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Multi-Channel, Multi-Amplifier Audio System Using Software Crossover and Multichannel-DAC

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dualazmak

dualazmak

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Hello @etc6849,

Although I am still out of home on business travel, today I could find and spare my time responding to your inquiries as follows based on my limited experiences and implementations which have been sharing on this project thread.;)

This would give me 32 digital channels in and out. One of the RME sound cards would act as a master clock, ensuring that all AES outputs going to the individual DACs would always stay insync.

Yes, RME's sound cards and DAC-ADC devices are having very nice master-slave clock-sync functionalities for which I have been already well aware of.
ref. my recent post here and here.


I'd want full DSP capability such as: FIR filters, time delay and level. Plus some sort of virtual sound card driver that is a must.

I would like to suggest you to try paid-up (USD 149.00) DSP software "EKIO", if you are using Windows 10 or 11 PC. The paid-up EKIO can have unlimited numbers of I/O channels, and where the audio handling/processing capabilities are only dependent on the bit rate (up to 192 kHz) and your CPU power.

I presently use JRiver MC and EKIO (as well as web browsers, Google Chrome and Microsoft Edge) for 12-CH I/O into EKIO and 8-CH multichannel DAC (OKTO DAC8PRO) plus stereo DAC KORG DS-DAC-10 up to 192 kHz processing on rather outdated completely silent Windows 11 Pro PCs (ref. here) with no PC processing power issue at all.

EKIO uses IIR filters, not FIR filters, but its internal XO/EQ/Group-Delay/Relative-Gain processing are in 64 bit biquad (cascade 2nd order direct form II biquad in 64 bit floating point); very fast stable and low workload to CPU; essentially no post- and pre-ringing at all.
- EKIO uses IIR filters; cascade 2nd order direct form II biquad in 64 bit floating point: #138-#142
- EKIO (using IIR filters) gives audible post-ringing or pre-ringing, or not?: #143
The nicely beautifully designed GUI of EKIO would be also very much suitable for your tests/evaluations where you can configure almost all of the parameters on-the-fly, I mean while listening to music tracks. EKIO also has ABX comparator features for any pair of your saved many EKIO configurations.


Which software based option is the most stable that will definitely never ever allow unfiltered audio to reach my tweeters? Are any of these stable enough to where they show up as a virtual sound card that works well with all Windows programs (Netflix and Youtube in browser, JRiver, etc..)?

Just same as I described above, I highly recommend you to test EKIO as system-wide DSP Center under VB Matrix VASIO/VAIO I/O routing. Using VB Matrix, you can simultaneously (mixing) or selectively use Windows WDM audio routing (by setting VB Matrix's VAIO as Windows default audio playback device) to be fed by e.g. web browsers listening to YouTube clips and pure ASIO routing (by setting VB Matrix's VASIO channels) to be fed by JRiver MC, Roon and/or other ASIO-Out capable audio players (ref. here).


It would seem if my motherboard's BIOS makes noise during boot up, could this harm my drivers? What about as Windows 10 loads -is there ever a risk of outputting unfiltered sound to my drivers then (prior to when any virtual sound card driver loads)?

Yes, it is really important issue, especially in fully active multichannel audio setup where the SP drivers are directly and dedicatedly driven by multiple amplifiers, and I have been carefully implementing several hardware and software (including my hand-operation) safety features.

First, the "all-in-ASIO Routing" would be highly recommended as I wrote my (historical) stance and policy shared here. Now, using VB Matrix, you can quite easily establish all-in-ASIO routing even all of the Windows WDM (WASAPI) audio playback devices are fully disabled! Also as I recently (today) briefly wrote here, in case if you would dare to use VB Marix VAIO too as Windows default audio playback device, you need to carefully digitally attenuate their gains (I presently set -16 dB) in the VB Matrix Grid so that it would be level-matched with your main VASIO (Virtual ASIO) routing. We should be careful enough about some (many?) poorly QC-ed Youtube video clips have unusually high gain audio tracks; e.g. even a very quiet smooth jazz Youtube video clip sometimes uses full of 24 bit dynamic range (or even above 0 dB clipping level) which would be really odd and unacceptable in CD release.

