Originally Posted by
LumbermanSVO
In short: Yes.
You must understand that REW and APL Workshop are measuring different things. In REW you have a couple basic types of measurements. You can run a single sweep, from a single point in space, and the information gained from that will show you amplitude(volume), phase, group delay, cool waterfall plots, and so on. Those things are useful, but the single point in space is a limitation. If you want to work around the single point limitation, you can play Pink Noise from the signal generator, and use the RTA window to average the response over several points in space. The problem with this method is that you are ONLY getting an amplitude average, and nothing else. Even if you could measure all those things, do you have the tools to manipulate m ore than just amplitude?
APL Workshop measures amplitude, phase, and group delay, like REW does, but it measures it in multiple points in space. So for a typical 5-minute tuning session I'll actually measure those three things in 200+ points in space, covering the whole listening area. It then processes the data and spits out an FIR file that can actually correct amplitude, phase, and group delay. Because it can adjust these things every 6Hz, it can do quite a good job at stomping out these peaks and nulls. If the peaks and nulls still exist, they will be narrow enough that they don't really matter anymore.
What's better than how everything measures after applying the filters, is how it changes the sound. It's pretty damn cool, and why I'm such a fan, and don't mind the price.