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Industry Circles => Hollis Audio Labs => Topic started by: Kazoom on 5 Sep 2023, 10:34 pm

Title: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Kazoom on 5 Sep 2023, 10:34 pm
Hi All,
Good News Everybody! My DSPNexus shipped today!   :thumb:
Thank you HAL!  :notworthy:

So lets get this “build” thread started.  My goal is to not only share my journey, but to provide a reference point for members of the community interested in taking their path to audio transcendence down the road of DSP and active crossovers.

This thread starter has tons of detail, but I think it all matters in the greater scheme of things. 

I believe I am typical of audiophiles on a budget who do their best with what they have to develop their systems over time.  Over the past 25 years, I focused on the best bang for my buck with each improvement.

Except for the speakers, this is the biggest upgrade I have ever made.

Intro
I am not an audio engineer.  Not even close.  I learned my way around REW through a “monkey see monkey do” approach.  I also built my chip amp using the same approach.  So, bear that in mind when I start asking stupid questions.   :scratch:

My interest in DSP and active crossovers started pre-covid when I was watching HAL’s thread on adding his monolithic 6x12” open baffle servo subs to his line arrays. 

About a month ago, I was chatting with @captainhemo when he suggested looking into the DSPNexus and going active.  I don’t know what it is about that guy, but he rivals the skills of Satan when it comes to sowing the seeds of audio temptation.  I have made more changes to my system based on conversations with him.  That guy kills me!
:tempted:

So I reached out to HAL with all sorts of questions.  His thorough answers showed his passion for helping others improve their systems which ultimately brought me here, taking it all to the "next level" on a system that is already considered at the "next level" by many.  This hobby is brutal.   :icon_twisted:

At this point it is in my best interest to add that my wife is a saint! :angel:  I know that because when I show folks my system, the first thing they say, without fail, is “Wow!!  Your wife is a saint!”.  I consider myself very lucky she puts up with my obsession.

As Is
I am running GR-Research NX-Tremes with what I affectionately call the “Don Bombs Crossover Network”.  This is the first NX-Treme kit ever built by @captainhemo and his buddy Don.  Don sparred no expense in doing it right and worked with Danny Richie to take the crossovers to another level using the best copper he could find.  You can see some pics of that here:  https://www.audiocircle.com/index.php?topic=152137.0 (https://www.audiocircle.com/index.php?topic=152137.0).  So active crossovers have their work cut out for them in this upgrade.   :D

Amplification
The speakers are bi-amped using a McIntosh MC7270 for the mids/tweeter (Nordost Red Dawn speaker cables) and a Folsom DIY 7293 chip amp driving the 8 woofers on each channel (DH Labs T14 speaker cables).

I am supplementing the bass with the 3x12” open baffle subs.

Pre-amp is a Rowen PA1.  This is a Swiss built piece of kit that is very transparent.  As it is purist, that means it is all manual and no remote control.

My cables are mixed.  The interconnects are primarily DH Labs White Lightening and Bluejeans cable to the subs. 

Digital
My digital music is controlled by Roon (Tidal, Qobuz and CDs burned to my NAS).  I am using convolution filters I built using REW for room correction (shout out to Obsessive Compulsive Audiophile for his videos on how to do this).

A Raspberry PI plays the roll of a Roon bridge to my Topping D90MQA DAC.

Everything that runs through my projector (Nvidia Shield, PS5, Sony 4k Bluray) is fed to the system via an optical SPDIF cable to the topping DAC

Analog
Old school pioneer turntable with a Denon 103 cartridge.

I alternate between a Parks audio budgie (tube phonostage) and Puffin (very fun ss phonostage).

Room
Damn near a square (20 X 21 X 7.75).  While the figure 8 sound wave pattern of open baffle helps with that I need to beat it into submission with quite a bit of diffusion and a makeshift bass trap in the back corner.

To Be
The arrival of the DSPNexus in will change things up a bit.  First, it is the active crossover for the subs, the woofers, the mids and the tweeters.  It will also take on some of the pre-amp functions, in particular volume control for the whole system.

I will add a topping “PA5 II plus” amp due to its solid review on audio science, and more importantly its price.  My planned assignment of amps is as follows:
I will be using 3 different speaker cables based on my perception of their strengths:

Expectations  :rock:
@HAL, since you have my money already, please correct me if my expectations are misguided.

In the spirit of improved sound quality, I am trying to solve for the following:

Constraints/Compromises to the implementation :duh:

As I am not running amps directly to the speakers at this point so I need to couple the speaker wires to the speaker cables.  I will be using cheap things I found on Amazon.  I do not want to invest in decent couplers when the goal is to eventually connect the amplifiers directly to the speakers without speaker cable.  If this proves problematic, I may re-purpose the tube connectors on the passive crossovers to improve the signal path.  If get flamed hard enough I might even solder the connections.

My current two amplifiers are not balanced, so will be using Neutrik XLR to RCA adapters.  This should not be an issue, but once again, this is not the most optimal.

Thread Starter Conclusion
Please feel free to question anything I said.

I will edit this starter as appropriate for grammar and clarity

So with that said, lets all patiently wait for the FedEx truck.
 :popcorn:
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: HAL on 5 Sep 2023, 11:41 pm
Kazoom,

The dspNexus 2x8 should do what you are looking for even without the first upgrade that will be coming for the EA units that will be shipped when done.  That is the new ADSP21569 dspBlok from Danville Signal that will add a lot of throughput and new capabilities.  One of which is having both long FIR filters that process at the same time as the DSP path.  I have a few customers that already will be able to take advantage of the new capabilities. 

The new hardware and firmware are in testing, so hopefully it will be soon.  The 4 DAC's, DSP module and ADC's are all plug-ins, so not a hard thing to upgrade.

REW is being used by most customers now to add room correction below 300Hz.  Simply measure the room with REW and a XLR phantom powered mic input on the front.  Once the measurements are complete, REW can calculate the room response PEQ's to flatten the response.  Those can then be entered into the Audio Weaver block diagram for each channel for trials.  Once you are happy, then the block diagram can be compiled and downloaded to the dspNexus 2x8 to use every time it is started. 

If time delays are needed to compensate for the NX-Tremes position relative to the servo subs, that can be input to the block diagram.  That makes a big difference even for systems with Line Force speakers and 3x12 servo subs.  :)

The remote control and battery are in the box.  Once you have your Audio Weaver software downloaded, I will help with the installation.  That is part of the documentation that Danville has not finished, but after over 10 years of using the Audio Weaver software, have a pretty good idea of what is needed to get you up and running.

The unit should be there this week, so the fun will start soon.  :)
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Kazoom on 15 Sep 2023, 06:07 pm
Good News Everyone!

My DSPNexus arrived and it is time to play. 

I will do two posts at a time.  The first has the subjective stuff and experiences, the second is procedural stuff to easily reference for those taking this path.

I do not have the exact crossover specs for my speakers yet and am waiting for an Audiomatica Clio to measure those values, so today was basic setup and testing to make sure it is all in order.

The first step is using AudioWeaver, to transform the dspNexus into a DAC .  It takes a while for configurations to be applied to the Nexus, so testing it as a DAC first makes a lot of sense.

All the outputs on my unit tested out fine.  I did have issues with the headphone jack, but the ¼” adapter is looking more suspect than the Nexus.

