# Easy guide to measuring through J River



## brucemck2 (Apr 10, 2007)

I've got J River 20. 

I can either use a UMIK, or, a calibrated mic via a Tascam US-322. The latter is what I normally use, using the Tascam's ASIO drivers.

I always use the Tascam for driving the signal to my AV preamp, as the line out in my laptop does not work reliably.

Can someone help me configure both REW and J River so that I can measure the results in my room with equalization turned on inside J River? I'm trying to determine how my J River convolution filters and PEQ settings are working in practice


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## 3ll3d00d (Jun 6, 2006)

I use asio line in for this , here's one post I wrote showing the config I was using at the time - http://yabb.jriver.com/interact/index.php?topic=86792.msg594719#msg594719

basically you send your REW output to a certain channel on the physical device then open jriver asio line in with an offset that means it sees those 2 channels as its input channels 1 and 2. You then apply jriver dsp as usual and measure the result with your mic.

if this doesn't make sense then showing your actual config will probably help, e.g. how many channels does the tascam have and what is your physical configuration (channels to speakers).

You can also use the WDM driver or WASAPI loopback but I find the former slightly annoying (the need to keep the WDM driver "awake") and the latter flaky. Your system may behave differently of course.


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## brucemck2 (Apr 10, 2007)

That did not make much sense to me ... I'm obviously confused. My current settings in REW preferences and hardware connections are as follows:

Drivers set to ASIO
Sample Rate set to 48k

ASIO device is Tascam (it's a two channel device; two in and two out)
Ouput 1: Ch 1
Input 1: Ch 1

Timing Reference Output 2: Ch 2
Timing Reference Input 2: Ch 2

I connect to the Tascam via USB
My mic preamp is connected to Input 1/L on the Tascam
My analog output to my amps is connected to Output 1/L on the Tascam
Input 2/R is connected to Output 2/R on the Tascam for the timing reference

I only need to get frequency response, so I don't need a timing reference, if that helps. I want to get before and after pictures of frequency response, using REW, with and without the J River convolution filters and PEQ filters in place

Thanks.


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## 3ll3d00d (Jun 6, 2006)

brucemck2 said:


> That did not make much sense to me ... I'm obviously confused. My current settings in REW preferences and hardware connections are as follows:
> 
> Drivers set to ASIO
> Sample Rate set to 48k
> ...


set REW to output to channel 1 and to measure on input 1
open asio line in in jriver, 2 channels with offset 0
play a signal from REW & check that you see it come through correctly in the jriver dsp studio analyser

you may find this doesn't work as a quick google says the tascam asio driver is not multiclient capable, you can instead install http://www.steinberg.net/forums/viewtopic.php?f=34&t=48 and use this as the target driver. This provides a multiclient capable facade basically.

If neither of these options work then you can try the WDM driver next (if you are using jriver20?)


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## brucemck2 (Apr 10, 2007)

I got the Steinberg program installed. 

I can get the Steinberg AsioClient to output via the Tascam, which I verified by sending a volume calibration signal and checking to see if it shows up on the input meters of my AV processor. I see both the output and the reference input in the REW preferences page. So far so good.

I go to File, Open Live in J River and configure for the AsioClient. At this point I can see in the J River Analyzer the REW test signal playing (which I confirmed by altering the volume of same in REW, and I see the level change in the Analyzer window.) So, I am getting the REW output signal sent to J River

However, at this point there are no changes within J River that are reflected in the output going to the AV processor. At this point J River is not having any impact on the analog signal coming out of Ch 1 of the Tascam.

I'm a lot closer. Suggestions?

*******************************

EDIT One approach that will work is to attach a second USB sound card and then set the output of J River to that device. I have confirmed that this works. Expensive if you don't happen to have a second high quality USB sound card sitting around. BUT, QUESTION: would I use this device in my calibration file, or the calibration that I did for the Tascam, or, do I have to create a new REW calibration file that chains both devices?


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## 3ll3d00d (Jun 6, 2006)

You can't reuse the same channel to send to jriver as you do to go out to the amp. What is downstream of jriver here? ie What is your normal playback chain? Ideally you wild use the tascam just to feed jriver and read from the mic, another audio device would be used to output from JRiver to your speakers.

If your tascam is your normal audio device then I think you will need to send REW output on channel 2, open line in for 1 channel with offset one then mute the R channel in jriver and use the L channel in jriver as your channel under measurement. Alternatively wasapi loopback or the wdm driver is probably be more convenient in this case as then you use a different audio device for output (like your mobo onboard audio for wasapi or jriver audio device for wdm). You would use the Java driver in REW in this case so you can select different devices for input and output.


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## brucemck2 (Apr 10, 2007)

Got it. I'll try that later today. (Now I clearly understand why adding the second sound card worked.)

Normally there is no sound card device between the computer running MC20 and my dac, as I use a USB input dac with ASIO drivers provided by the dac manufacturer. I only use the Tascam outboard sound card when I'm doing REW and/or Acourate measurments.

So, for the purpose of this thread it's best to think of the Tascam as being my only device downstream of J River (and as configured in my earlier post, upstream of J River).

As an aside, I've never seen nor been presented with an option for any device to use a WDM driver, either in the J River Tools Options pages or in Windows playback/recording devices tabs. When J River installed MC20 it said it was installing those drivers. I'm unclear how to access WDM drivers.


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## 3ll3d00d (Jun 6, 2006)

the WDM driver is installed by default and should show up in the windows audio devices list as a playback device, if it doesn't show up then you probably want to refer to the relevant interact thread to find out why.

OK having another device makes it much easier then. You should configure jriver for playback as usual, i.e. outputting to your DAC via ASIO. You then open asio line in as you have been, offset 0 and for 2 channels. REW is therefore seeing the tascam only and jriver is bridging the REW output down to your DAC as usual. This can then pass through the convolver as usual and you can measure the output via your mic.


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