# how to record or measure a 300 square wave using REW's generator



## BMF (Dec 29, 2011)

I've used REW to measure headphone FR successfully for 3 years.

I can Generate a 300 Hz Square Wave with REW's Generator but cannot determine If it's possible to record the generated signal.

Is it possible to use REW's Generator to produce a 300 Hz Square Wave and record/measure the results? If so, How?

Thanks for REW! ...and any assistance is much appreciated.

~ BMF


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## jtalden (Mar 12, 2009)

You want to view the shape of a measured headphone response?

I haven't done it, but maybe you could play the signal and measure the result with REW. Then go to the "scope" panel and scale it to view the shape of the captured measurement. You can't save that to a .wav file, but you can capture it with a screen save.

REW only temporarily holds the scope result of the current measurement. It will not be saved with a measurement file.

Another option may be to capture the measurement in Audacity or similar. You can view it there or save it in a .wav file format if that is what is needed.


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## BMF (Dec 29, 2011)

jtalden said:


> You want to view the shape of a measured headphone response?
> 
> I haven't done it, but maybe you could play the signal and measure the result with REW. Then go to the "scope" panel and scale it to view the shape of the captured measurement. You can't save that to a .wav file, but you can capture it with a screen save.
> 
> ...



Thanks for the reply and help!

I want to view the measured 300 hz square wave. I can generate it using REW's 'Generator' tab but I cannot figure out how to measure it. When the square wave is generated, I hear it through my headphones but as soon as I select 'Measure" the tone stops. I don't need to save it; I can use Grab to capture a screen shot.

I'm not familiar with Audacity and its functions. If possible to do what I want within REW, that's the way I'd prefer to go...to keep it simple.


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## jtalden (Mar 12, 2009)

Ah yes. That's what happens when I don't give it a try. 

Your are correct, REW will close off that signal when asked to take a measurement. I don't see a way to do it only using REW.

An option to using Audacity may be to install another PC software signal generator on your PC and use that to generate the signal. You would of course send the REW signal to an inactive location. So while the new generator was playing an REW measurement could be made. Then the Scope panel should have the measurement.

You could also search for a PC software oscilloscope. If found, it should have both the generator and the capture facility. I haven't looked for these recently.

I'm just trying to provide some other ways around this for you. They may not be helpful and there may be better solutions.


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## BMF (Dec 29, 2011)

jtalden said:


> Ah yes. That's what happens when I don't give it a try.
> 
> Your are correct, REW will close off that signal when asked to take a measurement. I don't see a way to do it only using REW.
> 
> ...



I'm grateful for your time and assistance. I will search Audacity and PC oscilloscope software.

I thought about running REW on 2 Macs, one for Generator and one for recording. The problem, at this point, is I don't see a way to record from REW. There must be a way to do this since REW can Generate square waves.

Many thanks!


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## AudiocRaver (Jun 6, 2012)

TrueRTA is a RTA program which includes a true oscilloscope function. There are several levels including a free level, and I am pretty sure that the free level includes the scope function. REW's scope function is quite limited.

Recording the square wave can be done with Audacity, but you need a way to feed REW's output to Audacity's input. VB-Audio (follow this link) offers a free virtual audio cable that can be used to do just that. Once installed a multichannel "cable" appears in the "recording" and "playback" device panels of Windows and as an available input/output for selection within application preference panels and you can use it to run signal between applications.

Another way to do it is with Reaper, with the ReaRoute function installed. ReaRoute creates a bunch of virtual ASIO ins/outs running into/out_of Reaper for internal connection to other applications. Reaper is a Digital Audio Workstation (DAW), so recording is what it does well. The learning curve is kinda wicked with Reaper, though. If you decide to go that way, two tricks that will save you several days of pain:

Install 32-bit Reaper, then install 64-bit Reaper. If you don't, the ReaRoute functions never shows up. After that, you can use either version.
ReaRoute is the ONLY option upon installation that is not "checked" by default. You have to track it down and select it or it will not be installed.
Good luck.

Edit: TrueRTA also has a signal generator built in.

Edit: Updated the link above.


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## BMF (Dec 29, 2011)

AudiocRaver said:


> TrueRTA is a RTA program which includes a true oscilloscope function. There are several levels including a free level, and I am pretty sure that the free level includes the scope function. REW's scope function is quite limited.
> 
> Recording the square wave can be done with Audacity, but you need a way to feed REW's output to Audacity's input. VB-Audio (follow this link) offers a free virtual audio cable that can be used to do just that. Once installed a multichannel "cable" appears in the "recording" and "playback" device panels of Windows and as an available input/output for selection within application preference panels and you can use it to run signal between applications.
> 
> ...


Fantastic! Thanks for the help.

I'll check TrueRTA and Audacity.

~ BMF


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