Impressions, Challenges and Considerations

Inputs and Outputs
Besides the obvious 8 XLR channels out, it also has an SPDIF in and out (Both are RCA type coax connections), Analogue balanced in, and a USB type A in.  On the front of the unit there is a head phone jack and an XLR in for a phantom powered mic.
 
Menu
The menu system is pretty easy to navigate, I do wish it was customizable.  For example; every source has an inverted version of that source (USB and USB Inverted, SPDIF and SPDIF Inverted, etc…).  This not something I will likely be using, so customization would be nice, but I am being nit picky and I am sure the development team has enough on their plate right now.

Sound
The DAC sounds very nice and clean.  It is a bit early in the process, but I feel it is rendering quite a few more details than my Topping (which is one helluva DAC for the money).  So, we are off to a great start.

I did not listen too critically but noticed more breath in the horns with more details in the strums and plucks of acoustic instruments.  It just sounded more real to me, like the characteristics of the instruments was more dialed in. Considering Danville uses only the best DAC chips on the market, I would hope this to be the case.
The analog input is transparent, there was no veil or colorization that I noticed right off the bat, which is exactly what I am looking for.  I was most happy to being able to adjust the volume of evenings entertainment from a remote (no remote with current pre-amp).  It helped ease my wife’s pain of seeing cables strewn across the living room.

It’s Called “Early Adopter” for a Reason Folks
We did have a few issues to investigate. 

In all reality, these are all minor considering how much configuration is done by the end user.  No major headaches that a little aspirin won’t sort out.

S/PDIF Output
The first challenge we hit was trying to use the S/PDIF out.  We were not successful in getting that to work with the Topping.  Not super high on my priority list, but S/PDIF out is a pretty cool feature I can easily find uses for.  So will keep this on my radar. 

XMOS Drivers
Apparently, there are known issues with the way Roon communicates with the XMOS drivers on Linux based bridges/endpoints. 

After about an hour of listening I noticed distortion that started as clicks and pops and quickly morphed into fully distorted music.  I adjusted the sampling conversion settings in two places on Roon - The device specific settings and from the “Muse” window.  This seems to have solved it but will only know with time.

To be sure the distortion was not caused by the Nexus, I hooked up my old Linn Majik without touching the Roon settings to see if I had the same problem.  It has been playing happily for a couple hours as I type this up.  BTW, this DAC and the Linn are a great combination.  The Linn is an older model and had a habit of needing a hard reboot from time to time.  This was quite annoying so it will not find a permanent place in my main setup.

There is Always a Solution
Due to the potential of those Linux drivers going flakey I decided to give one of HALs windows based servers a try.  Will hear how that sounds and report back.

Crash and Burn
I did manage to crash the Nexus at one point requiring me to reload the DAC configuration from AW.  HAL is working with Danville to see what is up with that.  Not too worried at this point.  This early in the product lifecycle, there are bound to be a few bugs that will result in such behavior.

Honestly, I think I would have been disappointed if I did not manage to crash it once. Like I was losing my touch or something.   :lol:

Conclusion
So far so good and no major regrets.  The real fun will begin once we start with building the active crossover network and getting the timing right.  I have high hopes for this unit and so far I do not see any reason it may disappoint me.

I will post some pics eventually.
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Kazoom on 15 Sep 2023, 06:43 pm
@HAL - Keep me honest here and please let me know if I missed or misrepresented anything.

Procedural Stuff
So here how you setup the nexus for the first time to test that it is working as expected.

Getting the Needed Software
First things first.  Get AudioWeaver up and running. 

DSP Concepts (AudioWeaver) Account
Open up an account with DSP Concepts (https://dspconcepts.com/).  This is required to get the software licensing to work.

Word of advice: when creating your account, do not use the fancy automatic browser secure password generator.  Pick something you can remember or you will find yourself fumbling around your browser settings trying to find the password so you can cut an paste it in.

The Nexus unit comes with a license which is sourced and managed by Danville.  It is updated yearly, so don’t worry when it starts warning you it is soon to expire as it will work the day after. 

The Software Package
Danville has their own version of AW which they send you before the Nexus arrives with an email containing a DropBox link.  It’s about 700MB of Zip file to download.  Having a speedy internet connection is nice.

HAL also sends pre-written code to turn the Nexus into a DAC for the first part of the installation and testing.

Install the XMOS Drivers
These are supplied in the zip folder and it is pretty straight forward.

The Trickery When Installing AudioWeaver
Everything to get the software up and running is in that zip file but there is a little trickery you need to do after the installation. 

Post Install
1.   Create a folder called Archive in C:\DSP Concepts\AWE Designer 8.C.1.3.B Standard\Bin\ (This path is the default path for the windows installation.)
2.   Copy these files from C:\DSP Concepts\AWE Designer 8.C.1.3.B Standard\Bin\ to your newly created Archive folder.
a.   AWE_Server.exe
b.   AWE_Server.ini
c.   FrameDll.dll

Now that those are backed up, we overwrite them with the files of the same name found in the zip file provided by Danville.

You now have a Nexus friendly version of AudioWeaver.

Firing AudioWeaver Up
Use the shortcut the installation put on your desktop.

Login In
When starting AudioWeaver it asks for your “DSP Concepts” login.

Two Windows for the Price of One
after you enter your login in details, two AudioWeavers windows open up. 

One is called AWE Server.  This has connectivity related info.  The other is AWE designer and it looks a lot like Visio.

Connect The Nexus
The nexus comes with a USB B to A cable (the same that most old school printers have) if you do not already have one. 

Connect the nexus to your computer and then turn the nexus on.

Open the “Server” window and from the top menu select “Target” and then “Change Connection”.  This connection entry is defaulted to “Native”, click the down arrow in the box and select “DanvilleXMOS” and then close.

You will see under the “Output” tab a heading of “Target Information” with the dspNexus as the name.  If you don’t, something went horribly wrong.  Let HAL know.

Import Files
Import the file Rich sent you called dspNexus_AWD_multifeature-DAC8-2xxxxxx.awd (the “x”s are the version number).

Load the DAC functionality to the dspNexus
There is a blue icon that looks like a “Play” button.  Click that and AudioWeaver will do its thing for a minute to compile and upload this DAC functionality to your Nexus.

Test by Playing Some Tunes

Safety First - Turn the volume down on everything you can turn your volume down on. 
Do this with every new thing you connect to the Nexus.  No one wants surprises in this arena. 

Now your Nexus is a very nice functioning DAC that we can start testing. 

Keep your USB connection to your computer.

Test the Ports (Plug Stuff In)
The easiest way to accomplish the first test is to plug in some headphones, hit the youtubes or your favorite music player and listen.

More tests and if you do not have headphones:
My headphones only played one channel.  However, I was using a potentially janky and very untested adapter, so I will not blame the Nexus yet.  I sprung plan B into action (which is the next step anyway) and plugged the outputs from the number 4 and 5 XLR outs into my pre-amp and tested that way.  It worked!

The Nexus has XLR outs 1 - 4 assigned to the right channel and outs 5 - 8 assigned to the left.  Test all channels to make sure it is good to go.

Hooking Up Your Sources

BEFORE DISCONNECTING THE COMPUTER FROM THE DSPNEXUS – Go to the server window and click the disconnect check box in the lower right corner.  This finalizes the connection properly and makes sure your configuration stays on the Nexus.  Think of it as safely removing a drive, but Danville really means it!

Conclusion of Initial Install and Testing
At this point I was for the most part done using my computer so I connected my streamer via the USB port.  I use a Raspberry PI with DietPi and the Roon bridge.  I also have an older Linn Majik that I added to the system for reasons stated in the post above.

