[Wayne A. Pflughaupt]

I passed on this yesterday because I figured someone more knowledgeable would jump on it. Oh well – guess you’re stuck with me...

EDIT – I see Anthony dropped a post while I was composing mine, so some of this might be redundant.

I guess the best answer is to study the features and measurement capabilities of all three offer and decide which of them you need.

For instance, trueRTA and (I think) ETF both do real-time analysis. You can certainly use that to plot your system response, since at some point it “snapshots” a reading and produces a graph. But when it gets right down to it, you don’t need a real-time feature to do that. REW’s system of reading a sweep and then showing a graph afterwards is just as effective for capturing a response graph.

As someone familiar with the use of old-school RTA’s, I can tell you that REW is just too cool for words. The old stand-alone RTAs, you had to run that pink noise signal through your speakers and keep it playing the whole time you were equalizing, which could be time consuming since the LEd's would be jumping all up and down because of the random nature of pink noise. Lemme tell ya, that’ll send your wife running out of the house screaming and pulling her hair out! I doubt it’s as bad as that with trueRTA and ETF, but with REW the sweep runs for only 2-3 seconds. I’d be surprised if the real-time packages can get a reading that fast, but then I haven’t used them. Not to mention, REW is designed especially for adjusting equalizers. I don’t think the others do that.

That’s not to say that RTA’s don’t have their uses. I have my AudioControl R-130 connected to my system’s tape loop, to give a real-time full-spectrum reading of program material. Helps reassure to me any sound problems I hear is the program material, and not my speakers. For instance, if the male voices sound really boomy – sure enough, the RTA shows the signal is really hot in the 80-100 Hz range.

But as I said, unless you have a reason for tracking real-time response, you really don’t need it that in a room measurement program.

Now, if you are into building DIY speakers and subs, or want do want to do more thorough evaluation of equipment that passes through your place, you probably have a need for more comprehensive graphing, like Ilkka and Ed Mullen do with their reviews - group delay, power compression, THD@frequency, etc. If that’s the case, you’ll need to find the program that delivers the tests you want to perform. REW may do all or some of these, I don’t know – I’m still getting my feet wet with it. That’s why I wish someone better informed had replied. Maybe they will, if only to fill in the blanks where I might have missed it here.

Regards,
Wayne A. Pflughaupt