Minidsp DDRC-88A Dirac Multichannel DSP Review

[Chromatischism]

Thank you @amirm. This is one review I was very eagerly waiting for.

I am a bit confused with the comments. I use the DDRC-88A with a pre-pro that does Dobly/DTS decoding for a 5.1 setup (I don't use Atmos or DTS-X). Is there a single-box solution for the same that measures better that this combo?

Regarding using a PC with some software into a device like Okto, where and how would the Dolby/DTS decoding occur? How would that play along with Dirac on the PC?

I was waiting for someone to say this. I think most people don't understand the purpose of the device. This came out to serve the needs of home theater at a time when there was no other way to get 8+ channel Dirac live into your system.

 

[TulseLuper]

I'm curious to know the breakdown of use cases for owners of this and other similar miniDSP products. I use one as a crossover for active 2-way speakers + subwoofer in a stereo setup (it would also accommodate 3-way speakers and 2 subs). You could also use it as a preamp with multiple pairs of speakers - each pair could have it's own config, EQd separately and level matched. Or does everyone just use it as a surround processor with Dirac?

 

[Chromatischism]

As previously stated I bought a NAD T758 V3 after Amir's review because I didn't expect to need to drive it into the distortion Amir observed above -6dB and only use its HDMI input. This is indeed the case as I am well below these levels in my room with my speakers. Even with my use case it might still be considered flawed by some (many?) but I look at this review and when comparing the measurements I'm struggling to see how the DDRC-88A would be considered as a good value alternative to the NAD which offers a 7.1.4 solution with 7 internal amplifiers (4-channels of external amp reqd for the full 7.1.4) plus ATMOS/DTS-X decoding along with Dirac 3.0. Especially because I purchased it new for about $11 more including full range Dirac vs the DDRC-88A at full price.

I might well have tin or cloth ears, I certainly have 60+ years old ears, but the T758 sounds fine to me. I do wonder if there is a tendency to over think and over complicate for many consumers, especially around AVR solutions, with a possible tendency to over emphasise specification at the cost of pocketbook, functionality and usability.

I understand Amir's goal is to drive manufacturers to improve measured performance, particularly when it should be affordable to do so. Clearly, its not Amir's mandate to find use cases for equipment that fails to measure up. However, it would be nice to see a little more exploration of that because I can certainly appreciate Amir having chosen to specifically call out how the NAD performed at the -6dB point, since it helped me decide the T758 might be a good entry point to surround sound with Dirac for me.

At the time this unit was released, it was the only way to get Dirac into an Atmos setup.

 

[amirm]

Someone asked for RCA/unbalanced performance. Alas, it is much worse than balanced:

 

[TimW]

This DDRC-88A is based on the same platform as the 4x10 HD right? I was interested in maybe picking one of those up but the balanced analog input performance is just okay and the single ended input is borderline unacceptable. At least by my standards. I wonder how the 4x10 HD would measure using a digital input and therefore bypassing the ADC. Is it likely that the ADC is severely limiting performance here and we could gain 10 db of SINAD by bypassing it?

 

[Vasr]

Even with my use case it might still be considered flawed by some (many?) but I look at this review and when comparing the measurements I'm struggling to see how the DDRC-88A would be considered as a good value alternative to the NAD which offers a 7.1.4 solution with 7 internal amplifiers (4-channels of external amp reqd for the full 7.1.4) plus ATMOS/DTS-X decoding along with Dirac 3.0. Especially because I purchased it new for about $11 more including full range Dirac vs the DDRC-88A at full price.

I don't think anyone is suggesting this unit as a replacement for an AVR of whatever brand or performance. In fact, there is discussion of how difficult it is to incorporate into an AVR-like use case. Also it is not being pitched for its performance (which is barely acceptable) but rather for its main feature which is Dirac correction in use cases that does not need a whole AVR purchase. Just like the NAD, the use of the Dirac connection will likely override in user satisfaction any deficiencies

Buying an AVR for a clean slate upgrade is not the main use case to consider this as an alternative. It is a way to incorporate Dirac into many existing audio stacks. You may have realy good set of external amps and an AVR front-end without Dirac. Being able to use this is a better solution than replacing all of it with an AVR (compomising on the power amps) or spending enough money to get all the features you already have back in another AVR or paying a lot of money. So, it is not just NAD with mediocre measurements, it could be another AVR with great measurements. Same argument would apply.

