miniDSP 2x4 HD Sweetspot-audio Mod Review

[ZolaIII]

There never whose more unified voting then regarding this one. Seams it deserves other panther the one with piggy bank.

 

[wwenze]

Maybe a bit of points for the more expensive components. When I was a boy I too used to believe expensive components e.g. film caps instead of electrolytic = better sound.

 

[AdrianusG]

The covid issues probably have made hifi manufacturers create worst and more worst products.

I don't see how covid issues and measures would or could be related to capable or lack their-off engineering.
that's no excuse to make a product which is "barely"good enough worse.

 

[amirm]

@amirm can you tell if the stock unit you measured was the older or newer version? Someone posted a few days ago measurements of the newest version of the 2x4HD that show slightly better results (Sinad >100db iirc) it would be good to have a side by side comparison or that the OP post his results here as well.
PS: thanks for revisiting this classic. They should give one to every student in audio enthusiasts schools


edit: here it is:
Thread 'miniDSP 2x4 HD (DDRC-24) V2 simple measurement and teardown pictures' https://audiosciencereview.com/foru...mple-measurement-and-teardown-pictures.50900/

Mine is 3 to 4 years old.

 

[Chagall]

My observation has been that companies are using that as an excuse to market even lower quality at an ever higher price to the customer. Covid is over.

This is a bit of a generalization. Products that came out during covid were in development much earlier, in some cases by years. Some of those products were not good, some were. In the last couple of years (post-covid) everything got more expensive because of various factors (transportation fees, inflation, wars and uncertainty) but some of the best stuff also came out. No legit company wants to make a bad product and ultimately shutdown. There is no conspiracy, but companies want to make money, that is just reality.

 

[pogo]

I can simulate 50 Hz 240v but I think it will be waste of time.

This can be used to simulate the supply voltage, but certainly not the other typical users/interferers, e.g. in Germany, such as data exchange via the power grid, ....

 

[DrCWO]

Oh my God

Money for nothing

 

[Dennis_FL]

But how they have managed to make it worse?!

Good question. If they just replaced some components with better ones.

 

[amirm]

This can be used to simulate the supply voltage, but certainly not the other typical users/interferers, e.g. in Germany, such as data exchange via the power grid, ....

You forgot that the weather is different too.

 

[wwenze]

Good question. If they just replaced some components with better ones.

People with oscilloscopes have measured worse noise results from their SMPS when they replaced the capacitors with even lower ESR ones. It is simply not easy to predict the outcome of the whole system by changing one part.

What does better mean anyway? LM4562 is better than NE5532 but has twice the current noise.

 

[peng]

Mine is 3 to 4 years old.

Amir, my concern with the 2X4 HD has been their 2 V maximum specification. Any chance you can measure it at higher voltage? If you are concerned about 4 V being risky, how about 3 V, or even 2.5 V. Most people probably use it with their AVR's sub outs, and 2 V maximum really is not a great spec at all for such applications, yet people don't seem to have issues. Either they do have issues but not aware of it, as in the deep bass range, high distortions level may not be very noticeable. Or the 2 V max spec is a very conservative one, that it actually can do much better.

Thanks in advance.

 

[Killingbeans]

But how they have managed to make it worse?!

By making changes and "verifying" only by ear

 

[Sokel]

Amir, my concern with the 2X4 HD has been their 2 V maximum specification. Any chance you can measure it at higher voltage? If you are concerned about 4 V being risky, how about 3 V, or even 2.5 V. Most people probably use it with their AVR's sub outs, and 2 V maximum really is not a great spec at all for such applications, yet people don't seem to have issues. Either they do have issues but not aware of it, as in the deep bass range, high distortions level may not be very noticeable. Or the 2 V max spec is a very conservative one, that it actually can do much better.

View attachment 339285

Thanks in advance.

2V is the standard unbalanced output voltage for consumer devices and it seems they made this way.
What's on the high side though is its output impedance at 560 Ohm,such devices are usually at the 50-100 Ohm range.

