Recent content by JohnPM

REW API beta releases

As are the response peaks due to room modal resonances.

A little something I've been working on. I had a couple of mind-numbing weeks extracting REW UI text into properties files to allow translation. To escape the monotony I decided to have a go at coding a 3D surface viewer. Not the sort of thing I've played with since the 80's, but it's going OK :)

Use 1/6 octave. Here are some other views of the Control L then VBA L.

The lower graph of the EQ window, here showing the waterfall, can also show impulse response, phase, group delay or a pole-zero plot.

In the EQ window the graph below the filter adjust graph can be selected as Phase, showing measured and predicted phase.

There's an Italian translation of much of the help for the V5.20.13 version of REW, a lot of it remains relevant for the current release.

The scope is quite limited in what you can do with the data. For the next beta build I have added a Save button that saves the visible portion of the current traces as measurements in REW, they can then be exported and/or re-imported from there.

A bit late noticing I was mentioned in this thread, sorry. A couple of comments: It isn't meaningful to compare wavelets of different frequencies, that's why Pat picks the crossover frequency for his wavelets and why the Alignment tool's impulse mode applies the same filter to each response...

That would be a pretty poor stimulus for FSAF as it has a very sparse spectrum. Difficult to get a meaningful impulse response if the stimulus lacks energy across most of the spectrum.

If you measure a driver over a range that is less than the driver's bandwidth there is in effect a frequency domain truncation of the driver's response, which will result in ringing in the time domain in the IR corresponding to that measurement and a broadening of the IR commensurate with the...

I noticed the speaker was measured up to 300 Hz. Measuring a system below its bandwidth will produce a result which has a correspondingly altered IR, with a strong acausal component. The speaker would be better measured using all the available bandwidth (i.e. to half the sample rate) to properly...

The acoustic timing reference is mean to be played back by a speaker or driver that can reproduce it. That can be different to the speaker or driver being measured, and of course would be when measuring a subwoofer. It doesn't need to be co-located, just in a consistent position relative to the...

That has been fixed for the next build. Total input rms was being used as the reference for plots instead of the relevant tone level for the chosen IMD measure. If you encounter an error please take a moment to report it e.g. using [email protected].

The position shown is to the sub's acoustic centre, which REW treats as being in the middle of the front face of the sub's representation. For an actual source it is typically close to or a little behind the driver dustcap.