Upgrade from miniDSP 2X4 HD to SHD Studio in a DEQX based system?

[Satanica]

1 hour ago, davewantsmoore said:

Yes, that is what I would expect.

They use a "special technique" to minimise the latency.

I don't understand how it works, but I think I remember reading that it's probably a patented mixture of FIR and IIRC filters. 

Edited August 8, 2020 by Satanica

[Satanica]

59 minutes ago, Irek said:

It looks like Andy has similar plans. 

 

" Mine is to replace my miniDSP 10x10HD.  Currently, I run this in 2x8 mode, so:

• digital in
• 8x analogue channels out (sub / bass / mid / ribbon, either side)
• at 96kHz

with:

• a nanoDIGI 2x8 (digital in & 4x digital out), running at 96kHz
• plus 4x Topping E30 DACs - to give me my 8x analogue channels out.

What this does is give me better output DACs than are used in the miniDSP 10x10HD.

 

Andy "

Yes, I think the nanoDIGI would also work although a bit of overkill with 8 channels of digital output when I only need 4. From what I can tell I would need to spend an extra 99USD because I would need to add the DDRC-88BM software plugin that does not come with the nanoDIGI as standard. 

 

miniDSP have enough products to somewhat confuse me but I think the SHD studio would still be the best choice. 

Edited August 8, 2020 by Satanica

[Sinewave]

And yet when I am speaking to VAF, who sell the DEQX as part of their I93 active system- they say that’s the only downside to them. 

[Satanica]

18 minutes ago, Sinewave said:

And yet when I am speaking to VAF, who sell the DEQX as part of their I93 active system- they say that’s the only downside to them. 

Sorry I don't follow, what is the only downside? 

[Sinewave]

4 hours ago, Satanica said:

Sorry I don't follow, what is the only downside? 

The latency. So if you have a source of my Oppo for example, you send Centre and surround signals to the appropriate channels, and L + R to the DEQX- they will be delayed too much to use

[Sinewave]

I mean you could delay all the other channels individually if your player of processor can do that but that kind of  seems like an unnecessary step. 
 

That’s a big reason I have the Lakes. The lowest latency of any digital crossover I know of.

 

I use an Anthem AVM60 and the latency is unmeasurable in my situation 

[almikel]

On 07/08/2020 at 1:00 PM, Satanica said:

I think I could potentially add another DEQX in a master\slave configuration and from memory @almikel does exactly this.

Hi @Satanica - correct - I run 2 x DEQX HDP3s in a master/slave config...with the master DEQX having digital outputs to feed the "slave" DEQX.

 

Way back in 2010 when I bought my original HDP3 I never considered digital outputs (it was an option at the time), and when I added a sub to my PSE144 + TD18 mid bass (4 way) around 2015, I had to  daisy chain an analog dbx Xover to the DEQX to achieve a 4 way crossover.

Alan at DEQX sourced me a 2nd hand HDP3 with digital outputs for double DEQX - which is my current master DEQX, feeding my original HDP3 "slave" unit.

Alan even came to my house to help setup the "double DEQX"...

...over my 10 years of ownership of DEQX I regard their product support as exemplary.

 

On 07/08/2020 at 1:00 PM, Satanica said:

While DEQX is probably as good as anything as an up to 3-way digital crossover it IMO lacks at sub-woofer integration and room correction in general as it cannot room correct EQ per channel but rather globally (same room correction EQ applies to both L and R channels).

Agreed - not having individual EQ control over individual subs is IMHO a feature lacking from DEQX.

 

On 07/08/2020 at 1:00 PM, Satanica said:

While DEQX is probably as good as anything as an up to 3-way digital crossover

Off topic - but if I was starting from scratch, and only looking at 3 way active mains (ie no subs), I would still seriously consider a DEQX HDP5 as a premium 1 box pre-amp/DAC/3 way Xover/speaker correction/room correction solution.

 

Going 4 way takes the cost of a DEQX solution over the top...but for 3 way active mains with no subs, it's still a killer solution IMHO.

 

cheers

Mike

 

 

 

 

 

[almikel]

1 hour ago, Sinewave said:

The latency. So if you have a source of my Oppo for example, you send Centre and surround signals to the appropriate channels, and L + R to the DEQX- they will be delayed too much to use

I would doubt the propagation delay through a DEQX would be an issue, ie the speed of processing...

