Minidsp Flex Review (Audio DSP)

[Merkurio]

Anyway, your recommendation about the Moondrop Dawn really caught my attention @staticV3, do you know if it's possible to connect it to a balanced amplifier (L50, A90, etc.) with something like this?:

It would be great to this kind of setup without a "bulky" cheap DAC like the D10B, since it's hidden behind the computer and without displaying the sample-rate (which I couldn't care less about).

 

[staticV3]

do you know if it's possible to connect it to a balanced amplifier (L50, A90, etc.) with something like this?:

Possible yes, but I would first contact Moondrop support and ask them if the pentaconn GND is connected to the Dawn's GND or if it's simply left disconnected.
You want your DAC and Amp to be grounded to each other.

 

[Merkurio]

Possible yes, but I would first contact Moondrop support and ask them if the pentaconn GND is connected to the Dawn's GND or if it's simply left disconnected.
You want your DAC and Amp to be grounded to each other.

Thank you, as usual!

If it's not grounded, wouldn't the A90's "lift" option help?

 

[staticV3]

If it's not grounded, wouldn't the A90's "lift" option help?

The common GND between DAC and Amp is there to prevent a ground potential from frying the DAC's output or the Amp's input.
It was discussed in more detail here.
I don't think the ground lift switch would help here

 

[Merkurio]

The common GND between DAC and Amp is there to prevent a ground potential from frying the DAC's output or the Amp's input.
It was discussed in more detail here.
I don't think the ground lift switch would help here

Got it!

I've already asked Moondrop about the GND connection between the 4.4 connector and the device itself for use with an external balanced amplifier, as you indicated.

End of the off-topic...

 

[MCH]

Not at this moment, but maybe in the future I appreciate that extra connectivity using studio monitors as desktop speakers.

Still in that case, you don't really need 4 channels. My advice (if you are really on a budget). Buy a normal 2 channel dac/hp amp and see later when you want to add something else. Of course your decision there are many happy owners of flex here

 

[Merkurio]

Still in that case, you don't really need 4 channels. My advice (if you are really on a budget). Buy a normal 2 channel dac/hp amp and see later when you want to add something else. Of course your decision there are many happy owners of flex here

In fact, that's exactly what I just did.

Following the advice of @staticV3, I purchased the Moondrop Dawn (although the 3.5 version with 2V output) with a L30 II and I think it was the best possible decision for my current needs, fueling by my intention to buy a DCA Aeon 2 in a few months.

BTW, Moondrop replied me through their official store on AliExpress and told me that the 4.4 version of the Dawn works properly with balanced amplifiers, the representative told me that one of the technicians tried it with the SMSL SP400 without any problems.

 

[juliangst]

Have you calculated how much it would cost you to order from minidsp direct these days? My country -in EU- has a relatively low VAT and it would be ca 700eur after taxes fees etc. I think audiophonics price is quite good now (you get local support + 2 years warranty instead of one for probably less than 50 eur more...)

I changed my mind and don't want to get the minidsp anymore. It's just too expensive in the EU for the feautures it has.
A Topping DM7 with a Raspberry Pi or PC can do more powerful DSP things, has 8 channels and is 150€ less expensive. I hope they'll come up with a 4 or 6 channel version of the DM7 for even less money

 

[Marc v E]

I changed my mind and don't want to get the minidsp anymore. It's just too expensive in the EU for the feautures it has.
A Topping DM7 with a Raspberry Pi or PC can do more powerful DSP things, has 8 channels and is 150€ less expensive. I hope they'll come up with a 4 or 6 channel version of the DM7 for even less money

Going by experience I would say to my past "me" that buying the right equipment at an early stage might seem a big sum if money, but it is less than buying a product and upgrading over time. .....I have lots of dacs to sell...note to self: sell them.

My advice to you based on the above is to buy the minidsp with the future use of subs in mind.

 

[euge_lee]

Not that I could audibly tell a difference either way but... from a theoretical perspective... if I use Roon to send my MiniDSP Flex 96kHz upsampled audio rather than native 44.1... would that "alleviate" the MiniDSP from having to upsample internally before doing DSP? Or does the MiniDSP simple process EVERYTHING even if it comes in at its native sampling rate?

Is there a way we can "measure" this? If @amirm was to use Roon upsampled vs native into the MiniDSP... could his measurement tools perhaps "see the difference" somehow?

Again, not that it really matters sonically to me, but since I have Roon and it's just a couple clicks to upsample... I'm quite curious.

