Minidsp DDRC-88A Dirac Multichannel DSP Review

[Vasr]

I've often thought the miniDSP DDRC-88A was made for use with the Outlaw Audio Model 976 pre/pro and Model 7000x 7-channel amplifier. That gives one a 7.2 channel Dolby TrueHD / DTS HD Master Audio / Dirac capable 130WPC system for less than $3,000 that would likely measure and perform better than any of the recent crop of Dirac receivers. The only thing missing are height channels.

Martin

The 976 is an over-kill for using this. You cannot use any of the bass management and eq features of the 976 just use it as a HDMI audio extractor with a source switch. The Outlaws (perhaps excluding the ATI builds) have not so far measured better than at an average AVR level. Perhaps the older 975 on a clearance might be a good budget build.

I am also not convinced that it is a good idea to use the DDRC unit to directly drive a power amp (except for those with low input sensitivity) because of the head room needed for the Dirac correction resulting in lower outputs. Works best going through an integrated or analog multi-channel pre-amp that can provide an analog gain to get the maximum from a power amp or a power amp with gain control.

This works best in a one-of narrow use case where you can get a fairly low budget set up. Say a single HDMI source going through a HDMI extractor like the Essence Evolve 4k to this unit to a low input sensitivity (or with gain control) multi-channel power amp. Or a PC based source going through a multi-channel USB sound card (or internal card) to this unit to the amp, etc.

 

[Vasr]

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?

Any of the media players on a PC will decode Dolby/DTS (up to 8 channels).

How to set it up:
https://www.audiosciencereview.com/...s-a-8-ch-pre-pro-experiment.14785/post-462671

 

[tecnogadget]

milosz Thanks for such a detailed insight and explanation of DEQX for multichannel porpuses. Yeah, it's going to be messy going that route for multichannel. I wish I could implement Dirac 3.0 + Bass Control in my system but the hardware options are scarce, measures bad, and extremely expensive. I'm up to my eyes waiting for miniDSP to release some kind of sneak peek for their supposedly future nano AVR and solve this hardware void for once for all

 

[tecnogadget]

The biggest issue ongoing Dirac for Pc is trying to flawlessly play Blu Ray discs as a standalone player does. If this limitation did not exist then I would have gone full Okto multichannel.

 

[Xulonn]

...Say a single HDMI source going through a HDMI extractor like the Essence Evolve 4k...

The US$300 Essence Evolve 4K unit (top pic) looks like yet another variant of the ubiquitous generic 4K extractors available from many sources including AliExpress (bottom pic) for just over US$40.

Does the Essence unit add enough value to justify an extra $250 over the generic units?

The Essence unit looks like yet another repackaged no-name A/V component using no-name packaged "commodity" Chinese-manufactured PCB's. I considered one of the generic models, but ultimately decided to get a much more expensive IOTAVX 4k 7.1 AVP (another product that appears to use customized "commodity" class PCBs). I also considered MiniDSP units, but I am happy with my decision, and the much larger IOTAVX 4k 7.1 AVP gives me just the features and control I want - plus XLR out - for about $900.

 

[PeteL]

The US$300 Essence Evolve 4K unit (top pic) looks like yet another variant of the ubiquitous generic 4K extractors available from many sources including AliExpress (bottom pic) for just over US$40.

Does the Essence unit add enough value to justify an extra $250 over the generic units?

View attachment 82378
View attachment 82379

The Essence unit looks like yet another repackaged no-name A/V component using no-name packaged "commodity" Chinese-manufactured PCB's. I considered one of the generic models, but ultimately decided to get a much more expensive IOTAVX 4k 7.1 AVP (another product that appears to use customized "commodity" class PCBs). I also considered MiniDSP units, but I am happy with my decision, and the much larger IOTAVX 4k 7.1 AVP gives me just the features and control I want - plus XLR out - for about $900.

I'd like to see that measured, I had in the past the first version of this, with HDMI always changing, it's a paper weight now. Not compatible with newer computers, but even when it worked, never liked how it sounded (I know, I know, subjective comments have no value ) Didn't do it for me.

 

[Vasr]

The US$300 Essence Evolve 4K unit (top pic) looks like yet another variant of the ubiquitous generic 4K extractors available from many sources including AliExpress (bottom pic) for just over US$40.

Does the Essence unit add enough value to justify an extra $250 over the generic units?

I'd like to see that measured, I had in the past the first version of this, with HDMI always changing, it's a paper weight now. Not compatible with newer computers, but even when it worked, never liked how it sounded (I know, I know, subjective comments have no value ) Didn't do it for me.

My comment was in the context of bringing Dirac room correction into the chain. The DDRC is a good fit for a budget-constrained way to do it for one example narrow use cases for which a HDMI extractor is good enough. It is not a good fit for trying to duplicate a full-featured AVR with Dirac nor is it duplicated by something else without Dirac.

Good question about the Evolve Essence. It seems to be stuck in Amir's queue for a while now for review so we will see whenever it comes out.

