Minidsp Flex Review (Audio DSP)

[JSmith]

It's great to see some companies focusing on performance with their new products and I'd suggest it's partly to do with the testing done here. @amirm you're gradually changing this industry, kudos.


JSmith

 

[Ultrasonic]

First of its kind to land in the blue "excellent" category!

That's not true, given the existence of the miniDSP SHD (not SHD Power that was bizarrely included in the SINAD comparison plot).

 

[amirm]

I'm sorry to ask, but can someone please explain the DSP functionality to me and why I would need it? Does it do similar things as Dirac?

Yes. Dirac is automated. You can do similar work manually with the filters in this box. In addition, you can also route low frequency to subs. Or implement an active speaker system.

 

[voodooless]

It's great to see some companies focusing on performance with their new products and I'd suggest it's partly to do with the testing done here.

Well, not so fast. The thing still only has 16-bit equivalent performance despite the 110+ SINAD, and word on the street is the second pair of channels is significantly worse. It almost looks like companies also know that Amir only measures the first set of channels

 

[Ultrasonic]

I'm sorry to ask, but can someone please explain the DSP functionality to me and why I would need it? Does it do similar things as Dirac?

Firstly you can pay to buy a Dirac Live licence on the Flex.

The standout feature the the Flex not mentioned so far is that is it's functionality for subwoofer integration into a stereo music system. This is not an automated process but it provides users with the capability to apply crossover filters to main speakers as well as a subwoofer (or two), and to set time delays to optimise integration (including delaying the signal to the main speakers).

 

[abdo123]

Well, not so fast. The thing still only has 16-bit equivalent performance despite the 110+ SINAD, and word on the street is the second pair of channels is significantly worse. It almost looks like companies also know that Amir only measures the first set of channels

Do you know Amir’s FFT window settings? I’m thinking of doing my own measurements later today.

 

[Ultrasonic]

Yes. Dirac is automated.

To avoid confusion I think it's best to describe Dirac Live as semi-automated. The measurement process is very much manual, and there are a range of ways to do this which will affect the results. There is also intended to be user interaction to optimise the results to personal taste, rather than there being a single 'corrected' result that the system offers. Dirac Live is better than a fully automated system but it does rely on users being prepared to to put some time and effort into it to get the best results. It is though considerably quicker and easier than what can be done more manually using REW to define PEQ filters via the Flex.

 

[voodooless]

Do you know Amir’s FFT window settings? I’m thinking of doing my own measurements later today.

No idea. You should be able to use the ADC to measure the 2nd DAC output I guess. ADC is pretty good

 

[abdo123]

No idea. You should be able to use the ADC to measure the 2nd DAC output I guess. ADC is pretty good

I have an ADC already with like 115dB SINAD. Should be more than enough to show if the channels are identical.

 

[Sommer]

Hi!
Been lurking around this forum for a long time now.
@amirm It looks on the picture of the back, that it is the balanced version (TRS) in your review, correct?
I read through the review, but I can't see it mentioned anywhere that this is the balanced version.
The price for the balanaced version is 550.
It would also be nice to see a review of the standard version (RCS), to see if it comes close to this performance as well.
The Standard version costs 475.

BR Sommer

 

[voodooless]

It is though considerably quicker and easier than what can be done more manually using REW to define PEQ filters via the Flex.

And don't forget that Dirac is more than just a bunch of PEQ's. It also tries to optimize the impulse response, so time aligns your speaker units. But unless you have a coaxial system, this only works well on the listening position though. I've also had some interesting results with sidewall reflections on my desk setup. There, it is really evident that it does much more than frequency response correction!

 

[BeerBear]

Does anyone know what the latency is for the analog I/O, with some EQ running?
(edit: not linear phase EQ, if possible - but any info would be welcome)

edit2: and also the latency when using it as a soundcard via USB. From the manual it looks like it uses a Thesycon ASIO driver. But I wonder if the DSP itself adds any significant latency.

 

[stemfencer]

For purposes of some functionality, is this basically the minidsp SHD without the streamer (if you add the Dirac license; the SHD includes the Dirac)? Whereas the minidsp SHD studio is the SHD without the preamp/analog i/o?

As to expanded functionality, is it essentially an upgraded version of miniDSP 2x4HD that provides Dirac (as an option)?

I understand it has additional uses beyond what the SHD/Studio offer (thus my question as to how it relates to the 2x4) but from a basic end-users perspective I'm looking for clarity on its use. I did read the web page and elsewhere. A few comments on other forums also suggest a bit of confusion as to where this product fits vs minidsp's similar offerings?

The way I see it:

SHD - streamer + DAC for analogue outputs
SHD Studio - streamer without DAC, only digital outputs (need a DAC to connect to speakers)
Flex - no streamer but DAC for analogue outputs

Once you add all the options to the Flex (balanced, Dirac license, UMK microphone and a streamer) the price is ballpark to the SHD units.

If only they added a 12V trigger to this, connect any of these units to a Hypex/Purifi power amp and you are pretty set, requirement of preamp is dissappearing with units like these.

 

[abdo123]

@amirm is it possible that the internal resampling of the MiniDSP is causing the added distortion for IMD and multi-tone?

Since multi-tone is 192KHz it has to be down sampled to 96KHz internally first. I’m not sure at which sample rate the IMD test is.

 

[Ultrasonic]

And don't forget that Dirac is more than just a bunch of PEQ's. It also tries to optimize the impulse response, so time aligns your speaker units. But unless you have a coaxial system, this only works well on the listening position though. I've also had some interesting results with sidewall reflections on my desk setup. There, it is really evident that it does much more than frequency response correction!

I'm aware although I remain unconvinced how truly beneficial this may actually be. For context I own and use both a miniDSP 2x4 HD and SHD.

Also, the Flex without Dirac Live has the capability to apply FIR filters to manually make some phase adjustments. Although the total number of taps limits the frequency range over which this can meaningfully be done.

 

[Crosstalk]

We want more like this from brands like topping instead of pushing sinads to levels where it doesn’t matter anymore.

 

[voodooless]

Also, the Flex without Dirac Live has the capability to apply FIR filters to manually make some phase adjustments. Although the total number of taps limits the frequency range over which this can meaningfully be done.

It can So if you're willing to spend some time you can do lots of fun stuff. Mind you, Dirac only used like 1k taps as well, but also employs IIR filters. It's just about being smart about it.

 

[Ultrasonic]

It can So if you're willing to spend some time you can do lots of fun stuff. Mind you, Dirac only used like 1k taps as well, but also employs IIR filters. It's just about being smart about it.

No, Dirac Live uses a mix of FIR and IIR filters.

Edit: actually that may have been what you were saying .

 

[Ultrasonic]

In my personal experience I'd say the advantages of Dirac Live over what can be done manually with the Flex are very much in the ease of use rather than performance category, although for the majority that simply won't have the inclination or aptitude to do more manually there will effectively be a performance benefit too.

Edit: it's perhaps worth highlighting that the version of Dirac Live available for the Flex will not optimise subwoofer integration in terms of time delays or crossover filters though. All it will do is smooth the combined response of the main speakers and subwoofer(s), which in itself is of course very useful but not fully optimal.

 

[kopczas]

I`ve been waiting for this from the moment, they showed this dsp. Thanks!!