Integrating Roon and Dirac Room Correction

[Mohmm]

Now that Dirac offers a standalone version of DiracLive, I managed to do the measurements and produce a filter for Dirac Live Processor (DLP) on the MacMini where Roon Server resides.

From Roon you need to establish a virtual connection using AudioHijack to the Mac's Digital Out. I use an optical connection to Devialet Dialog, which is connected to the Phantoms by ethernet. The AudioHijack window shows this:

Application: Roon > AU: DLP > Output Device: Digital

Both, the AudioHijack window as well as the AU-DLP window show sound indicators, but those in the DLP window are very low, indicating relatively low amplitude.

In Roon I set volume to DSP and I can regulate volume from within Roon and from the Phantom Remote.

However, there seems to be glitch in my volume settings that is perhaps the cause of the low amplitude shown in the AU-DLP window. The consequence is that when I switch to another app, such as AppleMusic, I get a frighteningly high volume from the Phantoms.

I am at a loss and don't know how to configure the chain for a decent volume level for all apps.


By the way: The sound with Dirac is unbelievable. Controlled bass and clear mids and highs.

[njaiswal]

Dirac Live is a game changer, IMHO, when you use it with the phantoms. I'm using a JBL SDP-55 to enable Dirac Live and i can't believe how much "bass bloat" there was in my rooms. Unfortunately, I don't have an answer for you on why you have the volume issue. :-(

[supaDean]

Dirac Live is a game changer, IMHO, when you use it with the phantoms.  I'm using a JBL SDP-55 to enable Dirac Live and i can't believe how much "bass bloat" there was in my rooms.  Unfortunately, I don't have an answer for you on why you have the volume issue. :-(

I agree. Digital room correction is a must for best sonic performance used with whatever physical room correction your listening space may have or which you have installed. In my case I've rugs and plush couches which do a good job of dampening. I haven't installed any panelling as that is another level of physical room correction I don't want to get into, because of aesthetics and cost.  

I'm currently using DiracLive via a miniDSP Studio for two-channel stereo music playback. It is a game changer and makes the Phantoms shine. Especially when used with the Mutec reclocker. I currently have a pair of Phantom II 98db (Phantom Reactor 900) on Legs stands, and have just ordered a pair of Phantom I Classic Glossy 103dB and Tree stands, which I can't wait to setup once they arrive.

@njaiswal you must have quite the home theatre setup with so many Phantoms?!

[Mohmm]

I will add how I solved this problem to spare others the unpleasant experience.

When you play music through this chain all of the elements have a potential contribution to the final volume. So when you have a remote control for your Phantoms (either physical or an app on your phone) check the following items one by one. Be sure to turn down the remote and stop the music in Roon.

1. In Roon set the device volume control to fixed.
   
2. In Audio HiJack: Set the AudioUnit for Dirac Live Processor (DAP) to max or a bit below the max for safety.
   
3. Start Dirac Audio Processor (the real one, not the AU) and set the volume to max or close to max.
   The problem is that the real DAP reduces the volume of its AU without this fact being reflected in the slider setting of the AU. That is, AU may still show max, while the music is low because the real DAP is not on max.
   
4. Mac Audio settings: set Dirac Virtual Audio Device to max in the sound settings.
   
5. Control volume entirely from your Phantom remote.
   

Even Dirac support (not to mention AudioHiJack support) didn’t mention this interdependence between real DRP and its AU. They should know their own recommendations better.
Otherwise, Dirac’s effect on the quality of reproduction is overwhelming. Be sure to give it a try.

[ogs]

Hi,

it is possible to save the Dirac correction as a file. The following is an adoption of an instruction I got from the author of brutefirwrapper (BrutefirDrc for LMS), for recording the output of my Tact RCS 2.0. This was back in 2010... A stereo wav should be directly usable as a convolution filter in Roon. Whether this will capture all of what Dirac does is something you need to try (I think it will). You'll capture Dirac's digital output from Audio HiJack and record it in for example Audacity for editing.
A user here at DC,  @Alec_eiffel has much experience in this field. Hopefully he can advice further if necessary.



