TOPIC:

Hello, I have been consulting the forum but I haven't found an answer to my problem. If it has already been answered, I apologize in advance.Currently, I own a miniDSP DDRC-22D that I use in my stereo setup. I am considering the possibility of adding a subwoofer initially and converting my setup into a 2.1 system. If everything goes well, I might consider adding more subs to have a 2.2 or 2.4 system.The question is as follows: Dirac Live creates filters based on individual measurements of the right channel and the left channel, but in a 2.X system, the channels share the subs. If DIRAC equalizes the channels individually, how should we correctly address this issue?Thank you in advance and greetings.

HI,

The unit you have is only 2 channel and for more channels to control you need a DDRC 2x4 where 2 go in 4 go out but that is with AD/DA conversion, your DDRC22D is in the digital domain.
You might want to look at the DDRC88D version that gives you maximum of 8 channels of Dirac. i've got one running with Bass Management and gives a lot of options. 

Hope this helps.

Jeronimusch wrote:

HI,

The unit you have is only 2 channel and for more channels to control you need a DDRC 2x4 where 2 go in 4 go out but that is with AD/DA conversion, your DDRC22D is in the digital domain.
You might want to look at the DDRC88D version that gives you maximum of 8 channels of Dirac. i've got one running with Bass Management and gives a lot of options. 

Hope this helps.

Thank you very much for your response.Firstly, I would like to clarify a few aspects. The system I want to set up is a stereo system, not a multichannel system. Configuring it as a 2.X system does not mean it ceases to be stereo. It simply means that the non-directional bass zone is shared between the two channels.I want to use the subwoofers for two purposes. Firstly, to reinforce the low end of the spectrum. Secondly, to naturally flatten the even harmonics in the modal zone by placing paired subwoofers along different axes of the room.That being said, what I want is to have a stereo signal at the output of the DRC (Digital Room Correction), and I want the entire process to be done in digital so that the analog conversion happens at the last moment with a DAC (Digital-to-Analog Converter) of my choice. Using the suggested hardware options would involve unwanted AD-DA (Analog-to-Digital and Digital-to-Analog) conversions in the first case, and in the second case, if I keep the signal in digital, I would need to use different DACs for each channel.In my humble opinion, the issue lies not with the hardware being used but with the Dirac Live software. I could use it in a conventional manner, but since the subs are common to both channels and Dirac calculates filters based on individual measurements of each channel, the resulting filters calculated by Dirac would not be correct. At the very least, the bass zone would be "over-equalized."I posed this question in case someone else had encountered the same problem and had come up with a solution. Therefore, if anyone else has any input, it would be appreciated.In any case, thank you very much.

hi,
i think i see the confusion or my explenation is too short...
I've a 2.1 system with Dirac i use three Dirac channels i.e. multi channel (not to be confused with 5.1 or 7.1 home theater (HT) setup).
as each frequency is filtered let's say 20-80 Hz left woofer and 80-20K hz left speaker and 20-80Hz right woofer and 80-20K hz right speaker requires three channels.
That is why i use the DDRC88D with BM that allows for the crossovers and the Dirac to work as you want as well. 

My system is a hybride stereo and home theater:
I've a stereo  setting as described above and a setting in HT done within the DDRC88D configurations.

In stereo the DDRC88D uses a 3 channel configuration (2.1) and in HT it is a 5.1 configuration and uses 6 channels.

But to make things more complex i've four physical subs but in stereo i use the 2 front subs measured as a single virtual sub and in HT i've all 4 subs working as 1 virtual sub.
my front end goes into the DDRC88D the .1 channel and center go into a 4x10HD on eas/ebu and use 4 channels as the center is routed out to an external dac.
so i measure the subs in REW to work in stereo mode as a configuration in the 4x10 and do the same for a configuration for the HT setting with 4 subs. 
then when this is done the DDRC88D does Dirac on a single virtual sub while in reality there are 2 or 4 subs working. again 2 configurations 1 for stereo and  for HT.




