Recent content by Clayton Williamson

Ahh, thanks! Dang, I tried dBFS, dBV, and dBV, but didn't think to try dBSPL. That's odd to me though, since the measurements were made in dBFS. Why does x dBFS / x dBFS not equal 0dBFS?

Team, Using REW 5.31.3, the division trace arithmetic is 3dB different from what I expect. For example, here is a measured curve (from the RTA) divided by itself. Rather than a flat line at 0dB, it is flat at 3dB for both A/B and |A| / |B|. Did I miss a setting?

OK, thanks. That makes sense. The signal is from a BTLE wireless device. The problem appears either in the LC3 codec or the ASRC -- I'm working to track that down now. Thanks for your insight!

Here are the distortion settings, which look reasonable to me. Here is the spectrum, showing the artifacts of the heavy clipping, especially the odd order harmonics, yet a vanishingly small THD. The input frequency to the device via REW generator is 1kHz, though the FFT peaks show 1.024k and...

When using the stepped level sweep, the distortion reads unexpectedly low. For example, with a -10dBFS 1kHz output, I measure this clearly distorted output from the device I am testing.. But, the THD reading is roughly 0.2%. The distortion values are dominated by the odd harmonics as...

Whoa, that's great! I never noticed that option. I'll test it out now. Thanks John!

REW has excellent functionality in terms of setting a level and sweeping through a wide range of frequencies to determine and improve the behavior of the system. A valuable addition would be a level sweep, where the frequency is fixed and the output is swept through a wide range of levels...

@dcibel Oh, that's an interesting idea. I find that trimming the file in Audacity or similar, makes it easy to analyze just the section of interest, but it would be cool to do that in a more flexible and non-destructive manner completely inside REW. For example, my wave files generally have an...

@sm52 For example, a recording of the background noise of a device or environment can be analyzed to show problem frequencies and their amplitudes, and/or the overall noise level. So, when changes are made to improve things, the same analysis can be used to quantify the improvement, and guide...

The ability to analyze wave files in addition to real time signals via the RTA is super handy. There have been a surprising number of occasions where that turned out to be very useful to post-process recordings. Thanks for adding such a cool feature!

That's great, thanks for your quick work!

On the maiden voyage of 5.20.12, I got an error message I haven't seen before while trying to save. This was an mdat file created in 5.20.09, which was opened in 5.20.12 and appended with a number of new measurements Any suggestions? Thanks in advance!

The new "generate measurement from predicted" is an excellent addition to make this a simple and direct procedure. I find it very handy to compare before / after / various EQ iterations. Thanks for continuing to make improvements!

Ahh, I've only been using it at 48kHz where it seems to work well. Wait, what/why the heck are you testing at 384kHz SR?

I recently found that you can also accomplish this with ASIO4ALL, so REW can access any combination of input and output device that your system can find.