If one were looking to buy an AVR or replace what they already have, then it would be a comparison between different AVRs with Dirac if Dirac was a requirement. There are increasing number of units coming out with Dirac, nothing seems like a must-have till now because of various reasons.

 

[Vasr]

Someone asked for RCA/unbalanced performance. Alas, it is much worse than balanced:

Yeah, this is what I was afraid of for the most common use case of this. I would not consider it a recommended product especially given its price with this kind of performance.

Unless one felt that having Dirac gives enough aural benefits to ignore everything else (like in some AVRs) and this turns out to be the best way to get it in for one's specific situation of existing components in a multi-channel set up.

 

[stunta]

Its not just about Dirac with this unit. The bass management, crossover, mixing and routing functionality gives a level of flexibility that I have not seen in any AVR. I hate having this many wires and two separate units (pre/pro + miniDsp), but the feature set and ease of use are the main reasons I keep this unit.

 

[OverTheAir]

At the time this unit was released, it was the only way to get Dirac into an Atmos setup.

To add Dirac to a 5.1, 7.1 or 5.1.2 was a valid use case in the past. But I've seen others suggest using this to add Dirac to an existing AVR today and that seems much more questionable.

 

[Vasr]

Its not just about Dirac with this unit. The bass management, crossover, mixing and routing functionality gives a level of flexibility that I have not seen in any AVR. I hate having this many wires and two separate units (pre/pro + miniDsp), but the feature set and ease of use are the main reasons I keep this unit.

I should mention that a PC-based solution with all of the above can be done more cost-effectively, and all in digital without the A/D conversion. The only caveats are no multiple external sources switching and no DRM content playing. The DDRC-88D alternative to the PC will be more expensive but possible to get as clean a path. Not direct replacements, one is more suitable than the other depending on needs.

 

[stunta]

To add Dirac to a 5.1, 7.1 or 5.1.2 was a valid use case in the past. But I've seen others suggest using this to add Dirac to an existing AVR today and that seems much more questionable.

What is an alternative that measures at least as good?

 

[OverTheAir]

Buying an AVR for a clean slate upgrade is not the main use case to consider this as an alternative. It is a way to incorporate Dirac into many existing audio stacks. You may have realy good set of external amps and an AVR front-end without Dirac. Being able to use this is a better solution than replacing all of it with an AVR (compomising on the power amps) or spending enough money to get all the features you already have back in another AVR or paying a lot of money.

I've seen some still suggest that buying an AVR and then adding DDRC-88A for Dirac would make sense. What I was illustrating with my example is that using the DDRC-88A to upgrade an existing audio stack doesn't make much sense given its performance vs the NAD. It wouldn't preclude using existing external amps unless they needed a high pre-pro output. Sure, if there are specific features or capabilities that an existing AVR has that the NAD couldn't replicate then maybe it would make sense but then you would be cascading potentially average AVR analog performance with average DDRC-88A performance, which doesn't seem to be desirable.

 

[OverTheAir]

What is an alternative that measures at least as good?

For my use case, i.e. pre-amp output well below -6dB, the NAD met my needs with SINAD of 88/89dB. YMMV.

 

[Vasr]

I've seen some still suggest that buying an AVR and then adding DDRC-88A for Dirac would make sense. What I was illustrating with my example is that using the DDRC-88A to upgrade an existing audio stack doesn't make much sense given its performance vs the NAD. It wouldn't preclude using existing external amps unless they needed a high pre-pro output. Sure, if there are specific features or capabilities that an existing AVR has that the NAD couldn't replicate then maybe it would make sense but then you would be cascading potentially average AVR analog performance with average DDRC-88A performance, which doesn't seem to be desirable.

Yes, you are right in that since buying this would involve doing so holding your nose for the Dirac capability, you could potentially do the same with the NAD instead.