I hooked my current pre-amp up through the analog section to watch a show and test how that works. 

I may use the phono-stage capability in the future but still trying to figure out how to get all my sources routed through dspNexus effectively.

There You Go!
You are now able to play music through the DAC, if not, I suggest calling HAL at this point.

I believe the next procedural post is adding in the active crossover programming and getting the timing right.   :popcorn:
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: HAL on 15 Sep 2023, 07:42 pm
Kazoom,
Great write-up of the EA dspNexus 2x8 system setup!

Only comment is that the Right channels are 1-4 and the Left channels are 5-8.  That should put the violins on the left and double basses on the right.  My typical test to see if I did connect it correctly.

Getting the package ready with the HAL MS-6 and CLIO Pocket to make the crossover measurements to get the NX-Tremes system running as a 3-way XO with your servo subs.  The MS-6 will run the CLIO Pocket for measurements and can act as the ROON Bridge from the ROON Core system via Ethernet or WiFi.  I would use a 5G WiFi connection for music transfer if not hardwired Ethernet.

If you measure the distances from the NX-Tremes to your chair and the center baffle of the servo subs to your chair and see what the difference is, that becomes the time delay needed to time align the speakers.  A great thing to do with the DSP crossover.  Each channel can have a different time delay if needed.  Have done that for one customer that has his woofers and subs running to make flat response with REW measurements and the PEQ's filter data it generates.

Rich
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Kazoom on 15 Sep 2023, 08:45 pm
Fixed the Left/Right in the post.  I rolled the dice on that one.   :lol:

I did test by killing the left channel in Roon and sure enough, music only came from the right.  So got it half correct.   8)

Dialing this in is going to be a ton of fun.
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Jaytor on 15 Sep 2023, 10:10 pm
Glad to hear you are making progress. I've had my dspNexus for a couple of weeks. It took a little finagling to get the USB to work from my computer. I adjusting the timeouts as explained in the dropbox installation doc, but it was still not working reliably to generate files on a big design like the three-way crossover.

I had left my dspNexus powered on and connected to the computer over night and the next day, it worked fine with no hickups. So my guess is that the timing changed subtly after it had warmed up for a while.

I bought an inexpensive active speaker (Rockville RPG8) to use for testing. This has a volume control so I can turn everything down when I'm playing with filters, and I don't have to be concerned with damaging my expensive speakers.

I am hoping to find some time this weekend to dig into this to see how much I can get down in setting up the full crossover. I am planning to use this with my Line Forces and OB subs, so I'll be bypassing the passive crossover completely.

I'm thinking of starting with 24db/octave crossovers at 180Hz and 1800Hz. Rich - do you think this sounds reasonable?

Kazoom - are you using IIR or FIR filters for your crossovers and PEQ?
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: HAL on 15 Sep 2023, 10:27 pm
Jaytor,
The crossover points sound reasonable for the BG NEO10 and GRNEO3 drivers.  Been 8 years since I measured the first pair at Danny's with the dspMusik 2x8.

I typically use 8th order XO's with planar drivers.  Works well with the BG NEO10/GRNEO3 combination in the Super Mini's using the dspNexus 2x8. 

Also add the time delay offset if the line array and servo subs are offset in distance to the listening position.  That was a good sounding change when we did it for imaging.

If you do use FIR filters there is a change to the AWE Server INI file that eliminates a weird USB related signal that is being worked on for FIR's.  The change is being checked in a new system on Sunday, so will see if that solves the issue until the fix is implemented.

Rich
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Kazoom on 16 Sep 2023, 02:13 am
@jaytor

I have not done anything with filters or building the cross overs yet, nor do I totally get the technical ins and outs between the two and why FIR is considered better for audio and IIR for video but yet both are used in both applications (engineers are so confusing).  My suspicion is I will be using FIR but I am no audio engineer, and will take HALs guidance to get this up and running. 

Once I am stable, happy and my configuration is backed up and locked away offsite I will likely venture into playing around with pretty much anything someone thinks should be tried.  My love for hi-fidelity is only surpassed by my love to mess with stuff to try and find a better way.  From your posts on the various sites we frequent, I think you are in the same camp.  😀

Part of the purpose of my thread is to get ideas to try from folks way more versed in the technical aspects.

BTW, I would love to hear your set up the next time I am in the Portland area (I believe you are around there), you have a ton of experience and ideas I would love to steal...  I mean listen to.   :green:
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Jaytor on 17 Sep 2023, 12:57 am
Quote from: Kazoom on 16 Sep 2023, 02:13 am
@jaytor

BTW, I would love to hear your set up the next time I am in the Portland area (I believe you are around there), you have a ton of experience and ideas I would love to steal...  I mean listen to.   :green:

I'd be happy to have a listening session when you are down in Portland. I assume you live in the Seattle area? Before moving to Portland, I lived in Sammamish, Bellevue and Redmond.

I played around with the dspNexus a bit today and I'm a bit confused. The sample 3-way crossover design seems to be working except for output 1. Instead of the high-pass output from the right channel, it seems to be outputting a full-range single from the left channel. All the other outputs are working as I'd expect. I don't see anything obvious in the Audio Weaver design, but it is pretty complicated and I'm FAR from being competent with this program at this point. I sent an email to Danville to get some assistance.
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: HAL on 17 Sep 2023, 01:11 am
Jaytor,
Post a screen capture of the crossover block diagram and I might spot something for some feedback.

Just need the crossover section not the upper level controls block diagram.
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Jaytor on 17 Sep 2023, 02:36 am
Quote from: HAL on 17 Sep 2023, 01:11 am
Jaytor,
Post a screen capture of the crossover block diagram and I might spot something for some feedback.

Just need the crossover section not the upper level controls block diagram.

Thanks. Here it is.


(https://www.audiocircle.com/image.php?id=256705)
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Low distortion on 18 Sep 2023, 05:13 pm
Can someone explain to me what this product has over the Minidsp Flex 8?

https://www.minidsp.com/products/minidsp-in-a-box/minidsp-flex-eight


 Minidsp shares the measurements taken with an APx555, it’s dead easy to use, and only costs $599. Has anyone compared the 2 subjectively? And do we know the objective measurements of the Nexus?

Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: david45 on 18 Sep 2023, 06:04 pm
Already asked
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Jaytor on 18 Sep 2023, 06:48 pm
Quote from: david45 on 18 Sep 2023, 06:04 pm
Can someone explain to me what this product has over the Minidsp Flex 8?

https://www.minidsp.com/products/minidsp-in-a-box/minidsp-flex-eight (https://www.minidsp.com/products/minidsp-in-a-box/minidsp-flex-eight)


Minidsp shares the measurements taken with an APx555, it’s dead easy to use, and only costs $599. Has anyone compared the 2 subjectively? And do we know the objective measurements of the Nexus?

Just asking out of curiosity

At this point, the dspNexus uses essentially the same DSP as the miniDSP you linked, but the dspNexus uses a modular architecture and Danville has promised a free upgrade to the 21569 which is way faster, particularly for FIR filters.

The Audio Weaver software is certainly more complicated than the software Dirac includes, but also WAY more flexible, so kind of depends on what you are after.

I would expect the dspNexus DACs and analog hardware to be higher quality. The power supply is certainly higher quality, and it has balanced outputs with programmable analog gain. With the miniDSP, you have to give up more of the DACs dynamic range for level adjustments between outputs.

