Minidsp Flex Review (Audio DSP)

[keiron99]

Thanks. Yikes. I see this thing is not for the faint hearted. May as well be written in Chinese as far as I'm concerned! Think I'll just stick to plonking a few cushions round the room and tweaking the tone controls to taste!

 

[Overseas]

Thanks. Yikes. I see this thing is not for the faint hearted. May as well be written in Chinese as far as I'm concerned! Think I'll just stick to plonking a few cushions round the room and tweaking the tone controls to taste!

Feeling the same. You would need to get a scientist friend.

Some other time just try some Yamaha with YPAO, works with the push of a button.

 

[mglobe]

Feeling the same. You would need to get a scientist friend.

Some other time just try some Yamaha with YPAO, works with the push of a button.

It's a bit daunting when you first look at it, but once you set up the input and output of the flex, making the Dirac calibration measurements is pretty easy, as is selecting and applying the default dirac target curve. It's only a bit more effort to adjust the target curve to your liking. But yeah, it's not just connect a microphone and push a button easy.

 

[radix]

It's a bit daunting when you first look at it, but once you set up the input and output of the flex, making the Dirac calibration measurements is pretty easy, as is selecting and applying the default dirac target curve. It's only a bit more effort to adjust the target curve to your liking. But yeah, it's not just connect a microphone and push a button easy.

It's not too much worse than doing the room mic setup on an AVR, where you put the mic in a couple positions. It is worse (more steps and UI), just not too much. There are decent youtubes on it.

 

[mglobe]

It's not too much worse than doing the room mic setup on an AVR, where you put the mic in a couple positions. It is worse (more steps and UI), just not too much. There are decent youtubes on it.

Totally agree.

 

[catch22]

Hi all,

I currently have a 2.1 setup without EQ.
It sounds OK, but I will trust response graphs more than my ears.
I want to start experimenting with Flex + REW + UMIK-1, and to apply Low Pass for sub, High pass for speakers, + EQ filters.

Current setup:
Libreelec on RPi4 -> USB -> SMSL DL200 -> Yamaha A-S700 -> Elac DBR62 + Yamaha Sub YST-SW515 (sub is connected to speaker B posts, and the amp is in A+B mode).

I reckoned a Flex Unbalanced is a perfect fit for my 2.1 setup with future addition of one more sub, maybe.
However, for just 55 USD extra a Flex Eight can be had. Which is surplus to my current needs, but why not? Definitely giving more flexibility for example to connect a different amp to outputs 5,6 or a set of active speakers and can use Flex Profiles to compare different gear. I mean, why not?

Now the question is, are there any downsides of Flex Eight over the standard Flex for my case?
(For one, I know there are no analog inputs in Eight, but I don't need them. If I want to play CD, I will connect my CD player to Flex, or to Flex Eight, using toslink or coax.)

Another difference I read here, that I do not fully understand:
https://www.minidsp.com/applications/dsp-basics/fir-vs-iir-filtering
miniDSP Flex (without Dirac Live). Supports a total of 4096 taps dstributed across the four output channels.
miniDSP Flex Eight (without Dirac Live). Supports a total of 4096 taps dstributed between the two input channels.

1. Are FIR better and more useful, in reality, than IIR, or IIR are good enough?
2. Does the above mean that the Eight is quite limited in using of FIR? I mean, I logically understand the benefit of applying of different set of FIRs to each individual output. But if applied to input channels, that essentially means that all eight outputs will receive the same filtering, defeating the benefit of per-channel output tuning?

 

[diablo]

Hi all,
However, for just 55 USD extra a Flex Eight can be had. Which is surplus to my current needs, but why not? Definitely giving more flexibility for example to connect a different amp to outputs 5,6 or a set of active speakers and can use Flex Profiles to compare different gear. I mean, why not?

I have both the standard Flex and the Eight model. When I only had the normal Flex I did some speaker comparisons - though needed to hang the subwoofer off the amps I was using - as of course there weren't enough outputs for a separate sub. So I found some more cash and got the Eight, which is ideal for lots of things.

Very well worth the extra $55 in my opinion.

I have the Dirac versions of each. As far as I know the Dirac correction is done on the two input channels, using both IIR and FIR filters. So I've only ever used the IIR ones on the outputs using Biquads calculated by the REW EQ screen.

It takes a bit of practice to make good use of the REW EQ system, or at least it did for me. Though these days I quite often only use the REW compensation, preferring the sound I get.

 

[catch22]

It takes a bit of practice to make good use of the REW EQ system, or at least it did for me. Though these days I quite often only use the REW compensation, preferring the sound I get.

Yeah I am looking forward get into this stage when I get a Flex / UMIK, for now I am on the learing curve thanks for explanations!

 

[catch22]

I have the Dirac versions of each. As far as I know the Dirac correction is done on the two input channels, using both IIR and FIR filters. The output channels (be it 4 or 8) share the same number of FIR filters I think. Though I've only ever used the IIR ones using Biquads calculated by the REW EQ screen.

I will likely skip Dirac for now. If I not wrong, I understand that Dirac is easier and perhaps will give better fine tuned results, but and the moment I think that manual configuration will help me better understand the EQ kitchen

 

[diablo]

I will likely skip Dirac for now. If I not wrong, I understand that Dirac is easier and perhaps will give better fine tuned results, but and the moment I think that manual configuration will help me better understand the EQ kitchen

I was very impressed with Dirac when I first used it (though that was on a DDRC24). For example I could hear individual voices in a choir, rather than them being mashed together.
I later realised the importance of exact timing, which Dirac is good at. I still use Dirac to set timings, even when using REW EQ. It can be done with REW itself, though you need to know where to look and do some sums. So I get the same clarity without Dirac.

