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Focus Fidelity Filter Designer
#91
Hi Everyone,

The measurement tool is now available for download at https://www.focusfidelity.com/download
Big thanks to @Confused for his help testing the beta release.

Kind regards,
David
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#92
(25-Dec-2021, 04:30)Focus Fidelity Wrote: The length of the filter, number of taps generated by FFFD is selectable, choosing the 0.743/0.683 seconds option (on the view filter screen) will mean it generates 65536 taps for sample rates of 88200 and 96000. The generated files for sample rates 176400 and 192000 will be twice as many taps, 44100 and 48000 half as many.
Modern PCs can EASILY run filters of these lengths at these sample rates doing 64-bit double-precision math.

David - Thanks for the information, my learning curve continues! 

To put the above into perspective, I have actually checked the CPU usage of my PC running HQPlayer upsampling to 24/192 and using 192000 sample rate Focus Fidelity Convolutions.

The load on the PC seems to be surprisingly trivial, with HQPlayer requiring less than 1% CPU usage. (it actually flicks between 0.3% and 0.4%, occasionally reaching 0.5%) This is with an i9-9900K PC.

In my earlier post I was asking is there was a "simple hardware solution will run 65536 tap length FIR filters". Here I was thinking about a miniDSP style product rather than a PC. So something that you could conceivably place on a hifi rack between a turntable / phono stage and the digital input of the DAC / Amp, and hence get the benefit of DRC convolutions with a turntable as source. Someone had mentioned to me that there was product that could do this, miniDSP "OpenDRC". This sounded promising, but I have subsequently checked this out, and the OpenDRC is limited to a relatively lowly sounding 6148 taps. Maybe one day miniDSP will bring out a project that is a little more powerful?

Also, the relatively low CPU usage of HQPlayer with convolutions makes me wonder if the Devialet CI board is actually capable of running convolutions like this. OK, the CI board does not have an i9-9900K processor, but neither would it need one based on the very low CPU usage that the convolutions seem to require.

Just a thought.
1000 Pro - KEF Blade - iFi Zen Stream - Mutec REF10 - MC3+USB - Pro-Ject Signature 12
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#93
(28-Dec-2021, 11:55)Confused Wrote:
(25-Dec-2021, 04:30)Focus Fidelity Wrote: The length of the filter, number of taps generated by FFFD is selectable, choosing the 0.743/0.683 seconds option (on the view filter screen) will mean it generates 65536 taps for sample rates of 88200 and 96000. The generated files for sample rates 176400 and 192000 will be twice as many taps, 44100 and 48000 half as many.
Modern PCs can EASILY run filters of these lengths at these sample rates doing 64-bit double-precision math.

David - Thanks for the information, my learning curve continues! 

To put the above into perspective, I have actually checked the CPU usage of my PC running HQPlayer upsampling to 24/192 and using 192000 sample rate Focus Fidelity Convolutions.

The load on the PC seems to be surprisingly trivial, with HQPlayer requiring less than 1% CPU usage. (it actually flicks between 0.3% and 0.4%, occasionally reaching 0.5%) This is with an i9-9900K PC.

In my earlier post I was asking is there was a "simple hardware solution will run 65536 tap length FIR filters". Here I was thinking about a miniDSP style product rather than a PC. So something that you could conceivably place on a hifi rack between a turntable / phono stage and the digital input of the DAC / Amp, and hence get the benefit of DRC convolutions with a turntable as source. Someone had mentioned to me that there was product that could do this, miniDSP "OpenDRC". This sounded promising, but I have subsequently checked this out, and the OpenDRC is limited to a relatively lowly sounding 6148 taps. Maybe one day miniDSP will bring out a project that is a little more powerful?

Also, the relatively low CPU usage of HQPlayer with convolutions makes me wonder if the Devialet CI board is actually capable of running convolutions like this. OK, the CI board does not have an i9-9900K processor, but neither would it need one based on the very low CPU usage that the convolutions seem to require.

Just a thought.
I am quite convinced that the embedded processing capacity of the DSPs in the Devialet is sufficient for executing those filters. After all this is just bread and butter for those kind of DSP. 

I think that the real ‘issue’ from Devialet’s perspective is the interface that would need to be offered, and the potential for problems and troubleshooting that they could have to face from a support perspective. 

My two cents,

Jean-Marie
MacBook Air M2 -> RAAT/Air -> WiFi -> PLC -> Ethernet -> Devialet 220pro with Core Infinity (upgraded from 120) -> AperturA Armonia
France
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#94
Well I guess it couldn’t be any more complex than the current Sweet Room implementation Wink
Would be nice to have a feedback from Devialet on this - maybe someone can contact them/support about it.
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#95
Hi @Confused I'm not aware of any small embedded MiniDSP style devices that will handle long FIR filters.

The only high res photos of the CI board I can find show an ADSP-21488 400MHz processor which is pretty much the same part used here https://www.minidsp.com/products/minidsp...4-x-out-hd

I assume that your Devialet already has a good ADC in it for the turntable input, if the ADC output could be routed through the USB interface to your PC you could run the convolutions on your PC using https://accuratesound.ca/products.html and send the audio back to the Devialet also over USB. Basically, the Devialet just needs to appear as a USB audio interface with with 2 input channels and 2 output channels.
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#96
USB of a Devialet amp is just that, two channels in and two channels out.
If HLConvolver could be made to use digital I/O from USB AND Devialet could put the USB port in digital loop mode (output whichever input you've selected to USB and expect the signal back on the USB inputs) this could work!
I actually suggested the loop idea to Devialet (Mathieu Pernot), but using SPDIF I/O. I was going to check if USB could be used for this but then I sold my 250 Pro CI so I didn't do more about it.
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Devialetless!
Roon, ROCK/Audiolense XO/Music on NAS/EtherRegen/RoPieee/USPCB/ISORegen/USPCB/Sound Devices USBPre2/Tannoy GOLD 8
250 Pro CI, MicroRendu(1.4), Mutec MC-3+USB
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#97
HLConvolver running standalone will do what's needed, I already use it like that with an appropriate USB in/out interface. Hopefully, the Devialet is flexible enough to route the audio appropriately.
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#98
Is there someone who is in contact with Mathieu Pernot - he should be easily be able to provide feedback.
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#99
(29-Dec-2021, 22:31)markush Wrote: Is there someone who is in contact with Mathieu Pernot - he should be easily be able to provide feedback.

I've sent a message to Mathieu. Let's wait till over the weekend and see what comes out of it.
*
Devialetless!
Roon, ROCK/Audiolense XO/Music on NAS/EtherRegen/RoPieee/USPCB/ISORegen/USPCB/Sound Devices USBPre2/Tannoy GOLD 8
250 Pro CI, MicroRendu(1.4), Mutec MC-3+USB
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(29-Dec-2021, 22:31)markush Wrote: Is there someone who is in contact with Mathieu Pernot - he should be easily be able to provide feedback.

I had an answer from Mathieu this morning. Bad news I'm afraid..

The current datapath on Expert amplifiers does not allow the necessary signal routing to/from USB to make this work.

Mathieu says that today's hardware (I'm guessing the CI version here) can do it "but the amount of code to rewrite is quite considerable"

This definitely means "not soon" and most likely "maybe, some time in the future".
*
Devialetless!
Roon, ROCK/Audiolense XO/Music on NAS/EtherRegen/RoPieee/USPCB/ISORegen/USPCB/Sound Devices USBPre2/Tannoy GOLD 8
250 Pro CI, MicroRendu(1.4), Mutec MC-3+USB
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