 

[HarmonicTHD]

This is a review and detailed measurements of the miniDSP 2x4 HD as is, and as modified by German company sweetspot-audio. Later version was kindly provided by a member and costs US $191 (EUR 175) on top of the cost of the 2x4 HD ($225).
View attachment 339205
As you see, the main indication that the 2x4HD has been modified is their sticker. This is what the company says they modified:

Scope of modification:

• 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)

Total changes: 21

The 2x4 HD was one of the earliest measurements I had made with my older analyzer. So let's first update that with a handful of new measurements.

miniDSP 2x4 HD Measurements
We start with our dashboard:
View attachment 339207
We are just there as far as performance (all tests use Toslink input), clearing the 16-bit audio hurdle by a hair. Such is the case with dynamic range as well:
View attachment 339208

Jitter test shows some harmless interference:
View attachment 339209

IMD sweep shows that noise floor could be lower:
View attachment 339210

Wideband THD+N vs frequency shows rather poor performance:
View attachment 339211
It could be due to filtering (did not measure).

miniDSP 2x4 HD with sweetspot-audio mod Measurements
Note: I used the US power supply that my minidsp came with. The one supplied has the same rating but has European plug. I don't think this is something that is upgraded.

Let's go back to our dashboard:
View attachment 339212
Well, this is not good. We lost 6 dB of SINAD performance which we could ill afford. The cause is increased noise:
View attachment 339213

Same story continues through the rest of measurements:
View attachment 339214
View attachment 339215

Clearly there is no reduction in noise or distortion as company claims.

Conclusions
Focusing on sweetspot-audio modifications, seems like you are paying a lot of money (almost the cost of 2x4 HD) only to get worse performance! Owner has indicated that he measures. If so, very strange to get the results we are seeing.

The 2x4 HD seems to have just good enough performance. Company makes higher end products with much better performance so if that is what you want, getting one of those would be a better bet than going with the above mod.

Needless to say, I can't recommend the sweetspot-audio modifications for miniDSP 2x4 HD.
------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Thanks for continuing to expose products which do nothing or even making things worse while charging money. There is a word for those products and such companies ….


Piggy bank panther would have been my vote.

 

[peng]

2V is the standard unbalanced output voltage for consumer devices and it seems they made this way.
What's on the high side though is its output impedance at 560 Ohm,such devices are usually at the 50-100 Ohm range.

Agreed, but I remember reading some (don't remember which ones but will try to search and link) of the AVRs/AVPs specs that show the subwoofer outputs have higher rated/or maximum output voltage so I thought it may be better to have the minidsp capable of up to 3 to 4 V. Just because the unofficial standard is 2 V, does not mean the maximum should be limited to 2 V.

 

[Sokel]

Agreed, but I remember reading some (don't remember which ones but will try to search and link) of the AVRs/AVPs specs that show the subwoofer outputs have higher rated/or maximum output voltage so I thought it may be better to have the minidsp capable of up to 3 to 4 V. Just because the unofficial standard is 2 V, does not mean the maximum should be limited to 2 V.

In that case they should also spec the input clamp voltage (haven't look)*
Cause if that's the case with sub outputs it's input should be capable too and the output would be the least of our concerns if it's not.

Edit: I obviously talk about it's 2in/4out voltages which it's not how Amir measured it (he used Toshlink)
*Edit 2: it's input can receive 2or 4V,switchable but can only output 2V,I checked.

 

[HarmonicTHD]

…. Just went to their website. They even provide a so-called Tuning Certificate stating that the device has been improved. If I were a customer I would sent back my purchase and demand my money back according to their two year warranty.

From what I see apparently they are unable to test any of their work, so all the other mods they of at best work by chance. But likely do nothing or make things worse. I’d call that a scam.

 

[FrantzM]

Another One Bites the Dust

Thanks Amir

Peace

 

[Multicore]

What a curious story. How do the mods cause these performance differences? Are we sure it's the mods that explain them? What did Sweetspot-audio measure as differences?

So many questions

 

[JustJones]

I always find it amusing no matter how lousy something measures there's always a few great votes. I could see not terrible or maybe fine but great?