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[maglevrabbit]

I am using the DSP studio in MC29to create a three way active crossover using convolution, RePhase, an Asus Xonar multi channel sound card, and three cheap class D amps, with various drive units. Seems to work well. However, I would like to test the accuracy of my crossover using a mic and my TrueRTA speaker tes software. In other words to check that I am getting a nice level response.
So I need to be able to somehow play the test sine wave sweeps through JRiver MC (and it's multi channel Asus Xonar sound card), then capture the results through a second sound card (calibrated Behringer USB card) and a Dayton calibrated mic.
I was hoping to be able to do this via the "Open Live" facility in MC, but I see no way of getting it to work. Currently all I get is a "Playback is not working" message when I try the "Open Live" menu entry. Prior to this I could actually establish the Open Live function using VLC media player to play a media file, but it usually did nothing or occasionaly would play the VLC source but very distorted and not smoothly.
Does anyone have any idea if what I amtrying to is even possible, before I waste any more time with this?
What I was really hopin for is a simple menu option in MC29 that simple says "Play Source from:" and then allows you to nominate a output on a specific sound card. No such straightforward function seems to exist that I can find.
Can anyone help?

[mattkhan]

Various options described in https://wiki.jriver.com/index.php/Verifying_DSP_Studio

Why do you need to capture the results in both a sound card and a mic?

[maglevrabbit]

Various options described in https://wiki.jriver.com/index.php/Verifying_DSP_Studio

Why do you need to capture the results in both a sound card and a mic?

Maybe i didn't explain myself too well. I am capturing the sine wave sweep from the speakers via a Dayton microphone connected to a Behringer (USB) sound card. The reason I do not use the mic input on the Asus card is that the mic has an XLR connection and needs phantom power - neither of which exist on the Asus Xonar. Also, the Behringer sound "card" (USB) has been calibrated with TrueRTA.

[mattkhan]

OK so the link I posted earlier explains how to do this using REW, you have 2 options

1) use the external sweep method
2) route audio through MC either using the WDM driver or the ASIO line input

the former is playing a sweep with a timing reference embedded in MC and then configuring REW to wait til it hears that reference
the latter requires a multiclient asio driver for the asio line in approach, not sure if your driver is multiclient capable but sounds like not. If not, it means configuring the WDM driver to play the measurement to the default windows audio device so that MC can then play that back.

I don't use TrueRTA so can't say exactly whether this can work as is in TrueRTA or whether there is some other method. REW is free though and it doesn't seem TrueRTA offers any features that REW doesn't have for this use case.

[maglevrabbit]

OK so the link I posted earlier explains how to do this using REW, you have 2 options

1) use the external sweep method
2) route audio through MC either using the WDM driver or the ASIO line input

the former is playing a sweep with a timing reference embedded in MC and then configuring REW to wait til it hears that reference
the latter requires a multiclient asio driver for the asio line in approach, not sure if your driver is multiclient capable but sounds like not. If not, it means configuring the WDM driver to play the measurement to the default windows audio device so that MC can then play that back.

I don't use TrueRTA so can't say exactly whether this can work as is in TrueRTA or whether there is some other method. REW is free though and it doesn't seem TrueRTA offers any features that REW doesn't have for this use case.

Looks to me like what I really need is a stand alone DSP engine like CamillaDSP or BruteFIR rather than the DSP engine in MC which is not really designed to be a stand alone DSP server. I can use TrueRTA with a hardware DSP crossover like the DBX PA2 which I have and use, but unfortunately this does not do FIR filters, only IIR. Same with my MiniDSP setup. MiniDSP does sell hardware that does FIR filtering but MiniDSP seems to be room correction oriented rather than active crossover.

Anyway, thanks for the help.

[mattkhan]

fwiw BruteFIR isn't available on windows as far as I'm aware & camilla doesn't support ASIO on windows (which is a dealbreaker if you need to use asio). If MC has the DSP capability you need then simply using measurement software that has the features required sounds like a simpler path to me.

[maglevrabbit]

fwiw BruteFIR isn't available on windows as far as I'm aware & camilla doesn't support ASIO on windows (which is a dealbreaker if you need to use asio). If MC has the DSP capability you need then simply using measurement software that has the features required sounds like a simpler path to me.

You may well be right. However, learning the intricacies of yet another piece of software is rather daunting, especially as there seems to be a rule that as the software gets more complex and difficult to use, the documentation for that software gets smaller and smaller. Nowadays you need to do weeks of trial and error and hundreds of forum posts to get anything working. Nothing seems intuitive, nothing is properly explained.

JRiver MC is one of the more intuitive pieces of software I have found, which is just as well since there is so little documentation. The documentation that there is (online) is very good and concise but so much detail is missing.

I have a feeling that at age 68, designing and testing active dsp based speakers is just one or more bridges too far.

Thanks once again.

[mattkhan]

If it's any help REW is one of the better documented apps around because it is free and widely used. I would guess it's not a big leap from using truerta to it, feel free to ask here if you do decide to try it.

[maglevrabbit]

I have ended up running brutefir on a headless Raspberry PI 400 using both an usb Asus Xonar U7 MKII with Creative Gc7 combination (the GC7 for a Toslink receiver) or a Creative X4 (with built in Toslink input) multi channel sound cards, fed from a Laptop running JRiver MC29 through a Creative G6 (for Toslink out). The X4 sounds really good even at an early stage of optimisation. I am finding getting the drivers of active speakers finely balanced is not easy.
At present I am using Brickwall filters at 80hz and 2000 hz with a Scanspeak SSD2608 tweeter and a 5 inch SB Acoustics poly mid-woofer, and a 15inch sub. The little $AU160 Raspberry PI 400 is able to handle brutefir using a 48Khz 24 bit stream, 64 bit floating point processing, with 6 filters using 131072 taps each, using the 64 bit version of Raspberry PI OS (Debian Bullseye). I have even had brutefir running on a 176.4Khz audio stream at 131072 taps per filter - does'nt miss a beat and never gets even warm.