Review and Measurements and miniDSP 2x4 HD DSP and DAC

[jjk]

If you are using the 2x4 or the 2x4HD strictly for EQ of the subwoofer channel (I have 3 subs), does the low SINAD matter much below 200 Hz?
Alternatively, if you were to copy the sub channel in JRiver to the unused channels (unused 7.1 channels in a 5.1 system) and connect an extra dac would there be a noticeable increase in subwoofer fidelity?
Thanks.

 

[ernestcarl]

thats Odd, I have the khadas and a few other DACs and the Minidsp 2x4 always sounds pretty awful compared to not using it. Even with the DSD engaged it still sound better without it in the chain.

How is it 'awful' exactly? Are you talking about the 2x4 or 2x4 HD? Can this 'awfulness' in comparison to other DACs be at least realistically described or more precisely be quantified?

I've had issues with the 2x4HD's input gain wreaking audible havoc on louder high frequency transients (likely clipping), so I just don't raise its input gain now, but adjust elsewhere. Other than that, I have not noticed any major awfulness worth writing home about.

 

[ernestcarl]

If you are using the 2x4 or the 2x4HD strictly for EQ of the subwoofer channel (I have 3 subs), does the low SINAD matter much below 200 Hz?
Alternatively, if you were to copy the sub channel in JRiver to the unused channels (unused 7.1 channels in a 5.1 system) and connect an extra dac would there be a noticeable increase in subwoofer fidelity?
Thanks.

Likely not. Do some of your own testing. But I wouldn't lose sleep over it.

 

[mieswall]

Hi, new here.
After extensively measuring my room with the umik-1 mic and REW, I was enthusiastic about trying these minidsp devices. But this is not a simple hardware to buy, as there are so much options to choose from. I had to study a fair amount of documents in order to decide which one to buy, until deciding to go for this 2x4HD. Anyway, a nice, entertaining gadget.
Before using the EQ features, though, I tested its sonic performance as a plain DAC device. And I'm a bit shocked on its harshness (and even a bit bass shy) compared with both my Emotiva Stealth DC-1, or even an old Ayre QB-9 that I normally use. Could this be explained by the poor measurements of sine waves you reported? I've tried many dAC's before in my system, and this one is by far the one that I gave me instantly perceivable differences in sound, and not for the better. Not totally unlistenable, but certainly a bit annoying.
That said, once you start playing with the PEQ features, you can completely change the sound signature. For example, just a slight low-shelf equalization in the bass region of inputs (the two inputs channels and 4 outputs channels can be EQed independently), and the sound is magically transformed. Just starting my experiments with this, though. Anyway, I'm wondering if a) this base underperformance of the DAC does worth the effort of trying extensive EQ, b) go for the upgrade software upgrade of Dirac support, or c) just forget about all this EQ thing and keep my current plain DAC. Any comments would be appreciated.

 

[ernestcarl]

Hi, new here.
After extensively measuring my room with the umik-1 mic and REW, I was enthusiastic about trying these minidsp devices. But this is not a simple hardware to buy, as there are so much options to choose from. I had to study a fair amount of documents in order to decide which one to buy, until deciding to go for this 2x4HD. Anyway, a nice, entertaining gadget.
Before using the EQ features, though, I tested its sonic performance as a plain DAC device. And I'm a bit shocked on its harshness (and even a bit bass shy) compared with both my Emotiva Stealth DC-1, or even an old Ayre QB-9 that I normally use. Could this be explained by the poor measurements of sine waves you reported? I've tried many dAC's before in my system, and this one is by far the one that I gave me instantly perceivable differences in sound, and not for the better. Not totally unlistenable, but certainly a bit annoying.
That said, once you start playing with the PEQ features, you can completely change the sound signature. For example, just a slight low-shelf equalization in the bass region of inputs (the two inputs channels and 4 outputs channels can be EQed independently), and the sound is magically transformed. Just starting my experiments with this, though. Anyway, I'm wondering if a) this base underperformance of the DAC does worth the effort of trying extensive EQ, b) go for the upgrade software upgrade of Dirac support, or c) just forget about all this EQ thing and keep my current plain DAC. Any comments would be appreciated.

Dunno where the harshness you mean comes from. Have you checked all individual settings? Perhaps something is set incorrectly. Are you using the SPDIF, USB, or Analaog input? Check your gain staging etc. DACs by themselves should not add any flavour/coloration/smoothness/harshness unless such were engineered badly. "Magically" enhancing the audio signal is a job appropriately designated to DSP/EQ.

 

[jjk]

I agree with the harshness comment.
I believe it is the performance of the 2x4 HD DAC. This is backed up by Amir's measurements.
I was using the 2X4 HD as an office DAC but it replaced with the new Topping DX7 Pro. Huge difference. Also backed up by ASR measurements.
Now using the HD as a subwoofer EQ/DSP only, in my main system. Although I wonder if that performance is "sub"-standard as well.

