HAF - Home Audio Fidelity (Room Correction / convolution filter creation)

Volpone

See previous comment below from Thierry to myself regarding DSD:

"Regarding DSD, there is no convolution possibility on such raw format : all players usually convert to PCM & apply filters at high sampling rate (I have created filters at 384 kHz for HQplayer for instance)

Kind regards,
Thierry"

I’m not alone using DSD upsampling and tempted to try HomeAudioFidelity convolution filter files to get room correction.

You can upsample to DSD after the convolution if you want, see example.

See previous comment below from Thierry to myself regarding DSD:
“Regarding DSD, there is no convolution possibility on such raw format : all players usually convert to PCM & apply filters at high sampling rate (I have created filters at 384 kHz for HQplayer for instance)
Kind regards,
Thierry”

Yep, no DSP of any kind possible on the DSD raw format, PEQ, convolution, resampling always require conversion to PCM. Your DSD file can still benefit from DSP/convolution of course, Roon (and every other player) will simply and seamlessly convert them to PCM first.

Hi Guys (and/or gals)

I got my HAF filters from Thierry last night, and below is the before and after graphs he sent me for my set-up.

Wouldn’t have a clue what’s good or bad within the graphs as I’m a complete novice at all this

Levels before correction:

Levels after correction:

Spectrogram comparison (top = w/o correction, below = with correction) for the sweet spot:

Interesting. It looks better, but how does it sound with the filters applied? Significantly better than without?

Orgel

Not had a real chance to listen to much music since I uploaded the filters last night, but what I have listened to some songs have parts in them I’ve never noticed before.

Off course some songs will have little if any change and others far more - but which these are time will only tell until I listen to more songs.

Suffice to say that at present all I can hear is all positive additions to the music, with no negatives at all

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I am sorry to report I could not perform the test Dirac vs HAF filters. The Dirac driver didn’t work well on my recent Windows 10 Intel Nuc i5… Seems that I am not the only one having Windows support issues with Dirac. The sound was horrible, noisy, scratchy, even though the measurements went well.

One lesson learnt for me : the implementation of convolution and other DSP is the job of the player (Roon, Jriver, HQ player, Foobar/Convolver & Co.). This is the only way to ensure at the same time performance and sustainability.

I think I have to try this, if only to check how it compares to the REW filters I have now.

Btw, here is a picture of how to do measurement in Dirac, I would guess thats a good way to do measurements in this case as well, also easy to explain to them (just attach picture or say Dirac single char measurement)

Below is the before and after in my case (using REW and my guide):

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I did the free trial with one tune (Sing by Travis), its not an optional tune for testing cross talk but it is a very complicated tune for generally testing sound quality. I did notice an improved sound stage, separation and surprisingly an increase in dynamics, and all in all an improvement over my room correction generated in REW.

I ordered the filters and will report back when I have done more testing with the final filters.

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Good news! Keep us posted. The increase in dynamics comes very likely from the phase correction, the better the time alignment, the more impacts are “coherent” across the spectrum, the higher the levels.

The sound stage benefits a lot from the reverberant field correction (which helps your brain to "disconnect’ from the unnatural tones of your room), and in some cases from the x-talk reduction, depending on the type of recording. I had a funny experience this week-end listening to Bill Evans Trio / Live at Village Vanguard, all filters activated : in between songs I could hear very clearly the waiter serving drinks at the very far left… about 5 meters beyond the walls of my apartment, as he was floating in the air (I live at the 9th floor…).

For the intellectually curious like me : here are for illustration the HAF filters for my left channel. It’s easy to import them in REW : File / Import Impulse Response. For a given speaker (left speaker in this case), the first channel is for amplitude and phase correction, the second channel is for the reverb tuning (+ X Talk in option).
The first graph shows the first channel of the filter : amplitude correction in dark red, phase correction in light red.
Please note that what we see here is the filter slope: a low in the filter corrects a peak in room/speaker behaviour, a high in the filter is here to boost some frequencies. You can see I have a very strong room mode at 55Hz, and a peak in my tweeter around 6-7kHz, and many other things happening in my room (yours is probably not any better if it’s a family living room…). The phase correction is not as tortuous as it could be for others because my speakers are conceived to be well time aligned thanks to a specific time delay filter on the tweeter side. Don’t mind the crazy behaviour of the phase around 55Hz and 3.2Khz, these are areas that are non minimum phase and can’t be corrected.
You would get similar filters using Accurate, REW/Rephase or Dirac (except that with Dirac you can’t access the phase correction and cannot import in REW as one need their `ù$^àç audio driver, sorry for cursing).

The second graph shows the “reverberant field” correction : there is a clear boost between 1 and 6Khz, with a plateau between 2 and 5, which is the crossover area (quite large as my filters are 12dB/oct only). What is remarkable is that these numbers matches with what the theory of HAF predicts : maximum correction around the crossover, with typical mid woofers and tweeters. And Thierry from HAF had no clue what was my crossover upfront! All the info was computed from the initial measurements only.

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Got the filters from https://www.homeaudiofidelity.com/ and they provide a very noticeable jump in sound quality compared to my old REW + PEQ room correction. Quieter background, more dynamic and wider stereo imaging. From a sound quality perspective, its the best money I have spent.

They also give a very big boost in volume, without any clipping (compared to using REW + PEQ). My current Roon volume is at 20, and that’s about the same volume level as 40 was for the old filters, and I have tried to provoke it with some tunes I know can easily cause clipping, but so far no blinking red light in Roon.

