Review and Measurements and miniDSP 2x4 HD DSP and DAC

[bluefuzz]

My main concern is that the minidsp 2x4 HD would degrade my music via the USB/TOSLINK input, let alone analog

Why would you think that? While the 2x4HD isn't quite 'state-of-the-art' measurement wise it's audibly transparent for actual human hearing for almost any use case. The biggest problems with it is the somewhat janky looks and ergonomics. I have used the 2x4HD for headphone correction with an RPI4 (Moode) USB > 2x4HD > Topping L30. It sounded every bit as transparent as doing correction with CamillaDSP on the Pi and using Topping E30 instead of the MiniDSP.

Currently I'm using the 2x4HD as crossover for LXminis. NAD C658 (analogue out) > 2x4HD > 4 channel Hypex UCD180 amp > LXminis. It sounds marvellous. Yes there is audible hiss if you put your ear to the tweeter but not audible more than 15 cm away. Not a problem. I may one day 'upgrade' to the balanced Flex but that is more for looks and ergonomics. I very much doubt I would be able to actually hear any difference in sound quality for this (or any) use case.

 

[Lawhaus]

Why would you think that? While the 2x4HD isn't quite 'state-of-the-art' measurement wise it's audibly transparent for actual human hearing for almost any use case. The biggest problems with it is the somewhat janky looks and ergonomics. I have used the 2x4HD for headphone correction with an RPI4 (Moode) USB > 2x4HD > Topping L30. It sounded every bit as transparent as doing correction with CamillaDSP on the Pi and using Topping E30 instead of the MiniDSP.

Currently I'm using the 2x4HD as crossover for LXminis. NAD C658 (analogue out) > 2x4HD > 4 channel Hypex UCD180 amp > LXminis. It sounds marvellous. Yes there is audible hiss if you put your ear to the tweeter but not audible more than 15 cm away. Not a problem. I may one day 'upgrade' to the balanced Flex but that is more for looks and ergonomics. I very much doubt I would be able to actually hear any difference in sound quality for this (or any) use case.

Agree.

Janky ergonomics is a good description.

I already shared the problems with the volume control via remote. But now that you mention this. It reminds me, having the optical-in and usb at the front makes no damn sense.

It’s the only ugly cabling cabling in my setup, see pics.

 

[Willem]

I am considering using one to implement Multi Sub Optimizer filters, but do not quite fancy the pedestrian measurements (my DAC is the superb RME ADI-2 DAC and I would connect the minidsp to the rca output of the DAC). Admitedly, this would only be for frequencies below some 80 Hz where it does not seem to matter too much, but even so, something measuring better would appeal to me. For the same reason (and more strongly, given the frequencies involved) I would not want to use it as a high pass filter for the power amp and main speakers (Quad electrostats). Should I bear with it, in the knowledge that for subs the measured quality does not matter much, if at all?

 

[Alexium]

How does the non-HD version compare to the HD? I can't find any measurements of the older unit (which is odd, I'm sure it was measured by many enthusiasts back in the day).
I have an offer of a used great condition non-HD MiniDSP 2x4 for $42, seems like a great price if it were to perform like the HD does, so the question is - how much worse it is. I'm only interested in the analog inputs.

 

[MCH]

Hello team,
Is there a way to know what is the incoming sample rate when using toslink input?
Thanks!

 

[Berkut]

It is 18 dB worse than Topping D50 which puts it around 90. The test was with my old analyzer and I was not computing the SINAD then.

Ok, old topic, new question : I offered a Yamaha R-N402D with a CD-S300 and a NS-SW300 sub along with a pair of Focal Aria 906 to my aunt. She mostly listens to CDs, but occasionally to Internet radios and TV sound.

Unlike the R-N803D tested by Amir, the 402 dos not feature a sub pre-out, its Hi-Z inputs are hooked up to the Speaker B terminals (means I'm driving the Focals full range and just want to fill the very-bottom end with the sub). I have a bump in the room at around 43 Hz, that is I created a new problem that wasn't really there before. Like most Yamys there is a High-Pass tone control at 50Hz, but it not surprisingly just deprives the sub of any juice....

