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Which miniDSP box is best for my setup?

ToTo Man

the band not the dog
I've thus far resisted adding a miniDSP box to my system but, with the imminent arrival of two more subwoofers, it has now become a necessity.

A visit to their website today has left me confused about which one of their magic boxes is best suited to my need. I see sthey've also added new products and removed some old ones since I last looked.

My decision is complicated by the fact that I don't know which direction I'm going to take my system in. E.g. whether I'm sticking with passive loudspeakers or go active, and whether I'm willing to replace the DAC that I really like the sound of with a miniDSP DAC.

1) The most conservative option is inserting a miniDSP box between my amplifier and my subs. This would allow me to DSP the signal going to each sub. Everything else would remain as it is at the moment.

2) The most radical option is replacing my existing DAC with a miniDSP box. This would allow me to DSP the entire signal chain, main speakers and subs, presumably independently.

There are probably permutations that fall somewhere between these two extremes.

Points of interest:
- I currently use parametric EQ plugins in Audirvana+ to achieve the desired in-room response from my loudspeakers. This, of course, only works when playing music in Audirvana, it doesn't work system-wide on my Mac Mini, nor on my other digital or analogue sources.
- My analogue sources go through a vintage Technics SH-8065 graphic EQ that allows me to approximate my Audirvana EQ settings.
- My DAC's RCA outputs also go through the Technics EQ so that I can EQ the TV signal (XLR is otherwise my preferred output).
- I'd happily ditch the Technics EQ if a miniDSP could do the same job.

Questions/concerns:
- Looking at the info on the various miniDSP boxes, even though they have USB ports, USB is not listed among the digital inputs. Does this mean the USB input is only for controlling the miniDSP software or can it actually be used to output digital audio from my Mac Mini to the miniDSP box? If it can't then that's a deal-breaker.
- Is it possible to easily bypass all DSP settings on the miniDSP box. E.g. if I'm listening to my headphone amps or recording audio onto tape then I'm obviously not going to want any DSP engaged! If not then I'm probably better keeping my existing DAC for use with my headphone amps and tape decks.

This is how my system is setup at the moment. Note the light grey boxes at the bottom right corner are future additions still to be incorporated.

system-wiring-february-2023.jpg
 
I don't have any MiniDSP products, but it seems that the MiniDSP Flex or MiniDSP SHD would best suit your needs. Both should act as a USB/toslink/spdif DAC, while also being able to process an analog stereo input, and outputting on 4 channels.

You may be content with an Unbalanced MiniDSP Flex, if you're willing to do away with your XLR headphone amp (or retain your current DAC and XLR switch for this function)

If you do want to mix XLR and Unbalanced signals, I think a MiniDSP SHD is best (it has 4 outputs, each with XLR and unbalanced signals). It also takes digital and analogue inputs (with the possibility of switching between the analog XLR and analog unbalanced ones at will). This would allow you to play with your existing sources and compare them with the integrated DAC and EQ features of the MiniDSP SHR

Both of these devices measure fairly well if you're into SINAD numbers and the like.
 
If you are wanting to integrate your subs and improve the bass response, then a Minidsp 2x4hd between the amplifier sub out and the powered subs would work. Setting up the Minidsp requires measurements using a supplied Umik mic and REW software (free) on a pc. The pc usb output must be fed through the main amp for test tones measurements. REW analyses the results and you can either manually adjust filters in the Minidsp or create filter files which are imported onto the Minidsp. This is all done below 200hz frequency so if you are adjusting high frequencies with the graphic eq, then this should still be useful. Minidsp do an expanded version (2x8) which would support 4 subs.

A simpler device to use could be the Dspeaker Antimode 8033s ii. Fitted in the same way, it automatically measures and creates the filters for up to two sub. The subs would be in mono and must have one 180deg phase out from the other.

If you want to replace the graphic eq and work on full spectrum sound correction e.g. with Dirac, then its different ball game. This would need a Minidsp flex or SHD. Setting up gets more complicated and there's a steep learning curve. Dspeaker X2 is an alternative and simpler to setup. Neither of these will support more than 2 subs.

Hope this helps!
 
The subs would be in mono and must have one 180deg phase out from the other.

why is this ? I thought the opposite would be the case
 
The subs would be in mono and must have one 180deg phase out from the other.



why is this ? I thought the opposite would be the case



If you have a look at the Antimode 8033s II details it is a mono processor and the two outputs are provided out of phase.
 
