New loudspeakers & room digital correction service

[SwissBear]

The comment from Swissbear on classical music is linked to the crosstalk reduction. There is a higher interest in reducing crosstalk for recordings made on the simple 2 mics principle, and usually such recordings are classical or jazz music. My experience is that the xtalk reduction is not detrimental for other type of recordings but the effect is less predictable (it depends on how the mixing was done)

Agreed.

[Confused]

@Confused : if you have the choice for your listening position, then you should pick the one giving the maximum bass as it will be easier to correct.

The comment from Swissbear on classical music is linked to the crosstalk reduction. There is a higher interest in reducing crosstalk for recordings made on the simple 2 mics principle, and usually such recordings are classical or jazz music. My experience is that the xtalk reduction is not detrimental for other type of recordings but the effect is less predictable (it depends on how the mixing was done)

OK, thanks Thierry.  A simple response but that does make sense and actually answers my 'sweet spot' question perfectly. 

As for the crosstalk reduction, without a doubt I listen to some music that has some appalling mixing, and some electronic stuff where the notion of correct mixing may not even be a valid concept.  So I am guessing the 'without' crosstalk filters might be a safer bet or might it still be worth trying the 'with' filters?

Plus, I did think of another question, hopefully my last for now!  I currently use Roon, which feeds HQPlayer.  I see you can make the filters for either of these, but does it make any difference if the filter is in Roon or HQPlayer in this set up?  I suspect having them in HQPlayer might be best, but this does limit future options, for example the new Devialet OS Board is likely to be compatible with Roon but not HQPlayer.

[homeaudiofidelity]

It's always worth trying the xtalk reduction as it can give a very nice 3D presentation on some multi tracks recordings. I personally always stay with the xtalk reduction even for pop/rock stuff. But it's always a matter of taste, this is why I'm leaving you the choice...

I am not at all an expert in the Roon/HQPlayer architecture but in principle there should not be a difference if convolution takes place in Roon or HQPlayer (same mathematical operation). Maybe some more knowledgeable guys can answer.

[SwissBear]

Plus, I did think of another question, hopefully my last for now!  I currently use Roon, which feeds HQPlayer.  I see you can make the filters for either of these, but does it make any difference if the filter is in Roon or HQPlayer in this set up?  I suspect having them in HQPlayer might be best, but this does limit future options, for example the new Devialet OS Board is likely to be compatible with Roon but not HQPlayer.

The correction impulses supplied by Thierry are stereo impulses. One for the left channel and one for the right channel. This fits directly into Roon if you transform the config file supplied by Thierry from .txt to .cfg and zip it together with the two stereo impulses into a zipped folder which name is given to Roon.

In case of HQPlayer which does not support stereo correction impulses, one has to split the impulses into mono impulses and feed four mono impulses into HQPlayer.

When you will be there, Thierry or I will explain you how to do this.

The operation of splitting the correction impulses from stereo to mono and conversely to combine two mono impulses into a stereo one can be easily done via a free software called Audacity.

[Confused]

Plus, I did think of another question, hopefully my last for now!  I currently use Roon, which feeds HQPlayer.  I see you can make the filters for either of these, but does it make any difference if the filter is in Roon or HQPlayer in this set up?  I suspect having them in HQPlayer might be best, but this does limit future options, for example the new Devialet OS Board is likely to be compatible with Roon but not HQPlayer.

The correction impulses supplied by Thierry are stereo impulses. One for the left channel and one for the right channel. This fits directly into Roon if you transform the config file supplied by Thierry from .txt to .cfg and zip it together with the two stereo impulses into a zipped folder which name is given to Roon.

In case of HQPlayer which does not support stereo correction impulses, one has to split the impulses into mono impulses and feed four mono impulses into HQPlayer.

When you will be there, Thierry or I will explain you how to do this.

The operation of splitting the correction impulses from stereo to mono and conversely to combine two mono impulses into a stereo one can be easily done via a free software called Audacity.

OK, so easiest to use the filters in Roon, better compatibility keeping the filers in Roon (option to use RAAT or Roon AIR, OS Board), and per Thierry's earlier comment, no sound quality penalty keeping the filters in Roon even if Roon then then feeds HQPlayer.  So it looks like using the filters in Roon wins this one.

[Alec_eiffel]

The correction impulses supplied by Thierry are stereo impulses. One for the left channel and one for the right channel. This fits directly into Roon if you transform the config file supplied by Thierry from .txt to .cfg and zip it together with the two stereo impulses into a zipped folder which name is given to Roon.

In case of HQPlayer which does not support stereo correction impulses, one has to split the impulses into mono impulses and feed four mono impulses into HQPlayer.
...

One quick comment as I am since today a customer of HomeAudioFidelity. Thierry provided a zip file fully packaged for Roon, no need to edit any .txt or .cfg file. I'll provide my comments a bit later but in a nutshell : 

[SwissBear]

OK, so easiest to use the filters in Roon, better compatibility keeping the filers in Roon (option to use RAAT or Roon AIR, OS Board), and per Thierry's earlier comment, no sound quality penalty keeping the filters in Roon even if Roon then then feeds HQPlayer.  So it looks like using the filters in Roon wins this one.

