• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Minidsp DDRC-88A Dirac Multichannel DSP Review

ronnzi

Member
Joined
Aug 20, 2021
Messages
50
Likes
27
Links to useful application notes on minidsp:

Using MSO (appendix at bottom illustrates using 88 and 2x4 together)

Using the BM module for bass management

Minidsp will also respond to emails if you run into any trouble or have questions
Awesome - appreciate the links!
 

ronnzi

Member
Joined
Aug 20, 2021
Messages
50
Likes
27
Someone asked for RCA/unbalanced performance. Alas, it is much worse than balanced:

View attachment 82414

I have a question about SINAD and how it relates to the audio quality of a system here.

I am currently using an Onkyo RZ810 AVR with a Monoprice Monolith x7 amplifier, and will be inserting a MiniDSP DDRC-88A-BM into the chain via RCA to add Dirac Lice room correction.

While I’m making an assumption here since the only testing you’ve done on a similar Onkyo receiver to mine is the PR-RZ5100, but if my AVR is of similar quality, then it sounds like it’s SINAD is around 83db. I will be connecting the MiniDSP via RCA like I said (my AVR does not have XLR pre-outs), so it looks like the SINAD of the MiniDSP device will be the worse numbers here.

Should I be that concerned about this, or should the benefits I’ll be getting from using Dirac over the very limited AccuEQ system more than make up for that?

FWIW, I also have the main channels running though Jensen isolation transformers to eliminate a ground loop issue caused by my home theater PC (the HDMI from my NVIDIA RTX 3090 graphics card causes the issue, and this was the only solution I could find after trying many things).

My system is 5.2, so I will also be running my subwoofers through a MiniDSP 2x4HD first to combine the signals into a single input for the DDRC-88A to process.

Ultimately, I know I will have to judge for myself in my room whether the room correction makes a big enough difference, but I thought I would ask to get insights from you all, who have far more knowledge and experience with these things than I do.

Thank you!
 

ronnzi

Member
Joined
Aug 20, 2021
Messages
50
Likes
27
Reporting in to say, measurements or not, my system sounds so much better integrated and balanced running Dirac through the MiniDSP 88A than it did using the Onkyo only and AccuEq. It’s noticeably better. Given that I’m able to use my same equipment and I picked up the MiniDSP used, this was definitely money well spent so far!
 

tonybarrett

Member
Joined
May 14, 2020
Messages
54
Likes
69
I have a question about SINAD and how it relates to the audio quality of a system here.

I am currently using an Onkyo RZ810 AVR with a Monoprice Monolith x7 amplifier, and will be inserting a MiniDSP DDRC-88A-BM into the chain via RCA to add Dirac Lice room correction.

While I’m making an assumption here since the only testing you’ve done on a similar Onkyo receiver to mine is the PR-RZ5100, but if my AVR is of similar quality, then it sounds like it’s SINAD is around 83db. I will be connecting the MiniDSP via RCA like I said (my AVR does not have XLR pre-outs), so it looks like the SINAD of the MiniDSP device will be the worse numbers here.

Should I be that concerned about this, or should the benefits I’ll be getting from using Dirac over the very limited AccuEQ system more than make up for that?

FWIW, I also have the main channels running though Jensen isolation transformers to eliminate a ground loop issue caused by my home theater PC (the HDMI from my NVIDIA RTX 3090 graphics card causes the issue, and this was the only solution I could find after trying many things).

My system is 5.2, so I will also be running my subwoofers through a MiniDSP 2x4HD first to combine the signals into a single input for the DDRC-88A to process.

Ultimately, I know I will have to judge for myself in my room whether the room correction makes a big enough difference, but I thought I would ask to get insights from you all, who have far more knowledge and experience with these things than I do.

Thank you!
I don‘t have the expertise to answer this properly but from what I’ve read on this site, frequency response is the single most important attribute for perceived good sound quality. Also, though members are focused on best practices in audio engineering and measuring distortion to a high level, in actual use, and with speakers almost inevitably having much higher levels of distortion than electronics, we can get away with higher levels of SINAD than the best without much or any noticeable degradation in sound quality. We will notice some things like hum or a high noise floor (even then, mostly when there’s no audio playing). That’s my uneducated take, anyway. I think there was some discussion of this under the review of the DDRC-88A. My personal experience is that my sound is very much audibly improved by the addition of the minidsp.
 