The dspNexus includes a high quality analog input if you want to use analog sources, and a powered microphone input allowing the use of a higher quality mic for measurement and calibration.

The miniDSP is a great value if you want something simple though.

Rich may be able to chime in with more detail.
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: HAL on 18 Sep 2023, 07:30 pm
Let me see if I can help with the dspNexus 2x8 system understanding of differences.

The EA dspNexus 2x8 uses an ADSP21469 UAC2 dspBlock as its DSP engine, this is to be updated soon to the ADSP21569 UAC2 dspBlok that will be more capable with the MAC and FIR processing of long FIR's done simultaneously with more memory available.  There are customers already building FIR based crossovers that require the ADSP21569, so those will be upgraded for free for the Early Adopter units.  The final version dspNexus 2x8's will the ADSP21569 dspBlok.

The system uses an AKM AK5578 ADC and four AKM AK4493 DAC's in the standard 2x8 configuration all balanced connections.  It has remote selectable ADC, S/PDIF and USB2 inputs, where the ADC's can be used for line input or RIAA phono input via a balanced connection.  Both the ADC and DAC's have level gain controls and also volume controls on the DAC's via the remote. 

The system it totally modular, so the ADC, DAC's and DSP are upgradeable as time goes on.  There are already plans to offer an AKM AK4499EX version of the DAC boards.  A prototype of the AK4499EQ boards was done at LSAF2023 with very high praise from both consumers and companies who attended to listen.

The AKM AK4493 DAC's are 32bit so that they have extended range for digital volume control.  The AK4499EX DAC is the next generation DAC that will be an upgrade.  I have replace a Pass Labs Aleph P and Ono with the dspNexus 2x8 as the front end.

Audio Weaver is a considerably powerful programming system for the dspNexus DSP.  Every channel is independent and programmed as needed.  This way Filters and PEQ's can be put on the channels where they are needed, not just a given number per channel. 

The system as pointed out has an ASIO USB driver that works with PC and MAC, and will work with Linux if the person setting up the system knows how to go into their audio system and select the correct output. 

There is no RPi4 in the system, and only a Windows PC can be used to program the dspNexus.  Once the program is the way the customer wants, it can be flashed to the DSP and will always run on power-up.  It can also be changed at anytime with Audio Weaver for updates to the block diagram.

Audio Weaver has high precision audio filters available that have been compared to the typical stock DSP filter topologies that have lower distortion.  That is a propriatery capability of the system.  The Linkwitz-Riley multiway crossovers are one example of a high precision filter.

The system allows time delays per channel in either sample, time or distance options to correct for things like main and subwoofers being placed at varying spacing to deal with room acoustics. 

There is a headphone output that disconnects the speaker feeds automatically when plugged in.  It becomes a full bandwidth DAC channel and the headphone amp will driver planars like Audeze LCD-MX4's. 

Next to the headphone output is a phantom powered XLR mic input for acoustic measurements that is compatible with Room EQ Wizard.  This is being used by customers to dial in the room response below 300Hz for multiple woofer/sub configurations. 

This has also been A/B'd in a DEQX Express 2x6 system with a DCX2496 running the subs and the customer chose the dspNexus 2x8 as it sounded better.  He now uses it with REW for his acoustic measurements and PEQ settings with his ACO measurement mic and preamp. 

I have suggested that the dspNexus 2x8 be tested with one of the Audio Precision systems that Danville has access to via another company.  They also know about ASR doing measurements.  That is their decision.

If you have any other questions, please let me know.
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: david45 on 18 Sep 2023, 07:44 pm
Quote from: Jaytor on 18 Sep 2023, 06:48 pm
At this point, the dspNexus uses essentially the same DSP as the miniDSP you linked, but the dspNexus uses a modular architecture and Danville has promised a free upgrade to the 21569 which is way faster, particularly for FIR filters.

The Audio Weaver software is certainly more complicated than the software Dirac includes, but also WAY more flexible, so kind of depends on what you are after.

I would expect the dspNexus DACs and analog hardware to be higher quality. The power supply is certainly higher quality, and it has balanced outputs with programmable analog gain. With the miniDSP, you have to give up more of the DACs dynamic range for level adjustments between outputs.

The dspNexus includes a high quality analog input if you want to use analog sources, and a powered microphone input allowing the use of a higher quality mic for measurement and calibration.

The miniDSP is a great value if you want something simple though.

Rich may be able to chime in with more detail.

Thank you for the reply, Jaytor.

You set the bar pretty high with your passive crossovers and at the end of the day, what matters is how it sounds in your system. I’m super happy to hear that you can get the free 21569 upgrade. Hopefully it’s a good fit for you when you get it to work and everything is dialed in perfectly :)

For the rest of us average users, measurements, subjective comparisons and ease of use comparisons would go a long ways.
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Kazoom on 19 Sep 2023, 05:02 am
I will post measurements as I pull them.

Clio arrives Tuesday afternoon as well as the HAL music server, so lots to get busy with.  Will likely do a recap of the day on Thursday with the procedures, impressions and next steps.

But first a little house keeping, discoveries and further impressions.

XMOS and RaspberryPI
I let the RasberryPI streamer play over night trying to reproduce the distortion issues I mentioned, and so far I am not able to.  I am quite confident that the Roon settings have solved that issue.

BlueTooth
Tried out the Bluetooth connection today. Aside from my car and work headsets, in the last 10 years, I have not used bluetooth for anything audio in the home.  I have always noticed the degradation in the sound and just did not bother. 

I will assume the technology got better since I last tried because The dspNexus did one heck of a job with my Qobuz stream from my phone.  I am most impressed.  Bluetooth is a definitely a viable source.

Menu Customization
You can customize the menu.  (I spoke too early in my last post).  While playing around I found that you can turn off any un-used outputs and they do not show up in your selector. 

Very happy about that.

DAC Impressions after much more listening
I spent quite a bit of time comparing my current DAC to the "dspNexus as a DAC", and to my ears, it is indeed better on tracks were details really count. 

For example, one of my favorite testing tracks: "Sheffield Lab: Drum and Track disc".  The room they play in reached a new level of life I did not hear before.  I also noticed more feeling/realism with the dspNexus.

Another group I like to test with is "The Dead Weather".  Alison Mosshart's vocals can have quite a bit of sibilance that gets vicious on the ears at higher volume levels, but with the dspNexus I could crank "I Can't Hear You" without without feeling pain.  Still sibilant (as I believe was intended), but detailed and clean.

Enough for Now

What really counts is the final product.

It sounds pretty good so far and we still have the crossovers and timing to dial in.  And then we can see what it does with room correction.

Fun times ahead!
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Kazoom on 20 Sep 2023, 04:28 am
Exciting day for me.  Not so exciting for posting but will post anyway to keep the thread alive and do my best to make it at least entertaining.   :D

We used the Clio and HALs MS 6 (learn more here https://www.audiocircle.com/index.php?topic=175173.0 (https://www.audiocircle.com/index.php?topic=175173.0)) to measure the crossovers.

The MS 6 was preloaded with Audio Weaver and Clio software, so that little box, with only an Atom processor, was pushed to its limits performing streaming, measuring, dspNexus design loading and email client duties.   

Mapping the crossovers was not the easy task we initially thought it would be.

