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Introducing Hang Loose Convolver from Accurate Sound

DWPress

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@mitchco - any progress on the multichannel version of your convolver?
 
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mitchco

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I’m planning a future implementation of AudioLense XO and want to use several sync’d stereo DAC’s. I had therefore concluded that I would get a Mac Mini so I could use the Aggregate Device function to route the channels. But then I started to read about Daphile and I’m wondering whether it would be a better option. As it is Linux based am I correct in thinking HLC would not be compatible with it?

Hi @Dichotome, I have not compiled HLC on Linux yet, but it is certainly possible. Note that HLC is currently stereo convolution at this time. Unless the stereo DAC's have been designed to be sync'd together, you would be better off with a MCH DAC. Even better a MCH AD/DA converter with an analog mic and mic pre to avoid the inevitable timing issues using multiple clocks. While most of these timing issues can be overcome, they can be completely avoided with the suggested approach.
 
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mitchco

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@mitchco - any progress on the multichannel version of your convolver?

Thanks for asking. I have been busy working on a few other DSP projects plus taking some needed vacation time. So I have not made any progress on the multichannel version yet. Planned for this fall, but I am focusing on a proper DSP project for high resolution FIR filtering for headphones currently.
 

MFJG

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@mitchco Great idea and execution, bravo. I purchased this yesterday and have been playing around with this non-stop. Thank you for the cool name and icon as well.
 

tecnogadget

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HLC is designed to run on any platform and work with any audio source. For Mac, there is a standalone app plus VST3 and AU plugins. On Windows there is a standalone app and VST3 plugin. Shortly will be available on popular distros of Linux, with standalone app and VST3 plugin followed by iOS and Android apps. That's 9 convolvers running on the majority of platforms for a one time perpetual license of $129 with with free upgrades.

HLC is a fully fledged DSP engine. Getting easy to use convolution on the majority of platforms is phase 1 of this release, in addition to it's specialized capability. There will be other "DSP" features moving forward that I am not ready to disclose yet.

Dear @mitchco , I greatly value your numerous contributions to the DSP scene.

I want to take this opportunity to consult you about something I have been wanting to do for years, and maybe it will be of interest to other members. Besides enjoying the correct and accurate reproduction of music, I also love movies and think that at certain times the soundtrack far exceeds 50% of the experience. It takes some work to implement DSP the right way on 2.0, 2.1, 2.2 systems, but this becomes exponentially tougher for multichannel systems.

Since the birth of Blu-Ray we have the masters of these lossless soundtracks, either in Dolby Digital True HD, or DTS HD MA. It is therefore natural that we want to apply correction to all channels of the system and take advantage of these tracks.

The strategy I plan to follow is as follows:
  • Have physical Blu Ray and UHD discs, movies in Mkv, h265, or BD Folders.
  • Use an HTPC for video playback and DSP application (must have Intel processor compatible with SGX, and be of sixth to tenth generation to play UHD)
  • Have an external UHD reader of these disks connected to the HTPC.
  • Connect HTPC via USB-C to a MOTU UltraLite-mk5, to be used as a transparent multichannel DAC (it has 10 fully-routable line outs with 112dB SINAD)
  • Connect MOTU outputs to multichannel inputs of SOTA AVR to be used purely as an amplifier.

The playback of UHD Blu-Ray discs with menu included can be performed with JRiver (from version 24, the current version is 27 and 28 in development), and also with PowerDVD 21. The difference is that JRiver integrates a Convolver and DSP functions, while PowerDVD 21 does not.

My DSP experience is summarized to PEQ filters generated with REW. I am new in the world of convolution. So I would like to know if HLC would be useful or not for my applications and sound chain. What I have clear for the moment is that I will have to take measurements with my UMIK and create the filters with one of these: Acourate, Audiolense, Focus Fidelity.
The functionality of being able to switch between different filters in real-time is great and very useful, but it is not my main motivation, since I have very well-defined target curves. I find it very interesting in its specifications and your comments, that it is supposed to be system-wide, so it would apply to the sound output of any program (although I imagine that maybe in Windows it needs some routing configuration).

So this would mean that when playing UHD discs, using HLC I would not be limited to having to use JRiver convolver, since HLC itself is a convolution engine? And above all, if we talk about system-wide, this would also solve any other application of the HTPC either YouTube audio, any streaming app like Netflix, Prime Video, Disney+, and any player like saying VLC or Foobar ?

