1 (edited by Derp 2023-01-19 20:32:39)

Topic: Dirac compatibility

Good evening,

I've been researching for a bit but cannot figure it out to save my life.

Let me preface this by saying that I own an ADI-2 DAC FS as my desktop device and particularly appreciate its dynamic range and loudness feature set. So I am somewhat superficially familiar with the device.

I have considered to rework my living room somewhere down the line and been laying out options. Ideally I'd like to "future proof" in terms of feature sets, insofar they are, at all, compatible. A second ADI may thus be on the menu.

The chain, in my mind, would generally look something aching to this:

TV (SPDIF)/BT Receiver(SPDIF)/PC (USB)/... -> RME ADI-2 DAC FS (Pro) -> (Power Amp) -> (Stereo Active Speakers) / Active Speakers

Now my question is, whether a dirac device (DDRC-22D / DDRC-24 depending on the chain placement for example) would be compatible without losing either the ADI's Loudness/Dynamic Range feature (ADI would connect into the minidsp) or the dirac feature (minidsp would connect into the ADI).

Can this feature set be stacked or will one DAC effectively "override" the other? The chain would be kept entirely digital throughout. Assuming they could be stacked, should dirac or the ADI be the preprocessor?


TV -> DDRC-22D -> RME ADI-2 DAC FS -> (Power Amp) -> (Stereo Active Speakers) / Active Speakers


TV -> RME ADI-2 DAC FS Pro -> DDRC-24 -> (Power Amp) -> (Stereo Active Speakers) / Active Speakers

Dirac doesn't hold any particular value to me right now but it may in a few years time so I want to verify whether this is even possible or is a fool's errand.

In case it is a fool's errand (a very a costly one at the very least): I also got a decommissioned raspi 4 laying around, if that seems more feasible but would require some key words/hints to get me started walking down the correct path.


2 (edited by KaiS 2023-01-20 00:15:49)

Re: Dirac compatibility

DIRAC is a problem fixer.
What’s the problem you like to fix?

If it’s about room acoustics, don’t expect too much beyond what ADI-2 can do.
Room acoustics is more a time domain problem, think “Echo”.
Dirac (and other equalizers) work in the frequency domain only, leaving the echo untouched.

EQ’s are very good in fixing mis-tuned systems, or re-tune a system to a personal preference:
more or less quantity of bass or treble or midrange, in great detail.
But they cannot remove wall reflections, “Echoes”.

It boils down to invest personal time into speaker placement, even selecting a speaker that fits to a room, or fit the room to the speaker.

Example 1:
You have a room with lot’s of reflective surfaces, like glass and naked walls.
If your speaker has a controlled, high directivity, focusses it’s sound more on the listener and less on the walls, less reflections will be produced, you get a clean sound.

Example 2:
Your speaker has a wide dispersion, spreads the sound all around.
You have treated your room with some absorbing materials like carpets, curtains and drapes, maybe a filled bookshelf and textile seatings.
Again, you get a clean sound.

It’s about pairing, and there’s not much an EQ can do if the pairing doesn’t fit.

What EQ can do:
Give some retouch to an otherwise well-paired and optimized system, bringing the quality a notch or two up.
Remove little annoyances, that stick out more if everything else is already on a high level.

There’s one area where it’s just the other way round:

With headphones it’s very much about frequency response tuning, time domain is clearly dominated by it, simply because much less is going on in the time domain of headphones.
For headphones an EQ can make a night and day difference.

3 (edited by Derp 2023-01-20 07:27:09)

Re: Dirac compatibility


thanks for the reply.

KaiS wrote:

DIRAC is a problem fixer.
What’s the problem you like to fix?

Right now, in regards to dirac or EQ, none, really. Our living room is relatively long and narrow, maybe ~2.5m speaker distance at best.

I am mostly looking to throw out my NAD C368, as I personally do not think it does my pair of Dual CL730's any justice (I am  a bit of a grave digger). Further I had hopes for a NAD HDMI 2.1 MDC Module but it is 2023 now and I am not about to hold my breath.

Prior to setting up the Duals in the living room I had them hooked to my desktop for a little while using an ADI and Topping PA5. They sounded rather brilliant, at very least in contrast to the NAD.

So at the very least I'd like to ditch the NAD, pick up another ADI and reinstall the PA5, for as long as the latter may live, as apparently there have been some potential production issues with them.

The ADI would become the "brain" and volume controller for any active amp or a pair of active speakers, such as a pair of Mackie MRs, which I am also fond of and could work due to the narrowness of our particular living room.

So what about dirac?

Ultimately I would expect another ADI investment to serve me well for years to come, this includes moving to different/various places and situations, which may or may not turn out to be infinitely more complex than our current situation.

Unfortunately I am a bit of an idiot when it comes to sound technicalities overall. I am simple man and I like "good" sound.

So dirac would throw money at a problem that would be perfectly solvable through other means. It would be effectively aching to calling an electrician to have your stove connected: What you cannot or are unwilling to do yourself, you have to pay others for.

Hence this is more of a question of general compatibility first and foremost. I merely want the option of the easy, if expensive, way out, should it come down to it.

If I understood you correctly however, then the ADI would be almost, if not equally powerful in regards to settings and EQ capabilities that it could do what dirac does, albeit with more personal investment.

The headphone amp portion for that setup would be moot, as rarely, if ever used. My desktop been driving a plethora of headphone splendidly though.

This at very least would confirm that throwing an ADI into the living room isn't one of the worst ideas I've ever had and I could always take things from there, should there ever be an actual need for either dirac or dirac-esque corrections.