In functionality it is exactly like the other generic HDMI extractor you linked. But in theory, this uses the same business model as the IOTAVX in branding with OEM/ODM in this case and marketing it under Evolve brand. Unlike the generics you find in Amazon and eBay, this seems to be designed with known reputable DACs (TI Burr Browns) with a better quality case and hopefully better QC. You will also find some software to install custom EDIDs etc that you don't find with the generics. We will know more to evaluate once it is measured and reviewed. Evolve marketing is a bit too much hype for my tastes but that doesn't necessarily mean the product is bad.

Kal R., at Stereophile reviewed it and gave it a good review for subjective evaluation.

 

[AndrewDavis]

I've often thought the miniDSP DDRC-88A was made for use with the Outlaw Audio Model 976 pre/pro and Model 7000x 7-channel amplifier. That gives one a 7.2 channel Dolby TrueHD / DTS HD Master Audio / Dirac capable 130WPC system for less than $3,000 that would likely measure and perform better than any of the recent crop of Dirac receivers. The only thing missing are height channels.

Martin

Or you could skip the dongles and use RCA to connect this with the Emotiva MC-700 processor and A500 amp for $2200. Also a great value!

 

[Robbo99999]

I got a question about this bit of kit, can it take an optical input (Toslink) from say a Sky Box (living in UK here), and then process that Dolby Digital 5.1 signal into a seperate stream for each speaker, and then I'd be able to EQ each stream/speaker? But I'd need a multichannel amplifier too or instead 5 active speakers and an active subwoofer. It might make more sense to get an AVR, but I do like the very flexible nature of miniDSP given my experience with miniDSP 2x4 which I'm using at the moment for my TV. (My question here is in reference to a potential upgrade of my parents 5.1 Onkyo Receiver system as there's is probably broken, gonna check it out at the weekend).

 

[voodooless]

I got a question about this bit of kit, can it take an optical input (Toslink) from say a Sky Box (living in UK here), and then process that Dolby Digital 5.1 signal into a seperate stream for each speaker, and then I'd be able to EQ each stream/speaker? .

No, this device is analog in and out only (hence the A in the product name). None of the miniDSP products can do any kind of surround decoding as far as I know.

 

[Robbo99999]

No, this device is analog in and out only (hence the A in the product name). None of the miniDSP products can do any kind of surround decoding as far as I know.

Ah, ok, thanks, so the pic of the back of the unit, it shows a Digital Toslink input, but now that I look again it looks like the input is "blanked out", so I guess they do another unit with a Digital Toslkink input and have just used the same chassis and "blanked out" the unused ports?

 

[voodooless]

, so I guess they do another unit with a Digital Toslkink input and have just used the same chassis and "blanked out" the unused ports?

Yes, I have the 4x10HD in the same casing which provides those digital options (no Dirac though).

 

[thebabyparrot]

In five years, I hope we get software that is free and open source. It's only a matter of time before room correction becomes free.

 

[TNT]

Where is the GUI?

Post #739

https://www.diyaudio.com/forums/pc-...crossovers-correction-etc-74.html#post6330745

I'm about to install this myself so not so much insight yet...

//

 

[Robbo99999]

Yes, I have the 4x10HD in the same casing which provides those digital options (no Dirac though).

Ah, I see, and the 4x10HD wouldn't be able to do the decoding of a 5.1 Dolby Digital signal from a Sky Box I'm thinking!?

 

[voodooless]

Ah, I see, and the 4x10HD wouldn't be able to do the decoding of a 5.1 Dolby Digital signal from a Sky Box I'm thinking!?

Like I said, none of the MiniDSP products do any surround decoding.

Post #739

https://www.diyaudio.com/forums/pc-...crossovers-correction-etc-74.html#post6330745

I'm about to install this myself so not so much insight yet...
//

Yes, It’s quite a nice project! I’ve been followings it from the background for a while, was even the first to have a OS X build . Hope to check out the UI in the future.

@Robbo99999, you could probably have a Linux box do the decoding and use above to to multichannel room correction.

 

[OverTheAir]

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.

 

[TNT]

Camilla Description

Thank you for that link! I hadn't seen that -- it looks like a good project.

The architecture they chose is a little unfortunate though... it's using a push-based model rather than a pull/event-based architecture, suggesting that the author isn't particularly experienced with writing low-level real-time audio processors. The model he chose works with ALSA because there's a feedback mechanism, but unless you're working with a single clock domain on Windows or OS X (i.e., a hardware loopback device), you'll basically have to use the resampler.

The way you describe it is of course a good way to do it but apparently it seems that if you aim for a multi-platform system, it would require a lot of work.. This may be the reason for the architecture chosen.

//

 

[TNT]

In five years, I hope we get software that is free and open source. It's only a matter of time before room correction becomes free.

This was post #53 -> check post #54 ;-D

//

 

[voodooless]

This was post #53 -> check post #54 ;-D

//

Well, we’re not quite there yet.. while this allows you to actually run the room corrections, it won’t automatically create them for you.. that is a whole different kind of dark art.