Minidsp Flex Review (Audio DSP)

[antcollinet]

Hi all,

Happy owner of the balanced flex since a couple of months back, replacing my 2x4HD in a 2.1 configuration (KEF LS50, svs sb1000 with topping pa5 / dynaco st 70).

One item that I am trying to work around is the ADC balanced input, when using RCA plugs and connecting my riaa/vinylrecord player to the input I loose a substantial amount of sound level headroom compared to running my usb streamer (normal audio levels at -7db with riaa compared to -25 db with streamer).

I assume this is just the nature of running RCA to balanced input as I had similar issue running the 2x4HD to my topping.

Though, can a self-wired rca-trs cable improve audio levels (cable similar to minidsp recommended output cable for flex) or would i have to look at a balanced riaa or quality converter of sorts?

thanks!

It is simply a voltage level issue. Best case, RCA connection will only deliver half the voltage compared to a balanced input. Add to that - your phono preamp is probably putting out much less than the 2V of a CD player, probably more like 1V peak at most (depending on the preamp gain, and cartridge output). So you are probably already -12dB or lower when connecting your phono input to the flex, compared to a digital input.

Not a big issue - you could (if you wish) use one of the presets for vinyl use, with +12 - +15 db (whatever gives you the best match with your streamer) of gain applied in the Flex plugin settings.

 

[Geertidow]

I've owned this unit for about 6 months now. I was not able to get my Flex (balanced) working to intergrate my subwoofer with my speakers in combination with DIRAC using the official tutorials from MiniDSP and additional tips using the customer support. Finally, after using @abdo123 's method of time alligning the sub with the mains with DIRAC I managed to get it all working. Although I still don't get the time allignmnet (2 ms, but speakers and sub are at nearly the same distance, definitely not 60 cm difference) I have accepted it blindly. EDIT: I involed custumor support since 5 weeks.

I would still say it's a great unit when everything works. In a 2.0 setup with or without DIRAC it's perfectd. In a 2.1 of 2.2 setup without DIRAC it's perfect.
In a 2.1 or 2.2 setup with DIRAC it may be a pain in the ass, and the tech support was a huge letdown for me. They really tried to help but sometimes really seem to imply that it was all my fault. I agree that may be the case becasue human errors are so frequent, but the way they say some things can be a bit harsh.
The combination of a little DSP or volume alignment before DIRAC was severely punished by very strange and unsatisfactory results.
Other problems I had: errors (DSP FAIL!) an a short volume increase when switching presets (more annoying than you think it is).

Although they did try to help and really did their best, sub integration with a stereo dirac license (2 dirac channels) is just difficult.
I'm now waiting for a request to swap the unit. EDIT: MiniDSP and SoundImports have agreed to take back the unit.

 

[vicenzo_del_paris]

I've owned this unit for about 6 months now. After many, many, many, many interactions with the MiniDSP tech support I was not able to get my Flex (balanced) working to intergrate my subwoofer with my speakers in combination with DIRAC. Finally, after using @abdo123 's method of time alligning the sub with the mains with DIRAC I managed to get it all working. Although I still don't get the time allignmnet (2 ms, but speakers and sub are at nearly the same distance, definitely not 60 cm difference) I have accepted it blindly.

I would still say it's a great unit when everything works. In a 2.0 setup with or without DIRAC it's perfectd. In a 2.1 of 2.2 setup without DIRAC it's perfect.
In a 2.1 or 2.2 setup with DIRAC it may be a pain in the ass, and the tech support was a huge letdown for me. The combination of a little DSP or volume alignment before DIRAC was severely punished by very strange and unsatisfactory results.

Although they did try to help (after first telling me it was probably my fault).
I'm now waiting for a request to swap the unit but so far to no avail.

Sub integration without built-in support is always a pain!

Especially when you don't have , at first, the background and knowledge to fully understand how to do and why.

I am in the same situation (2.2) and integrating subs is not straightforward. After many months, I am still trying to get it right after many tries and errors.
I am very close to reach what I was expecting.
In the meanwhile, I learned many things in that process and this is valuable

But keep in mind that Flex is only a stereo device. I has a very large sets of features including manual sub integration into a stereo setup.
I can't think about any other standalone Device providing same features with Dirac capabilities in this price range.

Regarding its intented use, it is a super great device.
For my point of view, only missing Dirac bass management to be the utimate DSP device.

 

[MCH]

Sub integration without built-in support is always a pain!

Especially when you don't have , at first, the background and knowledge to fully understand how to do and why.