Second, even with all the other safety measures, you (we) need to have protection capacitors for our treasure midrange-drivers (I use 68 microF film caps), tweeters (I use 10 microF film caps) and super-tweeters (I use 10 microF film caps); ref. here and here. Of course, I carefully measured the SPL curves before and after the protection caps confirming their transparences in audible sound (ref. here and here).

Third, you should not exclude utilization/incorporation of HiFi "integrated amplifiers" (or HiFi pre-amplifiers) in your multichannel active audio setup where you can completely volume down (to minus infinity) the gain into your SP drivers during system start-up (ignition) and shutdown (and also during intensive DSP parameter tuning/change processes; you can carefully/gradually gain-up after the tuning). This is also one of the main reasons for that I use four HiFi "integrated" amplifiers in my setup on the policy of "right-person-in-right-place" amplifier selection (ref. here and here). Furthermore, these integrated amps and/or preamps would enable very safe and flexible relative gain control for SP drivers (i.e. tone control) in analog domain on-the-fly while listening to music in our preferred total sound volume (ref. here and here).

Fourth, the digital numeric keyboard value input/change of gains on-the-fly (while listening to music) should be always avoided since we may easily have mis-typing the value, e.g. we may type as dangerous "+35 dB" instead of actually intending "+3.5 dB". In this context, I highly recommend you using mouse-wheel-rotation up-and-down on gain controllers in EKIO for on-the-fly gain/volume control; in EKIO the granularity of mouse-wheel rotation is 0.1 dB, which is really nice. (I myself actually requested the mouse wheel operation, and Guillaume of LUPISOFT very quickly incorporated it into updated EKIO.) Furthermore, EKIO's "Mute" and "Solo" buttons in each of the output chanel panels are really nice and useful for specific-channel(SP-driver)-only listening and/or any combination of all the SP drivers, even L-only, R-only, L+R, etc., during your precise DSP-parameter tuning procedures.

Fifth, in any of multichannel audio systems, we need to carefully perform our "startup/ignition sequences" and "shutdown sequences" eliminating/avoiding any of pop and other possible harmful sound intrusions into our SP drivers (ref. here for my such sequences). In this context, I do not like and never used the triggered simultaneous startup/wakeup of my audio gears.


I assume my further experiences and implementations under this spoiler cover would be also of your interest and reference:
- In depth insights on SP attenuators and their elimination in multichannel system: #248, #251, #99(remote thread), #100(remote thread), #101(remote thread)

- Elimination of magnetic susceptible metals in SP signal handling: #250, #013(remote thread)

- Perfect (0.1 msec precision) time alignment of all the SP drivers greatly contributes to amazing disappearance of SPs, tightness and cleanliness of the sound, and superior 3D sound stage: #520

- Not only the precision (0.1 msec level) time alignment over all the SP drivers but also SP facing directions and sound-deadening space behind the SPs plus behind our listening position would be critically important for effective (perfect?) disappearance of speakers: #687
 
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adLuke

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Hello @dualazmak, thanks for sharing your insight and congrats on the depth and breadth of your experience.
I think you might be one of the best people to answer a curiosity I have been having for some time.
Below is my ideal/dream/endgame setup:
Digital source (internet and local streaming);
Wireless transmitter/receiver of bit-perfect hi-res music (say 96khz/24bits, DSD128);
Dacs for each speaker up to 4 channels, with 120+db SINAD;
Each Speaker has dedicated amps for each way, with adequate power and 100+db SINAD;
Ability to switch between Stereo, AmbioSonics, and Spatial Audio (Atmos, DTX, etc), so 2/4/11+ speakers, for listing to different sources with prespecified DSP and room correction for each case.
I believe the source should be a PC, hoping one day it'll be possible to decode Spatial audio via software, otherwise a Cinema Processor is needed.

So my question is: when do you think this will become possible without spending a fortune?
To me, it seemed far away in the future just a few years ago. But looking at the evolution of DACs, class D amps, wireless HiFi active speakers, and reading about your experience it looks like it's much closer than I thought it possible.
Thanks and all the best for your music enjoyment.
 

gac800

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Hi @dualazmak . Do you have any experience using EKIO with a higher bitrate than 44.1kHz? I use Roon with Tidal streaming, which can output 192kHz, so I am considering adjusting my set up to account for this.
 