 

[antcollinet]

Not that I could audibly tell a difference either way but... from a theoretical perspective... if I use Roon to send my MiniDSP Flex 96kHz upsampled audio rather than native 44.1... would that "alleviate" the MiniDSP from having to upsample internally before doing DSP? Or does the MiniDSP simple process EVERYTHING even if it comes in at its native sampling rate?

Is there a way we can "measure" this? If @amirm was to use Roon upsampled vs native into the MiniDSP... could his measurement tools perhaps "see the difference" somehow?

Again, not that it really matters sonically to me, but since I have Roon and it's just a couple clicks to upsample... I'm quite curious.

Upsampling processes if done proplerly are "perfect" (In that they don't introduce any artefacts into the signal). So if both Roon and the Mini DSP are doing it properly (which I would expect) there will be no difference wherever you do it.

 

[voodooless]

would that "alleviate" the MiniDSP from having to upsample internally before doing DSP? Or does the MiniDSP simple process EVERYTHING even if it comes in at its native sampling rate?

Since the clock source of the external data is unknown, the DSP usually has its own clock domain, so there will always be resampling involved. No point in letting Roon do it for you. In fact, it's said that resampling to the same rate may actually be worse than differing sample rates, but I haven't seen any concrete evidence of this.

 

[Red_Red]

I changed my mind and don't want to get the minidsp anymore. It's just too expensive in the EU for the feautures it has.
A Topping DM7 with a Raspberry Pi or PC can do more powerful DSP things, has 8 channels and is 150€ less expensive. I hope they'll come up with a 4 or 6 channel version of the DM7 for even less money

Going by experience I would say to my past "me" that buying the right equipment at an early stage might seem a big sum if money, but it is less than buying a product and upgrading over time. .....I have lots of dacs to sell...note to self: sell them.

My advice to you based on the above is to buy the minidsp with the future use of subs in mind.

Not to mention the price of the cables (rca to XLR), and the time to install the multiple programs on the RPi, etc. The advantage of the Flex Eight is clearly its integration. also having spdif inputs and bluetooth in addition to the usb is a plus for example to connect it directly to the TV and / or an external audio player or a smartphone in addition to a computer.

For my part, with a Nanodigi, I was thinking of getting three Topping E30s in addition to the one I already have to improve my active crossover. But when you calculate everything, including taking into account the price of the cables and the ugly "octopus" aesthetics of their number, the choice is quickly made. The Flex Eight is obviously a winner.

On the other hand, it is clear that the price charged (for now) in Europe is excessive. At 800 euros it would be more suitable. But at 1000 euros for example on Audiophonics, it is even better to order it directly from the minidsp shop, even if it means losing the 2-year European guarantee.

But maybe before taking the plunge, it would be wiser to wait for Amir to do the full review. Even if Minidsp demonstrated with the previous Flex, their ability to do things correctly.

 

[juliangst]

Not to mention the price of the cables (rca to XLR), and the time to install the multiple programs on the RPi, etc. The advantage of the Flex Eight is clearly its integration. also having spdif inputs and bluetooth in addition to the usb is a plus for example to connect it directly to the TV and / or an external audio player or a smartphone in addition to a computer.

For my part, with a Nanodigi, I was thinking of getting three Topping E30s in addition to the one I already have to improve my active crossover. But when you calculate everything, including taking into account the price of the cables and the ugly "octopus" aesthetics of their number, the choice is quickly made. The Flex Eight is obviously a winner.

On the other hand, it is clear that the price charged (for now) in Europe is excessive. At 800 euros it would be more suitable. But at 1000 euros for example on Audiophonics, it is even better to order it directly from the minidsp shop, even if it means losing the 2-year European guarantee.

It's actually easier than you think.
You just have to install MoOde or Volumio on the Pi which both come with CamillaDSP build into it.

If you need an optical input you can simply buy a HifimeDIY optical to USB adapter (about 30€) and select input the input source in MoOde.
You can do all the DSP,PEQ and convoution stuff inside camillaDSP and I didn't have any issues running it under MoOde so far (I only used it in stereo so I can't comment on multichannel DACs).

The Topping DM7+Raspberry Pi is the real winner here IMHO.
You get SOTA balanced 8 Channel DAC, extremely powerful DSP and local file/Airplay/Spotify/Roon streaming for about the same price as a unbalanced Flex here in EU.

 

[Red_Red]

It's actually easier than you think.
You just have to install MoOde or Volumio on the Pi which both come with CamillaDSP build into it.