All in all, a very big “thumbs up” for Thierry, I don’t know how he did it. but whatever it was it worked like magic :slight_smile:

PS: as far as I can tell, this room correction is better than Dirac, although i don’t have it available for a proper A-B test.

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Hi,
This is great :+1: but as a newbie on this.
How does I get the files or zip files into the Convolution in Roon’s DSP?
Because I have my Core on my computer, using Allo USBridge and a iPad as remote control!
But this comes up when I push the Browse bottom!

Best Anders

You can’t upload filters from phones of tablets. It only works from a Windows or Mac running a Roon client. Any computer connected to the same network will do (can be the computer running the core). The filter will be uploaded to the Roon Core immediately.

If you have several variants of the filters - like X talk and non-X talk version of the HAF filters - I recommend to upload them all :

  • add filter / load filter 1
  • add filter / load filter 2
    You will then have two “convolution” lines on the left, that you can activate / deactivate from the iPad. Do not activate both filters, no risk of damage but it could sound funny as your room will be corrected twice :slight_smile:
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Hi @alec_eiffel
So you mean (I’m just checking so I understand you wright).
I can download the files or zip files on my windows computer, there I have my Core and the Roon Core will receive them?
Shall I put them in the same map as the Roon Core is?
After I have done it, so will I have them on my remote control iPad and can choose and control them in the DSP convolution?

I have been reading the hole Topic about this and it seems like many other here’s, recommending The Home Fidelity program. It’s even giving a free trial, have you tried it or are you using something else?

Thanks :pray: for your great help, Anders

I can download the files or zip files on my windows computer, there I have my Core and the Roon Core will receive them?

If you have installed the Roon Remote on your Roon Core computer as well (this is the default), just launch the Roon app on this computer and upload the filters (from a USB Stick, your local hard drive, a network hard drive…).

Shall I put them in the same map as the Roon Core is?

I don’t get that one.

After I have done it, so will I have them on my remote control iPad and can choose and control them in the DSP convolution?

Yep, you will be able to activate/deactivate them.

I have been reading the hole Topic about this and it seems like many other here’s, recommending The Home Fidelity program. It’s even giving a free trial, have you tried it or are you using something else?

I have tried HAF filters on the recommendation of very expert thought leaders on French Hifi Forum, after lots of experimentation on my own. It took me 30 seconds of listening of the test songs I received to acknowledge their superiority and measure the benefits (we are not speaking here of a very subtle improvement like one you’d get from a cable upgrade, but something between “clearly better” and “spectacular”).

There is a growing consensus by several independent thought leaders on various forums that these filters are at least as good and in most cases better than the alternative DIY or commercial solutions available. Thierry would not challenge me saying he is not the best at marketing his solution… but the technology behind and the performance are outstanding IMHO.

No I have only the Roon Core installed on my pc laptop!

I was wondering if I should put the files into the same place as my Roon Core is on the computer.

Does you have any files or zip files that you could send to me?
Just so I can test if it works?

You wrote just launch the Roon app on the computer! But it’s only open Roon and a little Roon app is open in my background! I can’t open it only right click on the mouse and it’s stands, that Roon is running and if I want Roon to open then I starting my computer and quit! Nothing more!

If you’ve installed Roon Server version, just also install the normal Roon on the same machine, and when you run it, tell it to connect to your core and it will then run in ‘remote mode’ so you’ll be able to browse/load filters as well as do all the usual Roon playback controls and browsing.

It doesn’t matter where they are as long as you can browse to them from your pc.

Once you’ve loaded them, save a DSP preset and you’ll always be able to recall the convolution, even from your iPad.

It’s not a nice system IMO, but it works once you get the hang of it. It would be better if Roon just save any installed convolutions somewhere they can always be accessed - even from an iPad - but there you go…

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Hi @hifi_swlon

I have a full version of Roon on my computer, if something would get wrong when I installed the Roon Core, and the Allo USBridge as Roon bridge, and finally the Roon remote control on my iPad!
And it’s was lucky because all my different settings, library and DSP settings wasn’t on my iPad when I connected to the Roon Core :slight_smile:.
So I had to go back and open the full version and make a new backup!
And when back to the new way, and go to the backups and load the new backup from my iPad, so was everything there!
I’m sure that it’s finds a easier way to do it, but everything works perfectly and it’s the most important thing :smile: even if my way took some time to do!

So I just open that full version and download the files/zip files and make a backup! And when open the Roon Core and my iPad and load that backup so are they on my iPad!
Or is there a easier way?

Thanks @hifi_swlon

Hi Anders, sorry, i don’t really get what you’re at. Simply install “Roon” for Windows from the download page of Roonlabs, this will install the Roon Remote app on the PC, from there you will be able to access your (old) core.

It you want to try and import a set of convolution files, here are mine https://www.dropbox.com/s/tt3m7f399p01kl4/config_HAF_44.zip?raw=1

Of course this correction is not suited to your speakers/room but mine so it might sound a bit funny :slight_smile:

Hi @alec_eiffel
I’m sorry for not being able to describe it easier, but I will do as you are writing!
And it’s so I was meaning.
Thanks For all your help and knowledge about this, I shall download your file and testing!
How knows it’s maybe are perfect for my room and equipment, it’s things that happens sometimes!
I will reply to you how it works to get the files on place and how it sounds!
But it’s not the most important thing in this case, the priorities are to getting your zip files on place :+1:.

Best Anders