• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Any portable DAC that supports convolution?

Kirby47

Member
Joined
Mar 13, 2023
Messages
8
Likes
2
Hello Everyone.
I have finished my HRTF effect rack on the computer recently.
My iOS doesn't seem to have any music player or mobile internal support for loading convolution, as far as I know..?
It seems that I need a portable DAC to process convolution.

Do you have any suggestions?
 
If you want to use your own WAV files, then the Smyth Realizer is all I can think of.

Besides that, there's the Creative SXFI Amp.
You download their App, take three pictures of your face, left pinna, right pinna, it processes that and spits out an impulse file which is loaded onto the DAC.

It's a take it or leave it situation, as there's no way to adjust the effect.
 
If you want to use your own WAV files, then the Smyth Realizer is all I can think of.

Besides that, there's the Creative SXFI Amp.
You download their App, take three pictures of your face, left pinna, right pinna, it processes that and spits out an impulse file which is loaded onto the DAC.

It's a take it or leave it situation, as there's no way to adjust the effect.

I'm sorry.. my question was not expressed clearly.

This topic is seeking recommendations for portable DACs that support loading pulse files. I have completed the creation of HRTF and WAV pulse files.

It seems that iOS does not have any music player that supports loading pulses, so I have to seek external hardware to process it (just like MiniDSP IL-DSP, although I'm not sure if it can load convolution).
 
Last edited:
You could put Roon on a PC running the convolution then stream that to their mobile app. Believe it works awat from your home WAN.

But it ain't cheap.
 
It seems that iOS does not have any music player that supports loading pulses, so I have to seek external hardware to process it (just like MiniDSP IL-DSP, although I'm not sure if it can load convolution).
The Il-DSP does not support convolution afaik.

Your question was well understood, it's just that the only external device that I can think of, which supports loading custom WAV impulse files for convolution, is the Smyth Realizer.

This is obviously less than ideal, so I proposed the SXFI Amp as a compromise, as it is the only DAC I can think of, with HRTF Processing in a fitting form factor.
 
A RaspberryPi + DAC hat with Volumio software and FusionDSP plugin may do the trick (although I’m not sure what your definition of ‘portable’ is…).
 
The Il-DSP does not support convolution afaik.

Your question was well understood, it's just that the only external device that I can think of, which supports loading custom WAV impulse files for convolution, is the Smyth Realizer.

This is obviously less than ideal, so I proposed the SXFI Amp as a compromise, as it is the only DAC I can think of, with HRTF Processing in a fitting form factor.

SXFI Amp looks good, but I use a high-precision generated SOFA. The smartphone camera has reduced the expected effect.

Thank you all! It seems that considering using Android or Hiby R6 is a better choice..
 
Just use the free JamesDSP and a cheap Apple dongle.

Edit: Sorry, after a quick search I found out that JamesDSP is apparently just for Android.
 
Hello Everyone.
I have finished my HRTF effect rack on the computer recently.
My iOS doesn't seem to have any music player or mobile internal support for loading convolution, as far as I know..?
It seems that I need a portable DAC to process convolution.

Do you have any suggestions?
I asked qudelix devs about convolver and they said it's too computationally expensive, they would only be able to support a few hundred taps. For now your only portable option is android + jamesdsp.
 
I asked qudelix devs about convolver and they said it's too computationally expensive, they would only be able to support a few hundred taps. For now your only portable option is android + jamesdsp.
I was under the impression that convolution was actually computationally cheap...maybe I'm mistaken?
 
It looks like if the processors were a little better, you'd be able to do convolution fine. Convolution just adds together all the mutiplications of the signal with the impulse response. If you had 100 "steps" in the impulse, two channels at 384kHz each, then that would be 100 * 384000 * 2 = 76.8 million multiplication and addition operations every second. The Qudelix DAC has a 300MHz ARM core and a 600MHz DSP core, so it would be close but not impossible for the DSP. For the Qudelix amp, its chipset has two 120MHz DSP cores and a single wimpy 80MHz ARM core, and that definitely couldn't handle convolution. But if you used 48kHz instead, then you'd have a better chance.
 
Uh-huh... There are players/recorder's on iOS that supports it but it's paid in app purchase tho not much.
Convolution kernel is not all that computing intensive tho it has latency but it can be kept low enough not to be disturbing for video. Old V4A worked fine on quad core Arm A5~A7 at 1 GHz. I am not an iOS user... Today you have in your pocket more CPU power than say Intel N300 (8E core's).
 
If you'd be willing to move away from ios,
foobar2000, on Windows, does convolution with the Convolver add-on. Works great, and it's totally free...
 
Uh-huh... There are players/recorder's on iOS that supports it but it's paid in app purchase tho not much.
Convolution kernel is not all that computing intensive tho it has latency but it can be kept low enough not to be disturbing for video. Old V4A worked fine on quad core Arm A5~A7 at 1 GHz. I am not an iOS user... Today you have in your pocket more CPU power than say Intel N300 (8E core's).

can't compare a phone CPU to what we find in a DAC
 
can't compare a phone CPU to what we find in a DAC
Depends how you look at it (DAP, SoM, SoC, IC...). Anyway I answered first question. It's not CPU power bound but useful interface and implementation problem beyond any OS discussion. Tho I think I did see N100 mini (iTX) boards with one of two PCI-E 1 lines dedicated for card expansion. Even rather good x86 pretty dedicated software like JRiver comes with far from great convoler but it has normal VST plugin support that foobar lacks (you can run one through old plugin but don't even try to run a chain). So in his case back to rack anyway. I currently use MconvolutionEZ (and MFreeformPhase) from their free pack and it works fine.
 
It looks like if the processors were a little better, you'd be able to do convolution fine. Convolution just adds together all the mutiplications of the signal with the impulse response. If you had 100 "steps" in the impulse, two channels at 384kHz each, then that would be 100 * 384000 * 2 = 76.8 million multiplication and addition operations every second. The Qudelix DAC has a 300MHz ARM core and a 600MHz DSP core, so it would be close but not impossible for the DSP. For the Qudelix amp, its chipset has two 120MHz DSP cores and a single wimpy 80MHz ARM core, and that definitely couldn't handle convolution. But if you used 48kHz instead, then you'd have a better chance.
Lol, first thing you do when you do convolution is drop the rate to 44.1 or 48kHz. Even your PC can't do shzt worth of convolution at 384kHz sample rate... (edit: well it can, taking a significant chunk of your CPU and leaving little for other stuff, also depends on the latency acceptable to you etc.) Your estimate is however over-high if FFT is used (again depends on latency)
 
Last edited:
Lol, first thing you do when you do convolution is drop the rate to 44.1 or 48kHz. Even your PC can't do shzt worth of convolution at 384kHz sample rate... (edit: well it can, taking a significant chunk of your CPU and leaving little for other stuff, also depends on the latency acceptable to you etc.) Your estimate is however over-high if FFT is used (again depends on latency)
I'm using foobar's convolver for room correction impulse files, made with REW.
44.1 up to, and including 352.8 khz - with no issues.
Following the convolution, I up-convert it to DSD 256 in real-time with foobar's DSD Processor.

Works great, and CPU never goes over about 15%... (on a quad-core Win 10 PC).
 
I'm using foobar's convolver for room correction impulse files, made with REW.
44.1 up to, and including 352.8 khz - with no issues.
Following the convolution, I up-convert it to DSD 256 in real-time with foobar's DSD Processor.

Works great, and CPU never goes over about 15%... (on a quad-core Win 10 PC).
What does "making a room correction impulse file" with REW consist of?
 
Back
Top Bottom