If you need an optical input you can simply buy a HifimeDIY optical to USB adapter (about 30€) and select input the input source in MoOde.
You can do all the DSP,PEQ and convoution stuff inside camillaDSP and I didn't have any issues running it under MoOde so far (I only used it in stereo so I can't comment on multichannel DACs).

The Topping DM7+Raspberry Pi is the real winner here IMHO.
You get SOTA balanced 8 Channel DAC, extremely powerful DSP and local file/Airplay/Spotify/Roon streaming for about the same price as a unbalanced Flex here in EU.

I know, but on the one hand it's not so obvious for everyone, and on the other hand we lose practicality.

For example, the Flex Eight can be used, for people like me, as a tool for designing passive crossovers for diy speakers. With an RPi running Moode/CamilliaDSP good luck getting to do this in real time and a measurement microphone, and the necessary software, etc. So yes, this is a very special use here.

Otherwise, yes, I understand your point of view. Moreover, once the crossover has been determined with a tool like the flex eight, you can very well use an RPi under camelliadsp to apply it! but the reverse is not really possible if it is not by complicating the task enormously.

 

[juliangst]

I know, but on the one hand it's not so obvious for everyone, and on the other hand we lose practicality.

For example, the Flex Eight can be used, for people like me, as a tool for designing passive crossovers for diy speakers. With an RPi running Moode/CamilliaDSP good luck getting to do this in real time and a measurement microphone, and the necessary software, etc. So yes, this is a very special use here.

Otherwise, yes, I understand your point of view. Moreover, once the crossover has been determined with a tool like the flex eight, you can very well use an RPi under camelliadsp to apply it! but the reverse is not really possible if it is not by complicating the task enormously.

Its as easy as with the Flex. You can access the CamillaDSP Gui over your browser and all filters and crossovers you set get applied instantly. This makes it even easier compared to the Flex because you don't need a physical connection to your PC with the Pi.
Just do measurements with REW from the listening position and export filters to the Pi over the network.

Both the Flex and CamillaDSP require you to do your own measurements and create your own filters and crossovers.
You can upgrade the Flex with Dirac Live but that won't take care of your crossover setup either.

 

[Red_Red]

Maybe I need to take a closer look at this. I'm so used to using the Nanodigi or a sound card that it's possible that I missed what you're talking about. In my mind, this could not be possible because of the latencies between the remote Rpi and the measurement computer preventing, for example, the calculation of the acoustic phasing between the loudspeakers.

 

[juliangst]

Maybe I need to take a closer look at this. I'm so used to using the Nanodigi or a sound card that it's possible that I missed what you're talking about. In my mind, this could not be possible because of the latencies between the remote Rpi and the measurement computer.

It of course depends on the measurement method. If you use sine sweeps it could become a problem or not.
But with pink noise and the RTA method you don’t get any problems.

I might just get this HifiMeDIY optical to USB converter and find out if there really is any delay

 

[Red_Red]

It of course depends on the measurement method. If you use sine sweeps it could become a problem or not.
But with pink noise and the RTA method you don’t get any problems.

I might just get this HifiMeDIY optical to USB converter and find out if there really is any delay

The RTA method makes it possible to correct the faults of the listening room but not to achieve the crossover between several loudspeakers of the same speaker in a neutral environment (outdoor or anechoic). In this case, of course, there is no problem measuring everything remotely as you do. But it's not the same thing at all.

 

[mdsimon2]

Maybe I need to take a closer look at this. I'm so used to using the Nanodigi or a sound card that it's possible that I missed what you're talking about. In my mind, this could not be possible because of the latencies between the remote Rpi and the measurement computer preventing, for example, the calculation of the acoustic phasing between the loudspeakers.

Although a bit more complicated CamillaDSP is definitely a viable option for crossover design. There a few different ways to do it, I probably wouldn't use moode but rather the ubuntu setup documented in my signature as it gives you a bit more flexibility.

With both the Flex and DM7 + CamillaDSP you can only use acoustic timing references as they do not have an analog input for a true loopback with an analog mic. If you are using an audio interface like the MOTU Ultralite Mk5 + CamillaDSP then you have a lot more options as you have an analog input.

In terms of getting a REW signal in to CamillaDSP if you are using a Mac airplay is a viable completely headless option or you can run the RPi in USB gadget mode. Of course if your computer has a SPDIF output (or you have a USB to SPDIF card) and your interface has a SPDIF input like the UL Mk5 or Okto dac8 pro or you add a SPDIF to USB card to your RPi4 with the DM7 that also works.

So lots of options to make it work.

Michael