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dualazmak

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Hi @dualazmak . Do you have any experience using EKIO with a higher bitrate than 44.1kHz? I use Roon with Tidal streaming, which can output 192kHz, so I am considering adjusting my set up to account for this.

Of course, Yes!!
All the signal paths for multichannel DSP processing (by system-wide one-stop DSP Center "EKIO", in my case) of ;

"JRiver MC --> VB Matrix --> EKIO --> VB Matrix --> DAC8PRO"
and, e.g.,
"Web browser (for YouTube) etc. --> VB Matrix --> EKIO --> VB Matrix --> DAC8PRO"

can work upto 192 kHz processing; you need to carefully set all the I/O in 192 kHz, though, including on-the-fly 192 kHz encoding in JRiver's DSP-studio (set all to 192,000 kHz).
 

gac800

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Thanks! I use: Roon —> Motu 828ES —> EKIO —> Motu 828ES
The Motu adjusts automatically to the bitrate of the source, so I will adjust everything else and see if that works. Do you think I need to adjust the settings in the Sound properties in windows as well? I think it is currently set to 44.1
 
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dualazmak

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Do you think I need to adjust the settings in the Sound properties in windows as well? I think it is currently set to 44.1

Are you using Windows WASAPI (and/or VB Matrix's VAIO) I/O? If this would be the case, you need to set the WASAPI (and/or VAIO in VB Matrix) I/O to 192 kHz at the Control Panel -- Sound -- Playback Device -- Properties (and VAIO Control panel of VB Matrix). If you are using all in dedicated ASIO drivers I/O, then you have no need to do this.

Of course EKIO should be set in 192 kHz (preferred buffer size = 5120, in my case) on the "Settings" screen.
 

gac800

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I’m not using WASAPI or VB Matrix. I use the Motu ASIO from Roon. So all I need to do is change the EKIO setting?
I tried it earlier today and it was crashing the Motu. Should I try “Request buffer size” And set it to 5120?
C441CC75-3141-4EE6-AE25-9CD38BB801E8.jpeg
 
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dualazmak

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So my question is: when do you think this will become possible without spending a fortune?

Hello again @adLuke,

Since I have been always sticking to "all wired" I/O connections including my home LAN, I know little about recent advancement of reliable and stable "Wireless transmitter/receiver of bit-perfect hi-res music (say 96khz/24bits, DSD128)". I assume if you mean the wireless transfer of "intact music tracks" from some server or smartphone to your audio PC, I believe that reliable high-speed WiFi I/O would be already available.
Edit: I use home high-speed WiFi only for our smartphone access to internet.

Various active SP system (e.g. 3-way, 4-way) having built-in multiple-amplifier and multichannel DAC will be available very soon, I believe, such as Sigberg Audio's new development project. As you may agree, this element would be most critical for our budget scheme.

After you (we) would soon have such "active multi-driver SP system having built-in multi-amplifier and multichannel DAC", We would only need to feed stereo digital signal into it by using one-cable USB ASIO routing, or one-cable AES-EBU/SPDIF digital routing, or ASIO over Ravenna/Dante ethernet connections.

Even in above case, I still would like to have system-wide independent DSP center within my PC (as you indicated that "I believe the source should be a PC"); at least for me, I still very much like DSP "EKIO" to take care of all the DSP (XO/EQ/Group-Delay/Relative-Gain) processing since EKIO can save various different settings in its "configuration files" and within EKIO I can control/change/tune almost all the DSP parameters very easily safely even on-the-fly using its well designed GUI operations.

We can load multiple "configuration file" onto EKIO and easily change/select them for actual DSP processing which would meet for your request of "Ability to switch between Stereo, AmbioSonics, and Spatial Audio (Atmos, DTX, etc), so 2/4/11+ speakers, for listing to different sources with prespecified DSP and room correction for each case."

Consequently, in general considerations, I agree with you that we would fulfil/realize your dream audio settings/systems much earlier than we have been thinking.

Edit:
In case you are seeking for WiFi "wireless" active SP system, then you need to wait availabilities of those "wireless capable" SPs, even though several units are already available but not so HiFi with no multiple-amplifier nor multichannel DAC in it.