******************************************************************
I have no experience with Tact [Dirac], so this advice is all guesswork:


You'll need an "Impulse Response" of the room correction filter, and you should be able record that directly if you can play the impulse through Tact [Dirac], and simultaneously record its digital output. (ie no amplifiers or speakers in the measurement chain; just Tact [Dirac] -> computer input)

You need to play an impulse through Tact [Dirac]. That is, a file with all samples zero (silent) except one, which should be (I guess) half full scale (or -3dB). It looks like this:

_______|_______

Record the Tact [Dirac] output in stereo - this is your Tact [Dirac] filter Impulse Response. You should see a main spike, and you may need to adjust the amplitude of the input impulse (normalize) so that the recorded Impulse Response is nearly full scale without clipping. There may be a brief rising edge in advance of that spike, and there should definitely be other ripples behind the main spike. Save 64k (65536) samples to a wav file, with the spike near the middle of the file (position doesn't matter, but definitely avoid cropping any non-zero samples)

******************************************************************

[Mohmm]

Hi,

it is possible to save the Dirac correction as a file. The following is an adoption of an instruction I got from the author of brutefirwrapper (BrutefirDrc for LMS), for recording the output of my Tact RCS 2.0. This was back in 2010... A stereo wav should be directly usable as a convolution filter in Roon. Whether this will capture all of what Dirac does is something you need to try (I think it will). You'll capture Dirac's digital output from Audio HiJack and record it in for example Audacity for editing.
A user here at DC,  @Alec_eiffel has much experience in this field. Hopefully he can advice further if necessary.



******************************************************************
I have no experience with Tact [Dirac], so this advice is all guesswork:


You'll need an "Impulse Response" of the room correction filter, and you should be able record that directly if you can play the impulse through Tact [Dirac], and simultaneously record its digital output. (ie no amplifiers or speakers in the measurement chain; just Tact [Dirac] -> computer input)

You need to play an impulse through Tact [Dirac]. That is, a file with all samples zero (silent) except one, which should be (I guess) half full scale (or -3dB). It looks like this:

_______|_______

Record the Tact [Dirac] output in stereo - this is your Tact [Dirac] filter Impulse Response. You should see a main spike, and you may need to adjust the amplitude of the input impulse (normalize) so that the recorded Impulse Response is nearly full scale without clipping. There may be a brief rising edge in advance of that spike, and there should definitely be other ripples behind the main spike. Save 64k (65536) samples to a wav file, with the spike near the middle of the file (position doesn't matter, but definitely avoid cropping any non-zero samples)

******************************************************************

It would of course be great if the Dirac correction could be added to Roon as a convolution file. However, if your information is from 2010, I am not sure if Dirac even existed 12 years ago.

My other question is, how would you combine the time domain and frequency domain in one file?

In fact, the Audio HiJack sometimes stops working for no apparent reason and is not very reliable. Therefore I am considering a miniDSP between my macMini and the Dialog. Any idea which one would fit best for my simple DRC task?

[ogs]

All information is in the impulse response, both time and amplitude. This thread https://community.roonlabs.com/t/near-fi...er-in-roon over at the Roon forum explains the same thing, but you'll have to read most of the thread to understand how KMan does it.
The miniDSP SHD series are a very nice units, but doesn't have optical outputs so you'll need to convert from coax to Toslink.

[alandbush]

What about the DDRC-22D

[ogs]

Yes, with Toslink I/O this should absolutely work.

[bpo]

There’s also this to check out:

https://www.minidsp.com/products/minidsp-in-a-box/flex

You have to scroll down to see the reference to an all-digital version listed.  If you download the “Product Brief” PDF it has a chart comparing the different models and showing the Digital one that has Toslink, USB and SPDIF outputs.  There is no AES input/output though like the DDRC-22.  However, it looks like it will have more processing power and may have a longer future life as the DDRC-22 was released in 2014 so who knows if it will support later versions of Dirac beyond the 3.0 Live it currently supports.

The biggest problem with the Flex Digital will be getting your hands on one as the regular one is already sold out and they still haven’t released the digital, which I suspect could be delayed, as their website says release at the end of Q1 2022…

I’ve been looking at both but haven’t pulled the trigger yet.  If anyone has thoughts on these models or other suggestions, they would be great to hear.