...the inherent delay (irrespective of DSP processing power) of all filters gets longer the lower the crossover frequency and the steeper the filter (irrespective of topology - analog/digital/active/passive).

 

1 hour ago, Sinewave said:

I use an Anthem AVM60 and the latency is unmeasurable in my situation 

The processing/propagation delay of the Anthem may be miniscule (desirable), but the laws of physics will define either the Group Delay for an IIR filter, or the delay for a linear phase FIR filter.

These inherent delays of filters can't be avoided, and just need to be managed appropriately.

 

Mike

 

 

[Satanica]

2 hours ago, Sinewave said:

The latency. So if you have a source of my Oppo for example, you send Centre and surround signals to the appropriate channels, and L + R to the DEQX- they will be delayed too much to use

If the Oppo can compensate for the typical 15ms or less delay of the DEQX then that would not be the case. So can it? 

[Satanica]

7 hours ago, Sinewave said:

I mean you could delay all the other channels individually if your player of processor can do that but that kind of  seems like an unnecessary step. 
 

That’s a big reason I have the Lakes. The lowest latency of any digital crossover I know of.

 

I use an Anthem AVM60 and the latency is unmeasurable in my situation 

Delaying the other channels is not unnecessary if it's necessary   And it's trivial for a digital processor. I'm not sure what the "Lakes" are but if they are a digital crossover then surely they must introduce some delay? The delay of the DEQX is seemingly less than what is induced by typical TV and Projector processing so a non issue really.

Edited August 8, 2020 by Satanica

[almikel]

50 minutes ago, Satanica said:

if they are a digital crossover then surely they must introduce some delay?

it's important to remember that every filter has inherent delay (analog/digital/passive/active), it's just that digital filters also have processing/propagation delay (while they compute the output) in addition to the filter's inherent delay.

 

For digital FIR linear filters the processing power required does increase as you go steeper/lower...essentially the processing/calculations increase as you increase filter steepness.

In most cases the processing power of a digital filter won't be a major factor unless very low and very steep...the terminology for digital IIR filters is the number of taps, and the number of taps required increase as you go lower and steeper.

IIR filters don't require as much calculation/processing when implemented digitally, so will have less "propagation/processing" delay, but the inherent filter delay will vary with frequency (ie Group Delay), rather than just linear delay.

 

Always compromises...platforms such as DEQX will only allow IIR filters (eg LR4 or shallower) below specific frequencies based on timing (delay) thresholds.

 

Mike

[Satanica]

3 hours ago, almikel said:

Agreed - not having individual EQ control over individual subs is IMHO a feature lacking from DEQX.

I also think that Dirac Live can also provide superior room correction because it will use data from multiple locations, allow EQ'ing of each channel individually (not just each sub), attempt to correct phase issues.

[davewantsmoore]

22 hours ago, Satanica said:

a patented mixture of FIR and IIRC filters. 

Yes, like that.  You do "IIRC"   

[davewantsmoore]

10 hours ago, almikel said:

it's important to remember that every filter has inherent delay (analog/digital/passive/active), it's just that digital filters also have processing/propagation delay (while they compute the output) in addition to the filter's inherent delay.

 

For digital FIR linear filters the processing power required does increase as you go steeper/lower...essentially the processing/calculations increase as you increase filter steepness.

At this risk of diving into a rabbit hole.... I think this is a bad way to think about it, and confuse anyone folling the topic very closely (trying to learn, etc.)

 

It is better to say, that rather than waiting for the "propogation/processing" (which is actually extremely short, so short it isn't relevant) ..... what you are actually waiting for is "the inherent delay of the FIR filter".

 

Quote

For digital FIR linear filters the processing power required does increase as you go steeper/lower

It isn't the "prcoessing power" which you need more of .... it is the "memory".   As you move to a lower frequency it needs to wait longer to read the longer frequencies (and store more signal in memory).

 

 

It may seem like semantics.... but if you think about it hard, hopefully you can see how this is quite critical to understanding what is actually happening with this type of filter.

 

Said another way.  The signal is not "more difficult to calculate" ..... it is just simply longer.

[Sinewave]

15 hours ago, Satanica said:

Delaying the other channels is not unnecessary if it's necessary   And it's trivial for a digital processor. I'm not sure what the "Lakes" are but if they are a digital crossover then surely they must introduce some delay? The delay of the DEQX is seemingly less than what is induced by typical TV and Projector processing so a non issue really.

