Introducing OpenDRC, Open Digital Room Correction engine

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Best Wishes for 2012 from the miniDSP team! Hoping you all had a great new year's eve wherever you are!
What a better way to start the new year than bringing up to our community a new platform? :) Here is a project we've been working on for the past few months... Following few weeks of testing with our partners, it's now ready for your eyes..

Introducing the OpenDRC-DI, a stereo Open Digital Room Correction platform that takes any FIR filter configuration. Think of it as a convolution engine that doesn't require a PC, a linear phase crossover box with all digital inputs (DI version) with AES-EBU/SPDIF/Toslink in/out. Controllable with our well proven USB technology from Mac/Win platforms, this lunchbox size DSP packs up a LOT of DSP power in a small aluminum box...
Check out the product page here!

@299USD only, the OpenDRC platforms will hopefully open a new trend, a new wave of exciting speaker processed products and custom applications for our community!

Stay tuned for further info,

DevTeam
 
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Hi,
I was a bit surprised to see that this box only offers stereo output. Yet the word "crossover" is mentioned several times on the product page. I guess you plan to release a product with more outputs soon? Could you please comment on this?

regards,
Øyvin Eikeland
 
@ Øyvin,

It's indeed a crossover unit for a 2way box. I.e. 2way box. It has all the processing and routing capability to make a high end FIR based + IIR based crossover which isn't exactly common at 299USD a pop for a fully enclosed solution. :)

Hoping this clarifies.

DevTeam
 
So, if i understand things right (which could very well not be the case...)
In order to use the OpenDRC as a crossover for a 2-way stereo setup, the options would be as follows:
1- Use 2 OpenDRC-DI modules set to mono, use OpenDRC to do crossover (IIR) and room correction (FIR), then take the digital signal out from each, and run each of them through a DAC (this setup would halve the FIR resolution).
2- Use one OpenDRC-DI to do the phase and room correction, then either keep the signal digital and pass it through a miniDigi/miniDSP for crossover duty, or pass it through a DAC and then into the miniDSP for crossover duty (though the latter option would kind of defy the purpose as one would be adding an superfluous AD/DA stage)

This would be different for the OpenDRC-AN.
 
@ Hajj,

As Curryman already confirmed, you're indeed correct with your assumptions.
I would think that 2 x OpenDRC-DI (all digital) would indeed be the best way to go for an all integrated solution. Easier to control this way.

Also not sure what you mean by 1/2 resolution. Each channel always get 6144 in mono or stereo configuration.

DevTeam
 
Is there a delay introduced when using FIR filtering and how significant?
Can this be used for Home theater without lip syncing problems?

Are there 2x8 or 8x8 versions on the way? I would really need something like 10x10HD except with bigger chip so it can do DRC.

Do I have to buy AcourateDRC plugin and for how much?

Thanks
 
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The initial delay (without filters) of the openDRC is quite low (<2ms) and will not cause any problems.

The delay with FIR filter depends on the type of filter used. In case of a symetric linear phase FIR filter (e.g. acourate will generate this type of filter) the delay will be half the number of taps divided by the sample rate. Using the maximum number of taps (6144) this will be 64ms. For minimum phase filters the delay might be much lower.

I am using openDRC together with a Panasonic Plasma (SPDIF out) and the video processing engine also has a significant delay (arround 70ms although I switched off most of the video processing). The SPDIF out delay can be adjusted and switched of and so I don't have any problems with lip sync (arround 10ms will be tolerable). Not sure though if SPDIF out delay can be adjusted for all TVs:scratch:

You don't need acourate to develop FIR filters (google for example DRC free as an alternative). It is very easy to use and gives great results though and thus I think it's definately worth the 80 euros;)
 
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Joined 2010
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In general I agree: a registration should not be necessary to buy products, though this is quite common in many shops.
However one of the biggest strengths of the miniDSP system is the great community that is always helping and giving lot's of inspiration. Thus I think the registration is giving you a great additional value and should be no show stopper ;)
 
I wonder how many other people will buy these and only thereafter realize that no operating software is included, and that they must also download several programs and then buy the plugin software to use it. This should have been a plug n' play system with instruction manual that was ready to connect to a computer interface and bet set up in minutes. The Python open room correction appear interesting if they can fix the horrendous phase shifts unique to that plugin and simplify (but not affect functionality of) the installation and operating.
Python 2.7:
Scientific Python: SciPy, Numpy, & Matplotlib
Scikits.audiolab
libsndfile
porc.py [-h] [-t FILE] [-n NTAPS] I F
python porc.py -t tact30f.txt -n 6148 l48.wav leq48.wav
sox -M le148.wav req48.wav equalizer.wav
This is the type of thing that confuses even the seasoned electronics or speaker designer who doesn't dabble in code. Currently, you need to be a computer specialist to use it, and we don't know if it works on XP Pro.
 
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@ Kouiky,

A plug&play solution is always better.. We agree... :) There are few things to keep in mind here and some misunderstanding:
- Python Open Room Correction is an Open Source project. i.e. not a product/software we sell, nor actually coded (work by Mason Green). It's free, and it's based on the concept of our platform being open for developing new processing capabilities. It's also v1.0 so who knows if in the future it won't be easier? As we mentioned in this section of the website with a little warning (Python Open Room Correction | miniDSP), it does appeal to people with some computer knowledge.

- If you want a plug&play software, then you should consider AcourateDRC (AcourateDRC | miniDSP) which will do everything you need from a neat User interface. Easy to use.

We certainly support work of either developers (Paying and non paying) and we think that it's always better to have a positive spin toward developers spending a lot of time to develop free software for the community and the benefit of speaker designers. We're not implying that the Python Room correction is for everybody... just saying it's a free option available for the OpenDRC (or any PC as that matter). That's it. :)

DevTeam
 
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