Rottmannash

Major Contributor
Forum Donor
Joined
Nov 11, 2020
Messages
2,223
Likes
1,870
Location
Nashville
Reporting in to say, measurements or not, my system sounds so much better integrated and balanced running Dirac through the MiniDSP 88A than it did using the Onkyo only and AccuEq. It’s noticeably better. Given that I’m able to use my same equipment and I picked up the MiniDSP used, this was definitely money well spent so far!
I have the same AVR and was seriously considering buying the new RZ50 with Dirac but your solution sounds better, costwise, as I don't use many of the amps in the AVR nor does the 8K feature interest me...yet so I may try the MiniDSP. Do you use Dirac and AccuEq together?
 

ronnzi

Member
Joined
Aug 20, 2021
Messages
50
Likes
27
I have the same AVR and was seriously considering buying the new RZ50 with Dirac but your solution sounds better, costwise, as I don't use many of the amps in the AVR nor does the 8K feature interest me...yet so I may try the MiniDSP. Do you use Dirac and AccuEq together?
Hi, Rottmannash.

Full disclosure, I do think getting the RZ50 would be a cleaner option (or especially the rumoured RZ70/90’s that might support full multi-sub, Dirac Bass Control support, which the MiniDSP doesn’t offer). If you don’t want to wait or get rid of your RZ810 to make up the difference though, I do the think the MiniDSP 88A is a great option. It’s been a night and day improvement for me over AccuEq - it’s not even comparable, in my room, the system sounds so much more cohesive and correct now. I had no idea what I was missing.

There are guides out there that help set everything up, but basically you turn off the room correction stuff in the AVR completely (for the Onkyo and AccuEq, you do this through the quick menu button on the remote). You also lower all channel levels to zero, lower the distances as far down as they go, and disable all crossovers in the Onkyo, before running Dirac on the MiniDSP. After Dirac runs it’s calibrations, you then add the crossovers back in using either the MiniDSP itself if you purchase the option Bass Management module for it (to be clear, this is NOT Dirac Bass Control, it simply adds the ability to apply crossovers in the MiniDSP itself, amongst other things). If you don’t get the bass module pluggin for the MiniDSP, you can add the crossovers back in using the Onkyo AVR, though you’ll still need to keep AccuEQ turned off.

You can leave the crossovers from the MiniDSP on if you re-run the Dirac calibration in the future since the MiniDSP does the test signals after applying them. If you do the crossovers in the AVR though instead, you’ll have to always make sure to turn them off again before re-running the Dirac calibration, as they’d be applied prior to Dirac getting the signals and you want it to be able to see the full signal bandwidth for calibration.

The main reason to go with the bass management pluggin with the MiniDSP vs the AVR’s crossovers, as far as I can tell, is just further flexibility and probably cleaner, better measuring crossover filters, amongst other things like further gain control, though I’m not sure. It’s pretty sweet honestly - you have the ability to control so many aspects of what lowend signals are going to the subwoofer (it’s labeled as LFE mgt. channel), and really tweak with things if you’re into that.

There’s so much more to mess with using the 88A that I’m not going into here, but if you’re the kind of person to really get into things and tweak, it’s an awesome tool! And it has paired great with my Onkyo Rz810 and sounds amazing. Only thing I still need to tweak are my gains - I did lose a decent amount of volume, though it’s still gets plenty loud. I think this may have to do with Dirac calibrating things based on my sub volumes (I should probably raise by subwoofer gains), though there are also gain management techniques that can help bring the volume levels back up.

Hope that all makes sense (and that it’s not too much unnecessary detail at this stage). If money isn’t an object, sure, there are other, easier and cleaner options to add Dirac. If you’re really on a budget and the 88A is easier to work in due to funds, though, IMO it’s definitely worth it, but be prepared to work a little. Running Dirac instead of AccuEq using the Onkyo Rz810 and external amplification, my system has never sounded better!
 

Rottmannash

Major Contributor
Forum Donor
Joined
Nov 11, 2020
Messages
2,223
Likes
1,870
Location
Nashville
Hi, Rottmannash.

Full disclosure, I do think getting the RZ50 would be a cleaner option (or especially the rumoured RZ70/90’s that might support full multi-sub, Dirac Bass Control support, which the MiniDSP doesn’t offer). If you don’t want to wait or get rid of your RZ810 to make up the difference though, I do the think the MiniDSP 88A is a great option. It’s been a night and day improvement for me over AccuEq - it’s not even comparable, in my room, the system sounds so much more cohesive and correct now. I had no idea what I was missing.