The few exceptions would be using its balanced I/O capability (for avoiding ground loops if present in one's setup or an all-powered speaker system that required balanced inputs) - lack of real estate for a full AVR height component (a real concern in some living rooms) and so using slimmer front-ends like the Outlaw or the Emotiva or the IOTAVX front-ends and slim Parasound or Class D power amps, not wanting the internal amps (electricity and heat) and so getting a lightweight pre/pro like the previous mentioned front-ends with amp/speaker combinations.

An existing stack may also be a combination of several hand-picked components that one has selected for various reasons that works well for music use and one may just want to add this for the HT use (with a pre-amp that allows HT bypass) for what Dirac can do. Buying a full AVR might not be necessary in this case.

The reviews here tend to be transactional for the date of the review and not always consistent in its subjective recommendations but the data is there for you to figure out the trade-offs and see what works for you. This is why, for example, I would personally recommend the HTP-1 in its class even if lost the beauty contest here for reasons that may not be relevant to a particular setup. So, we can still bash the NAD for not being exemplary but still decide that is the one we want to take home.

 

[stunta]

Is this NAD you are discussing the $6000+ USD unit? M17 V2?

 

[Chromatischism]

To add Dirac to a 5.1, 7.1 or 5.1.2 was a valid use case in the past. But I've seen others suggest using this to add Dirac to an existing AVR today and that seems much more questionable.

To do this, one would need an AVR that has preouts on all channels, or a preamp/procesor, and another set of amplifiers for all channels, since this device comes before amps. In the past this didn't make a lot of sense because there was no such thing as an inexpensive preamp/processor. However now that we have the Denon X3700H/X4700H with full preamp mode, we can assemble some multichannel amps and have a pretty decent setup, much better than the AVRs that come with Dirac since you get Denon's reliability, feature set, and ease of use. You definitely need to get the $99 BM add-on for the 88A for proper bass management, though. Unfortunately we would give up Dynamic EQ which is such a killer feature that I would just stick with Audyssey and save my money. It really is that important to me in my system. It may not be to others. My $0.02...

 

[Newman]

For about the same price you can grab the Okto and implement software version of DSP, yeh ends up a little more expensive but you get pristine measurements with your chosen DAC.

I think people need to get over hardware based DSP when software is more versatile and allows you to choose the best equipment to implement it with....

Okay, so how do I go the software route with a need to playback SACD, CD, Blu-ray, PVR, and streaming services?

 

[Trdat]

Okay, so how do I go the software route with a need to playback SACD, CD, Blu-ray, PVR, and streaming services?

Look, I am not an expert in SACD, CD, Blue Ray, PVR or streaming I only listen to digital music stored on my PC. I am presuming you use a PC somewhere in your chain?

That said, everything stays as per normal in your system(if you have a PC). You add a convolution(essentially a file that you have EQ'd) to Jriver or your any advanced listening music platform. If you listen to music outside this platform you a can also route the convolution for all things played on your desktop.

All you need is a external soundcard and microphone you take your measurement from the listening position and then the software, time aligns, flattens frequency curve according to your taste automatically. Doing exactly the same thing as Audyssey or Dirac or any of those programs with more power including digital crossovers.

Audiolense and Acourate seem to be the more popular ones, Uli from Acourate is on this forum and Mitcho is the in house expert who is very well versed with both of these softwares using them interchangeably depending on what his goals are.

 

[jhaider]

Its not just about Dirac with this unit. The bass management, crossover, mixing and routing functionality gives a level of flexibility that I have not seen in any AVR.

StormAudio/Bryston is about there or close You pay for it though.

 

[Trdat]

But how do we get Atmos and DTS:X decoding?

You don't. This is the problem with software DSP or even using multichannel DAC's instead of a AVR. The miniDSp above also doesn't offer any decoding only AVR's do. This has been the biggest issue in terms of what people want and what we can't get in the audio industry.

You either go

PC>software DSP>really well measured DAC> no decoding or possible Jriver decoding for surround(no one can really vouch for how good JRSS decoding is)
or
PC>AVR(average DAC and Amp) all your decoding needs.
or getting something really expensive that measures well but you have to be super rich for that...

This discussion has been ongoing and I have initiated a handful of posts with some solid information.

Try this. https://www.audiosciencereview.com/...-some-basic-concepts.11346/page-7#post-410360

Just use the search engine and you'll find heaps of info to untangle this dilemma.

Essentially its either or for now.