I am in the same situation (2.2) and integrating subs is not straightforward. After many months, I am still trying to get it right after many tries and errors.
I am very close to reach what I was expecting.
In the meanwhile, I learned many things in that process and this is valuable

But keep in mind that Flex is only a stereo device. I has a very large sets of features including manual sub integration into a stereo setup.
I can't think about any other standalone Device providing same features with Dirac capabilities in this price range.

Regarding its intented use, it is a super great device.
For my point of view, only missing Dirac bass management to be the utimate DSP device.

It is a pending task for me as well to go ahead and do a proper 2.2 integration with MSO and Dirac (i use a ddrc24 though, but I think the process is the same.
The good news is that there are very good step by step tutorials and videos. They were looking relatively straight forward when I checked. Let's see how it translates to reality....

 

[Geertidow]

Sub integration without built-in support is always a pain!

Especially when you don't have , at first, the background and knowledge to fully understand how to do and why.

I am in the same situation (2.2) and integrating subs is not straightforward. After many months, I am still trying to get it right after many tries and errors.
I am very close to reach what I was expecting.
In the meanwhile, I learned many things in that process and this is valuable

But keep in mind that Flex is only a stereo device. I has a very large sets of features including manual sub integration into a stereo setup.
I can't think about any other standalone Device providing same features with Dirac capabilities in this price range.

Regarding its intented use, it is a super great device.
For my point of view, only missing Dirac bass management to be the utimate DSP device.

I wholeheartedly agree with this. I have also learned valuable things so far. But I do feel MiniDSP oversells it.

Quote from the Tech support:
"Note that it's all fine this being said. It's never been an issue for the past 12years we tune countless Dirac live installs and sell the platforms for all our stereo Dirac to do a 2.1 or multiway with a stereo Dirac live license. As a matter of fact, it's indeed better. Why? Because using only 2 x channels for say a 2.1, you are indeed Sweeping and tuning BOTH the main and the sub = You are correcting the system at the transition/crossover section. If you were using 3ch, you indeed wouldn't get as good of a crossover transition/tuning because Dirac wouldn't tune the sub to main section. Do you understand what we mean?
Here are some app notes that all our customers are following:
https://www.minidsp.com/applications/subwoofer-tuning/sub-integration-dirac"

I don't agree with this though

 

[Marc v E]

I wholeheartedly agree with this. I have also learned valuable things so far. But I do feel MiniDSP oversells it.

Quote from the Tech support:
"Note that it's all fine this being said. It's never been an issue for the past 12years we tune countless Dirac live installs and sell the platforms for all our stereo Dirac to do a 2.1 or multiway with a stereo Dirac live license. As a matter of fact, it's indeed better. Why? Because using only 2 x channels for say a 2.1, you are indeed Sweeping and tuning BOTH the main and the sub = You are correcting the system at the transition/crossover section. If you were using 3ch, you indeed wouldn't get as good of a crossover transition/tuning because Dirac wouldn't tune the sub to main section. Do you understand what we mean?
Here are some app notes that all our customers are following:
https://www.minidsp.com/applications/subwoofer-tuning/sub-integration-dirac"

I don't agree with this though

Do I understand correctly then that because Dirac live only uses 2 channels, it determines by itself the crossover point based on the volume of the sub? That seems what the tutorial is implying and would indeed be strange.

Then you would have 2 options: do it manually and have left, right speaker and sub each in a seperate channel. This way you can manually configer the crossover point.

Do it with Dirac live and have only 1 channel with left speaker and one channel with right speaker + sub. Or maybe left speaker + sub and right speaker + sub.

That would imply that Dirac sets its own crossover point and combines left and right bass into 1 channel to the sub. Is this a correct interpretation? Seems very odd to me.

 

[Geertidow]

Do I understand correctly then that because Dirac live only uses 2 channels, it determines by itself the crossover point based on the volume of the sub? That seems what the tutorial is implying and would indeed be strange.

Then you would have 2 options: do it manually and have left, right speaker and sub each in a seperate channel. This way you can manually configer the crossover point.

Do it with Dirac live and have only 1 channel with left speaker and one channel with right speaker + sub. Or maybe left speaker + sub and right speaker + sub.

That would imply that Dirac sets its own crossover point and combines left and right bass into 1 channel to the sub. Is this a correct interpretation? Seems very odd to me.

No. You set a manual crossover. It is a stereo DIRAC license so you only have to DIRAC channels.
In essence:
DIRAC1 ch -> sub + left speaker
DIRAC2 ch -> sub + right speaker

You set an XO, time, and volume allignment between sub and speakers yourself.
I ran into problems following the tutorial of minidsp, but on this forum there are working methods (abdo123's method worked well for me)

 

[agag206]

Hey all. I'm new here and maybe it could be a silly question. I have a 16 channels cinema processor which has no Dirac. I'd like to bring it to my system, MiniDSP only has 8 channels available. Does anyone know if is possible to match two devices in some way to get it working as a 16 ch?