The best reason to add a DSP box (I always liked the heavy machinery from DEQX), is to actively cross between the SUB-woofer and the main speakers.
Depending on speaker size and room dimensions, crossover frequency would be anywhere between 70 to 120 Hz at 24dB/Oct.
With integrated amplifiers, this would require a pre-out--main-in connection.
Thanks, Yair
 
I am a miniDSP retailer. Even setting aside your proposed future additions, I don't think that there is a miniDSP processor that can meet all of your requirements. However, by stacking together a miniDSP SHD with a Flex Eight, you could meet all of your present and future requirements.

In some miniDSP processors the USB port is only used to configure the device. In others it is also an audio input. In a few it can also be used for recording.

Most miniDSP processors have four presets into which you can save various combinations of settings for easy recall later. It would be easy to create a preset without equalisation, crossovers etc for recording or headphone listening.
 
I’m using a MiniDSP DDRC-24 (2x4 HD with Dirac) between my pre and power amps going into a 2.1 system. Works a treat. You can separately apply room correction (to a custom house curve) and additional eq, speaker delay, crossover settings etc.

i have used it as a usb DAC with my Mac and also a raspberry pi. No drivers needed.

if you care about measurements, the Flex rates the highest. 2x4 HD sounds great to my ears though…

Changing inputs and settings on the 2x4HD is a bit of a PitA as it has no display so maybe the flex is your best bet.
 
… and to address your second question, it’s possible to bypass all settings except speaker delay set by Dirac. Not sure why. There are workarounds too.
 
I am a miniDSP retailer. Even setting aside your proposed future additions, I don't think that there is a miniDSP processor that can meet all of your requirements. However, by stacking together a miniDSP SHD with a Flex Eight, you could meet all of your present and future requirements.

In some miniDSP processors the USB port is only used to configure the device. In others it is also an audio input. In a few it can also be used for recording.

Most miniDSP processors have four presets into which you can save various combinations of settings for easy recall later. It would be easy to create a preset without equalisation, crossovers etc for recording or headphone listening.

At first glance I thought the SHD offered me everything I'd ever need as it has 4x balanced and 4x single-ended outputs. However, after reading the specs, I don't think all 8x outputs can be used simultaneously, which is a pity because I could've used the 4x single-ended outputs into four subs, 2x balanced outputs into my stereo power amp that drives my passive speakers, and the remaining 2x balanced outputs for a pair of active speakers!

I could 'fudge' it by using only 2x of the single-ended outputs so that I can use the 2x balanced inputs into my integrated amplifier. The 2x single-ended inputs would be split between my four subs. This of course removes the ability to tweak each sub independently, but I won't know how important this is until I get all four subs in situ. I intend to place them in a mirror-imaged arrangement the same distances from the front and rear walls as follows:

Subwoofer-layout.png


My room, however, is not perfectly symmetrical in its construction and does not measure like one so the ability to control each sub independently by adding a Flex Eight to the SHD may prove to be very useful.

Is it possible to have devices plugged into all eight outputs of the SHD and use the OSD/menu to choose which four outputs you want to simultaneously use, or are you only allowed to have four cables plugged in at any one time? e.g. If you have RCAs plugged into RCA out1&2 can you also have XLRs plugged into XLR out1&2 and use the OSD/menu to switch between the two, or would the XLRs need to be plugged into XLR out 3&4?
 
With the SHD you have two input channels and four output channels. Each output channel is available via XLR, RCA and digital coaxial. You can connect each of the three physical outputs to a different device but you cannot switch them on or off independently. What you can do is control what is sent to each of the four output channels, which is what makes the stacked SHD + Flex Eight option work here.

With the Flex Eight you have two input channels and eight output channels. The inputs are all digital and the outputs are all analogue.
 
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I think you would benefit from a 10x10 HD, no longer available new though. I control 5 subs with this and feed in 8 parallel lines to add whatever is missing from each channel below 50 Hz
 
You could meet all of your current requirements by stacking a Flex Digital and Flex Eight together. These two would cost a little under £1,500. The only real issue is that you will not have the spare analogue outputs required to add more subwoofer channels in future. However, it would leave a spare digital output to accommodate adding a second Flex Eight or Flex RCA to the stack in future. The other minor issue is that you would need to use RCA to XLR cables to connect to your headphone switch.

Just a quick note on the 10x10 HD recommended above. The USB socket on this model is for configuration only. It is not an audio input. Also, as an older model the 10x10 HD does not offer the same performance as the Flex and SHD models. This probably does not matter with subwoofers, but it will be very obvious with a decent main speaker or headphone.
 


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