In short, my intrigue is to know and understand if after designing the corrections for each channel, HLC would be the host and engine of the convolution filters and therefore the fixes would be applied to any output generated by any program within Windows OS. So I would avoid having to configure such programs individually (if they allow convolution) or having to resort to plug-ins.
 
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mitchco

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So I would like to know if HLC would be useful or not for my applications and sound chain.

Hi tecnogadget, thanks for your kind words. Note that HLC is currently a stereo convolver. I have MCH planned, but no ETA as of yet.

So this would mean that when playing UHD discs, using HLC I would not be limited to having to use JRiver convolver, since HLC itself is a convolution engine? And above all, if we talk about system-wide, this would also solve any other application of the HTPC either YouTube audio, any streaming app like Netflix, Prime Video, Disney+, and any player like saying VLC or Foobar ?

Yes, HLC is a convolution engine. In standalone mode HLC can provide convolution system wide and with any app, but currently stereo only.

HLC would be the host and engine of the convolution filters and therefore the fixes would be applied to any output generated by any program within Windows OS.

Yes, but as noted... HLC in standalone mode uses VB-Cable for loopback (BlackHole on the Mac). The operations guide goes into detail how to install (easy) and configure for loopback so all audio is routed through HLC.
 

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Thanks for asking. I have been busy working on a few other DSP projects plus taking some needed vacation time. So I have not made any progress on the multichannel version yet. Planned for this fall, but I am focusing on a proper DSP project for high resolution FIR filtering for headphones currently.

Just a note - to really be feature proof I would need support for at least 64, but better 512 channels... The reason is that I would like to use it with ambisonic RIRs and headphones with head-tracking :) Basically to switch between rooms with different DSP/DRC applied ;)
 

3ll3d00d

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In short, my intrigue is to know and understand if after designing the corrections for each channel, HLC would be the host and engine of the convolution filters and therefore the fixes would be applied to any output generated by any program within Windows OS. So I would avoid having to configure such programs individually (if they allow convolution) or having to resort to plug-ins.
bear in mind you can do this today in jriver via the WDM driver

latency is the problem though for both live and video applications, would be good if HLC is leaner than jriver for live use but for video then you need the video engine to delay to match the filter delay (which jriver does automatically)
 

Eurasian

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Just a note - to really be feature proof I would need support for at least 64, but better 512 channels... The reason is that I would like to use it with ambisonic RIRs and headphones with head-tracking :) Basically to switch between rooms with different DSP/DRC applied ;)
That is hard core brother! Pictures and description please.
 
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Is an android version (without the need of root) still being planned?
It would be the first convolver for android which doesn't require root and there only exist two apps -v4a and jdsp.
Unfortunately it's getting harder to root samsung devices these days, not mentioned the us versions with their locked boot loader.
I have no use for hlc's main approach of switching irs quickly, just need a simple 4 channel /full stereo convolver for headphones, even within a dedicated player would be fine for me.
130$ would be an extraordinary high price for an android app, is a simple convolver as a light version conceivable?
 
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SDX-LV

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That is hard core brother! Pictures and description please.
The equipment for what I mentioned is a bit extreme and not ready yet. But if it all sounds useful - I suggest you read up on Binaural Room Scanning as researched by Harman, Bang&Olufsen, TU Berlin and others. This is not easy, but financially and technologically possible to use even for crazy individuals. A bit like DIY Smyth Realiser on steroids.
 
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mitchco

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Is an android version (without the need of root) still being planned?
It would be the first convolver for android which doesn't require root and there only exist two apps -v4a and jdsp.
Unfortunately it's getting harder to root samsung devices these days, not mentioned the us versions with their locked boot loader.
I have no use for hlc's main approach of switching irs quickly, just need a simple 4 channel /full stereo convolver for headphones, even within a dedicated player would be fine for me.
130$ would be an extraordinary high price for an android app, is a simple convolver as a light version conceivable?
Yes, an Android "lite" version is planned, but I don't have an ETA.
 
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Glad to heqr that. Will it run on unrooted devices with 4channel (full stereo) support and which android version will be required as minimum?
I hope the convolution is done by the app and device itself rather than running on a server or other device in the background with the smartphone just acting as a remote control receiving the signal.
 

