Hi.
I’m looking for a way to apply separate filters to my stereo speakers, where each eq is tailored to each speaker and it’s position in the room.
So far I’ve been using volumio, where I had the option to add two independent convolution filter for left and right channels.
Thanks ahead,
Stefan
Not quite sure what the issue is, Roon seems to happily use stereo filters, with different adjustments for each speaker (I generate mine with Focus Fidelity, but REW or something else would work just as well).
It’s not an issue, I just don’t know how to use them both. Do you label them left and right, or what?
I use convolution files created by Home Audio Fidelity. These files are all bundled into one zip file.
This is a partial screenshot from one of these zip files. Maybe this will help you. Each file is a wav.
Also: have you read this?
No,m you just need to save stereo WAVs from whatever you use to create convolutions. Something like this:
I guess I’ve never thought about a single stereo convolution file. I’ve been using rephase for some time now and saving the filter as a mono.
Thanks to both, it helped a lot.
You need to create a .cfg file for each sampling rate [Or you can have Roon resample] and place this into a zipped folder with your left and right convolution corrections wav’s.
Example:
My config @ 44.1
My config @ 96k, and so on.
I wrote about convolution here:
Interesting. According to Focus Fidelity manual at least, you do not need .cfg files for Roon. I zip up just the .wav files, give the archive to Roon, and it uses them quite happily with stereo .wav files and no .cfg
I’m running 4 discrete channels, for my active JBL M2s. Not stereo.
The .cfg works to route signals for up to 8 USB channels.
The .cfg is required to route and configure channel assignment, without it nothing happens.
Without a .cfg how does Roon know which convolution to apply to which DAC channel? I.e DAC outputs 2 up to 8 channels?
Maybe it is needed for multichannel configurations. For stereo it would be rather obvious…
I can’t see how applying independent stereo convolution is ‘obvious’ for the player to assign. (Unless there’s a default naming standard for files) what are you naming the independent stereo waves?
The software will require some method to apply the correct file to the correct output.
I would suspect, Roon would have no method of applying the stereo correction convolution without being told which file is what (left or Right) and which USB output it should be applied?
I.e via naming or .cfg…
If you were applying a mono convolution across both left and right channels on a simple two output USB device, perhaps this would be doable without a .cfg. I never tested without a .cfg.
Focus Fidelity generates filters as stereo WAV files. The WAV file header assigns the left and right channels.
Home Audio Fidelity filters use separate mono WAV files for left and right channel, so config files are required.
I guess everyone here should have checked Roon documentation first (me included).
According to Roon, .cfg are not necessary if your impulse response files are multichannel (or you are actuakly using the same convolution for all channels).
They specifically state:
If you provide a monaural impulse response file, it will apply to channels of the source material. If you provide an impulse response file with multiple channels, then they will be mapped onto the channels in the source material appropriately.
So for the OP, if @Stefan_Denic wants to apply stereo convolutions, he either needs one stereo impulse response file (or one per sample rate), or two mono impulse response files and a .cfg indicating which one is left and which one is right.
Yes - that’s what I said. lol
Yep. Thanks
Most users will use REW, or rephase, etc to generate convolution files.
So this comment would not apply to 97% of users.
Most if not all convolution users would be generating either combined stereo [mono corrections] or discrete channel convolution files for Stereo, MCH, or MCH crossover.
In terms of your setup, I suspect it might be a good idea to generate a .cfg, to ensure convolution is routed to the correct USB channels. At a guess Roon would be selecting the top convolution file in your zip (@ each sampling rate) and applying it to both channels.
It always pays to valid response, phase and impulse response, before and after.
What USB channels? I don’t have any USB channels.
And… there is only one file per each sampling rate, so there ia nothing for Roon to misidentify. It has been validated to provide correct filtering to each channel…
Hey Boris, sorry for confusing things.
I was referencing the routes/outputs as USB channels, because in my setup my outputs are addressed on a multichannel USB interface [Motu MK5 Ultralite]. DAC outputs is probably the better term, especially for those running traditional [non USB] stereo output devices.
Lets just leave it there, it’s becoming clear the application/execution of convolution is different depending on the software and method being used to generate the corrections. I for one, had never heard of [Focus Fidelity] stereo convolution execution without using .cfg files.
I think this discussion clearly highlights the Roon convolution guide is woefully inadequate for any new starters looking to apply convolution correction in Roon, compounded by further confusion due to the number of methods which can be used to generate convolution files.
Personally, I would just use a .cfg file, as it guarantee’s correct convolution assignment.
Right, it seems to be an issue of proper documentation being somewhere in the knowledge base, rather than being present upfront and clearly…
Roon obviously does know which output channel is which; otherwise it would not play even stereo, let alone multichannel, tracks correctly. And it it knows that, then it can properly apply filters, as long as a non-mono impulse response file has channels identified the same way.
I haven’t looked too closely at other filter design software, as Focus Fidelity appears to have a good combination of decent price and features I need, but they default to exporting stereo files, so it seems to be a common enough feature. You can export separate left and right filters, if you want to…
At least for stereo playback, lack of .cfg files does not seem to be a problem. I’ve measured “after” output, even when a wire to one of the speakers was bad and response (and therefore corrections) were noticeably different, and everything was corrected properly…