I strongly disagree with this idea. If HQPlayer has a single quality, its the DSP. So when using Roon with HQPlayer, it is, IMHO, mandatory to disable the DSP of Roon and use the one of HQPlayer. This is just a small effort of configuration to achieve, and the benefits are worth it.

[SwissBear]

One quick comment as I am since today a customer of HomeAudioFidelity. Thierry provided a zip file fully packaged for Roon, no need to edit any .txt or .cfg file. I'll provide my comments a bit later but in a nutshell : 

I was not aware of this option provided by Thierry. That's cool.
BTW, welcome to you on the forum, and among the customers of Thierry. You will be able to test an alternative tp REW/rePhase

[Alec_eiffel]

Warning: long post.

So here is my experience with HAF filtering, with a bit of background.

I had always been curious about acoustics and sound reproduction in general, being half engineer and half musician/fond of good music across all genres. After 10 happy years with DIY 2-way VIFA speakers floor standers powered by T-AMPs or alike (total cost 1000 €), I decided I deserved an upgrade for the next 10 years. Value for money is important to me, and I like to think long term when I buy or build expensive things.

I started with speakers last year : still an area where DIY allows to reach good performance at a fraction of the retail cost of a commercial product. I assembled my own version of an Atohm Bookshelf kit EURUS 1.0. I recently added a DIY sub  on the side to cover the 20-40Hz range based on a Dayton RSS210, a sono amp, and a miniDSP 2x4HD for filtering. The total cost of my speakers is approx. 3000 €. incl. the sub. 

Then the amp : Devialet D200 bought new for 4500 € some months ago. I guess the 220 Pro is better but was way out of budget for me. 

For streaming and library management, I started with a Raspberry PI / Digi + / Moode Audio solution (80€) and bought a 100€ Digital NAS. Worked very well but I couldn't benefit of the Air input, and the PI is not powerful enough for convolution. I had convinced myself convolution was the only way to cope with a very reverberant untreated living room (concrete walls, RT at 0.6 across the spectrum...). Treating the room was my first choice but not possible. 

I bought an Intel NUC and was convinced with the rest of the family that Roon was a good choice for performance / ease of use / multi-room. Convolution seemed well implemented.
 
I then got into REW/Rephase and thanks to the information gathered by the fantastic community around it (including SwissBear, merci encore !), I managed to build simple filters to remove the main room modes, and later on adjusting tone and phase with Rephase, achieving a "Dirac-like" correction. It was fun to do but it also turned out to be  time consuming and obsessive. There is always something new to try or optimise. I think what I did is OK but can be further improved. I had no time or motivation to further build my experience and expertise.

Overall I was quite happy with my setup. My only remaining frustration was the soundstage, too small (especially missing depth) and missing resolution. Stupid reverberant / room mode-ish living room.

Then  I came across some posts mentioning the approach of Thierry / HAF. Reading his technical paper and annexed references (esp. the Linkwist paper) was enlightening. There were actually filtering techniques that could treat the defects of the speakers and the room at the level of the reverberant field, making it psycho-acoustically more realistic an therefore improving the "illusion" of the stage originated by the speakers. I couldn't fight reverberation with room treatment, but it could be "normalised" through a set of FIR filters by Thierry. PLUS I could get an expert doing the phase and tone correction in a maybe more efficient way. 

All I had to do was to take some measurements with REW : took 20 minutes. A couple of hours later I add 2 demo songs... The first time I played the modded files there was really a WOW effect. I finally had a sound stage. My decision to buy was taken. Thierry was fast in assembling the files according to my need and I have spent a couple of hours today simply enjoying music. The next time I will change the filters will be when I move!

I highly recommend to consider HAF filters in the case you are not satisfied with the 3-dimensionality of your setup, esp. if your room is very reverberant. Additionnally you'll get a Dirac-Acourate like correction of tone (incl. room mode) and phase. The risk is low as you can get free samples. 

Regarding the cost : I cannot think of ANY other improvement of my setup that could bring the 15-20% subjective improvement I got. 

As an illustration here are the filters defined for me by Thierry for the left channel.
The first graph shows the amplitude and phase correction : 
- room modes esp. a very naughty longitudinal one at 55Hz
- softening of a 7Khz bump of the tweeter 
- phase correction is quite soft as my speakers are already well aligned (tweeter filter has a passive RLC "delay") and filtering slopes are only 12DB/oct. The phase curve goes nuts in some highly non minimal phase areas but this is OK


The second filter is actually applied to right channel and then reinjected into the left channel, and is adding some reverberation at the needed frequencies, creating the illusion of a more "natural" reverb correcting the speakers AND the room "unnatural" behaviour because of the speakers directivity mainly .  What is remarkable is that the highest correction is computed in the 2K-5K band which is exactly the overlap of the tweeter and woofer, as predicted by the theory (cf. Thierry's technical paper). 

[petrik]

Thierry provided a zip file fully packaged for Roon, no need to edit any .txt or .cfg file.

Exactly, installation of these filters couldn't be any more simple in Roon. You just need to select the zip file in Roon and that's it.

By the way, I noticed yesterday that the most recent Roon version is processing the convolution much more efficiently than before. Earlier the processing speed indicator was always showing something between 20x-50x. Now the processing speed indicator has disappeared, meaning that it's > 100x.