Assistance setting up REW

[HendrixStyle]

Hi all

W7 desktop
RME PCIe sound card w/breakoutcable
BEA 1073 mic pre
DBX RTA-M mic
REW 519

I have routed the r in of my s.card to the r out, as per the instructions. I assume everything here looks good?:



If I check levels, this is what I get:



Then I go to measure:



and I get this:



Not sure what to do here.


Do I leave the r in of my s.card to the r out in place, or do I remove it?

Thanks.

 

[John Mulcahy]

The loopback connection is just to determine the soundcard response, it should be removed and the mic connected. Make sure the input channel in REW is the channel the mic is connected to.

 

[HendrixStyle]

Thanks.

So, I measured, and this is what it looks like. This kosher?

 

[John Mulcahy]

Looks normal.

 

[HendrixStyle]

Thanks.

So, I am testing my D&D 8Cs.

I have the test sweep level @ -30. But - when I choose "LINE_IN" in REW, I get a warning that I am over the limit (116db). If I change to "Default Input", I get a java error.Any idea where I should start looking?

Furthermore, my RME PCIe sound card is not visible here?

Thx.

 

[John Mulcahy]

Use a current version to measure the 8c per the D&D article. Select your RME as the input device/input.

 

[HendrixStyle]

I have already upped to 520

I can select the RME under the prefs, but it is not visible in the measure page:

 

[John Mulcahy]

Those are the inputs the selected device offers, the device is selected from the soundcard preferences. If the input is clipping during measurement turn down the mic gain. To get meaningful SPL values calibrate the SPL reading.

 

[HendrixStyle]

I have done the spl cal proceedure.

"the device is selected from the soundcard preferences "

Not sure what that means - the scard is selected in the prefs, but it is not visible in the measure page. 'Lil confused here...

 

[John Mulcahy]

The Measure dialog allows you to choose between the available inputs of the input device that has been selected in the soundcard preferences.

 

[HendrixStyle]

I am confused. The input device that has been selected in the soundcard preferences is not available in the measure dial box.

 

[John Mulcahy]

There are two selections for inputs, the input device and which of the inputs that device offers to use. The soundcard preferences allows both to be chosen. The Measure dialog only allows choosing an input selection for the input device that has already been selected on the Soundcard preferences.

 

[HendrixStyle]

Ok, in the soundcard preferences, there is output device, and input device, and then there is output and input.

For the former, I have chosen my scard. For the latter two, I can not choose my scard, as it is not in the dropdown.

But that still dosnt help me with the measure window, where I have two choices:

LINE IN/OUT
Default In/Out

Again, the scard is not there.

Still having issues with:

LINE IN/OUT

And still having issues with:

Default In/Out

as depicted above.

What should I do?

 

[John Mulcahy]

The output and input choices belong to the output device and input device selected, The Line In/Out and Default In/out are the input and output choices your soundcard offers. If you selected a different device you may have different choices in the input and output dropdowns for that device. The device REW is using for input is the device chosen in the soundcard preferences, the input choice on that device is whatever you select. I don't know any other ways to state that.

 

[HendrixStyle]

Ok, now you said it - and now I get it, so thank you.

The "LINE_IN" is my scard, got it.

So, I do a check level, and I get this:

Then, I start, and get this:

I see the protection check boxes - should I uncheck those and continue?

 

[John Mulcahy]

You could, or run through SPL calibration to get correct SPL readings. If you don't have an SPL meter just enter a reasonable guess.

 

[HendrixStyle]

Thx

I am looking at instructions that tell me to Set the range of the vertical and horizontal axis after clicking the All SPL tab. Where do I find these adjustments please?

--edit--

Ok, I had a look at rew help, and I know where the vertical axis and horizontal axis zoom buttons are. And obviously, I can zoom using them. The 'set the range' instruction still has me stumped, however.

 

[John Mulcahy]

Use the Graph limits button above the graph.

 

[HendrixStyle]

K, Thx.

Any reason two measurements taken one right after together wouldn't be the same? Here is a screen of one, then the other. I changed nothing, and was in the same exact spot in the room.

 

[sm52]

HendrixStyle
the windows mixer could mix the measurement sound and other sound, for example from the built-in microphone in a laptop or from another source. You have Java driver, not ASIO.

 

[HendrixStyle]

I am using a desktop; there is no built in mic. I understand the "another source" idea, but I do not see how that is possible.

What to do to rectify?

 

[sm52]

Use an ASIO driver if possible. In playback and recording devices (right mouse button on the 'speaker' icon in the tray) for your RME, on the 'advanced' tab, check 'allow applications to use the device in exclusive mode'. For complete confidence, I turn off all devices, except one for recording and one for playback.

 

[HendrixStyle]

Thx. Switched to ASIO. 'allow applications to use the device in exclusive mode' is checked. All other devices are turned off.

Weird thing - this only happens when I do both speakers together. When I do 2 passes of the r speaker alone, both passes are 100% identical; same for 2 passes of the l speaker alone.

 

[sm52]

From the very beginning, your question was that different graphs are obtained from the right and left sides?

 

[HendrixStyle]

No.

If I do 2 passes of just the r speaker, both graphs are identical. Which is to be expected.

If I do 2 passes of just the l speaker, both graphs are identical. Which is to be expected.

If I do 2 passes of both speakers together, both graphs are different. Why is this? If 2 passes of the l are the same as each other, and if 2 passes of the r are the same as each other, shouldn't 2 passes of the l&r be the same as each other?