REW accuracy?

**bjs** · **06-23-08, 05:16 AM**

I've just discovered REW. Looks like a great program.

Has anyone compared it's accuracy against other programs (such as ETF, RDplus, ARTA, Praxis etc) or indepently confirmed it's validity?

I hope I'm not burned at the stake for asking such an impertinent question...but curiosity knows no limits...!

**Wayne A. Pflughaupt** · **06-23-08, 01:42 PM**

I'll leave the technical confimation to JohnM, the prolific creator of the program. I'll just say: Thousands of satisfied users, does that count?

At least one manufacturer is using REW graphs on their website.

Regards,
Wayne

**JohnM** · **06-23-08, 02:22 PM**

Yes, haven't played with Praxis but I have checked against the others mentioned and some more besides.

**Bob_99** · **06-23-08, 02:29 PM**

I use RplusD and REW and found that the biggest differences are in the features. FR measurements are very close and the waterfalls appear to be just a bit different. I have leaned more to RplusD only because I have used it longer but now that I haven't been able to run it under MS Vista (others have no problem with that issue), I have been using REW more. As I originally said, each have some very good features that would be nice to have combined in one package.

Bob

**JohnM** · **06-23-08, 06:22 PM**

Quote:

Bob_99 wrote:

the waterfalls appear to be just a bit different.

You may not have come across this in the REW help: ETF users should note that ETF gate times are specified in a different manner to REW window durations, to convert an ETF gate time to the approximately equivalent window width, multiply by 1.4. That also applies to RplusD.

**Bob_99** · **06-24-08, 07:12 AM**

Thank you, John. I've read the manual but obviously missed that information. Also, let me add my thanks to all the others for an amazing program. The fruit of your labor is very much appreciated.

Bob

**DrWho** · **06-27-08, 11:32 AM**

I've taken my measurement rig into the Klipsch anechoic chamber over in Indianapolis and my measurement was within 0.5dB from something like 100Hz to 10kHz.

They're using Leap and TEF.

I also get comparable results to Praxis.

Ultimately, the accuracy of REW depends on the accuracy of your soundcard. If your noise floor and distortion are low, then you'll get a fairly accurate measaurement. Usually the microphone is going to be the limiting factor in this case...

**jlohl** · **03-23-09, 02:17 PM**

Quote:

You may not have come across this in the REW help: ETF users should note that ETF gate times are specified in a different manner to REW window durations, to convert an ETF gate time to the approximately equivalent window width, multiply by 1.4. That also applies to RplusD.

Thanks, this is written in the REW manual but could JohnM explain why are those gate times not equivalent ?

**JohnM** · **03-23-09, 05:29 PM**

Quote:

jlohl wrote:

Thanks, this is written in the REW manual but could JohnM explain why are those gate times not equivalent ?

You'll have to ask Doug Plumb, I don't recall there being a way to plot what window extent a particular gate time gives in ETF or R+D so can't tell how the figure is used there. In REW you can see the window shape on the Impulse Response graph, the widths of the windows are the times you set.

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