Minidsp DDRC-88A Dirac Multichannel DSP Review

[SirMaster]

Yes, it requires some twinkling for sure... rePhase is as easy as EQing the phase with sliders... still it's doable if one is really interested. And it's free

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Is there a good instructions for using Rephase with REW measurements?

I think you can then apply the EQ with EqualizerAPO which is my preferred EQ software right now.

Last time I tried to do rephase I just got lost.

Why is there no way to do AutoEQ like REW does, but for phase correction with FIR filters?

 

[kevinh]

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.

It's not like your getting a range of Dolby, or other decoders for surround plus Dirac and top of the line measurements.

You could get the digital I/o version and add the October to that. I am considering that approach.

 

[Vasr]

You could get the digital I/o version and add the October to that. I am considering that approach.

Except you need the $325 USB to AES dongle to just connect it inline between the original USB multi-channel source and the Okto unless you have a multi-channel AES output source as your use case. Not many in this world. A $40 USB transceiver inside the DDRD-88D would have solved this ... but no this is miniDSP!

 

[Soundstage]

What makes you think that? I was under the impression it was extremely rare for them to make a new series.

Pure speculation.

1) Measurements show that this product was release before the MiniDSP shd generation which has much better results.
2) Dirac and DSP improvements will make it obsolete if it is not compatible.

It does not mean this is not great for DIY dsp/EQ. But given the price, I’ll save my hard earned money for the next round.

 

[Aerith Gainsborough]

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.

Well standalone players aren't always flawless.
I have two normal BDs here (legally bought) that my standalone refuses to play (despite being a much newer device, that is 4K-Disk capable) but PowerDvD does.

 

[wje]

Pure speculation.

1) Measurements show that this product was release before the MiniDSP shd generation which has much better results.
2) Dirac and DSP improvements will make it obsolete if it is not compatible.

It does not mean this is not great for DIY dsp/EQ. But given the price, I’ll save my hard earned money for the next round.

Good points. Also, with newer hardware developments, they might be able to opt for a newer, higher-powered processor, etc. I'll stick with my DDRC-24 for the time being.

 

[Newman]

Yeah mate, can’t wait to rip my 2,500+ DVD and blu-ray titles to my NAS.

Don't forget to buy 1 TB of NAS storage for every ten UHD discs that you rip, too.

 

[Newman]

If you are just trying to make a rhetorical case that HTPC is not a feature-for-feature substitute for a full-fledged contemporary AVR (at least as yet), there isn't much controversy there. It is easy to do so pointing out the obvious differences - unified and convenient source switching, handling of DRM content, accommodating more than 8 channels easily, ability for anyone to use without some technical ability, etc. But that is just an academic chest-thumping/ideological exercise.

No, I'm genuinely asking.

For many vertical sets of features that one may actually use an AVR in their contexts (not everybody uses every feature of an AVR), there may be equivalents with a PC. And the ability to combine video and audio processing in the same PC has some advantages. There are some things AVRs cannot help in (except via a co-operating and often expensive video system) such as starting a movie in one room and shutting it down and resuming in another room at the same point (e.g., Kodi/Emby). Ability to do much better video scaling and processing (e.g., MadVR) than any inexpensive hardware (even better than the old Oppos) while playing and listening to a movie and completely transparently, etc.

But for your question taken literally, all of the different media formats you mentioned can be handled by any of the audio/video players on the PC either directly playing the discs with the drives attached to the PC or as most HTPC users do rip all media into a NAS and use a media server with Kodi/Emby/Plex etc. They can also play most anything bit-perfect into your favorite DAC (definitely anything within audible range of depth and sampling rate). It will also allow them to transcode optimized for various client devices in the house depending on the codecs available natively. A PVR can be incorporated into the HTPC system using a capture card and Kodi/Emby. These are all supported features of the software. And they even have really good library management for recorded or ripped media.

So the full potential of a HTPC is really as a house-wide A/V system using anything from tablets to dumb monitors and built in speakers or a HiFi stack - doing so with a combination of AVRs and Smart TVs can get very expensive or requires getting locked into an ecosystem.

