Review and Measurements of miniDSP SHD DAC, DSP And Streamer

[amirm]

@amirm, have you managed to resolve this ridiculous problem?

Yes, the company provided the software and Dirac to me. That is how I did the last set of tests with Dirac in and out of the loop.

I hope to do a proper Dirac test/review on it at a later date.

 

[Olli]

Amir - is there any feedback from Mini DSP on the jitter issue meanwhile?

 

[amirm]

Amir - is there any feedback from Mini DSP on the jitter issue meanwhile?

No, I didn't hear anything back. I think that is just what it does.

 

[nick-v]

Any idea when you'll perform a more in-depth review?

I'm thinking of selling my Wyred4Sound STP-SE preamp and my miniDSP DDRC-22D and switching over to the SHD.

I want to use the integrated crossover and time-alignment to better integrate my stereo subwoofers with my mains.

Also, based on the measurements, I'm thinking it's worth considering using the XLR outputs from the SHD only for my stereo Rythmik FM-8 stereo subwoofers, and keeping my Esoteric-SA 50 as the DAC for the high passed digital output instead of using the internal DAC's for the mains?

 

[amirm]

Any idea when you'll perform a more in-depth review?

Probably not for a bit as I have a lot of stuff that has been waiting.

What test were you looking for anyway?

 

[gingerbeer]

Anyone got some pictures of the insides?

Curious how much empty space etc as already dreaming up mods as the i2s ports are apparently exposed (inbound and outbound)

 

[amirm]

A couple of other measurements before I send the unit back.

First, testing S/PDIF input and Balanced output to see if jitter changes:

As noted on the graph, the response is almost identical. So this is intrinsic to the unit and internally generated noise and jitter interference.

 

[amirm]

And Balanced dashboard view:

This is still quite good but about 3 dB worse than unbalanced.

 

[nick-v]

Do you think the measured jitter would change using the S/PDIF output into an external DAC?

I'm considering selling my Wyred4Sound STP-SE preamp and miniDSP DDRC-22D (mostly for the DSP crossover functionality between my 3-way monitors and subwoofers).

Just wondering if I use the internal DAC in the SHD for the low-passed subwoofer ouptuts, but the S/PDIF output into my Esoteric SA-50 for the high-passed output to my 3-way monitors if I could expect better performance (than just using the converters and analog section in the SHD)?

The Esoteric SA-50 has a two-stage PLL reclocking circuit to reduce jitter from external sources and a dual mono differential implementation of the AK4392 chip.

 

[amirm]

Do you think the measured jitter would change using the S/PDIF output into an external DAC?

Sure. But surely there are lower tier products if you don't need the DAC, no?

Also, I don't think the jitter is an audible concern. Their levels at -120 dB or so.

 

[Olli]

Great review, thanks a lot, Amir!

 

[gingerbeer]

Is there any benefit/insight in measuring the digital outputs or Dirac? (Ie what the shd studio will have)

I’m assuming the jitter measurement in post #87 is from spdif in to balances analog out?

Thank you for all the measurements to date - very interesting!

 

[Synergist]

I know I am coming rather late to this game/thread...however, I am a "mature" audiophile...who has been indulging in this art and science for 30+ years...and would like to venture into the digital signal processing universe in the reasonably near future...(before my hearing acuity deteriorates to the extent that DSP will be inaudible to me...lol...)...

I am very much interested in possibly integrating a miniDSP SHD Studio into my system, in order to improve upon room/listening position frequency balance, as well as group delay and general phase issues between my stereo monitors and my subwoofers...HOWEVER, I do not wish to toss out the baby with the bathwater so to speak...(reduce the quality of the system sound in general...)

System basics:
Monitors: Audience - ClairAudient 1+1 series 2+, (crossover-less, dual, full-range drivers arranged in bipolar arrangement with dual, side-firing/"bipolar arrangement" passive radiators, 50 Hz - 21 kHz )...
Subwoofer pair: JL Audio - Dominion D108's, (8 inch forward firing active sub, approx. 31 - 112 Hz (±1.5dB)
Crossover: Marchand Electronics - XM44-2, (X-over set at 60Hz., 24 dB/octave) single-ended and balanced inputs/outputs...)
Digital to Analog Converter: Schiit Audio - Yggdrasil, (24 bit/192 Khz., single-ended and balanced outputs, SPDIF on RCA connector & AES-EBU on XLR connector inputs...)
Pre-Amplifier: Schiit Audio - Freya, (Selectable single-ended or balanced ended...)
Amplifier: Aragon 4000, (Stereo, Single-ended inputs)
Digital inputs (only): OPPO CD Player & USB/SPDIF output (via Schiit Audio EITR converter) from laptop internet music stream)

As I have a modest, but reasonably high resolution system, I wish to enhance the overall sound by better integrating the subwoofers with the stereo monitors, as well as the speaker "system" with the room itself...
I would plan on placing the SHD Studio between my digital signal sources, and my D/A converter, HOWEVER, in order to properly time align my subs, (18 millisecond group delay) with my monitors, (essentially 0.0 millisecond group delay), I might need to utilize the X-over function of the SHD Studio, (circumventing both my Marchand X-over...AND my Schiit Audio Freya pre-amp...???...)...