In case if you would find acceptably HiFi active SP system having "wired" LAN/ethernet I/O, then you may easily install the WiFi access-point network hardware/settings (WiFi router with wired LAN ports to be used as wireless relay access point) for the SP enabling wireless connection within your home LAN/WiFi even at present, I believe.
 
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dualazmak

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’m not using WASAPI or VB Matrix. I use the Motu ASIO from Roon. So all I need to do is change the EKIO setting?
I tried it earlier today and it was crashing the Motu. Should I try “Request buffer size” And set it to 5120?

I assume you are right.
In case if you are trying all in 192 kHz, please set the "Sampling rate" to 192000 Hz, and try "Requested buffer size = 5120" in EKIO's Settings.

If you would still experience crashing the Motu and/or other I/O sync/sample-rate mismatch issue(s), I highly recommend you to try VB-Audio Matrix as system-wide ASIO/virtual-ASIO I/O Center which can aggregate all the existing ASIO and WDM (wasapi) drivers/devices.
 
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adLuke

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Hello again @adLuke,

Since I have been always sticking to "all wired" I/O connections including my home LAN, I know little about recent advancement of reliable and stable "Wireless transmitter/receiver of bit-perfect hi-res music (say 96khz/24bits, DSD128)". I assume if you mean the wireless transfer of "intact music tracks" from some server or smartphone to your audio PC, I believe that reliable high-speed WiFi I/O would be already available.

Various active SP system (e.g. 3-way, 4-way) having built-in multiple-amplifier and multichannel DAC will be available very soon, I believe, such as Sigberg Audio's new development project. As you may agree, this element would be most critical for our budget scheme.

After you (we) would soon have such "active multi-driver SP system having built-in multi-amplifier and multichannel DAC", We would only need to feed stereo digital signal into it by using one-cable USB ASIO routing, or one-cable AES-EBU/SPDIF digital routing, or ASIO over Ravenna/Dante ethernet connections.

Even in above case, I still would like to have system-wide independent DSP center within my PC (as you indicated that "I believe the source should be a PC"); at least for me, I still very much like DSP "EKIO" to take care of all the DSP (XO/EQ/Group-Delay/Relative-Gain) processing since EKIO can save various different settings in its "configuration files" and within EKIO I can control/change/tune almost all the DSP parameters very easily safely even on-the-fly using its well designed GUI operations.

We can load multiple "configuration file" onto EKIO and easily change/select them for actual DSP processing which would meet for your request of "Ability to switch between Stereo, AmbioSonics, and Spatial Audio (Atmos, DTX, etc), so 2/4/11+ speakers, for listing to different sources with prespecified DSP and room correction for each case."

Consequently, in general considerations, I agree with you that we would fulfil/realize your dream audio settings/systems much earlier than we have been thinking.

Edit:
In case you are seeking for WiFi "wireless" active SP system, then you need to wait availabilities of those "wireless capable" SPs, even though several units are already available but not so HiFi with no multiple-amplifier nor multichannel DAC in it.

In case if you would find acceptably HiFi active SP system having "wired" LAN/ethernet I/O, then you may easily install the WiFi access-point network hardware/settings for the SP enabling wireless connection within your home LAN/WiFi even at present, I believe.
Great, thanks for your input on this.
Best
 

gac800

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I can switch between 44.1 and 48 kHz without issue, but when I try and change to 88.2 or higher it crashes. Any ideas what could be the issue?
 
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dualazmak

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I can switch between 44.1 and 48 kHz without issue, but when I try and change to 88.2 or higher it crashes. Any ideas what could be the issue?

I assume your crashing issue would be specific to "EKIO-->Motu 828ES". I never experienced such issue in my setup of "EKIO --> OKTO DAC8PRO".

Generally speaking, I have no idea for you since I never tried Matu 828ES and its ASIO drivers. I know nothing about the behavior and possible applicable parameters (such as sampling rate and buffer size) of ASIO driver for Motu 828ES.

Do you have same crashing issue when you feed 88.2 or higher stereo L&R signal into Motu 828ES directly from JRiver MC bypassing EKIO?
Have you tested VB-Audio Matrix I/O routing (ref. here) between EKIO and Motu? VB Matrix is a donation software, and you can fully test it for free.
 

gac800

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It seems the issue was the constant changing of sample rates. Depending on the file playing in Roon it could be 44.1, 48, or 96 kHz.

