• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Minidsp SHD Review Updated (DSP, DAC & Streamer)

aschen

Member
Joined
Feb 3, 2021
Messages
92
Likes
86
Is there anything I can do to effectively increase the gain er volume on the toslink input only? I use my shd with a bryston 4b3 set to high gain (29dB).

With analog in from my phono pre, and spdif from my source the volume range is fine, leaving that 10dB headroom for dirac. I also use toslink from my tv for my routine Tiny desk concert binges. I routinely run out of volume here listening at -5dB sometimes. Anything I can do in the software for this? I "think" the dirac clipping is not an issue since the toslink level must be way below 0dB but my understanding of this stuff is high level.
 

BossBunos

Active Member
Joined
Oct 17, 2021
Messages
123
Likes
140
Can someone explain to me why it is there is a 112db sinad in the dashboard at 4V but when the sweep is done (second graph) the sinad at 4 volts is more like 90? And the best sinad is at 3.7v
 

mdsimon2

Major Contributor
Forum Donor
Joined
Oct 20, 2020
Messages
2,477
Likes
3,315
Location
Detroit, MI
Can someone explain to me why it is there is a 112db sinad in the dashboard at 4V but when the sweep is done (second graph) the sinad at 4 volts is more like 90? And the best sinad is at 3.7v

I can’t quite tell but it looks like there may only be data points at 3.75 V and 4.25 V and the line is just linear interpolation between them.

Michael
 

RichB

Major Contributor
Forum Donor
Joined
May 24, 2019
Messages
1,946
Likes
2,611
Location
Massachusetts
Is there anything I can do to effectively increase the gain er volume on the toslink input only? I use my shd with a bryston 4b3 set to high gain (29dB).

With analog in from my phono pre, and spdif from my source the volume range is fine, leaving that 10dB headroom for dirac. I also use toslink from my tv for my routine Tiny desk concert binges. I routinely run out of volume here listening at -5dB sometimes. Anything I can do in the software for this? I "think" the dirac clipping is not an issue since the toslink level must be way below 0dB but my understanding of this stuff is high level.

There are input and output gains but they are DSP volume controls, so I don't see how they will help.
You might want to ask this question on the MiniDSP forum.

- Rich
 

jlock438

New Member
Joined
Apr 27, 2022
Messages
2
Likes
0
Hello everyone. Long-time lurker, first-time poster. I recently bought a SHD processor based largely on this thread. It's a great unit, but I've had a difficult time with Dirac Live. I was able to get through the calibration process one time, but most of the time I've tried to do this, the software gives me the dreaded low signal to noise error. I've turned off my fridge, radon system, even the air circulation fan on my furnace. I've run the calibration when other people in house are gone and/or quiet. The lowest level that I can turn down the microphone gain to (and still have a reasonable, less than deafening output level) shows background noise of -53 dB in the Dirac software. (This equates to a gain setting of 94 dB.) Is this background noise level still too high? Seems like I'm missing something, despite watching several Dirac videos on YouTube, exchanging messages with MiniDSP, and reading this forum. Any recommendations from this group on reliably getting through the calibration process would be greatly appreciated.
 

Audiomn

Member
Forum Donor
Joined
Apr 27, 2022
Messages
61
Likes
51
Hello everyone. Long-time lurker, first-time poster. I recently bought a SHD processor based largely on this thread. It's a great unit, but I've had a difficult time with Dirac Live. I was able to get through the calibration process one time, but most of the time I've tried to do this, the software gives me the dreaded low signal to noise error. I've turned off my fridge, radon system, even the air circulation fan on my furnace. I've run the calibration when other people in house are gone and/or quiet. The lowest level that I can turn down the microphone gain to (and still have a reasonable, less than deafening output level) shows background noise of -53 dB in the Dirac software. (This equates to a gain setting of 94 dB.) Is this background noise level still too high? Seems like I'm missing something, despite watching several Dirac videos on YouTube, exchanging messages with MiniDSP, and reading this forum. Any recommendations from this group on reliably getting through the calibration process would be greatly appreciated.
Which input do you have your mic connected to? The usb a on the minidsp doesn’t work for measurement. I had the same issue you did until I plugged in to my mac’s input.
 

jlock438

New Member
Joined
Apr 27, 2022
Messages
2
Likes
0
@
Which input do you have your mic connected to? The usb a on the minidsp doesn’t work for measurement. I had the same issue you did until I plugged in to my mac’s input.
I have the mic plugged into a USB jack on my laptop. Same for the SHD. It’s a very frustrating problem. The last time I tried, the first measurement went fine, but I could not get an acceptable reading in the second position.
 

