Can Room Correction Be Added to an Existing DAC?


  This is probably a stupid question, and I’ve been  hesitant to ask it since it will reveal the depth of my ignorance, but here goes.
  In my home I have 3 systems.  2 are HT systems with mid Fi equipment, then my two channel system is upstairs (my HE system).  I had added an Anthem AvVR to one of the HT systems and was duly impressed.  I added the same AVR to my basement system a few weeks ago and now I am blown away.  I am wondering what room correction could do in my main system.  However, I already have Bryston DAC3 in that system that I really like.  So my question is whether it’s possible to apply RC after the processing done in the DAC .  My intuition is Probably Not, since the RC is also processing the signal.
mahler123
It's not a stupid question, but he answer may not be entirely what you want to do.

DAC's which do not come with digital signal processing (DSP) built in can't have this compute ability added, BUT! you can do DSP in the digital domain before the DAC gets to it.

There are two popular paths I know of.  First is Roon with it's built in parametric and convolution capabilities.  The second is miniDSP which has a number of digital domain (digital in, digital out) equalizers.

Best,
E
I agree, it's best done in the digital domain before the DAC.

Among the miniDSP units (mentioned by @erik_squires ), the miniDSP SHD Studio is a digital-in, digital-out processor with Dirac room correction built in. Dirac is often mentioned as one of the best DSP systems for audio. You might give that a close look.

It will also give you a streamer.

Welcome to the fold of happy DSP users! I think it's the future (and increasingly the present) of high-end home audio.
My Auralic Aeries G1 file player, as well as the G2 and some other Auralic products have digital EQ built into the firmware to be used, or turned off.
I really like the Anthem RC, but to get it in two channel I would have to buy the preamp processor DAC unit for 4K, and that would sideline my Bryson DAC and my Cary Pre Amp.  Glad to know the processing can be done in the pre DAC stage and the price seems right at $900, but can anyone compare Dirac Room Processing vs Anthem?  I did compare the Anthem 520 vs Yamaha AVR RC and it was no comparison—the Anthem was much more immersive.
If you don’t need a streamer the Minidsp DDRC-22D would work. I’ve used ARC and Dirac they are comparable. You can use Dirac the same as ARC by accepting the correction it recommends or tweak it.
djones51 

I was just returning to this thread to ask that question—do they make the Dirac minus the streamer, since I have one already—and was delighted to see your comment.  I have always found your posts helpful because I think we tend to agree on a lot of issues and so I thank you for your comments regarding ARC and Dirac
Thanks, most find me a pain I believe. I  could get into Dirac and do more adjustments than ARC but in the end I used the recommended file. I didn't find either one very hard and they both do a good job. I ended up with ARC mainly because I liked the STR integrated. 
I'm a big believer in light touches. I don't use room correction when a couple of parametric EQ's will do.
Equalizers won’t necessarily address bass room modes.

There are software solutions (Accourate, Audiolens, Dirac, etc) available that will create filters for use in apps such as JRiver that has convolution ability built in.
I tried for years to like RC. First with Dirac running as an app on a Windows server, going through the setup many times and making many filters to get it "just right". Wasn’t happy with the app in general or their support so just dropped it. Purchased Acourate, a much more capable app but a steeper learning curve. Went through everything as before, this time the developer even helped directly in making the final curve. Also followed a very detailed 3rd party book on using Acourate written by m*****o. Installed the filters in JRiver. Started thinking something was not right a few years in. One day I accidently switched the filters out and holy crap the sound was so much better. More alive, is the best way to put it. Less artificial. Sure maybe some room modes are back but the payoff in general is worth it. Just my experience. I’m sure there are decent implementations.
Equalizers won’t necessarily address bass room modes.


What do you think convolution filters are doing??? Hahahahah.


Sorry. It IS true that pure signal processing rarely fixes a room mode regardless of the type, Dirac, ARC, whatever you call it, but in combination with good room acoustics you can go very very far.
I'm using a MiniDSP nanodigi to do all the adjustments digitally before sending to my DAC. I also have the 2x4HD but I find the DAC in it leaves a lot to be desired compared to my current one.
  • Yeah SHD Studio uses Dirac. You can save and remote access 4 settings with 2 outputs (think subs) It also has 3 digital inputs so you can process other sources. The included headphone amp is handy for breaking in earspeakers all night. I think that it ships now with a 2.4 wifii dongle, but I’d rather run it through a Bright Angel. It definitely sounds better with an Ultracap LPS 1.2 pushing it rather than the included switchbrick. It runs an installed version of Volumio that I like better than BluOS.  Just plug it in, use Fing to find it's IP, then log into it and save (or bookmark) the page. It comes with a calibrated mic to make setting DSP easy.
@ OP
Take a look at 
https://www.stereophile.com/content/music-round-57
The Dualcore can be used prior to or post DAC.
I‘d strongly recommend a linear power supply. The switching unit that comes with it is a source of noise.
I have used this unit for years post DAC (OPPO 205) using its XLR Input and Output (amps: LSA Statement and Bladelius ASK). 
The Stereophile  review is entirely consistent with my experience.
Good luck!
Paradigm PW Link is an inexpensive way to ARC. Optical in and corrected optical out.