There are guides out there that help set everything up, but basically you turn off the room correction stuff in the AVR completely (for the Onkyo and AccuEq, you do this through the quick menu button on the remote). You also lower all channel levels to zero, lower the distances as far down as they go, and disable all crossovers in the Onkyo, before running Dirac on the MiniDSP. After Dirac runs it’s calibrations, you then add the crossovers back in using either the MiniDSP itself if you purchase the option Bass Management module for it (to be clear, this is NOT Dirac Bass Control, it simply adds the ability to apply crossovers in the MiniDSP itself, amongst other things). If you don’t get the bass module pluggin for the MiniDSP, you can add the crossovers back in using the Onkyo AVR, though you’ll still need to keep AccuEQ turned off.

You can leave the crossovers from the MiniDSP on if you re-run the Dirac calibration in the future since the MiniDSP does the test signals after applying them. If you do the crossovers in the AVR though instead, you’ll have to always make sure to turn them off again before re-running the Dirac calibration, as they’d be applied prior to Dirac getting the signals and you want it to be able to see the full signal bandwidth for calibration.

The main reason to go with the bass management pluggin with the MiniDSP vs the AVR’s crossovers, as far as I can tell, is just further flexibility and probably cleaner, better measuring crossover filters, amongst other things like further gain control, though I’m not sure. It’s pretty sweet honestly - you have the ability to control so many aspects of what lowend signals are going to the subwoofer (it’s labeled as LFE mgt. channel), and really tweak with things if you’re into that.

There’s so much more to mess with using the 88A that I’m not going into here, but if you’re the kind of person to really get into things and tweak, it’s an awesome tool! And it has paired great with my Onkyo Rz810 and sounds amazing. Only thing I still need to tweak are my gains - I did lose a decent amount of volume, though it’s still gets plenty loud. I think this may have to do with Dirac calibrating things based on my sub volumes (I should probably raise by subwoofer gains), though there are also gain management techniques that can help bring the volume levels back up.

Hope that all makes sense (and that it’s not too much unnecessary detail at this stage). If money isn’t an object, sure, there are other, easier and cleaner options to add Dirac. If you’re really on a budget and the 88A is easier to work in due to funds, though, IMO it’s definitely worth it, but be prepared to work a little. Running Dirac instead of AccuEq using the Onkyo Rz810 and external amplification, my system has never sounded better!
Thanks for the detailed answer. A lot to consider. I may wait for the Onkyos to come out and see how the reviews are.
 

ronnzi

Member
Joined
Aug 20, 2021
Messages
50
Likes
27
Thanks for the detailed answer. A lot to consider. I may wait for the Onkyos to come out and see how the reviews are.
No problem. Yeah, that’s what I would do if I were you, as well. If the RZ70/90 really do end up having Dirac Bass Control for a decent price, I think that will be a major advantage. I was going to wait for it as well, but then I was able to get the MiniDSP 88A with the Bass Management module altogether barely used for $750.00, so I jumped on it.
 

tonybarrett

Member
Joined
May 14, 2020
Messages
54
Likes
69
Thanks for the detailed answer. A lot to consider. I may wait for the Onkyos to come out and see how the reviews are.
There can be a lot of unbalanced connections using both the 88A plus 2x4 minidsp, which I guess risks ground hum, so maybe a single unit is safer if you have that option and it’s decent. I have a tiny bit of hum from one of the SVS subs. You wouldn’t notice it even with the room totally quiet unless it was pointed out but it is there. I leave my subs on as their start up on signal function doesn’t seem to work well with my set up and my power amp has no trigger cable output. Having said that my system is cobbled together over the years and in a cupboard with router, turntable, Ethernet switches, Phillips lighting hub, mobile phone network extender, NAS, etc. and about twenty power outlets so I’m amazed I’m not picking up Radio Moscow.
 

K man

Member
Joined
Jan 1, 2022
Messages
30
Likes
11
Location
Sweden
With a SINAD of 90 dB, you are good using it on an amp having a SINAD of 80 dB. If the amp is any better than that, then the minidsp degrades its performance.
This statement confuses me and I've not been able to find any further elaboration on it or explanation of the ground it's based on.

So far I've been under the understanding that the end performance, at least when it comes to distortion, is defined by the lowest performing component in the chain. The bottleneck.

I don't see how that matches up with that statement though. Could someone maybe help me understand what I'm missing here?
 
Last edited:

somebodyelse

Major Contributor
Joined
Dec 5, 2018
Messages
2,832
Likes
2,138
That's more a rule of thumb statement than something considering all the facts. This thread has some detail on why the amp gain complicates things where noise is involved, as it is in SINAD.
 
Top Bottom