Minidsp DDRC-88A with Bass Management - Dirac Live 3

 

The MiniDSP DDRC-88A is a mini digital sound processor which integrates Dirac Live 3 room correction. I ordered the MiniDSP with Phoenix XLR Male and Female input and outputs:

"Introducing the miniDSP Dirac Series, powered by Dirac Live®, the world's premier room correction solution. We are delighted to offer you this software and hardware combination, the fruit of many years of experience in sound system tuning and extensive research and development. The DDRC-88A is the big brother of the stereo DDRC platform introduced early 2014. Based on our proven 8x8 DSP board and miniSHARC powerful module, the DDRC-88A combines two successful & proven platforms into a cost effective one rack unit processor. An infrared remote learning feature and the front panel rotary encoder allow for control of the DDRC-88A processor without any need for a connected PC, once the processor is configured and filters loaded.

Finally, the DDRC-88A is an upgradable platform thanks to the power of the DDRC-88BM plugin. The software plug-in extends the capabilities of the DDRC-88A multichannel Dirac Live® processor. 100% compatible with all DDRC-88A units in the field, the DDRC-88BM adds comprehensive fine-grained bass management and crossover capabilities. The input signals are low-pass filtered and summed to generate the subwoofer signal; a matrix mixer routes or mixes these channels for the Dirac Live® algorithm, which in turn has its outputs routed or mixed to the output channels, where additional high/low pass and parametric filtering takes place. In addition to improved bass management for conventional home theater signal paths, the DDRC-88BM allows innovative solutions like multi-subwoofer control and combined DRC/active loudspeaker setups."

  • Features
  • Processor: 32-bit floating-point Analog Devices SHARC DSP
  • Dirac v3.0 support
  • Input/output resolution: 24 bits
  • Analog inputs: 8x balanced RCA / 8x balanced phoenix terminal blocks
  • Analog outputs: 8x balanced RCA / 8x balanced phoenix terminal blocks
  • Internal operating sample rate: 48 kHz
  • Optional DDRC-88BM plugin for Bass Management + Dirac Live + Active Speaker processing (Crossover/PEQ/Delay)




Note: actual Phoenix connectors differ from picture above.

After wiring up the hardware I did run into a couple of issues. I read the instructions carefully and the online PDF conveyed that I needed to update the firmware. Turns out my update went bad and I made my unit a brick, or so I thought. MiniDSP support is wonderful and was able to walk me through the steps of resetting the device through an internal reset button while launching the MiniDSP software. They also informed me that I did not need to update the firmware but rather they needed to update the online manual. 

Once connected:





Turns out my headaches weren't over yet. I couldn't connect to the Dirac Live server when launching the software from within the MiniDSP software:


This issue existed because both my network adapter and router were using a Private DNS by Cloudflare address of 1.1.1.1. Once changed to Google's DNS of 8.8.8.8 the problem was resolved and I was able to connect to Dirac Live Servers and login to my account. 

Now, my computer room is some 30 feet away from the entertainment room. And since I don't have a laptop and really don't have a use for one I instead purchased 32-36 feet of USB cable with repeaters:


And this USB cable to run from the MiniDSP to my computer: Tripp Lite USB 2.0 Hi-Speed A/B Active Repeater Cable (M/M) 36-ft. (U042-036), Silver

Good to go I launched the Dirac Live software and ran my first measurements. Here's a screen shot from within the software. Note how flat the default Dirac Live target curve is [solid dotted line]:


I have a learning curve as today was my first day working with the Dirac Live software but I found this video on YouTube which was pretty informative:


Loaded a Dirac Live Target Curve by NAD which many are recommending. The default Dirac Live target curve is rather flat. The full frequency NAD curve can be found here: https://nadelectronics.com/dirac-live/

Also note that additional Harman Research curves for Dirac can be found here below. I plan to load various curves into the MiniDSP presets for varying media such as music or theater: https://mehlau.net/audio/dirac-live-2/

Below, the solid dotted line is NAD target curve, thin line is actual before room correction frequency response, and bolded line is corrected room correction:





Here's the MiniDSP unit ontop of my Onkyo PR-RZ5100:


Other equipment consists of Parasound Halo A31 and ACInifinity Cooler. Check out the other reviews on this site for more information on the rest of my gear: Disqus.Social


Update: Since the above article was published I changed my target curve to the Harman Research +4db curves. The center channel was tweaked for a flat frequency curve. In the below screen shot Group 1 is the Left and Right mains. Group 2 is the Center channel. Group 3 are the Left and Right Subwoofers:


Update 2: I'm now using the Harman Research +4db curves for both left and right mains as well as the center channel. However, I'm running the +6db Harman Research curves for the subs. I absolutely love the newfound fidelity. 


Note: in the above image of the subs +6db Harman Research curve I've implemented the crossover to cut below 20hz.

Happy Listening!


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