The simply mad genius wizardry that Danny employs in his designs (including inverted drivers) made this procedure trickier than originally anticipated.  I am just saying that you should not let that humble Mr. Good ol' boy, "Hello Everybody, I'm from Texas" charm fool you.  That man's skills are not to be underestimated or trifled with.  I watched him bring my second gen B&W 801s to a whole new level by overhauling the crossover design.  Furthermore I was told by an Emmy winning studio designer that Danny's set up is the best thought out system he has ever heard.  Straight up unsolicited bona fide kudos!

Mad respect!  :green:

Enough kudos, I now digress.

So HAL and I persevered.  We scratched our heads.  We solved a few puzzles (ok, so HAL solved a few puzzles anyway), and got what we needed in relatively short order.  I probably should provide full disclosure; my roll was really just taking pics and putting alligator clips where HAL told me to, but it was a team effort and we prevailed none the less. :)  :whip:

Due to schedules and the work HAL took on to translate the measurements into an AudioWeaver design, the next play day is looking like Friday.

So Friday will bring something for everyone's reading pleasure as they pre-funk the weekend.  :beer:
 
:popcorn:

PS - As I finish this post listening to Edgar Winter's "Frankenstein" on the "dspNexus as a DAC only" with HAL's MS6, I must share that it sounds incredible enough to.... well.... share.   :thumb:
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Jaytor on 21 Sep 2023, 05:32 pm
I had a video chat with Emilson from Danville this morning to discuss the problem I was having with output 1. Turns out that the channel 1 output mux was set to test mode so was selecting the wrong signal. Apparently this is the way it defaulted from the factory. To fix this, I had to select the Menu on the remote and then enter the Measurement function. I didn't have to change anything - just hit menu again to go out of measurement which set the output mux to normal operation.

The output is working as I would expect now so I can start working on testing on my speakers.

Emilson also explained how the output level adjustments are done. The gain block in the Audio Weaver design for each channel can be adjusted for fine adjustments, but the Audio Weaver also includes an analog gain block which can be adjusted with the remote. Click on Menu and then use the left and right arrows to find DAC Settings. Selecting this option with the center button shows a sub-menu which allows selection between DAC level, DAC delay, polarity, etc. The level of all the DACs can be adjusted in 3db steps to set the maximum gain for all channels. This is done with the DAC Level - All function.

Selecting the DAC Level 1-8 function allows the level to be set for each channel separately. There is a < or > symbol shown on the display to indicate whether you are selecting the specific DAC channel or the level for that channel. Clicking the center button on the remote selects which way the < or > is pointing (left to change channel, right to change level). In this case, the level can be adjusted in 0.25db steps. Every 3db step is done by the analog gain adjustment hardware, and the smaller steps are done by adjusting the digital levels feeding the DAC using the DSP.

Next step for me is to make some speaker patch cables so I can connect my individual amp channels to the drivers. Once I know that the dspNexus is going to work for me, I'll do something more permanent with higher quality connections. I'm thinking of building an amp for the high frequencies that will sit where the passive crossover currently resides and will include a speaker-level pass-through for the mid frequencies to connect to a  separate external amp. My sub towers which use the Rythmik HX800 amps will connect to the low-frequency channel.

I'm currently thinking of using my 300B SET monoblocks on the mid frequencies (180Hz to 1800Hz) and building a small class A/B amp (probably a composite chip amp) for the upper range.
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Kazoom on 27 Sep 2023, 12:08 am
Howdy folks,

Missed my Friday deadline and apologize profusely.  But without further delay, here is an update on where things are at and how I got there.

House Cleaning
First thing I knew I had to do was sort out a buzz in my Folsom amp.  I spent my Thursday making sure all the wires were twisted, secure and what not.

Unfortunately, after all that work, the issue was still there.  I did discover that if I put my finger on the input cap I could pick up a local radio station.  So my amp is now a receiver, not exactly what I was looking for in my new setup.  :roll:

Thank goodness I have an old multi channel Rotel amp laying around that is known for good mids and highs, so it was an easy replacement.

So with the Folsom down, the new line up is as follows:

Prep Work and Unsolicited Product Promotion

We needed to figure out the gain from all these amps so they can be aligned properly.  Manufacturer sites have all these specs, so ez-pz.

The next on the list was to get the cross over values.  This went pretty quickly using the Clio Hal was kind of enough to lend me.  I would dive into the procedure but it happened so quickly, I can not even remember it.

What was cool of Hal, or a very clever marketing tactic, was him sending along one of his MS-6 Music Servers with the Clio software on it.  Very crafty of him as this thing sounds way better than my Linux based Raspberry PI that received high praises for measuring well on ASR.

The MS-6 sounds so much better due to Windows actually having done something right in how they handle audio.  Hal explained that Paul Allen (the VC who started Microsoft) is a hardcore audiophile and made sure they got that right. 

So if you are currently streaming with Linux or Mac, I highly recommend giving the MS-6 a try.  It is quiet and works great.  The price is nice too.  I don't think I could build my own for much less.

Another bonus was that it was plug and play and did not require adjusting any Roon settings.

So that little piece will not find itself in the box when I ship the Clio back.   :nono:

Up-sell executed successfully.   :thumb:

Measuring Time

Hal promptly got to work on the first draft of the Audio Weaver design and soon I had the an AWE file to upload in my inbox.

Rookie Mistakes to avoid
Yes, I was told, but for some reason it did not stick.  I wasted a ton of time on Friday trouble shooting my mistake of connecting all the amps in reverse order.  I thought I had blown my tweeter when it was not responding to the bass signal being pumped into it.   :duh:

The connections by default are as follows:

I got that sorted out and we were off to the races.  Well until rookie mistake number 2.

Rookie Mistake Number 2

Before measuring with the DSP Nexus, RTFM!  (Read The Flipping Manual) or you will experience what is known as a "PEBCAK" error (Problem Exists Between Chair and Keyboard).

There is a video that explains how things get measured and how to flip through the menus for more detail, but I will provide an abridged version to give you a feel for how this works.

That mistake only cost me about 30 minutes.

Taking Measurements


When measuring with the dspNexus, you need a phantom powered XLR mic which you plug into the front of the box.

You will plug whatever you are running REW on into the USB port on the back of the dspNexus.

Set your REW preferences


The dspNexus has a "Measurement" mode that you can get to by hitting the menu button on your remote control.  Scrolling right you get to the "Test Output" option.  From here you select which output you are testing (refer to the channel assignments mentioned earlier).  I have always measured with a USB mic connected to my laptop, and my lap top connected to my DAC or an analog in, so this was new to me. I dont know if this is typical of DSPs or not, but it is really nice to work with.

You do need to tell REW which speaker you are measuring, but other than that, it sends an isolated signal to the section you want to measure and sends the mic input back to REW.

Beyond the individual channels, It also has a L/R 2, L/R 3 and L/R setting that sends a signal to all your drivers in a 2 way setup, 3 way setup or, as in my case, the whole dang side you are measuring, respectively.

This made measuring pretty quick and easy Compared to the traditional ways I am used to.

So with Hal's version 1 (nothing but crossovers set up), this is what we were working with.
(https://www.audiocircle.com/image.php?id=256954)

The rest of the day was "wash, rinse and repeat" with Hal quickly turning around a new Audio Weaver file for me to measure with.

It should be noted that with each new iteration you need to be paying attention to how much you are abusing the CPU with the changes.  This is displayed in the AWE Server window.

For the most part of the day, the CPU was pegged at around 75%.  It was not until Hal started adding a few PEQs around version 7 or 8 did we see it hit 80%.  PEQs are costly in terms of CPU.  Mine sitting around 80% is actually really good, as I am told many guys are tapping out around 95%. 


