Roon & Home Audio Fidelity (Room Correction / convolution filter creation)

(John) #205


Do you mind me asking what’s these ‘Beta Xtalk Filters’ you’re talking about?

I got my HAF filters 6 months ago (Excellence set), so is this a new set of Filters by Thierry?

(Rémi) #206

The beta filters are the one tailored to your head shape. The standard Xtalk ones are with a “standard head”.
See here Roon & Home Audio Fidelity (Room Correction / convolution filter creation)

(John) #207


Thanks for replying so quickly.

So should I redo my measurements with the new ‘head shot’ included, and Thierry will send me an additional set of Xtalk filters?

(Larry Post) #208

No need to remeasure, take a headshot holding a ruler. Not sure yet if it will be an additional product or included in the Excellence pack.

(John) #209

How did you guys figure this all out, amazing :+1:

(Larry Post) #210

Email communications with Thierry. I’ve only had a few hours with my filters, using xtalk, primarily. It’s spooky good at times, and very very good all the time.

Reviewing the impulse and phase info in REW, it’s clear that in my setup, correcting phase has made the vast majority of improvement. Frequency response was not terrible but phase was all over the place between L and R. Now they track one another very, very closely.

I should restate, that I measured my worst case setup in my space. I setup and put away for each listening session my bookshelf speakers/stands and variety of absorbing panels. My speakers are in the space asymmetrically and without any acoustic panels and it sounds better than when I setup properly (on short wall) with panels all over. My goal was to obviously improve the sound but mostly to improve it in my quickest/easiest arrangement. Mission accomplished!

(John) #211


How do you put the HAF filter info into REW and compare with original measurements?

(Larry Post) #212

In REW, File, Import, Import Impulse Response, open any of the WAV files for L and R, sampling rate you choose does not matter. Click Overlay if you want to see them combined.

Have a good look at these first, then open your mdat file you sent to Thierry to compare with your measurements. I don’t believe looking at them together will really tell you all that much, apples and oranges, but I’m still learning how to interpret data from REW.

(John) #213

Managed to import the Xtalk filter files into REW along with my original measurements, but haven’t got a clue what I’m looking at :crazy_face:

(Rémi) #214

Well that’s a busy graph :slight_smile: .
For easier reading : check only 1-3 (left channel) or 2-4 (right channel). Change scale to 20Hz-20Khz horizontally and 50dB-115dB vertically. Use logarithmic scale instead of linear scale. Apply VAR smoothing. One can already say you had some gaps in the bass, one resonance at 80Hz. If the filter shows a high, it will increase this frequency, compensating for a low in your original setup, the cause being a resonance and/or the speaker response.
In order to see the phase correction of the filter, click on “phase”. If the phase of the measurement is all over the place you can apply a 1/6th octave frequency dependant windowing through the “IR FILTER” window.

Also HAF filters have a second channel that you’ve not imported here, with a lower response, that are meant to do the XTALK, spectral reverberation tuning, and “random phase” adjustments, see here Roon & Home Audio Fidelity (Room Correction / convolution filter creation)

(Larry Post) #215

From Thierry:

I plan to offer two different options for personalized crosstalk reduction : one based on head dimensions that is confirmed based on beta testing and one based on acoustical measurements with binaural microphones. The latter is still under testing and I don’t have a fixed date for introducing these options, hopefully during the second quarter…


(John) #217


New graphs with just Xtalk filters (Left & Right Channels) and original measurements (only L1, L2 & L3). Found the VAR Smoothing preference (think this is what you meant), also think this is the logarithmic scale but unsure (sorry).

Unsure what you mean about “Also HAF filters have a second channel” , 2nd screenshot of the files in my Xtalk Filter Folder (only 3 files).

Appreciate all your advice on this, thanks :+1:

HAF Xtalk Filter Files:

45 am

(Mark Allen) #218

Thanks for the info guys. I’ve always wondered how to do this, but I’ve been too busy just enjoying what Thierry(HAF) has done for my listening enjoyment.

(JohnV) #219

Best wishes on your new company. Looks promising.

(Larry Post) #220

Hi @John_V,

I wanted you to know, this is not my company, I’m simply a very happy customer with no other affiliation.

A modest French-man, Thierry, is the creator of the application he wrote to generate the convolution filters per system measurements.

(Larry Post) #221

Wow! After 3 hours or so, it’s the only adjective that appropriately describes the improvements to my listening experience. Some have reported they lost dynamics, for me it’s been just the opposite. I confirmed with Thierry there is no freq. push beyond where my 6" mid woofer naturally rolls off, at 38hz, to avoid damage. Bass is smoother and most certainly punchier, and I presume because both speakers are now working with the room and not canceling each other and/or wall reflections causing cancellations.

This morning, my better half said ‘That sounds really, really good’ what did you change? She was in another part of the house at the time.

The sound image created by good recordings is simply fantastic. Even AAC 320Kbps stream has some depth and realism to it whereas before it was totally lifeless.

Best $200 ($300 with mic) USD I’ve spent in decades.

(JohnV) #222

Thx Larry, I misread the thread. I saw your name, then the link to this new company, and I conflated the two. Thanks for the correction.

(Mark Allen) #223

:slight_smile: Another satisfied customer!

Yeah pretty much the same experience for me. Glad it’s working out for you. Enjoy going through all your favorite music and rediscovering it.

(Robert Siegel) #224

Thierry is awesome. I’ve been working with him for about 3 weeks on just a sample file. He noticed anomalies in my sweeps, and after exchanging microphones, running additional sweeps, etc., he diagnosed that the polarity of my tweeters was inverted. Spoke with the manufacturer and sure enough, my pair had the wiring reversed for testing and it was never corrected. Now that I’ve resolved the frequency response issues, I can run some legitimate sweeps! Looking forward to hearing what kind of difference the correction will make.

(Mr Fix It ) #225

I must say on a first reaction I too thought the same…I wonder if Thierry will frequent this forum?