My Dolby Lake Contours are the most powerful speaker processors that I know of. https://www.prosoundnetwork.com/archives/lake-technology-contour-pro-26-series-digital-loudspeaker-processor
 

they are specifically designed to process/eq/time align and equalize concert line array systems. Definitely never intend for home use! (I only know of one guy on AVSforums that has one- I have 3) Skywalker studios have 2 more than I do   
 

Anyway the whole point of these is that they have the lowest latency of any processor I know of, and have exceptionally high quality sound due to the need to power concert systems. And obviously you can’t have performers playing on stage and any delay to the front of house speaker array 

 

 

Edited August 9, 2020 by Sinewave
Clarity

[Sinewave]

17 hours ago, almikel said:

Hi @Satanica - correct - I run 2 x DEQX HDP3s in a master/slave config...with the master DEQX having digital outputs to feed the "slave" DEQX.

 

Way back in 2010 when I bought my original HDP3 I never considered digital outputs (it was an option at the time), and when I added a sub to my PSE144 + TD18 mid bass (4 way) around 2015, I had to  daisy chain an analog dbx Xover to the DEQX to achieve a 4 way crossover.

Alan at DEQX sourced me a 2nd hand HDP3 with digital outputs for double DEQX - which is my current master DEQX, feeding my original HDP3 "slave" unit.

Alan even came to my house to help setup the "double DEQX"...

...over my 10 years of ownership of DEQX I regard their product support as exemplary.

 

Agreed - not having individual EQ control over individual subs is IMHO a feature lacking from DEQX.

 

Off topic - but if I was starting from scratch, and only looking at 3 way active mains (ie no subs), I would still seriously consider a DEQX HDP5 as a premium 1 box pre-amp/DAC/3 way Xover/speaker correction/room correction solution.

 

Going 4 way takes the cost of a DEQX solution over the top...but for 3 way active mains with no subs, it's still a killer solution IMHO.

 

cheers

Mike

 

 

 

 

 

DEQX are definitely awesome, I’m super impressed you have 2. 
 

I use the same method, one processor as 3 way crossover/eq, AES digital our to the second one to control 4 of my 6 subs. 
 

As cool as one entire processor  for left and one for right in 4 way is, I prefer to implement the ‘summed mono bass’ method and take all LF from 80 hz and send to the subwoofer array. 

[Sinewave]

I feel like instead of contributing to this thread and helping, by mentioning different possible ways of multi way crossovers,  I may be hijacking it in my search for knowledge from guys who know more than I do. I will stop posting here and start my own thread to avoid annoying anyone too much.

 

Satanica needs advice on his setup

[Satanica]

1 hour ago, Sinewave said:

I feel like instead of contributing to this thread and helping, by mentioning different possible ways of multi way crossovers,  I may be hijacking it in my search for knowledge from guys who know more than I do. I will stop posting here and start my own thread to avoid annoying anyone too much.

 

Satanica needs advice on his setup

Hey, it's absolutely no problem, post away. 

[Satanica]

4 hours ago, Sinewave said:

Anyway the whole point of these is that they have the lowest latency of any processor I know of, and have exceptionally high quality sound due to the need to power concert systems. 

And what is that latency typically I wonder, especially with a crossover and EQ applied. I've had a quick look through the manual and which admits to it. There are some numbers in there but I assume those numbers are with no processing. 

Edited August 9, 2020 by Satanica

[davewantsmoore]

4 hours ago, Sinewave said:

Anyway the whole point of these is that they have the lowest latency of any processor I know of

That doesn't help in this instance.

 

The latency is causd by the filtter and not by the device.

 

ie.  a lake processor, running a phase linear 20Hz filter....   has 25ms of added delay, due to the filter.    So if the processor itself has 0.1ms of latency .... then the latency is 25.1ms.

[Phil Williams]

On 06/08/2020 at 5:00 PM, Satanica said:

Hi, my somewhat complicated setup is as follows.

I have 3 way main speakers (original Legend Big Reds) which are actively controlled with a DEQX.

 

From the L and R bass outputs of the DEQX I send the 150Hz and below L and R signals to a miniDSP 2X4 HD.

I crossover in the miniDSP at 80Hz sending L bass to L Legend bass unit and R bass R Legend bass unit from 150Hz to 80Hz.