Since I began using Innous server with Roon and convolution filters through Acourate running my ATC 150 asl/D&D 8c  there is no way back.
Mahler123, the answer is yes sort of. If you just use two speakers you can use a DAC after a room control unit by taking a digital output. The problem comes when using sub woofers. Now you need two 2 channel DACs. The good room control units allow tailoring the entire frequency band including and probably most importantly the bass. They include bass management software which gives you the best subwoofer integration possible. Units Such as the Anthem STR, DEQX and the Trinnov Amethyst include 4 DAC channels. IMHO a complete unit is the best way to go. If you do not use subwoofers and have a DAC there are certainly less expensive ways to go but, warning, bass can deviate +- 10 dB. Correcting this requires a speaker of massive power handling and a very powerful amp. You can deal with this by going into the program and reversing some of the correction to keep yourself from clipping amps and blown speakers.
gosta, I certainly agree. I have been using a TACT unit for 25 years. I have ESLs and subwoofers. Once you hear a system with full digital correction there is no turning back.
mijostyn, I would like to run stacked Quads with subs. Heard this in the late 70’s playing Little Feat Waiting for Columbus. Still a reference in my memory :-) Actually got a pair of Quads 63 in my wardrobe so maybe, but don't know how to get a stacked pair...
The original stacked quads were in a stand made by Mark Levinson. There was a Decca ribbon tweeter between the two and the system used 30" Hartley woofers. It used 6 ML 20 watt class A amplifiers. I think they were John Curl designs. The Preamp certainly was.
The Quad 63 does not have side plates. The best way to do this would be to turn the second speaker upside down and place it on top. You will have to fashion a bracket between the two and hopefully the whole mess will balance on #1's stand. You will need a cross over with a high pass filter and I would recommend crossing over at 120 Hz. You will need at least two subwoofers. I use 4. With a full function cross over you can use passive subs with an outboard amp. Fun! The Quads start rolling off at 
10K. They are 5 dB down by 20 K. You can fix this with room control.
Wow! Thanks. Actually I got the 63's with Gradient basses, stands and crossover. So maybe doable. Just need a little space :-)

If you want a top of the line solution you can check out Bacch SP. They have a version with built-in dac and one without. The most expensive version also has head tracking!

https://www.theoretica.us/bacch-sp.html
My dealer is experienced with Anthem and set up the 2 AVRs in my house.  I’ll query him about Dirac vs the Paradigm .  I am also wondering that I should go this route, should I add a sub to the two channel system, because the biggest improvements that I hear with ARC are bass oriented.  OTOH, my speakers are B &W 803D, and they are pretty full range
The MiniDSP SHD Studio is a much more modern component, with much better quality internals than other MiniDSP products. I would say say hardware wise the Paradigm PW Link is in a similar class as the MiniDSP 2x4HD. The SHD Studio is in a different league altogether.

Dirac and ARC are generally considered to be similarly good, with many people giving a slight nod to Dirac. I believe Dirac is much more flexible, allowing you to tweak the target curve to suit your needs exactly.

minuDSP does include Bass management upto 2 subs which is very flexible, but the Bass management part has a steep learning curve.
The benefit of a sub with good speakers is not so much better/deeper bass output, but more of flexible positioning to reduce room modes. I would recommend getting a UMIK-1 mic and downloading REW (a free audio analysis software) to measure your frequency response first, before deciding if a sub is needed.

Most people/rooms benefit from multiple bass sources, so room modes cancel each other. However, In my case my speakers when measured individually are quite flat, However when I measure the combined L+R response with a mono signal, I have all kinds of peaks and nulls in the bass region. Adding a sing sub, introduced some crossover anomaly but restored a flat bass response. With a little tweaking of the crossover, my overall combined response is now fairly flat.
I had the DSpeaker X4. Good stuff. Easy to use. Built in dac, but has digital out as well. Worth a look, but $$.
As many others have said, you can add a digital signal processor in front of your DAC.
Dirac with miniDsp is probably the most cost efficient solution. If you want to evaluate Dirac you can download a time limited evaluation installation for Windows or MAC.
I tried it and the effect is not mild. The balance achieved is an improvement bot overall I didin’t like that the stereo image becomes too wide, to an extent that I lose the central image.
Also, I own LS50 and tried the Acitve DSP-ed LS50w. I didn’t like the result. I think some detail is lost in the processing.
Try before you buy.
Also, bass modes you can’t fix completely with DSP. You can enhance in one spot to a certain extent. The best solution for that is multiple subs, minimum 2 optimum 4.
There was a company that sells time alligned set of 4 subs. You place 2 on one wall the other two at the opposite wall. When the wave of the front two reaches the rear wall, the rear pair of subs fires a wave in counter phase so that it cancels out the reflected wave. That virtually removes the rear wall and the wavelength can fully develop as if in empty space. To my knowledge that is the best solution for bass. You could ameliorate with room treatment but that works better for higher frequencies with shorter wavelength. 
Kii speakers (and the subwoofer module) does something similar. Their speakers have woofers in the sides and back that fire a counter wave  time aligned to cancel wall reflections. Effectively eliminating the room wall.

I have heard a demo, and the result is phenomenal! One of the best audio experiences ever..