Brad

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Hi Mitch,
I would be interested in a multichannel version of HLC. I am after a zero latency convolver for use with my active speakers, multi-sub, multi channel setup. My system has 30 acourate filters. It works with Jriver WDM driver for netflix etc, but I am after a solution for playback of an external UHD player.
I can get the external player working with the filters with acourate convolver, but the latency is still too high for use - even though filters are only 8192 taps in length and are minphase.
So do you think you could run 30 short filters with zero latency? Ie are you using direct convolution for all partitions, or just the first one?

Regards
Brad
 
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mitchco

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Hi Brad,

Working on it, no ETA yet. In the meantime, perhaps Bernt's Audiolense Convolver is worth a try. It is a 0ms latency convolver as well. I use it in my stereo triamp system with 6 channels and 65,536 tap length minphase filters. I don't notice any lipsync issues while looping back the Windows Netflix app through VB-HiFi Cable ASIO bridge and selecting Audiolense ASIO virtual sound card through the convolver and ASIO out to my Lynx Hilo. However, I could not say about an external UHD player. Perhaps worth a try...

Kind regards,
Mitch
 

Brad

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Hi Brad,

Working on it, no ETA yet. In the meantime, perhaps Bernt's Audiolense Convolver is worth a try. It is a 0ms latency convolver as well. I use it in my stereo triamp system with 6 channels and 65,536 tap length minphase filters. I don't notice any lipsync issues while looping back the Windows Netflix app through VB-HiFi Cable ASIO bridge and selecting Audiolense ASIO virtual sound card through the convolver and ASIO out to my Lynx Hilo. However, I could not say about an external UHD player. Perhaps worth a try...

Kind regards,
Mitch
Thanks for the info.
I did look at the audiolense convolver, but as far as i understand it only works with filters from audiolense. I demoed audiolense, but it can’t implement the dual sub config that I have. If the audiolense convolver does now support wav filters I would be happy to give it a try

Brad
 
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mitchco

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@Brad you're right, ALC uses its own proprietary ".alc" file format. I have been using it for so long I completely forgot...
 

lofiguy

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On Mac Catalina.

I played with HQPlayer, can't get it to route audio at all. Plus a few other bugs -- without having gotten a single audio signal out of it at all.

I played with HLC and it worked immediately! Just audio routing, not filters yet (free version just to test), but it looks great.

@mitchco for 2.1 system, do I really need multichannel HLC? If I look at minidsp system diagram, the filtering occurs after the routing and crossover. But I suspect this is more to do with dsp capacity planning than requirement to apply filter on each specific passband, at least for the FIR. In a system where the PC has essentially unlimited processing power, with stereo source, is it sufficient to apply the filter on that stereo source signal, and then afterwards to do the crossover (also digitally on the same machine)? If so then I presume that the same software (not HLC) which achieves the crossover can do any PEQ and gain/delay stages? It might not be as compact as being all in a single instance of HLC but will it work?

2ch input > HLC FIR > virtual device > crossover > PEQ > gain/delay > 3ch DAC

I kind of thought that the FIR block obviated the need for PEQ (given enough power [taps] for the FIR), so given my lack of understanding since clearly that's not how miniDSP describes it, maybe it's a dumb question!

If you look at makeMKV software on Mac, it can run multiple instances of itself. It does this so it doesn't fight itself over multiple BD drives. As long as your software doesn't step on itself it could potentially do that also. If the FIR and other filters have to come after the crossover, each filter specific to the passband, then would running multiple instances of HLC be a way to get multichannel support, at least for 2.1 setup? Obviously you can't do AB testing easily (or at all, given audio memory I guess), and other such things, but still then I can use HLC as convolver engine.
 
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mitchco

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@lofiguy yes, ideally MCH convolution where the FIR filter contains the digital XO, driver time alignment, driver linearization and room correction (i.e. magnitude and excess phase correction). This leverages the power of the PC using 65,536 taps or greater for complete low frequency control.

HLC is 2 channels I/O. You could try 2ch input > HLC FIR > virtual device > crossover > PEQ > gain/delay > 3ch DAC where the FIR filter contains room correction. But I have not tested this scenario... While HLC can be hosted as a plugin and have multiple instances, it was not intended to be used in the scenario you describe.

I am working on the MCH version of HLC, but no ETA. In the meantime, I think there is MCH convolver for the Mac in this thread that may work for you: https://www.avnirvana.com/threads/macos-convolver-that-works-with-audiolense.8030/
 
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