 

Hello again Jeronimusch.
First of all, I want to thank you for your interest, your help, and your extensive response.I think I understand your setup now (at least to some extent).

The first thing that became clear to me is that you are using the DDRC88D, which means you have 4 digital stereo inputs and 4 digital stereo outputs. This leads me to the conclusion that you will need several DACs for the analog conversion of these outputs. Although you didn't mention it, I have the feeling that you solve this with the DACs in your AV processor, both for stereo and cinema.

I also understand that even though you have 2 subwoofers in stereo, positioned close to each speaker, you use them as a single unit. Although I think this is a completely valid solution, I would appreciate it if you could satisfy my curiosity about why you chose this approach instead of using a separate subwoofer for each channel.

As for your multichannel system, I have nothing to say. The truth is that I have a high-quality home theater system with a somewhat independent audio system, but I have never been interested in multichannel. Explaining the reasons would take some time and would be out of context.

Given the above, there is no doubt about the interest that a device like the DDRC88D has. However, as I mentioned before, it requires one DAC per output channel. This could lead to a debate about the importance of DACs, the real differences between them, and whether it is necessary to spend a lot or little money on them. But that doesn't change the fact that multiple DACs would be needed.

Focusing on my problem, one possible solution would be to have a 2.2 system in which each subwoofer is only associated with one channel. This would meet the requirement of extending the frequency response but not the requirement of flattening the modal response or, at least, not in the way I explained before (cancelling even modes). Similarly, the solution of associating one subwoofer with each channel wouldn't make much sense in a 2.4 setup.

Once again, thank you very much, and greetings.

Hello DrFunk,

My best replies to your questions:
The first thing that became clear to me is that you are using the DDRC88D, which means you have 4 digital stereo inputs and 4 digital stereo outputs. This leads me to the conclusion that you will need several DACs for the analog conversion of these outputs. Although you didn't mention it, I have the feeling that you solve this with the DACs in your AV processor, both for stereo and cinema.
Jeronimusch: I use 4 stereo dac's the routing is a bit complex as my Front L and R are part of an active 2 way. that is 4 channels and the bass is seen from the DDRC88D 1 channel into the 4x10 HD to handle the subs. that is a .4 or .2 in a way depending on stereo or HT.

I also understand that even though you have 2 subwoofers in stereo, positioned close to each speaker, you use them as a single unit. Although I think this is a completely valid solution, I would appreciate it if you could satisfy my curiosity about why you chose this approach instead of using a separate subwoofer for each channel. 
Jeronimusch: From the HT approach with multipole subwoofers it is important they work together to achive a unison low extention of the sound including the LFE effects. Therefore a virual sub setup and check Youtube for instruction video's how to do this in REW you make sure the low frequencies don't cancel each other out and the sound is time alligned on the main listing position. If you take the subs seperate and basically a threeway system gives you less control over the lower end. one woofer can cancel some frequencies to the other. as the low end is omnidirectional you make the most out of all the engery in the room. you cannot hear left woofer bass seperate from the right. I can tell you the bass fundament with Metallica's Sad but True is fenominal you can clearly get the double bass even at low volume as the control in the time domain is corrected when you follow the virtual sub method.

Given the above, there is no doubt about the interest that a device like the DDRC88D has. However, as I mentioned before, it requires one DAC per output channel. This could lead to a debate about the importance of DACs, the real differences between them, and whether it is necessary to spend a lot or little money on them. But that doesn't change the fact that multiple DACs would be needed.
Jeronimusch: correct i switched from the DDRC88A to the D and use Schitt Modius' with AES/ABU as one of my DAC's. i'm saving up to buy the Okto8Pro which would complete my system...(for now ).

see  for some insight in the multi sub method.



 

An active system. I've been enjoying active systems for many years. The latest one I've been enjoying until recently was a four-way stereo system per channel, using a dbx4820 as a crossover, which was fed digitally, and a Denon AVC A1 as the amplification, driven by the Ext. In.Although I was already familiar with it, thank you very much for the video.Anyway, thank you for sharing information about your equipment. Greetings.