T18 and Omni 10.5 review

[RubiconProSound]

When measuring with a noise source it will come in 6 to 12dB lower than with a swept sine wave, depending on the resolution used.

I noticed that on John's DR250 when we went from pink noise to manually running a sweep and noting the spl at each freq. When we ran the pink noise I would calibrate the "mic" on TrueRTA by inputting the spl reading at the meter. Looking back at the RTA plots the overall SPL would be in the 100's (light blue bar on left of screen) but no single frequrency would get into that range on the actual plot... I just assumed a sum of all the frequencies added up to the toal output. (SPL)

What resolution would you recommend for future reference?

[Bill Fitzmaurice]

What resolution would you recommend for future reference?

Thr resolution doesn't matter, with any broadband source you will not get an accurate SPL. That can only be found with a swept sine. To calibrate a result measure a 100 Hz or 1kHz sine at 2.83v, then adjust your chart so that the broadband results at that frequency coincide.

[bgavin]

That was the method I used when I found the data bug in TrueRTA 3.3.3 version. The author says the data export/import bugs are fixed, but I have not yet tried the new version.

The data was wrong on both export and import. Error was cumulative, so each iteration increased the error. I exported the raw data from pink, then adjusted up all values so 100 Hz matched the SPL meter. When I imported it back into TrueRTA it was still wrong. Very wrong.

This should be a wish list option for the DIY analyzer: correlate measured Pink to Measured 100 Hz sine.