MCH

Major Contributor
Joined
Apr 10, 2021
Messages
2,581
Likes
2,197
Just to let you know if interested that minidsp did for the SHD what I wanted to do since long time ago for my streamer and never managed: A plugin to use the surface dial as remote volume control. Unfortunately I don't have plans to buy a SHD any time soon :-(
enjoy


PS: i don't get why they do this with a device that seems to be discontinued, only yo piss me off? I hate them
PS2: i have a surface dial that i don't use for sale if someone is interested (grrrrrrrr)
 

Darkscience

Active Member
Joined
Dec 15, 2020
Messages
109
Likes
102
I just picked got one of these units in today. I was wondering how I was going to make it work with my HPA4 and DAC3, since this in essence replaces all that. The DSP functions on it are so easy to use and so powerful, I am not thinking of selling the prior two. I mean, this does everything in a preamp. It lacks a headphone out, so I am thinking of turning the HPA4 into a strictly dedicated headphone amp next to me listening chair. I do not believe I can live without the DSP functions after messing with them just for a few minutes, my subwoofer has come alive. I was initially going to run this digital in / digital out to the DAC3 but is there any point whatsoever in doing that? (I would lose the subwoofer DSP control as well). Is the sound the same as DAC3? Maybe not the same but good enough that I would not be able to tell them apart in a blind test? idk but this unit is killer so far.
 

mikeTRON250LM

Member
Joined
Dec 25, 2021
Messages
12
Likes
1
Look at photos of the Flex rear panel. It has four separate outputs. You can use them as follows:

1. Right speaker
2. Left speaker
3. Subwoofer 1
4. Subwoofer 2

I don’t think you will hear any difference in sound quality between the SHD and the Flex.

I have the SHD. If I had the choice again I would buy the Flex.
Why would you buy the flex over the SHD?
 

terfenol-D

Member
Joined
Nov 11, 2020
Messages
28
Likes
14
For the SHD - can I use balanced connections to my amp and RCA to my subwoofer? I'm not sure if both RCA and balanced are active at the same time or it's an either/or situation. Thanks.
 

Keened

Senior Member
Forum Donor
Joined
Nov 2, 2021
Messages
329
Likes
219
Why would you buy the flex over the SHD?
Size and no built in streamer that will become obsolete.

If they offered a FlexPro which was the SHD shrunk down with TRS instead of XLR and dual USB ports so you can add an RPi streamer and still have another free for alternative computer sources I would have done that instead.
 

deercreekaudio

Member
Dealer
Joined
Dec 5, 2020
Messages
87
Likes
143
Location
Colorado
For the SHD - can I use balanced connections to my amp and RCA to my subwoofer? I'm not sure if both RCA and balanced are active at the same time or it's an either/or situation. Thanks.
All 4 RCA and all 4 XLR analog outputs are active all the time. The XLRs are isolated from the RCA outputs by the differential circuit drivers. For a 2.1 system, your subwoofer will need to be driven monaurally using output channel 3.

nXsjpfilqlV3eMUkzatmkAbzKqCNpYtka-4HINgVUQMWOsQAmrAugH5tQqFGbb7zNk50XKHYgy2x15mOXa_qSVZRXVOiX0hvOt6NWy05AhqdsLfYEi_5hoa1POe6D65oYqUGjdTGo20Psxf5Ig
 

Jeschiotz

Member
Joined
May 26, 2022
Messages
6
Likes
0
For a newbie ,About connecting two active subs to the SHD. Dirac will only correct two channels. Sub should be connected to output 3 and 4. But can I put the subs in mono somewhere in shd? And whatabout crossovers and levels?
 

deercreekaudio

Member
Dealer
Joined
Dec 5, 2020
Messages
87
Likes
143
Location
Colorado
Routing Settings


A 2.2 stereo subwoofer system would be used when the subwoofers are located in close proximity to the full-range speakers. This is the preferred method with subwoofers that have higher crossover frequencies and or were designed for direct placement underneath full-range speakers.