In the digital domain, I use VST3 PEQ plugins in Audirvana to stream Qobuz to the 402, and I can hear a difference (no furniture resonance at higher volumes...), but since my aunt mostly listens to CDs, I was considering the 2*4 HD unit between the CD player and the CD input.

SINAD-Wise down the signal chain :

CD-S303 with its Burr-Brown DAC claims 96dB of Dynamic Range (unsubstantiated)
MiniDsp 2*4 HD 90dB "only", worse when used with analog-RCA ins (as measured by Amir)
Yamaha R-N803D CD input to speaker terminals in "non-CD Direct" is a mere 73dB low (the 402 Model does not have that CD-Direct function which could boost its SINAD closer to the 803 or WXA-50 92dB as measured by Amir).

1) So I guess it all makes sense in this "poor" context (using MiniDSP as a DAC) not losing much down the signal chain, while improving overall sound in the room, would you agree ?

2) Were I then to replace the 402 by an 803 (for the sake of simplicity), and then moving the MiniDSP 2*4HD between the pre-out and the Sub(s), would you agree that YPAO-RSC would do something for the MIDs and Lower Trebbles, while/then the MiniDSP 2*4HD RCA to RCA would not mess-up the Low-End ?

3) I tried to place my RME DAC between the CD player turned transport and the poorly performing 402 and actually heard differences in A/B/C testing (analog CD in; digital in using internal 402 DAC; and Line in from the RME). Was I victim of biases, or is it really so important to keep the incoming analog signal as pristine as possible, even though it is then messed-up by internal noises ?

4) Would you then recommend a straight-in/out DAC between CD and 803 just good enough for RedBook quality that would not be so ugly in this Yamy stack, and not so expensive as to no longer make any sense in this price range (no single component is more than a few hundred euros) ?

5) Would it actually make sense to replace the 402 by an 803 in the first/second place ? That YPAO-RSC installment doesn't do anything in bass management (unlike most recent Yamaha AVRs). Plus, unlike AVRs, you don't know what YPAO is really doing and can't tweak any PEQ on any screen/display (no better served with the pricey R-N2000A "only game in town"). Finally, as measured by Amir, you're no better while streaming to it SINAD-wise...

Anyway, I hope this discussion brings something useful to the table, another discussion would be why is there such a gap in Yamaha's receiver catalogue between the "bluetooth in" only R-S202D (349€) and the R-N2000A (3699€) - part shortages vs profit margins ?- and why the heck room correction/PEQ is a given in AVRs and a premium in Hi-Fi ?

 

[baron-bob]

In Germany there are two company's that offer to upgrade the internals of the 2x4HD. It would be interesting to have them measured.

miniDSP 2x4 HD / DDRC24

Das miniDSP ist bereits ab Werk ein super vielseitig einsetzbares Tool. So bietet es mit seinen zwei Eingängen, sowie vier Ausgängen allerhand Potential, um zum Beispiel mehrere Subwoofer unabhängig von einander anzusteuern und perfekt an den Raum anzupassen. Aber auch zur Entzerrung eines...

www.sweetspot-audio.de

miniDSP 2x4HD

Das miniDSP 2x4 HD ist ein sehr präziser Digital Signal Processor mit 2 Eingängen und 4 konfigurierbaren Ausgängen. Über die eigene PC Software stehen etliche Filter und Anpassungsmöglichkeiten zur Verfügung.

www.authentic-cinema.de

 

[JSmith]

offer to upgrade the internals of the 2x4HD

Not much detail there...

