS Designer (9.4.2) is only loading the first line.
Can you confirm that Q-SYS Designer is loading all four lines for you? If the QSYS Designer Custom IIR Block doesn’t look like FIR Designer, and if it has no more than ~180 of phase change across the plot, then it’s only loading the 1st line.
Their support page
shows that the block should be capable of loading multiple lines.
I realised I needed to set the “Section Count” to the number of rows. With this set, all the lines of the CSV load correctly for me here.
EA Support17 May 2022 at 5:55 pm #475
The SMAART API grabs the transfer function as complex frequency domain values, with the frequency resolution determined by the current SMAART FFT size. SUT delay causes high phase slope in the transfer function. Further time averaging and frequency smoothing cause the delay to be blurred such that when the TF is converted back to an impulse response, the peak may not be distinct. The only alternative is to grab the impulse response through the SMAART API, and not the TF frequency values. I don’t think the API currently supports this – I’ll check with Rational – so in the meantime you’ll just have to remove SUT delay in SMAART.
17 May 2022 at 11:29 am #472
- This reply was modified 4 months, 3 weeks ago by EA Support.
BTW in the meantime you can open additional windows (using Project menu -> New Window), load the averaging session file and select a different averaging mode. This way you can compare different modes in different windows.