This comes out of the outputs 1 and 2 on my miniDSP.

Also in the miniDSP I send mono bass to two sub-woofers from 80Hz and below.

This comes out of outputs 3 and 4 on the miniDSP.

I EQ with the DEQX up till about 80Hz.

I don't do any EQ'ing with the miniDSP.

I do a little EQ'ing with JRiver Media Center (L and R) from about 80Hz to 250Hz.

JRiver Media Center is effectively my digital pre-amp where volume is applied (not in the DEQX).

Sorry if you're gotten this far and are already confused.

So, I'm considering swapping the miniDSP 2X4 HD with the all digital miniDSP SHD Studio and running it before my DEQX.

https://www.minidsp.com/products/streaming-hd-series/shd-studio

I would want the miniDSP SHD Studio to crossover from 80Hz and up and digitally send to my DEQX.
I would want the miniDSP SHD Studio to crossover from 80Hz and down and digitally send to a cheap DAC which would then send analog to my sub-woofers.
I would then want to use Dirac Live with the SHD Studio and probably no longer EQ with DEQX and JRiver Media Center.
Sound OK?

Qq with jriver is there any feature for room correction or do you adjust by ear?

[davewantsmoore]

9 minutes ago, philwill1971@gmail.com said:

Qq with jriver is there any feature for room correction or do you adjust by ear?

Not in-built.... but using its DSP it can run filters generated by other software, eg. DRC

[davewantsmoore]

6 hours ago, Sinewave said:

Satanica needs advice on his setup

I think his standing suggestion is a good approach.

 

It could be simplified (less boxes) by using the SHD (the one with analogue outputs) so he doesn't need an external DAC, but that's going to be probably >> $$$.

 

The only other things the could be done, involve getting rid of (or messing with) the DEQX .... and unless very sure of what is doing, I wouldn't recommend touching it (as it's been programmed by the speaker designer).

 

 

The only other thing I would mention (which Satanica is probably already going to do) would be to remove all "EQ" from the DEQX (from memory it was "EQing below 80Hz").    Just treat the DEQX as a "neutral loudspeaker manager" ... and then do all the EQ/levels (and Dirac Live) from the MiniDSP SHD.....  (or of course, in JRMC)

Edited August 9, 2020 by davewantsmoore

[Satanica]

35 minutes ago, philwill1971@gmail.com said:

EQ with jriver is there any feature for room correction or do you adjust by ear?

Just based on my DEQX room measurements.

[Satanica]

44 minutes ago, davewantsmoore said:

I think his standing suggestion is a good approach.

I'm glad you think so, gives me more confidence in it.

 

44 minutes ago, davewantsmoore said:

It could be simplified (less boxes) by using the SHD (the one with analogue outputs) so he doesn't need an external DAC, but that's going to be probably >> $$$.

Yeah the SHD is a few bucks more plus I like the form factor of the SHD Studio (not so wide).

 

Also, the I think the SHD Studio will allow AES\EBU into the DEQX and I happen to already have a cable. Not that I expect it to make a sonic difference but I just love those pro like cables that go click!

 

44 minutes ago, davewantsmoore said:

The only other things the could be done, involve getting rid of (or messing with) the DEQX .... and unless very sure of what is doing, I wouldn't recommend touching it (as it's been programmed by the speaker designer).

It's beyond me and you gotta know your limits. For me I'm happy in that my lack of knowledge means it's one less option for me to consider.

 

44 minutes ago, davewantsmoore said:

The only other thing I would mention (which Satanica is probably already going to do) would be to remove all "EQ" from the DEQX (from memory it was "EQing below 80Hz").    Just treat the DEQX as a "neutral loudspeaker manager" ... and then do all the EQ/levels (and Dirac Live) from the MiniDSP SHD.....  (or of course, in JRMC)

I'm glad you mentioned it because yes it is my plan to only do EQ in the miniDSP via Dirac Live. I do plan though (subject to advise) to first do a room measurement in DEQX and then just level match and time align the Legend bass units to the Legend mid\high units after setting an 80Hz crossover in the miniDSP SHD Studio. Then running the Dirac Live software and doing whatever measurements it wants and then setting target curve(s) to let Dirac Live decide what EQ and whatever else it wants to apply.

Edited August 9, 2020 by Satanica