IIR filters are much more efficient than FIR filters, so that is a place one can save cpu cycles if you find yourself running into a wall.  The upgrade should free up some of the CPU and enable more FIR implementation, if that is needed. 
@Jaytor - to answer your question from before, Hal did add in some IIR filters for bass management.  And we have been toying with FIR filters.

Actual measurements

As tedious as this work can be, I love hearing something barely listenable transform itself into that which sounds pretty darn good.  I still am always in disbelief that what I am hearing on the first iteration will actually go somewhere.  When it eventually does, then it is like Christmas for me. :xmas:

Within a few hours we were on version 11 which produced the response below. 
(https://www.audiocircle.com/image.php?id=256957)

This is a solid place for me to start playing with adding PEQs to AWE for room correction (which I will chat about in my next post).

 :popcorn:


Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: HAL on 29 Sep 2023, 12:37 pm
The Audiomatica CLIO Pocket is back from Kazoom and ready for the next project. :D

Always fun to read threads like this!
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Kazoom on 5 Oct 2023, 11:04 pm
Hello Audiocirclers!

I have been quite busy but faithfully using my little spare time to play with the dspNexus.

I am here to tell you that this thing is nuts.  After hitting a few pitfalls typical of the "unversed in audio engineering folks" like myself, it is sounding really good.  I am at a point were I have a good enough version of the Audio Weaver design to revert to when my next experiment goes horribly wrong and still be happy listening (and today I reverted version 17.6 back so I know it works).

This journey has been and still is, one heck of a learning experience with equal amounts of ways to succeed and screw things up.  It is just so dang flexible and makes you want to understand more so you can try new things.  If you enjoy revisiting your music collection every time you upgrade a piece of equipment, the dspNexus provides you that experience every time you tweak the design for the better.  I am sure it will slow down as you get closer to your version of perfection, but it is so much fun (and at points frustrating) on the way.  And if you don't like the changes, the reversion process takes minutes and you are back to your comfort zone.

Hal kept with me to achieve stability and for that I am most appreciative.  The support he has provided is exemplary.  He deserves a JD Edwards award for best customer service from a HiFi Lab. :thumb:   :notworthy:

So lets get into it.

Impressions

There is now an extra level of clarity in terms of separation of instruments.  Compared to running Roon with decent convolution filters, the Nexus wins in this department.  And that is achieved despite using a very old Rotel amp for the mids.

Soundstage is wider, deeper and in general more defined.  Having the timing right really helps  The top of the line DACs are probably not hurting things either.

The music has more life.  I am missing some of the details I had going before, but I am confident that with time and a better measurement mic (the uncalibrated behringer is definitely the weakest link) I will surpass my previous listening experience on all fronts.

There is now a ray light at the end of the proverbial tunnel and for that I am quite overjoyed.  It still needs work, but it is definitely on its way.

Issues Discovered and Lessons Learned

While fiddling around with REW measurements and entering the generated PEQ filters into my design, I picked up a horrible bit of distortion in the woofer section. 

It went from "I wonder what the hell that is?" to "this simply wont do!" during a track I use to test bass called "Chameleon" by Trentemøller.  It sounded like a snare drum vibrating with each pulse of the bass, but there are no snare drums in that song.
:wtf:
We tried all sorts of tricks to make it go away, and it just would not budge.  While some other less bass heavy tracks would mask it, it was very annoying.

So after quite a bit of trouble shooting there were a couple of things discovered:

In Audio Weaver, they have modules called "second order filter cascades" (SOFs).  This is where you add the PEQ filters you generated in REW.  You can actually enter a whole array of different filter types and as many PEQ values as you want as long as you dont push your CPU beyond 95% (I am currently bouncing between 85% and  90% depending on what I try).  You can adjust the number of filters you pack into the module and turn them on and off as needed.  You can even do this during run time, but I am not sure that is a best practice.  You will get a click sound while doing so.  Not a scary pop, but more of a chirp.  It did not bother me or scare me YMMV.  Consider yourself warned.

My "distorted" design has a SOF module HAL built with PEQ filters.  I fed that into another SOF with filters I had come up with.  I was thinking maybe I should not feed a SOF into another SOF.  So I combined the two and  the distortion was eliminated in one speaker while significantly reduced in the other. 

Figuring I was on to something and pondering that maybe the order in which the filters are listed in the SOF may have an impact, I searched the googles for answers. 
I found a video from Emilson discussing Second Order Filter modules that shed light on what was going on.  https://www.youtube.com/watch?v=6SNLdhrhez8

In brief, there are two different types of Second Order Filters.  Standard ones that I stumbled across and implemented in my design, and a High Precision version (which Hal had been using).  In our 192kHz dspNexus the standard ones allow distortion through and the High Precision ones do not.

I gave the high precision variant a try and... Bingo! Distortion was gone!

New rule - only use the High Precision version of filters! 8)

Its All About the Timing

When we first started setting this up HAL wanted to know the distances between the speakers/subs to the listening position.  I took these measurements with a tape measure as accurately as you can with a standard tape measure.  Hal plugged the correct delays for the subs into my design.

Since then I have moved the speakers around adjusting toe in realizing I might need to revisit the distances.

Now I do not know how exact this really needs to be, but if hooking your amp up directly to the drivers is an improvement over using 6 ft speaker cables, then i would think getting the timing as accurate as possible matters.  So that I did.  Off I went to the local home depot to get a decent laser tape measure that I mounted on my wife's camera tripod and marveled at the accuracy.   :D 

My left sub is the furthest away so I adjusted the timing from there, I also adjusted for the slight difference in how far the speakers are from the listening position (the delta between the two speaker distances was less than 2cm, but it was a difference none the less). 

I likely will repeat this process when I get seriously close to a "Final" design, but for now, they are within a +/-1.5mm of perfection (at least according to the fine people at Bosch Laser Tape Measures).

Test Tracks and Further Impressions to Support my Previously Stated Impressions

Well it is not all dialed in, but the sound stage and separation of instruments is at a new level for my system. 

The version of "Cantaloupe Island" on Herbie Hancock's "Dedication" album is a great indicator of sound stage.  When he starts hitting the keys the sound is everywhere.  Far to the left, right, and behind you.  It literally sounds like it is down the hall behind me on the right at times.  That track should be filling your room like surround sound. 

Before the Nexus it was wide, but now it is more prominent everywhere and even more locatable. 

My next sound stage track was Peter Gabriel's "Growing Up".  This track can really go off on a clear sounding system, but now it has really opened up and is bouncing all over the place.  Peter Gabriel takes his audio engineering seriously (there is one song with 5 different microphones my opera singer buddy really likes).  You know your system is performing when Peter Gabriel songs take on a whole new life you did not know they had before.

Pin-pointing the location of all the instruments in Henry Mancini's "Pink Panther Theme" is easier than it ever has been, its like I could shoot a spit ball from 30 ft and hit the stand up bass player between the eyes.

For reference, there is a great set of test tracks that I use listed at the end of this room correcting convolution files tutorial from Obsessive Compulsive Audiophile https://drive.google.com/file/d/17BwTGv933w4id3B3PFHy2zjyijtgZLDX/view  he does a great job of explaining what you should hear from each track to validate your system is set up correctly.

I will include an expanded list of songs I test with in my recap.

Post Script of this Post

So there we are.  I have a listenable, not yet perfect design that will carry me through until I achieve that awe inspiring sound I have been chasing for over 25 years.  I am confident that the dspNexus is the right tool to aid in my quest.