I enabled Sample rate conversion in Roon, so everything gets upsampled to 196kHz. I set Ekio and the Motu to 196kHz and it seems to work.
 

gac800

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Just a guess, but the number of ADAT channels changes between 44/48 (8) and 88/96 (4), imagine that might cause an issue when changing rates.

Michael
Oh that is interesting. I was using USB do you think it would still have an effect of the number of ADAT channels?
 
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dualazmak

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I enabled Sample rate conversion in Roon, so everything gets upsampled to 196kHz. I set Ekio and the Motu to 196kHz and it seems to work.

Oh, very nice to hear so!:) Now you (we) can fully enjoy and utilize the great flexibilities, even on-the-fly, of EKIO...
Yesterday, in my listening environment (since we very slightly modified our furniture physical alignment), again I was precisely/intensively checking L&R balance of each of my subwoofers, woofers, midranges, tweeters and supertweeters by using the "Solo" and "Mute" buttons of EKIO on-the-fly while listening to various tracks of my "Audio Sampler/reference playlist" (ref. here and here).

Many people are much concerned about "bass" sound, but little people take intensive care of balance phase (3D perspectives) and transparency of very high-Fq transient sound to be covered by tweeters and supertweeters. I believe EKIO's "Solo, Mute" buttons and the stunning reference track of "Bimmel Bolle Antique Orgel" would be the most suitable combination in this regard (at least in my audio setup).
 

gac800

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@dualazmak why did you decide to do volume control in JRiver instead of EKIO or OKTO Dac? My Motu 828es has 32-bit processing (the same as the OKTO I believe) so I am currently doing volume control for my multi-amp setup at that point.
 

TonyJZX

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i feel like this is a good way to re-use multichannel HT amps

if you have a 5-6-7 channel amp not being used then why not use them channels?

in theory if you have a 6 channel and a heap of wire and speakers you can tri-wire and some way to run the crossovers then you could have some experimentation to do
 
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dualazmak

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@dualazmak why did you decide to do volume control in JRiver instead of EKIO or OKTO Dac? My Motu 828es has 32-bit processing (the same as the OKTO I believe) so I am currently doing volume control for my multi-amp setup at that point.

Since I believe it is the most safe and convenient way of master volume control doing in most upstream digital domain, i.e. by music player JRiver. We can control the master volume by JRiver's "internal volume" with "volume protection" and "Enable volume when Bitstreaming".

Also, we can control the master volume with mouse wheel rotation when we place the mouse cursor near the volume slider of JRiver. We can also use our keyboard's volume up, down and pause keys. By using wireless mouse and wireless keyboard, we can easily and safely control master volume remotely.

@dualazmak and do you turn all of your amps to max volume, and do the balancing of levels in EKIO?
No,,, as you may know I use four "integrated" amplifiers, and my answer is clearly demonstrated in this diagram sharing my "standard volume/gain settings" (ref. here);
WS00006941.JPG


Generally speaking, almost all of the "integrated" amplifiers would work at their best performances (S/N, THD, damping, etc.) when the volume dial is set at nearly 12 o'clock position which is usually -17 dB to -15 dB range. The exception is with YAMAHA A-S301 (set at around 10 o'click volume position) driving really highly efficient supertweeters.

With these standard gain settings, in my listening environment, I never volume-up to 0 dB (100%) in most upstream JRiver; about 85 % (-7.5 dB) would be my loudest playback in the above standard settings. You can understand that I have quite enough "safety margins" below clipping level in digital and analog domains. You would please also refer to my recent post here for safety concerns (protection of our treasure SP drivers) in multichannel multi-amplifier fully active audio system.

I usually do not touch on the above shown output gain levels in EKIO (especially on-the-fly), but I flexibly control the relative gains (i.e. tone controls) by the volume dials of the four "integrated" amplifiers. This is one of the unique and very safe features of my multichannel multi-amplifier audio setup. You would please refer to my posts here and here for example cases of such flexible "on-the-fly" relative gain (tone) control. Of course you can do it in the same manner if you would implement preamplifiers plus power amplifiers.

My post here (done today) would be of your reference regarding the safety measures and digital peak meters plus DIY 12-VU-Meter Array.
 
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