They are not replacements for each other but serve both certain common and some disjoint purposes with unique advantages. Depends on one's actual requirements.

I was just responding to the comment about having a silent PC in the chain. For me, it will be a great idea but only if "in the chain" means I can put it between the players and the amplifiers. I am a bit surprised that this has been made as hard as it has. But so it goes.

I suspect that for my requirements a very expensive, low performing AVP is the way to go. Sadly. Especially if, as may well be the case, it turns out that I can't afford that approach.

 

[Vasr]

I was just responding to the comment about having a silent PC in the chain. For me, it will be a great idea but only if "in the chain" means I can put it between the players and the amplifiers. I am a bit surprised that this has been made as hard as it has. But so it goes.

It is a valid observation. The reason may surprise you. It is the $%#^ connector issue. Far too many types of connectors and lack of a good and inexpensive transceiver for any one of them (multi-channel capable) and almost nothing for a DIY PC solution except very expensive audio interface cards to get the channels into the box.

As I posted above you can look at the DDRC-88D as such a box (whether it is a Windows PC or an ARM/Sharc based processor with firmware is irrelevant) you can stick between players (sending decoded LPCM) and amp. But deciding what connectors to use becomes a problem let alone switching. USB would have been ok. But miniDSP being miniDSP chose the most useless ones for consumer use and charge $325 for another box to make it user-friendly to connect.

As a DIY project, I can build a DDRC-88D equivalent using a PC architecture in a small form factor thin mini ITX based MB and fanless cooling specialized to boot up and run only as an audio processor. It will cost around $400 max with off-the-shelf parts + Dirac license. It is very easy to put this together and make it all work EXCEPT for the connectors. I cannot easily put an incoming audio interface into it unless I pay somebody $600-$1200 for an interface card. So I can't make it look like an audio device to the upstream player unless I develop my own card and possibly write the firmware and the required device drivers or pay too much to make it worthwhile. I can do this in the RPi ecosystem but Dirac won't run on it.

 

[Trdat]

Except you need the $325 USB to AES dongle to just connect it inline between the original USB multi-channel source and the Okto unless you have a multi-channel AES output source as your use case. Not many in this world. A $40 USB transceiver inside the DDRD-88D would have solved this ... but no this is miniDSP!

Now, I am lost. Why would you connect the DDRD-88 to a Okto. Your Okto provides the multichannel requirement that connects straight to the PC which then you could use a software DSP. Am I missing something?

 

[Vasr]

Now, I am lost. Why would you connect the DDRD-88 to a Okto. Your Okto provides the multichannel requirement that connects straight to the PC which then you could use a software DSP. Am I missing something?

Not everybody using a computer as a media player wants to or is capable of installing and setting up the required DSP software and understanding and configuring it on the computer or there may not be a single unique player always hooked up. Some people just want an external plug-in solution. It was in that context.

 

[Trdat]

Not everybody using a computer as a media player wants to or is capable of installing and setting up the required DSP software and understanding and configuring it on the computer or there may not be a single unique player always hooked up. Some people just want an external plug-in solution. It was in that context.

Okay, fair enough. I have never thought of it in that context. Software DSP is simple, powerful and versatile. But, yeh if that is the case I can see why the mindsp product can come in handy.

 

[MrMatt79]

With the testing on this unit, what channels did you use? I own one of the units, and both Ch 1 & 2 are noisier than all the other channels, I get around -95db on the DSP meters, where with channels 3-8 are a lot better at closer to -110db. The noise is directly on the input channels, routing it to different channels it follows input 1 & 2. I'm curious if this is a strange fault on my unit, or if Ch 1 & 2 are noisier in the design.

 

[TimoJ]

With the testing on this unit, what channels did you use? I own one of the units, and both Ch 1 & 2 are noisier than all the other channels, I get around -95db on the DSP meters, where with channels 3-8 are a lot better at closer to -110db. The noise is directly on the input channels, routing it to different channels it follows input 1 & 2. I'm curious if this is a strange fault on my unit, or if Ch 1 & 2 are noisier in the design.