My next post will be a recap where I re-visit my check list to see if my initial goals were achieved, what I love, what I don't love (there are couple things) and anything new I may have come across between now and then.  I will include graphs and maybe even a picture or two.

Until then, I am going to keep playing tunes, crashing the system and chasing that "final" design that inspires awe.

 :banana piano: :drums: :guitar: :rock:

 :beer:
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Kazoom on 14 Nov 2023, 11:21 pm
Howdy folks!

I have had quite a bit of time to play with the Nexus and it is time for my final write up.

It has been a very pleasant journey and many thanks and kudos for HAL’s continued support!

Goals Met

Lets start with my original goals and if they were met:

Single volume control for the whole system with a remote

This was achieved.

I still need to use my pre-amp to manage the many sources I have in my system, but I have that set at 12 o'clock and control the volume through the Nexus.

My turntable is my only true analog source, but the Nexus only has one USB in, one Digital RCA (S/PDIF) and one Analog in to work with. 

I am less concerned with Audio Nirvana from my video sources and am happy using the fiberoptic out from my projector, but with no fiberoptic "in" on the Nexus, I am forced to use on of my DACs via the Pre-Amp.

A fiberoptic S/PDIF port would make a world of difference and free up the analog in for me to play with the RIAA functions for my turntable.  Not a showstopper, but I think there is a lot of opportunity I will miss in using the Nexus as a phono-stage.

Room Correction for all sources, including analog

Definitely achieved. 

My vinyl has never sounded better, and my AV, even when routed through my Topping or Schitt Gungnir has taken on new live.  Whether I was watching David Byrne’s “American Utopia”, Roger Waters “This is not a Drill”, Metallica “Through the Never” David Gilmour “Live at Pompeii” or any NPR “Tiny Desk Concert” it was sublime.

The improvement to vinyl was so profound that my wife mentioned it might be time to upgrade my Dennon DL 103 cartridge.  I knew what she really meant was that I should buy a Small Audio Manufacturing “Reference” Turntable and a Hana ML cartridge.  The turntable is en-route as I type.   8)

I have a collection of around 2000 LPs most of which are Jazz.  I am really looking forward to re-discovering them.

This turntable can accommodate multiple tone arms, so having the pre-amp in between works out when I splurge on a second tone arm.  I will eventually use my two Parks Audio phono stages (Budgie with step up transformer and the Puffin) to accommodate that.

Move more of the bass to the subs

Accomplished.

HAL setup the sub crossovers at 50Hz.  So the subs are more in play.  One thing to note is that the bass is significantly improved.  This is primarily due to the timing alignment.  With the Nexus, if I move my subs around I just need to measure the distance from the listening position to the subs and speakers, enter the values into AudioWeaver and presto! it is properly time aligned.

Easy and affordable upgrade path

Accomplished.

This is met in spades.  As you may recall from my thread starter, I am using a pretty janky method to connect the amps to the speakers (speaker cables into cheap connectors) as well as using my six channel Rotel amp to drive the mids.  Despite these shortcomings I am thrilled with the sound and can only imagine what connecting amps directly to the speakers will sound like.  My next goal once I recover from the turntable purchase is to buy a couple of three channel Hypex or Purifi based class D amps and place them directly behind the speakers.

Higher quality DAC for my BluRay player

This is accomplished. 

I can connect my Blu Ray using the RCA S/PDIF directly to the Nexus and as I stated earlier, the DAC in the Nexus is definitely higher quality and an improvement over my Topping D90 or my Schitt Gungnir.

Ability to learn more about sound engineering

Oh my, did I learn, and am still learning. 

The ability to control all aspects of the signal path with AudioWeaver has opened up a whole world of possibilities.  While there are certain things I just wont touch, seeing the end to end chain visually has immersed me into all that goes on in getting the signal just right.  The power of being able to add as many PEQs as I want to flatten out the response is not available with any other product I know of.  Most DSP implementations only allow for 10 PEQ adjustments, I hear that one Nexus user has over 45 PEQ adjustments flattening out their response.  If you have any kind of OCD, the Nexus will not disappoint.

Fun is an expectation

Ok, this journey is fun.  Very fun.  Very frustrating at times, but so rewarding once you figure it out and bust through a barrier.

I want to add that HAL was there to help throughout and a big part of what made this so much fun.  Again, Kudos to HAL!   :thumb:

As an early adopter, I hope to discover challenges and opportunities that lead to product improvements and solutions

I do not know if Danville Signal is paying attention to my thread, but I do know that HAL has sent a few of the issues we discovered over to them.  A few of these concerns should be addressed with the upgrade to more powerful chips.

Anyway, here are the challenges I see with this early version of the DSP Nexus:

•Power on/off and Standby Mode Pop Noise
This is a major concern.

Every time you turn the Nexus on, off or go into or out of standby you get a scary pop to the speakers.  You always need to turn off all the amps before turning the Nexus on.  This is an annoyance I do not believe belongs in a $3000 piece of kit. 

There is another Nexus owner out there with some pretty spendy Beryllium tweeters who rightfully is very concerned as he starts to set up the Nexus. 

I really hope that Danville Signal addresses this in the upgrade as I suspect this is something that will keep others from taking this journey.

•FIR Filters are not advised
This should not be an issue after the upgrade, however using these led to all sorts of weirdness from 2 seconds of odd sub rumbles in between songs to very audible distortion in the woofer section.   Stick to IIR with the early adopter versions.

•S/PDIF out not working
This is not something that I am overly concerned with right now so I did not apply more than 15 minutes of troubleshooting so could very well be on my end.  Danville was informed of this issue.

•Nexus Freezes
This one I figured out.
If your PC/Laptop is connected via USB to the Nexus (which is often the case when playing in AudioWeaver), after re-boot/power on, there is a good chance your Nexus will freeze up.  Turn off your amps, unplug the USB and restart.  I have yet to burn a final AudioWeaver Design to my unit, so I do not know if that will remediate this issue.  I am also of the school of thought that is ok leaving their system on 24x7.  I am blessed with very cheap electricity and have never had an issue with any of my equipment as a result to leaving it on.

And of course, I am looking forward to hearing the improvements afforded by active crossovers

Expectation met!

Major improvements.  The imaging is incredible.  A lot of this can be attributed to the better DAC and switching to HAL’s MS-6, but getting the timing right has opened up the system beyond where it ever was. 

You know where everyone is on the stage, instruments show up in pinpoint locations, your listening room becomes the room they are recording in.  Close your eyes and you are in the studio, club or concert venue.  Even less than optimal recordings come alive, it does expose the lower quality, but even then, these recordings are more listenable than before. 

All the overused cliche audiophile reviewer buzz words are present, but now I feel like I know what they really mean.

In Conclusion

I am very happy I took this journey.  While the Nexus is really a heck of a tool for speaker designers, this is one of the few gems out there for audiophile types that does not have diminishing returns.  When closing that final 5% of the way to perfection, the Nexus has provided the biggest jump forward I have experienced with any of my audio purchases. 

In my opinion it is the most significant improvement I have made in my 20+ years of chasing audio bliss.  It significantly improves everything across the board and gives you the control to take it as far as you want.  I am really looking forward to the upgrade and adding hearing what FIR filters can do with the added processing power.

My Test Track List

I wanted to include my test tracks list as I personally am always interested in what other folks use and what they are listening for.