 

[catch22]

I was very impressed with Dirac when I first used it (though that was on a DDRC24). For example I could hear individual voices in a choir, rather than them being mashed together.
I later realised the importance of exact timing, which Dirac is good at. I still use Dirac to set timings, even when using REW EQ. It can be done with REW itself, though you need to know where to look and do some sums. So I get the same clarity without Dirac.

So Dirac will help to set the benchmark for yourself, what level of improvement in sound CAN be achieved. And even if later you switch it off and do manual steps, at least you have learned from Dirac already
Do you know if Dirac licence can be added later if a unit is purchased without? A quick look at minidsp product portfolio doesn't show a separate item for Dirac licences.

 

[diablo]

I've purchased Dirac Live separately from them before. Though the procedure has changed - you now do it through the new Control Panel software -

Flex Dirac Live upgrade

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

 

[keiron99]

I'm very keen to try out dirac and the minidsp flex seems the way to go.

My listening is almost exclusively vinyl.

Could I plug my phone stage into the minidsp, and then connect that to the HT bypass of my Rotel 1592 integrated?

Edit: turns out there is no HT bypass! Oh well. Nevermind.

 

[staticV3]

Could I plug my phone stage into the minidsp, and then connect that to the HT bypass of my Rotel 1592 integrated?

You can definitely do Phono Pre->Flex (Dirac)->Rotel.

Not sure what HT bypass is. The only bypass on the RA-1592 is Tone bypass.

 

[plusforce]

I read as much as I could about balanced and unbalanced versions but couldn't understand which one is better for me. I want to do room correction. (sorry I am not an expert). Can someone help me?
I have a Marantz 6007 amp, two Revel M16 speakers, and an SVS-sb1000 sub.
The input will be toslink from the TV.
Thanks!

 

[staticV3]

I read as much as I could about balanced and unbalanced versions but couldn't understand which one is better for me. I want to do room correction. (sorry I am not an expert). Can someone help me?
I have a Marantz 6007 amp, two Revel M16 speakers, and an SVS-sb1000 sub.
The input will be toslink from the TV.
Thanks!

The Flex Balanced doesn't make sense, as neither your Amp, nor your Sub has balanced inputs.

Either the Flex RCA, or the Flex Digital would work in your case:


With the Flex RCA, you'd be forced to use the Flex's remote to control volume. The Marantz would need to be kept at a fixed volume.

With the Flex Digital, you can use either the Flex remote, or the Marantz remote.

The Flex HT/HTx would also work.
With those, you could use either the TV remote, or the Flex remote.

 

[staticV3]

Thanks! I did not consider Flex Digital because I thought the miniDSP DAC has higher quality than the DAC in the Marantz. Maybe I was wrong?

The Flex DAC has better measurements, but I wouldn't expect audible differences.

Actually, on second thought, even with the Flex RCA you should connect your sub to the Marantz. Not to the Flex:


That way, you can still use the Marantz remote to control volume, and you don't have to worry about accidentally changing the Marantz's volume, which with the sub plugged into the Flex, would change the relative level between mains and sub (annoying!)

Is there any downside if I get the balanced version in case I decide to upgrade my amp in the future?

Plugging an RCA Amp into a balanced output is not really straightforward and can lead to performance degradation. Generally not recommended.

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An RCA DAC on the other hand, can be plugged into both RCA and XLR Amps without performance degradation.

With the right cables, you can even make the Flex RCA impedance balanced, which comes with all the noise cancelling and ground loop breaking attributes of native XLR/TRS:

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So if you want to be prepared for both RCA and XLR Amps, then I'd choose the Flex RCA if you can do custom impedance balanced cables, or the Flex HTx if you want hassle-free connections with default cables.

Or the Flex Digital as you can combine it with the right DAC for your use case.

 

[Ze Frog]

Probably a silly question, I'm pretty new to DSP stuff...but does the DSP have noticeable effect on sound quality that anyone has noticed?

I'd be using it to cross to subwoofers, so in my mind any miniscule degradation if any would be well and truly out of any of the more important areas. Trying to decide if I want to go this route or just let my speakers play down and add subwoofers from high level. Are there any particular benefits to either aside from headroom with mains?

My current speakers have no issues with playing with full range signal, just wondering if relieving them from such extensions might improve midrange even more so. Or would a DAC with higher SINAD etc make more of the difference?

Trying to get the absolute best I possibly can quality wise as once it's done, that's it, absolutely final. I will never need to upgrade DAC as it's pretty much just for CD transport, no streaming really at all.

 

[anotherhobby]

Probably a silly question, I'm pretty new to DSP stuff...but does the DSP have noticeable effect on sound quality that anyone has noticed?

Yes, it improves sound quality by applying crossovers in the digital domain and also (should you so choose) by doing room correction (manual or Dirac). I gather you are probably more concerned with the inverse though, so no, it also does not degrade audible sound quality.

I'd be using it to cross to subwoofers, so in my mind any miniscule degradation if any would be well and truly out of any of the more important areas. Trying to decide if I want to go this route or just let my speakers play down and add subwoofers from high level. Are there any particular benefits to either aside from headroom with mains?

My current speakers have no issues with playing with full range signal, just wondering if relieving them from such extensions might improve midrange even more so. Or would a DAC with higher SINAD etc make more of the difference?

Applying crossover to mains does increase headroom and improve mid-range quality, especially if the mains are only 2-way.

 

[plusforce]

If I hook up the subwoofer straight to the miniDSP in a 2.1 speaker setup, I'll get way better room correction than if I connect it directly to the amp?