• Improvement 12v DC input voltage
• Improvement entrance level
• Improvement output stage
• Replacement of all operational amplifiers
• RFI measures
• Reducing the noise floor
• Distortion Reduction (THD)

• Stabilization and filtering of the input voltage
• Replacing the standard operational amplifiers
• Replacing the coupling capacitors
• EMI / RFI shielding of various assemblies

Modification description

The processing works very precisely and quickly in the miniDSP 2x4 HD, so our focus is on the other components.
The standard operational amplifiers are swapped for high-end versions from Texas Instruments. The coupling capacitors (capacitors) are replaced with high-quality film capacitors and additionally wired.
The input buffering is replaced by an ultra low ESR capacitor, which is also further filtered with a foil.
The DAC and the clocks are protected against RFI and EMI radiation with a special film.
Thanks to the new operational amplifiers, coupling capacitors and the ultra-stable, filtered input voltage, the DAC can fully demonstrate its audiophile qualities.
The result is a slag-free, open and detailed sound image.
It is ideal to use a 12V linear power supply. (also available from us)

JSmith

 

[milosz]

I'd like to see some well-conducted double-blind studies to see if anyone can actually hear any differences between high quality DACs. I suspect no one can hear these differences. We end up, then, chasing specs for the sake of specs - not audible performance benefits.

However, since DACs that measure extremely well are not all that expensive these days, there's nothing wrong with finding the DAC with the best specs in your price range. After buying such equipment, one needn't worry about replacing the DAC as "better" models hit the market.

 

[Sokel]

I'd like to see some well-conducted double-blind studies to see if anyone can actually hear any differences between high quality DACs. I suspect no one can hear these differences. We end up, then, chasing specs for the sake of specs - not audible performance benefits.

However, since DACs that measure extremely well are not all that expensive these days, there's nothing wrong with finding the DAC with the best specs in your price range. After buying such equipment, one needn't worry about replacing the DAC as "better" models hit the market.

Problem with this 2x4 is not distortion,is noise.
On it's own and far worst when filters applied.and noise can be audible and annoying as it gets amplified down the road.

 

[MCH]

Problem with this 2x4 is not distortion,is noise.
On it's own and far worst when filters applied.and noise can be audible and annoying as it gets amplified down the road.

i am not sure thereis much room for improvement though,
i read in the forum the 2x4hd comes with a dynamic range of 103 dB, and the ak4626 inside specs this....:

 

[Sal1950]

In Germany there are two company's that offer to upgrade the internals of the 2x4HD. It would be interesting to have them measured.

Not much detail there...

If the mods were as extensive as claimed I'd think they should just market their own product?
Sounds like snake-oil to me.
Of course if they're confident they should send one in to be measured.

 

[tjcinnamon]

In Germany there are two company's that offer to upgrade the internals of the 2x4HD. It would be interesting to have them measured.

miniDSP 2x4 HD / DDRC24

Das miniDSP ist bereits ab Werk ein super vielseitig einsetzbares Tool. So bietet es mit seinen zwei Eingängen, sowie vier Ausgängen allerhand Potential, um zum Beispiel mehrere Subwoofer unabhängig von einander anzusteuern und perfekt an den Raum anzupassen. Aber auch zur Entzerrung eines...

www.sweetspot-audio.de

miniDSP 2x4HD

Das miniDSP 2x4 HD ist ein sehr präziser Digital Signal Processor mit 2 Eingängen und 4 konfigurierbaren Ausgängen. Über die eigene PC Software stehen etliche Filter und Anpassungsmöglichkeiten zur Verfügung.

www.authentic-cinema.de

curious how they'd measure on Amir's bench.

@amirm

 

[Sokel]

Is that it's ADC?

HTTP 301 This page has been moved

Cause if it is the limits is already there,I guess they worked with what suited them,it's a handy chip containing 2 channel ADC and six channel DAC.
Not top measurements (in fact it's ADC is far worst than the 20 year old AK5385 where S/N and DR are 114db) but it's cost effective and decent I guess.

I don't think "improved" version will go further than this,a new measurement will be a waste of time.

