Minidsp Flex Review (Audio DSP)

[diablo]

So I received my Flex yesterday and started my sub integration attempts with REW and Umik-2.

It was an arduous journey. I crossed my KEF R3 and SVS 3000 Micro at 60Hz. Thank god for PEQ on the SVS sub. My room modals were like crazy. I actually had to remove the sub from a corner of the room and place it roughly 2 feet from the long room wall.

The toughest part was trying to EQ peaks and troughs between 60 and 300 Hz. Above 500 Hz the KEFs are extremely flat which is a good thing because Flex only has a 10 band PEQ.

It was a solid first attempt which took me like 3+ hours. And now I am getting used to a new and much flatter FR curve

If I'm guessing right you set the PEQs manually? Which is fine. But maybe if you have another few hours then maybe try out the auto EQ function in REW.

REW AutoEQ

miniDSP is a leading manufacturer of Digital Audio Signal Processors for the HomeTheater, Hifi, headphone and Automotive market. Join our large community of Audiophiles, Engineers and DIYers using our innovative products.

www.minidsp.com

It takes a bit of getting used to but it can achieve results very similar to Dirac in terms of flatness. And generally not even using all the bands! It is a remarkable tool.

I also have the Dirac option and can switch between the two. The only difference in sound which is obvious is the impulse response correction of Dirac. Impulse response sharpens dialogue, separates vocals in a choir etc. For some things I use it, some things better without.

 

[abdo123]

So I received my Flex yesterday and started my sub integration attempts with REW and Umik-2.

It was an arduous journey. I crossed my KEF R3 and SVS 3000 Micro at 60Hz. Thank god for PEQ on the SVS sub. My room modals were like crazy. I actually had to remove the sub from a corner of the room and place it roughly 2 feet from the long room wall.

The toughest part was trying to EQ peaks and troughs between 60 and 300 Hz. Above 500 Hz the KEFs are extremely flat which is a good thing because Flex only has a 10 band PEQ.

It was a solid first attempt which took me like 3+ hours. And now I am getting used to a new and much flatter FR curve

The optimum crossover (from looking at the frequency response from Erin’s site) Is to seal the ports of the R3 with a sock or a towel and apply a Butterworth 12dB/oct highpass @100Hz on the speaker and a Linkwitz-Riley 24db/oct @100Hz on the subwoofer.

Make sure that the SVS internal crossover is either disabled, or if it’s just as flexible as the miniDSP, use it instead.

 

[mike70]

I'll suggest to use the port plugs in the R3 ... to left all the low bass work to the sub ... but crossed at 100hz? It seems very high.

I use the port plugs with the crossover at 65 - 80 Hz in the sub ... but I'm not using Flex or Dirac, so I don't have the high pass filter, maybe that's the difference.

SVS recommends to use the "natural decay" in the speakers and not the high pass, but you really don't know if it's only a trick to sell subs without high pass.

 

[thenamelessone7]

If I'm guessing right you set the PEQs manually? Which is fine. But maybe if you have another few hours then maybe try out the auto EQ function in REW.

REW AutoEQ

miniDSP is a leading manufacturer of Digital Audio Signal Processors for the HomeTheater, Hifi, headphone and Automotive market. Join our large community of Audiophiles, Engineers and DIYers using our innovative products.

www.minidsp.com

It takes a bit of getting used to but it can achieve results very similar to Dirac in terms of flatness. And generally not even using all the bands! It is a remarkable tool.

I also have the Dirac option and can switch between the two. The only difference in sound which is obvious is the impulse response correction of Dirac. Impulse response sharpens dialogue, separates vocals in a choir etc. For some things I use it, some things better without.

I used the auto EQ feature in REW to create a filter to match the house curve. But I was not satisfied with the results. So while I used it as basis I still had to manually adjust it to further to my satisfaction.

 

[vodskilla]

Received the Flex and have it connected via USB to my PC for source. I noticed that even after everything is shut down the unit is still warm the next day... Do you guys turn off the power to the unit usually or just leave it warm/powered ?

 

[tonycollinet]

Received the Flex and have it connected via USB to my PC for source. I noticed that even after everything is shut down the unit is still warm the next day... Do you guys turn off the power to the unit usually or just leave it warm/powered ?

Mine stays in standby (if I remember to turn it off at all)

 

[coptician]

I am thinking of using the miniDSP Flex almost entirely for the PEQ features.

Is it possible to have it output on each of its outputs simultaneously, with different PEQ profiles? This way I don't have to switch between my different headphones and my speakers.

Also, can it auto switch between inputs, or does it have the ability to switch to a specific input via IR?

 

[tonycollinet]

I am thinking of using the miniDSP Flex almost entirely for the PEQ features.

Is it possible to have it output on each of its outputs simultaneously, with different PEQ profiles? This way I don't have to switch between my different headphones and my speakers.

Also, can it auto switch between inputs, or does it have the ability to switch to a specific input via IR?

Each output can have it's own EQ, but there are only 4 channels out, so 2 stereo devices.

However there are 4 profiles, and each profile has it's own EQ - There are direct buttons on the remote to select each profile.

Annoyingly it will auto switch to bluetooth when a connected bluetooth device sends it audio - this is a pain in the ass as a connected phone will switch of audio from any other source for a notification sound or similar. So I disconnect any bluetooth device unless I am using it. Otherwise, inputs are selected from the remote but you have to cycle through them - single button.

 

[will.b]

Each output can have it's own EQ, but there are only 4 channels out, so 2 stereo devices.