 

[ernestcarl]

I agree with the harshness comment.
I believe it is the performance of the 2x4 HD DAC. This is backed up by Amir's measurements.
I was using the 2X4 HD as an office DAC but it replaced with the new Topping DX7 Pro. Huge difference. Also backed up by ASR measurements.
Now using the HD as a subwoofer EQ/DSP only, in my main system. Although I wonder if that performance is "sub"-standard as well.

Interesting. I don't share this experience. What is this "huge difference"? It could partly be due to unit variance, your device chain etc. Just throwing out some possibilities. I have used other more expensive DACs before, and I have not noticed a "huge difference". You have to help elucidate better what and where this harshness comes from... Under most normal use case conditions the noise and distortion should be low enough to be inaudible -- in fact, most DACs tested here do. There must be some other variable unique to you here that makes you hear things many other people just do not. Maybe it's my (and others') ears that are applying auto "smoothness" to an otherwise harsh sounding, cheap DAC. I suppose we can call that sort of biological self-DSP, if such a thing even exists.

*I've had the issue before of one memory setting slot in miniDSP going glitchy. When loaded with the exact same configuration file, it gave different results e.g. crossover, delays etc. and measured output. Loading the same config to other slots gave different results. I reset the device twice. The glitch/possible memory corruption has since disappeared.

 

[jjk]

Thanks for the lecture on elucidating.
I'll just let Amir elucidate with the measurements.
Out.

 

[ernestcarl]

Thanks for the lecture on elucidating.
I'll just let Amir elucidate with the measurements.
Out.

I am not dismissing your claims as nonexistent. As I said, other variables could be at play. That's why I asked. Many, many people here use the miniDSP products, including the 2x4HD with fairly expensive speakers, and with no noticeable sonic "harshness" experienced. I believe MKZM mentioned he uses it on $4,000 speakers. I use it on my KH120s. If there is indeed a "huge difference" in sonic performance, then it is something current owners like us need to know. Are we actually compromising our speaker system with the use of such a product. Should we ditch our 2x4HD for something substantially better deserving of our own ears and speaker system?

Amir has measured many underperforming DACs -- many times he says that the noise and distortion should be inaudible, or is actually inaudible when doing listening tests. Usually, only the worse of the worst devices bear out actual differences on his listening tests. As I noted on my *postscript, things can go haywire with hardware/software combos.

 

[ernestcarl]

I don't have the Topping DX7 Pro on hand to compare, but here's a visual comparison between the Topping D10 and 2x4HD measured frequency response output to the KH120 & Rythmik F12.

The slope in the bass in this image looks rather severe (already have had this shelved down more with EQ), but this is actually zoomed in close. You can see an overall ~2dB difference in the slope between the two plots. Here, the difference of ~2dB is, yes, audible. The Topping is brighter than the 2x4HD. We can easily modify the curve via DSP to match. Neither to me sounds harsher, and can be approximated to sound the same via broad tone-controls/curve adjustments via DSP. Step response, impulse, distortion etc... coming out from the drivers in my MLP are close to identical. Only with a digital microscope zoomed-in super close would I even have noticed huge variances.

 

[Deleted member 2944]

You should have identical frequency responses there. Regardless, if you're looking for relative differences between DAC's you should measure them electrically not via your speaker systems with acoustic measurements.

"Harshness" is a subjective term. There's no way to reconcile that to any particular objective measurement.

Dave.

 

[ernestcarl]

I agree that it is indeed the best way to measure differences of DACs. This is just what I had already at hand. Nevertheless, this was taken at the same date and time, no movement of microphone and setup other than switching DACs with a switcher. It really is almost identical, other than the mild tilt -- which again can be DSP'd to flat perfection if one so wishes

 

[BDWoody]

I agree with the harshness comment.
I believe it is the performance of the 2x4 HD DAC. This is backed up by Amir's measurements.

Which of his measurements do you believe back up what you are hearing?

 

[mieswall]

Which of his measurements do you believe back up what you are hearing?

Perhaps the crude sine wave of the measurements?
Ernestcarl: I'm far from expert in this area, but I've used several DAC's in the past months in my system, going from Apple Express internal DAC- surprisingly good-, up to Ayre, Hugo and RME, and while in fact there aren't "huge" differences, there are definitively some noticeable ones (ranking from very noticeable ones in some cases, almost inexistent in others). Among them, and leaving aside a couple of very cheap headphone DAC's I've tried, sadly the worst performer has been the 2X4HD. I would describe the sound footprint as like comparing a class-A to a class-D amp (i.e: a bit cold and harsh). That said, I'm quite happy with the device. That base underperformance can be completely modified with proper EQ, that is easy to do with the 2x4HD.

 

[Deleted member 2944]

That base underperformance can be completely modified with proper EQ, that is easy to do with the 2x4HD.

How, exactly, are you doing that???

Dave.

 

[mieswall]

How, exactly, are you doing that???

Dave.