 

[TheBatsEar]

In Germany there are two company's that offer to upgrade the internals of the 2x4HD. It would be interesting to have them measured.

miniDSP 2x4 HD / DDRC24

Das miniDSP ist bereits ab Werk ein super vielseitig einsetzbares Tool. So bietet es mit seinen zwei Eingängen, sowie vier Ausgängen allerhand Potential, um zum Beispiel mehrere Subwoofer unabhängig von einander anzusteuern und perfekt an den Raum anzupassen. Aber auch zur Entzerrung eines...

www.sweetspot-audio.de

miniDSP 2x4HD

Das miniDSP 2x4 HD ist ein sehr präziser Digital Signal Processor mit 2 Eingängen und 4 konfigurierbaren Ausgängen. Über die eigene PC Software stehen etliche Filter und Anpassungsmöglichkeiten zur Verfügung.

www.authentic-cinema.de

Last year i tried to get one of them to send Amir an "improved" 2x4HD for measurement, i was willing to donate my unused one for that, pay for all the shipping, do all the logistics. As soon as independent measurements before and after where mentioned, the tone changed, it got unpleasant and went nowhere.

The 2x4HD isn't perfect, but it isn't bad either. There is no need to get it blessed by some audiophile Shaman in my opinion.

 

[Sal1950]

In Germany there are two company's that offer to upgrade the internals of the 2x4HD. It would be interesting to have them measured.

Now if they offered Tube based DAC upgrades, now they'd really have something !!!

 

[Sokel]

Now if they offered Tube based DAC upgrades, now they'd really have something !!!

They are probably waiting for the new tubes:

NASA develops speedy vacuum tube prototype for computers in space

Researchers have developed a vacuum tube prototype that is both fast and tough against radiation, making it ideal for computers in space.

www.theverge.com

 

[baron-bob]

Hey folks,

Short introduction to this post: I am not interested in hunting the best measurements for gear just for the sake of the best measurements. For me they are a tool to objectively describe something. Relevant for me is always if the description has practical consequences e.g. if it is audible in the real world by a real person. End of statement.

So, since I'm German and also living there I just piked up the phone today an called the owner of sweetspot-audio Mr Symanowski. I asked him about sending in one of the upgraded 2x4HD for measurement but he declined. Because he would have to buy one for that reason and have to upgrade it and also he don't want to appear as of sending it in only for business reasons. He has his own equipment for measuring and is fully confident in his work. Sounds reasonably to me. I also told him that none the less the community of this forum would be interested in the measurement because of passion for the hobby.

He explained to me in some detail what they are upgrading and for wich reasons, but since this is not my field of expertise I can not repeat it here. But for example they change some capacitors or elkos which cost about 4ct and replacing them with some for 4€. He can not understand why miniDSP makes such decisions relativ to the target group of his products but in relation of production-cost it is attractive for them of course. He also said that the upgrade makes no sense for the use with subwoofers but definitely for the use with speaker-channels and that the known downsides of the ADC/DAC path are solved with the upgrade.

We also talked a bit about my plans for my future home-cinema and that I just bought a used one from the fellow member TheBatsEar and that I probably would send him my own miniDSP in at some point anyway to make a comparisons for my self.

He then made me the offer that I could send him in the one that I just bought and that he would upgrade it for free so that I could send it in here for measurement because I would not need it anyway the next couple months until my HC is finished. I could not refuse that offer and going to do just that in about one or two weeks.

He is a really nice guy I think and sounded very trustworthy and honest to me. We had a pleasant conversation between audio enthusiasts. I'm curious about the measurements to but I would also just take his word for the quality of his work and that the upgrade is within reason and no snake oil.

 

[rvsixer]

He then made me the offer that I could send him in the one that I just bought and that he would upgrade it for free so that I could send it in here for measurement...

Thank you for understanding how getting devices tested here works, and going through the effort to make it happen (as in no amount of wishing or requesting others to do the work for them will make it happen). Much appreciated, this should be an interesting one...

 

[Ron Texas]

Problem with this 2x4 is not distortion,is noise.
On it's own and far worst when filters applied.and noise can be audible and annoying as it gets amplified down the road.

In that case the noise will not be audible with low efficiency speakers at typical listening distances.
I have one of these on the way.
If there is a limitation it is in the number of available taps. Some users want 15 filters. I'm not so picky.