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Discussion Starter #1
While doing custom audio setups, there are two measurements I often would like to do: Speaker distance measurement and speaker/driver polarity. Is this something REW supports in any way? Can I propose them as a feature if they don't?

I know REW supports measuring the speaker distance in a slightly cumbersome way by using the loopback as timing reference. But it would be nice to leave the setting which gives t=0 at IR peak, and still get a single figure of the delay.

I also would like to verify the polarity is the same across multiple drivers. All kinds of drivers, even drivers with HP filters like mids and tweeters. When working with PA-systems, I used to have a device which created a full-band pop/click. A receiving device used in close proximity with the driver showed a red or green LED based on the polarity of the driver. This worked fine on woofers as well as tweeters.

How can this be implemented? Make an asymmetric sound (is this where sinc pulse fits in?) and use a measurement mic in close near field to register the direction of the asymmetry? Wouldn't that work?
 

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To reply to myself: I found measuring by placing the meas mic very close (4-5") works. I could then use the overlay window in %FS impuse to view the polarity of the drivers. Perfect.

I just tested it on a speaker with dual woofers + mid + tweeter. And it works well even if the other woofers is also playing the sweep, just as long as the meas mic is kept in close proximity to the driver you want to measure. Works perfectly on the tweeter as well.
 

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I feel stupid and apparently not knowing all the details of REW well enough. I found the single figure speaker distance I was looking for as well. Great (and embarrased).

One question though: In the docs, it is stated that measuring speaker distance for subwoofers are uncertain due to the limited bandwidth of the speaker. Why is that? Isn't the maxima of the impulse response just as accurate as the maxima of a tweeter, just with larger risetime? (Technical explanation is OK, i'm BScEE)
 

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Aside from the broader IR of the sub, the contributions from nearby surfaces the shape of the IR and the position of the peak.
 
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