4 (edited by KaiS 2023-01-20 09:33:12)

Re: Dirac compatibility

As you already know, ADI-2 DAC as the central unit is a fine solution.

If you want to use Dirac, it has to be inserted BEFORE ADI-2 DAC.
This means, source selection (TV (SPDIF)/BT Receiver(SPDIF)/PC (USB)/...) needs to be done in the Dirac unit.
Check, if that’s possible.

Both speakers mentioned don’t need much correction per se, for basic adaptions they have their built-in controls.

Compensating one or two room modes could be done in ADI-2.
An iPhone with the app AudioTools by Andrew Smith, temporarily used as measurement tool would be enough to assist finding the right setting.

So if you buy Dirac it’s really more about expertise than hardware.

5 (edited by Derp 2023-01-20 10:14:51)

Re: Dirac compatibility

KaiS wrote:

As you already know, ADI-2 DAC as the central unit is a fine solution.

If you want to use Dirac, it has to be inserted BEFORE ADI-2 DAC.
This means, source selection (TV (SPDIF)/BT Receiver(SPDIF)/PC (USB)/...) needs to be done in the Dirac unit.
Check, if that’s possible.

Thanks, that was the vital information I could not piece together myself.

Going by today's options a DDRC-22D should work from my understanding, as it comes with digital ins and outs, where the outs would then feed into the ADI.

Whether that device is still around, superseeded or relevant by the time I would actually consider it, is another story but then there may be others, or replacement technologies altogether. So long as it has to go before ADI that is all I needed to know.

Thanks for the clarification and have a fantastic weekend.

6 (edited by WowFlutter 2023-01-20 11:34:58)

Re: Dirac compatibility

Hi, I have been using a DDRC-22D for room response correction since 2018. It works in the frequency, as well as the time domain (impulse response correction).

Having measured the room response once and defining the target frequency response, I found any other frequency domain setting downstream from the DSP (EQ, loudness, tone) is unnecessary.

I have recently bought an ADI-2 DAC and it works perfectly with my setup (of course, as KaiS pointed out, it connects to DDRC's digital output). In this setup, I might not have much use for ADI-2's own DSP and filtering, but ADI-2 DAC has enabled me to better understand the signal coming from the DDRC and adjust the output (ref level and volume) to best match my amp's input stage.

One thing that happens with a DSP like DDRC is the need to attenuate its input in order to compensate for the gain that might occurr during processing, which can lead to clipping. DDRC has four attenuation presets: 0, -3, -6 and -10 dBFS. Before getting ADI-2 DAC, I was never sure whether I was applying too much or too little attenuation - now I can see exactly.

Beni's Auto SPDIF Audio Switch --> miniDSP DDRC-22 Dirac --> ADI-2 DAC --> Marantz PM8200 --> Kef Q7

7 (edited by KaiS 2023-01-20 14:41:16)

Re: Dirac compatibility

WowFlutter wrote:

Hi, I have been using a DDRC-22D for room response correction since 2018. It works in the frequency, as well as the time domain (impulse response correction).

We are talking about different issues:
Fixing transducer imperfections is possible.

But – it’s physically impossible to remove room acoustics from a signal by any compensation.

The reason is simple:

If you try to compensate e.g. a single wall reflection, the compensation signal causes another reflection by it’s own, that would again need compensation, and so on.

Very bad if the reflection contains frequencies that are louder than the original – happens all the time for close wall reflections.
Then the compensation needs to be louder too, and the compensation of the compensation... - instability.

You get there figures?!

Then, in a real room, you get a large multitude of reflections, from multiple directions, which the auditorial system (ears + brain) can separate from the direct signal by some amount.
You even “learn“ your room over the time.

The measurement microphone can‘t do this.

So measurement and personal reception does not coincide - how could the measurement then be used to get a valid base for compensation?

Furthermore, any compensation would only be valid for one single point in the room, of few millimeters size.
Any deviation from this point renders compensation into error.
Unfortunately we have two ears spaced apart, and we move around...

The above is just scratching at the surface of room acoustics, there’s much more about it, filling books.

I’ve been running through this all through my decades long career, every time new technologies arose we thought: “Now we can trick acoustics”.
Then we though: “Why didn’t this come out like expected?”
Finally you always replace one error with another.

There‘s no way around good speakers, correct placement and a basic amount of room treatment, which may consist from normal furnishings for domestic use.

There‘s a reason recording studios invest on this.

Re: Dirac compatibility

I am quite sure that a great deal of knowledge, effort and money goes into equipping a good recording studio. Dirac is definitely not designed for studios or recording, and not even for monitoring. But it is also not "tricking acoustics" as it is based on recognised research in acoustics and signal processing, and not snake oil. Its correction is based on a signal model which - as any physical model - is a simplified approximation of reality.

However, this model is surprisingly effective in dealing with most domestic situations, where little or no optimisations beyond good speaker positioning can be done for reasons of aesthetics or economy. You will not see bass traps, absorbers or QR diffusers in many living rooms! It can't do wonders - a difficult room will stay difficult, but it does a fair job of reducing most prominent resonant modes and indeed does try to cancel the room impulse response - up to a reasonable amount.

Now the question is the user expectation - it won't turn a concrete stairwell into an anechoic chamber, for sure. But it does help an audiophile get rid of the most annoying imperfections induced by a living room not designed by an acoustic engineer, and allows us to take a step further in music enjoyment.

Beni's Auto SPDIF Audio Switch --> miniDSP DDRC-22 Dirac --> ADI-2 DAC --> Marantz PM8200 --> Kef Q7