Turboweekend, 'Sweet Jezebel' on Ghost Of A Chance - This tests your room correction and quickly identify any unwanted ringing resulting from your PEQs being wonky.  I got this from Obsessive Compulsive Audiophiles (OCA) Test Tracks.

Pink Floyd, 'Time' on The Dark Side of the Moon - I, and 99% of the world know this song so well that any differences stand out.  I noticed a whole new level of life and power with the Nexus.  Especially in those early bass notes right after the clock chimes.

Norah Jones, 'Little Room' on Not Too Late -Another one from OCA.  This makes sure your toe-in/balance is correct.  Norah is dead center in this track.

The Beatles, 'Her Majesty (2019 mix)' on Abbey Road (Super Deluxe Edition) - Another one from OCA.  If your toe-in/balance is correct then Paul should be walking between your speaker, not in front or behind, but directly in between them.

Henry Mancini feat. Monica Mancini, 'The Pink Panther Theme (extended version)' on Ultimate Mancini - Another one from OCA.  This is a great imaging track.  Instruments are easy to point out on the stage with this song.

Commodores, 'Nightshift' on 20th Century Masters: The Millennium Collection: Best Of The Commodores - Just a very well Engineered track.  I listen to this for hearing how well the different instruments are separated.  Every instrument is clear and in its own space.

Herbie Hancock, 'Cantaloupe Island' on Dedication - This is one of the best sound stage tracks I have heard.  When he starts going off on the keyboards, the sounds will be all over the room, behind you and down the hallway.  Great sound stage test track

Black Sabbath, 'Black Sabbath' on Black Sabbath - Another OCA recommended track.  The thunder storm is above and the rain is hitting where it is supposed to hit.  OCA believes this is one of the best engineered albums off all time I have no reason to doubt his assesment.

Béla Fleck and the Flecktones, 'Flight of the Cosmic Hippo' on Flight Of The Cosmic Hippo - Great bass clarity track.  Victor Wooten reaches deep somewhere around the 2.5 minute mark.  Those deep notes are clear and tight when your subs are properly integrated.

Roger Waters, 'Three Wishes' on Amused To Death - This is a great sound stage song.  When the system is set up right, the woman's voice at the beginning comes from far left of the speakers, the chorus is above and the genie is powerful and clear

Trentemøller, 'Chameleon' on The Last Resort - This will put all your bass to the test.  Most bass issues will show up with this track.

Tool, 'Chocolate Chip Trip' on Fear Inoculum - Sound stage and clarity.  The drums roll off to the left and right and around you.  On my system they are coming from 4 feet in front and 10 feet outside the speakers.  The drums sound like an actual drum kit is in your room.  Love this test track.

Willie Nelson, 'God's Problem Child' on God's Problem Child - Good all around test for how balanced your systems sounds.  The bass is deep but balanced with the mids and highs nicely.

Jacques Loussier Trio, 'Little Fugue In G Minor' on Jacques Loussier Plays Bach: Encore! - Just a fun track that adds a drum kit to a classical song.  Well engineered and you can hear the bow hitting the strings.

Yosi Horikawa, 'Bubbles' on Wandering - If you have not heard this song, it is an auditory adventure.  Not an everyday listening song (at least not for me) but the various balls bouncing around is distinct and clear.  You here them bouncing and rolling across the soundstage.  There is a lot going on in this song and the system should be able to distinguish between all the activity.

Baba Blues, 'Help me through the Day' on Excavations: Blues Is a Rainbow - These guys play through a PA system, so the crunch and resonance on the guitar notes is quite exaggerated and is a great indicator of how clearly my system is dialed in, especially in the mids and tweeters.  Very hard to describe, but once you hear it, you will not accept less.

Any Peter Gabriel Track.  His music really opens up on a good system.  I like "Growing Up", the song is all over the room when you are dialed in.  When you are not it can be a little on the blurry side.

Thanks Everyone

I hope this thread helps those deciding on trying out the DSP/Active route and provides a little guidance.  It is quite a lot to take on, but considering that I successfully pulled it off, then I think anyone can pull it off. 

As the marketing states - "..convert a very good loudspeaker system to a much better loudspeaker system regardless of the initial cost."

(this is good segue for HAL to call out what the folks at Magnepan told him during a recent visit at Capitol Audio Fest)

I will leave it at that and happy to answer any questions you may have either here or in PM.
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: HAL on 15 Nov 2023, 01:21 am
Kazoom,
This a great tutorial on how any user can get started with guidance with the EA dspNexus 2x8!  Thank you very much for all the time and effort to describe your journey with the system and get improvements in their system with existing speakers. 

This has been a long process to help define, test and support a system that brings this level of sound quality to music listeners to get them closer to the sound of the original recordings.  As an EE and music lover, this makes me very proud of the results of the system.

Here is the story about Magnepan employees visiting the HAL room.  Since principle people in Danville know principle people in Magnepan, when they were told I was using MG10/QR speakers they said, why not get a pair of 1.7i's as the MG10/QR was rapidly replaced by the MG10.1/QR with improved sound quality.  Basically, they did not sound that good.  From listening to the original crossovers and measurements they needed a lot of changes to redesign the crossover and with an 80Hz low end, they need subs for anything approaching something full range.  Thing is the used pair of MG10/QR's cost $400, so were a bargain to start the process.

I knew that GR-Research and Rythmik Audio had 8in servo subs and servo amps from the past and now with improved servo drivers so 4 could be run in parallel.  The look of the smaller baffles was something a lot of customers over the years have commented on with the 12in subs.   The mods get the servo sub system to extend to 30Hz.

Now with the dspNexus and servo subs, there was no problem redesigning the MG10/QR's DSP crossovers to correct the things I measured that were not very good.  This took a lot of EQ and time delay to correctly integrate the speakers and subs.

When they came in, it was easy to see they were from Magnepan, so got them seated and played Infected Mushrooms, Bliss on Mushrooms.  A very dynamic track with fairly modern electronic and acoustic instruments.  I played half the track and they were intently listing.  When they looked at each other the facial expression was a bit, what just happened?  First thing they said is they were familiar with the original MG10/QR and this system sounded really good.  To the point we got Magnepan buttons and very good feedback. My response was, this is not your grandad's pair of MG10/QR's!

Danville Signal is about 1 hour from Magnepan.  My suggestion was to take the 1.7i's to Danville and let us work on a DSP crossover.  We will see what happens. :)
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: danvillesignal on 15 Nov 2023, 02:58 pm
I do not know if Danville Signal is paying attention to my thread..... (Kazoom)

I want to think everyone for their kind words. I was fortunate to meet many of you at CAF.

I want to assure everyone, that I always read these posts. As was mentioned in this thread - the dspNexus was envisioned from the start to be a growing platform. The DSP, ADC & DACs are all implemented as modules.

Al Clark
Title: Re: The EA DSPNexus with NX-Treme and Servo Subs Integration Thread
Post by: Kazoom on 15 Nov 2023, 04:25 pm
Glad to see you on here sir, and now I know.   :D

I hope my posts are helpful feedback for you.  I obviously really love your product and appreciate the efforts you and your team put into bringing this to the consumer market.

I did add some clarification to my post above about the freezing issue.  I neglected to state that happens only during startup or reboot.  Once I isolated the issue, I did not have any random freezing issues as my post seemed to suggest.  This may already be documented somewhere, but I just did not catch it.

It looks like you and HAL had a great show in DC. 

I am really sorry I was not able to make it, would have been great to meet everyone.