fwqiJyYlTIO4kwtXl5qlCCddTcjRBwY-VJhBXXZ8vw1-BlqqRXI0Nh8Bgv4j9U5szmEOIXEyy_YqqnZbsKQknNyzlIRprtP2s9f6A_DwwSD0sN1jOxUCfJ0rP5YG6CRe_4QwIXs_mpcpvaqaeA


Routing table for a 2.2 stereo subwoofer setup


A 2.2 monaural setup can be beneficial in cases where aesthetics dictate the location of the subwoofers, or when the full-range speakers have large subwoofers. An added benefit of monaural subwoofers is the ability to cancel out room modes that otherwise might be present in the stereo setup.

NY3AcleIQ3vbwuK4gwXLuQ6qPlvRy_83QaoUTcBWqdj0wtsjxIfTumw-oSfF0C0JD7159A7AmZYMqLwMoYxKeqlZ6rB8oYzto0-pYiQIdvPc5r9fk8Vm3i2vf1QbAK-Luu4dsa9He1o-vglSKA


Routing table for a 2.2 monauralized setup


Relative Amplitude Settings

You can complete the basic setup by adjusting the relative levels of the subwoofers using REW and a miniDSP UMIK. From the central listening area, adjust the relative levels of the subwoofers to be equal. If you’re moving on to a Dirac Live project, these settings will remain in place. If you are new to REW, see Resources 5 and 6.

E-ZRiNZipHbL7-mYfvmZP00TjFGEwCMt9JehDmf1TQCWeSlPjlU6EepO1-GJK9GlsAF0w6t6sxSzqj81KIguR5jxx4qaB5_7g_uStXiBWUm4_HYjIkuzpiZ8PsZnTqXeZ0tfEtAHQoafjVP2MA


Subwoofer and two full-range speaker measurements after adjusting their relative amplitude settings


Crossover Setting

The crossover between the main speakers and subwoofer(s) is a technique that goes beyond applying symmetrical textbook high and low pass filters. We have found in our testing that asymmetrical filter slopes and shapes can produce significantly enhanced results.

A typical crossover would be the symmetrical 80Hz Butterworth 24dB per octave pictured below.
bX0y_FNicq5WTKxo1dl3-89HtTu1_-KCwhzkWiiB4Y_WKqKJoBzSVG3EbBCE3I9T8bXKNz0L_uZ1wURjPB4i1IeffuFx7iTDwJkG0VXazRksuERxYPpd8okDNeWuo5I8Q4iXIGN6vNygcmupjA


Example of a classic Butterworth symmetrical crossover found in early designs


The image below is an example of a crossover we use with a 12” full-range speaker and a high powered 15” subwoofer. What's notable is the soft high-pass slope for the mains and sharper low-pass slope for the subwoofer.

xVhM5XvjaoyET-Fl8nHRldK25WekB7Mt-6pbLHJAJKO5MSi6NkDn3RouQNEmcZuwiXq0g0S-rGHSTFEH8yfXNqU1Xnub_AFiYS2u_gsHP1B4Vrzzav8EEeb4MPslHpOaMFSjNzvucFPVzMDzUQ


Example of an asymmetrical crossover designed to optimize audio performance

After this is complete you can run your Dirac Live Project.

Deer Creek Audio is an Authorized miniDSP dealer.
 
Last edited:

Keened

Senior Member
Forum Donor
Joined
Nov 2, 2021
Messages
329
Likes
219
For a newbie ,About connecting two active subs to the SHD. Dirac will only correct two channels. Sub should be connected to output 3 and 4. But can I put the subs in mono somewhere in shd? And whatabout crossovers and levels?
Here's another setup method explained in another thread

The tricky thing is setting the timing for a 2.1 where the .1 is a different distance away from the L/R (as in off to the side). I'll revisit this later when I have time to experiment on my own, but I think it would require a physical sum-to-mono adapter placed after the 3/4 outputs. Then you could time align the sub frequencies on each stereo channel to their respective 'parent' speaker using the matrix and still get both channels sent to the same subwoofer.