No, sorry, no proper advice from here. I'm new in this PEQ thing. I'm also having some interface troubles with the UMIK-1 and REW in a Mac mini with Mojave, so I can't give you a full answer about EQ for the moment (I think the problem may be with REW beta 28; with beta 27 in a MacBook Air I have no issues, but my system is normally using the mini).
Anyway, as an example, I'm trying a simple boost of 3db at the input channels (low shelf @200 hz, gain 3db, Q:0.7), and the result is beautiful, that I previously couldn't achieve just tuning the SW (with my modest system: KEF LS50's monitors driven by a Densen DM-10 amp and a KEF Kube 12b SW, with crossover @75 Hz and very small gain).

 

[BDWoody]

Perhaps the crude sine wave of the measurements?

uh huh... I suppose it is easy to look at a scary looking graph and hear scary sounds...

 

[mieswall]

uh huh... I suppose it is easy to look at a scary looking graph and hear scary sounds...

In fact: because I heard the scary sound first is that I searched for articles and found this review. Much later than hearing that.

 

[ernestcarl]

Perhaps the crude sine wave of the measurements?
Ernestcarl: I'm far from expert in this area, but I've used several DAC's in the past months in my system, going from Apple Express internal DAC- surprisingly good-, up to Ayre, Hugo and RME, and while in fact there aren't "huge" differences, there are definitively some noticeable ones (ranking from very noticeable ones in some cases, almost inexistent in others). Among them, and leaving aside a couple of very cheap headphone DAC's I've tried, sadly the worst performer has been the 2X4HD. I would describe the sound footprint as like comparing a class-A to a class-D amp (i.e: a bit cold and harsh). That said, I'm quite happy with the device. That base underperformance can be completely modified with proper EQ, that is easy to do with the 2x4HD.

I have no doubt that at the final output stage that incorporates any DAC(s), there will be some small differences.

If it can be proven that the 2x4HD is making my monitors sound cold and harsh, then by all means, post such objective test findings.

But it's easy to say a device "sounds" harsh, cold, neutral, boring... what's harder is actually showing us all in a public science forum how and why that may be the case, compared to all the other devices you may have used in the past.

This reminds me of the recent video by Zeos on the Neumann KH80... he said the Neumanns weren't to his and his friend's aesthetic taste. Technically, as a speaker, he could not point to any flaws -- other than the apple connectivity issue. But he does not ever see using these speakers for listening to music. Maybe working with music, but not for listenig and relaxing/enjoying music. So what exactly was the issue? They are clinical and cold? Neutral and boring? Maybe the industrial/utilitarian design? Technically perfect, but unuseable to a regular joe, Zeos? If one were complaining about the narrow directivity waveguide and its effects on room dispersion, I can see and understand that point of view. If one were complaining about not having the equipment and know-how for using the monitors as network connected speakers/app problems etc., then I would understand the precise issue. These are marketed as studio monitors for professional use after all.

While I wasn't much surprised by the lack of depth in his review, this is not useful to us people who own Neumann monitors. I listen to hours on end daily with these monitors. They are neutral, as neutral monitors should be. I apply a curve with DSP, xo etc., as should be, to taste. Room correction can be applied to taste as well, and because they are neutral, not a whole lot has to be done/corrected. Save your configs, load/apply your configs.

But somehow, to an audiophile, such and such device is not suited to listening to music at home. Why, because they have class D amps... because of their form factor, cheap remote etc. Honestly, while I value objective information of a DACs performance to a degree S/N ratio etc., subjective valuations/devaluations of their "sonic character" aren't a whole lot useful to already satisfied users. If there is a flaw causing issues -- thereby surely degrading audible sound quality -- it would be better if qualifying measurements could be posted proving it to be as such. They are always welcome.

I've been itching for an upgrade to the okto dac8 anyway... so prove this case, and we can all be happy.

 

[mieswall]

For the record: I'm not saying I don't like the 2x4HD. In fact, I'm saying quite the opposite: I do like what it results from it when applying some PEQ.

The only "proof" I can, not provide but speculate, is in this same review: a terrible wave reconstruction, noticeable worse than most other reviews from Amir I've seen. I guess some audible distortions are not visible from standard measurements, or I can't explain this "slight" misbehavior of the 2x4HD (that, btw, the more I listen to it, the less it disturbs me).

Btw, there should be a reason for this device to be much cheaper than other similar products of Minidsp: I believe its DAC chip is even discontinued (I can't find it in the manufacturer's web), while the SHD uses one of the best ones by the same supplier. Even so, I didn't know a thing about this (chip used, poor sine wave, etc), when I found it underperformed my two other DAC's. Neither (I think) I'm influenced by the form-factor or built quality: in fact, I find it very cute; the less it shows, the better in my view (although a source selector, a volume knob and a little screen showing what going on would be nice). Neither I like a coloured presentation: I hate that common flaw of speakers exaggerating bass, for example; I felt in love with my LS50's (that replaced some theoretically much better transducers I previously had) because I found them very neutral, transparent and holographic, when properly positioned in the room. Nor I'm influenced by price: the $3000 Ayre QB-9 sounds to me almost identical to the badly reviewed $500 Emotiva I use. It was BECAUSE I found the 2x4HD wasn't performing as nice as my other DACs that I started searching about this, and that I knew about this review.