However there are 4 profiles, and each profile has it's own EQ - There are direct buttons on the remote to select each profile.

Annoyingly it will auto switch to bluetooth when a connected bluetooth device sends it audio - this is a pain in the ass as a connected phone will switch of audio from any other source for a notification sound or similar. So I disconnect any bluetooth device unless I am using it. Otherwise, inputs are selected from the remote but you have to cycle through them - single button.

That bluetooth feature was removed in the latest firmware.

From miniDSP:

V1.16 Firmware v1.25 / 14th June 2022

- Remove BlueTooth Autoconnect feature
- Fix bug of muted output on bootup for certain conditions on Flex Digital
- Fix bug of incorrect output sample rate metadata bit on Flex digital / 48kHz now showing correctly

 

[abdo123]

Annoyingly it will auto switch to bluetooth when a connected bluetooth device sends it audio - this is a pain in the ass as a connected phone will switch of audio from any other source for a notification sound or similar. So I disconnect any bluetooth device unless I am using it. Otherwise, inputs are selected from the remote but you have to cycle through them - single button.

I love that feature, do you know how annyoing it is to get up from the couch and go the flex just so i can use Bluetooth?

I'm actually not updating so i wouldn't lose it.

 

[aikofan]

Received the Flex and have it connected via USB to my PC for source. I noticed that even after everything is shut down the unit is still warm the next day... Do you guys turn off the power to the unit usually or just leave it warm/powered ?

I usually turn off power from a surge protector when I’m not using it, but today, I left it on for about 3 hrs with nothing playing, and I was surprised how hot it was when I touched the top panel. It was hotter than my similarly sized mini-PC while it’s running. So I’m going to continue shutting off power when I’m not playing music.

 

[dougi]

That bluetooth feature was removed in the latest firmware.

From miniDSP:

V1.16 Firmware v1.25 / 14th June 2022

- Remove BlueTooth Autoconnect feature
- Fix bug of muted output on bootup for certain conditions on Flex Digital
- Fix bug of incorrect output sample rate metadata bit on Flex digital / 48kHz now showing correctly

I updated to the latest firmware, but the last bug has not been fixed for me. My DACs still show 96kHz sampling rate on the output of the Flex digital.

 

[tonycollinet]

That bluetooth feature was removed in the latest firmware.

From miniDSP:

V1.16 Firmware v1.25 / 14th June 2022

- Remove BlueTooth Autoconnect feature
- Fix bug of muted output on bootup for certain conditions on Flex Digital
- Fix bug of incorrect output sample rate metadata bit on Flex digital / 48kHz now showing correctly

Oh, missed that - good news.

 

[tonycollinet]

I love that feature, do you know how annyoing it is to get up from the couch and go the flex just so i can use Bluetooth?

I'm actually not updating so i wouldn't lose it.

You do have a remote...

I think it depends on if you are mainly connecting via bluetooth, or mainly via other means. I just know that if I'm listening via USB, and the phone in another room gets a notification I miss part of the music while I switch it back to USB. And that can happen every few minutes if the kids have a messenger chat going on.

 

[coptician]

Each output can have it's own EQ, but there are only 4 channels out, so 2 stereo devices.

However there are 4 profiles, and each profile has it's own EQ - There are direct buttons on the remote to select each profile.

Annoyingly it will auto switch to bluetooth when a connected bluetooth device sends it audio - this is a pain in the ass as a connected phone will switch of audio from any other source for a notification sound or similar. So I disconnect any bluetooth device unless I am using it. Otherwise, inputs are selected from the remote but you have to cycle through them - single button.

Thanks so much!

I guess to get more outputs I'd need to get the new Flex 8.
Single-button cycling is unfortunate for automation purposes, easy to get desynced that way. Still worth considering, but the ADI-2 might fare better in this regard.

 

[MarcosCh]

Thanks so much!

I guess to get more outputs I'd need to get the new Flex 8.
Single-button cycling is unfortunate for automation purposes, easy to get desynced that way. Still worth considering, but the ADI-2 might fare better in this regard.

You could have the flex 8 outputing simultaneouly to 4 different stereo amplifiers (headphone or speakers) with different EQ each and just turn on the amplifier you are using at the moment, no need to change conf.
Same thing with the older flex and two amplifiers.

 

[coptician]

You could have the flex 8 outputing simultaneouly to 4 different stereo amplifiers (headphone or speakers) with different EQ each and just turn on the amplifier you are using at the moment, no need to change conf.
Same thing with the older flex and two amplifiers.

That is what I was thinking of I have a Stax amp, a dynamic/planar amp and my speakers. I could even consider settng up a separate sub-output, though currently my AV receiver is handling that.

Interesting idea

 

[deercreekaudio]

This was the one I've been waiting for since the announcement! Thanks for reviewing it this fast. The result is even better than expected, this is a brilliant piece of kit!

Whoooo. Hyped, hyped, hyped.


Edit: I have one question before I pre-order. I don't use long cable runs. Is there any advantage to the higher output voltage of the balanced version? Otherwise I see no reason not to get the RCA version for home use.

If you have an amplifier with balanced inputs you will want to drive it with a balanced FLEX (TRS) for the SINAD performance.

Deer Creek Audio is an authorized miniDSP dealer.

 

[juliangst]

Does the flex allow mixing inputs? If I want to hear Pc audio and audio from my iPad for example

 

[tonycollinet]

Does the flex allow mixing inputs? If I want to hear Pc audio and audio from my iPad for example

No