The issue with that setup is if you have a high power signal on channel 3 and then also a high power signal on channel 4 and they're not time aligned, you're going to be asking a single driver to go maximum excursion and then suddenly shift to do it again within a window that might be shorter then the frequency response it can handle. Or at least that what first strikes me as a problem with this approach, so it might end up being you can't time align a single woofer to two distinct time domains and need to use an averaged position.
 

deercreekaudio

Member
Dealer
Joined
Dec 5, 2020
Messages
87
Likes
143
Location
Colorado
For 2.1 systems we align the subwoofer and two full range to a single central central listening position. We monauralize the subwoofer low frequencies prior to setting delay. Below is our delay adjustment process using REW.

Delay Settings

It is important that the time of arrival of the audio signals from the full-range speakers and subwoofer are coincident. Using the REW delay measurement capability, the first task is to determine which speaker is acoustically the closest to the central listening area. This may take a bit of trial and error, as you need to measure a positive delay from the remaining speakers. It’s typical to see a few milliseconds of delay on the subwoofers, due to DSP processing and since they are often placed back against the wall.

In the example below we have routed the subwoofer output to the left channel with the main full-range speaker as the reference output on the right channel.
PKEtNHZ-6-fuXLqZ9h97wVFV6LfFDmc-BYfmWqczwh08mLhmL79oVTFwnIg0LBpenNd6rInQBdakhvYD9qFiPbzqapcLEN63sx_AwWU7506Hri91cbFl6-mOraq52GhfvhV-3g9yBAnKLD5kXw


Diagram. Subwoofer delay relative to right full-range speaker


If you have the measurement set correctly, you'll first hear a sharp chirp from the full-range speaker and then a short sweep of low frequencies from the subwoofer. REW automatically calculates the delay. In the example below the delay is 1.9 milliseconds, or a little more than two feet.

mEQtoZscGWu6TpI4LScUimiyTwpMrnlhw9dT7VcmKj7FZvUu9iEcCuaM6StN70Opl_-aooxr1-NYZ3NXO23Vj6HmstD6jwHtTumkxjvQ3sPB8XmdxFDaYv9hLp0sG6opqlw5ucRj41wbSYyJLQ



After you've gone through all of the delays and are confident that you've got valid numbers, you can enter the correcting delays in the plug-in output section. You should verify that you have minimized the delays by making the same measurements again.

jMTDB5pJm4UcOrIj7cPmXZUVk6GK7L8Y9lF5Hyp9_KvPaTKF2rjh887QahmtlRVL0D-2KMfO-gxvmOFsr7RN-XUzEgn1uPszuq2zkXNfMLw9eybD0gVQlJY7UcMNPUW7ze23JsFCiInicdZubA


We have just published our new white paper on this topic "Subwoofer Integration for Stereo Systems for miniDSP, REW and Dirac Live"

Deer Creek Audio is an authorized miniDSP dealer.
 
Last edited:

Godataloss

Senior Member
Joined
Aug 16, 2021
Messages
468
Likes
510
Location
Northern Ohio
All 4 RCA and all 4 XLR analog outputs are active all the time. The XLRs are isolated from the RCA outputs by the differential circuit drivers. For a 2.1 system, your subwoofer will need to be driven monaurally using output channel 3.

nXsjpfilqlV3eMUkzatmkAbzKqCNpYtka-4HINgVUQMWOsQAmrAugH5tQqFGbb7zNk50XKHYgy2x15mOXa_qSVZRXVOiX0hvOt6NWy05AhqdsLfYEi_5hoa1POe6D65oYqUGjdTGo20Psxf5Ig
I have a Hsu sub with 2 xlr inputs on the way. It will be my only sub. Are you suggesting I run it mono? The Hsu lit says to run it stereo.
 

deercreekaudio

Member
Dealer
Joined
Dec 5, 2020
Messages
87
Likes
143
Location
Colorado
In that case, you can run it with stereo inputs using the following routing matrix. The monauralization will be performed by the Hsu.

CLlSK4aJOc35Ul6IJXjU9vwpR2nEP2N7AuDsfYYln8hB8yO0ID2Ut1dqDw8u0Aq_kwX1T8HNr6Ng98vaHAAID9GD5FQe_G2Vi4fDk_VF4oCACr_TkEN9Qs0V_6TGMw257cD0LkHd5uQAwCe9wA


Or if you only want to run a single XLR cable from the SHD, you can contact Hsu and see if that will work and which input to use.
 
Top Bottom