 

[diablo]

Hey all. I'm new here and maybe it could be a silly question. I have a 16 channels cinema processor which has no Dirac. I'd like to bring it to my system, MiniDSP only has 8 channels available. Does anyone know if is possible to match two devices in some way to get it working as a 16 ch?

I use a single DDRC-88A with my Yamaha A8A. I route the most important channels through the 88A and run Dirac, then run the Yamaha YPAO to time align them and set the volume for each channel.

The YPAO doesn't make significant changes to the already corrected channels. And if it did I could edit them out.

I think the overall improvement is worthwhile. I could add extra MiniDSP channels, plus extra amps - but I doubt it would make a huge difference. HTH.

 

[Naturlig]

Has anyone tried to connect a Roon Nucleus streamer via USB to the miniDSP Flex? Will the DAC in the Flex be identified by Roon?

 

[enricoclaudio]

Has anyone tried to connect a Roon Nucleus streamer via USB to the miniDSP Flex? Will the DAC in the Flex be identified by Roon?

Just tried with my Intel NUC 10i7 Roon ROCK and the FLEX gets recognized and play just fine. So shouldn't be any problem with your Nucleus as my Roon ROCK runs the same OS.

 

[enricoclaudio]

@abdo123 could you please share the post where you describe the procedure to run Dirac Live with the MiniDSP FLEX? I want to compare the results with your procedure and the one MiniDSP does. Thanks for your help!!!

 

[abdo123]

@abdo123 could you please share the post where you describe the procedure to run Dirac Live with the MiniDSP FLEX? I want to compare the results with your procedure and the one MiniDSP does. Thanks for your help!!!

Sure! No problem. My procedure is basically manipulating the routing matrix so i can get Dirac to set the delays for all outputs for me.

DDRC-24 - Dirac Live on a budget?

No. you can purchase a Dirac license directly, and also get a Dirac bass control license, but then you need a DAC with as many outputs / channels as your inputs. I'm not sure if two stereo DACs would work. but DDRC-24 would work wonderfully for a 2.2 or a 2.1 setup.

www.audiosciencereview.com

 

[enricoclaudio]

Sure! No problem. My procedure is basically manipulating the routing matrix so i can get Dirac to set the delays for all outputs for me.

DDRC-24 - Dirac Live on a budget?

No. you can purchase a Dirac license directly, and also get a Dirac bass control license, but then you need a DAC with as many outputs / channels as your inputs. I'm not sure if two stereo DACs would work. but DDRC-24 would work wonderfully for a 2.2 or a 2.1 setup.

www.audiosciencereview.com

Thanks for sharing. It's basically the same procedure AustinJerry from AVS Forum recommends when calculating delays using Audyssey to put delays in miniDSP 2x4 HD for subwoofers.

 

[Naturlig]

Has anyone tried to connect a Roon Nucleus streamer via USB to the miniDSP Flex? Will the DAC in the Flex be identified by Roon?

The Roon Nucleus did not identify the DAC in the Flex (DL). I was able to enable it in settings/audio and select the device in Roon, but was not able to play any music. miniDSP support say the Flex DAC is "a standard UAC2 interface".

 

[TheBatsEar]

And MiniDSP is right. The reason must be with Roon. What did they say?

 

[Marc v E]

I have a question on Sinad performance when peq filters are active. Does this influence the sinad of the dac? Has anyone measured this? (I know @Sokel has, but I would like to see actual proof, ie measurements or proven theory that it cannot affect the sinad)

 

[Sokel]

I have a question on Sinad performance when peq filters are active. Does this influence the sinad of the dac? Has anyone measured this? (I know @Sokel has, but I would like to see actual proof, ie measurements or proven theory that I cannot affect the sinad)

I too REALLY like someone with proper gear and knowledge measure it under real world conditions.
Go on guys,is easy!

 

[Sokel]

I have a question on Sinad performance when peq filters are active. Does this influence the sinad of the dac? Has anyone measured this? (I know @Sokel has, but I would like to see actual proof, ie measurements or proven theory that I cannot affect the sinad)

Here is an interesting thread,on the last pages they are reporting something similar that minidsp is aware off and is about to be αdressed.
(used a translator,people who know the language can tell us more)

(They also report some horror stuff about melted tweeters with links to the minidsp forum)

 

[enricoclaudio]

The melted tweeters issue was reported by 1 customer only and it was fixed 2 or 3 firmware updates back. BTW, these issues reported only happens after switching from the original miniDSP Plugin (DDRC-24 or 2x4 HD) to the new miniDSP Device Console which was on BETA for the FLEX until 3 weeks ago.