Channels 1&2 uses different A/D. Channel 1 also has other hardware "issues" in it's buffer stage and it has buzzing noise peaks that you can hear with some setups. You should remap input 1 to subwoofer usage (and also use input 2 for something else than main channels). In my system I left 1&2 unused. On the AVS forum MiniDSP finally admitted that the buzzing is a hardware issue and they are looking into fixing it, but went completely silent after that...

 

[Vasr]

Pure speculation.

1) Measurements show that this product was release before the MiniDSP shd generation which has much better results.
2) Dirac and DSP improvements will make it obsolete if it is not compatible.

It does not mean this is not great for DIY dsp/EQ. But given the price, I’ll save my hard earned money for the next round.

I could be wrong but my feeling is that miniDSP will no longer update the pre-SHD devices going forward. They have been EOLing them one at a time rather than make any improvements.

With the SHD, they seem to have transitioned from a "productized DIY gizmo factory" that is always only 80-90% complete to an almost 100% stand-alone vertical SHD series products where they do all the work needed in the last mile. A bit up in the vertical chain from the DAC-based shops (Topping, SMSL, Schiit, etc) where they can leverage their DSP expertise to provide more feature-rich products.

This, to me, suggests a change of mindset/management (for the good in my opinion). But it could also mean end of those DIY type boxes (where absolute performance is not the primary goal) that could be used by the technically savvy and with no alternatives.

 

[stunta]

I feel like miniDsp has this golden opportunity to take what they have done well with the multi-channel devices and build a proper pre/pro with HDMI & Dobly/DTS decoding around it. If it measures even OK, the HT crowd will be all over it.

 

[Vasr]

I feel like miniDsp has this golden opportunity to take what they have done well with the multi-channel devices and build a proper pre/pro with HDMI & Dobly/DTS decoding around it. If it measures even OK, the HT crowd will be all over it.

In theory, yes. They would certainly have good experience to do so technically. But then they have not had to deal with the full messiness of HDMI with video pass-through (HDCP, arc/eARC/CEC, etc). That has sunk a lot of boats before.

In addition, a full function pre/pro will need to be a yearly (or two) product cycle type of product due to continuous update of protocols and codecs. That is a difficult business model to get into and has never been part of miniDSP gene. I don't think miniDSP can be price-competitive here due to all the licensing costs but without the volume from a mass-market capability (very expensive to do). So, it would be a very risky move and an expensive bet.

I think an evolution to a more full featured 2.x all-digital pre-amp market (good opportunity here to replace all of the aging analog pre-amp makers) with flexible source-switching, streaming, HT bypass, bass management and Dirac is much more likely and a safer bet.

 

[tonybarrett]

Channels 1&2 uses different A/D. Channel 1 also has other hardware "issues" in it's buffer stage and it has buzzing noise peaks that you can hear with some setups. You should remap input 1 to subwoofer usage (and also use input 2 for something else than main channels). In my system I left 1&2 unused. On the AVS forum MiniDSP finally admitted that the buzzing is a hardware issue and they are looking into fixing it, but went completely silent after that...

Oh, I’ve recently switched from 7.1 to 5.1 (trade off to keep my wife happy), so I’ve now got two redundant channels. So I can get much better performance by avoiding channels one and two?

 

[TimoJ]

Oh, I’ve recently switched from 7.1 to 5.1 (trade off to keep my wife happy), so I’ve now got two redundant channels. So I can get much better performance by avoiding channels one and two?

Little better and without buzzing noises (at least not at the same level). Other channels also have 5dB better SINAD (according A/D converter datasheets). With the BM-plugin you can change/swap channels easily with routing without need to recalibrate Dirac, I don't remember if basic version allows this.

 

[tonybarrett]

Little better and without buzzing noises (at least not at the same level). Other channels also have 5dB better SINAD (according A/D converter datasheets). With the BM-plugin you can change/swap channels easily with routing without need to recalibrate Dirac, I don't remember if basic version allows this.

Thanks for the great info