If the above is the only way to utilize the crossover feature in the SHD Studio, would I be doing my system sound MORE harm than if I just left utilized the downstream Marchand analog X-over...?...accepting the 18 millisecond group delay between the main speakers and the subwoofers?

I appreciate any and all input, as well as your patience in assisting a "newby"...

Peace/Namaste,
Synergist

 

[JaySlice]

I am wanting to buy one of these units to put between my source and my dac. Will this unit do great justice in that pursuit? I love room correction but hate being bound to the hardware that is coupled with it e.g. preamp, dac, amp, etc. So I am hoping more devices can take digital, room correct, then send out to whatever DAC of my choice. I suppose even a source with a remote that does room correction then digital out would be amazing too.

 

[Bamyasi]

I have tried to find the answer on miniDSP website but failed since there is no implementation details to be found anywhere inside their documentation. I still do not understand how it works and what Amir has actually measured? miniDSP claims SHD uses AK4490 for digital to analogue conversion but this is a 2-channel chip and SHD has 4 independent analogue outputs. Also, other products from miniDSP like their DDRC-24 processor have two chanels of digital input, Dirac Live and 4 channels of analogue output as well and no mentioning of a separate DAC at all. I am assuming the conversion is done in the DSP for all channels in this case. So what would be the role of AK4490 in the SHD (other than a marketing ploy)? Amir, can you tell which output channels you've measured, 1&2 or 3&4?

 

[Deleted member 2944]

Obviously two AK4490 DAC's.

miniDSP does not provide schematics nor detailed information of the internal architecture of their products. Users who feel they need more "audiophile" type information in this regard, will be disappointed.

All four outputs can be programmed in whatever fashion you like in the routing matrix and for DSP parameters. Amir tested the system with the DSP functions set for no processing so as to characterize as simple a configuration as possible. I suspect he measured outputs 1/2, but outputs 3/4 would measure the same.....if configured the same.
FYI, the inherent latency of this unit is about 25mS regardless of whether Dirac Live is engaged or not. If incorporating this unit into an HT system that would need to be understood.

It's a fine unit......albeit very expensive.

Dave.

 

[Bamyasi]

Obviously two AK4490 DAC's.

Well, their documentation and the description on their web page are very careful in not mentioning anything that could point to the number of DAC chips used, so however obvious it is, it might still turn up not being true.

miniDSP does not provide schematics nor detailed information of the internal architecture of their products. Users who feel they need more "audiophile" type information in this regard, will be disappointed.

I do not think a person who wants to know what he is paying for is necessarily an "audiophile". I do not count myself as such, especially considering my current system value is well under $1,500 However, miniDSP products documentation sounds rather vague on many occasions and since they list tons of hardware on their website, it makes it really hard to choose the one that fits your needs. ASR forum, and Amir's reviews in particular, were instrumental in my recent pursuit of better upgrade options but Amir tend to be overly compendious at times. I understand he has more interesting things to do than spend his whole life posting on ASR, so I am not complaining.

All four outputs can be programmed in whatever fashion you like in the routing matrix and for DSP parameters. Amir tested the system with the DSP functions set for no processing so as to characterize as simple a configuration as possible. I suspect he measured outputs 1/2, but outputs 3/4 would measure the same.....if configured the same.
FYI, the inherent latency of this unit is about 25mS regardless of whether Dirac Live is engaged or not. If incorporating this unit into an HT system that would need to be understood.

Good point, I did not think about the delay, thanks for the hint. The plan is to use it for correcting my 2.1 hi-fi system though, no TV set here and no plans to get one any time soon.

It's a fine unit......albeit very expensive.

Yeah, I am also undecided since the price is a bit steep and it includes many components that I do not actually need (like the network streamer which I already have) but otherwise it looks very attractive.

 

[Juhazi]

^I and many others are very happy with just the modestly priced minidsp 2X4HD, which would suit your needs with a 2.1 system well. It doesn't support Dirac, but do you really need that? Pretty normal manual IIR PEQ works well, and it understands FIR too. With REW and eg. rePhase you can semi-automatically create filter settings and have same effects as Dirac.

 

[Olli]

FYI, the inherent latency of this unit is about 25mS regardless of whether Dirac Live is engaged or not. If incorporating this unit into an HT system that would need to be understood.
Dave.

Anything one can do about the latency in a HT set up?

 

[Deleted member 2944]

Well, their documentation and the description on their web page are very careful in not mentioning anything that could point to the number of DAC chips used, so however obvious it is, it might still turn up not being true.
.

Would that fact that I've actually seen two AK4490 chips inside my own unit convince you?

My goodness.

Dave.