A guide how to do room correction and use it in Roon


(Larry Megugorac) #221

I am currently awaiting Thierry’s files…trying to figure out how to add them. I guess through Convolution filters I suppose? Must be a spot where the software asks about adding the filters and then you point that in the right direction. Then for Headphone listening you would turn that filter off I guess??

Cheers,
Larry


(Mark Allen) #222

That is correct. In the DSP section you should see an option under “DSP Presets” for Convolution. If you don’t see it click on “Add Filter” bottom left hand corner. Thierry will send you a file named something like “config_HAF_xtalk.zip” import it and enable Convolution and away you go.

I can’t speak about the Headphone filter.


(Anders Vinberg) #223

Yes, the headphone thing is a hassle.
I would have to switch my controller to headphone mode (fixed volume stereo output on, digital output to speakers off) and change the DSP preset ( Audeze provided convolution), and then remember to switch back correctly.

Instead I use a Geek Pulse headphone amp with a built in DAC, connected through a Microrendu. This way they are two separate zones in Roon, and I can leave the DSP in place. More costly, but I already had the gear… Is the DAC in the Geek as good as in the Meridian, and is the headphone amp in the Geek as good as the Bryston I own? Probably not. But good enough, and I choose the convenience.


#224

I’m sure you already know this but you can save all those differences as 2 DSP presets…I find that works pretty well and the Audeeze headphone symbol reminds you which ‘mode’ you’re in. Would be nice to have 2 different virtual endpoints though, as has been mentioned elsewhere.


(Noel) #225

Thanks for the quick response Magnus. To be honest, i’m not sure what you meant by “remove slopes in REW”.

As for the House Curve in Roon, are you referring to the Parametric EQ, and move the dots around to make it looks like the picture that you attached?

I’ve googled around but i still can’t get it into my mind… total newbie here… :frowning:


(Magnus) #226

Yes, in REW you can set slopes which defines the curve you see in blue, you can see them in the screenshot in step 11, called “LF Rise Slope” and “HF Fall Slope” with values 1.8. Set these to zero to create a totally flat blue target.

If you recreate the filter and listen it will sound rather dull and bright, so you then add a house curve (as in previous picture) in Roon as a Parameteric EQ. Now you can set and modify the house curve to your preferences without having to recreate the filters.

Having said this, you can also do as you did and as I suggested in the guide, but for you with that dip in high frequency I would prefer to have some room to experiment with the house curve.


(Magnus) #227

REW beta 8 is available now, where you can export to 352 and 384 khz, which is good if you (like me) up-sample to DSD since then Roon can use filters in correct sample rate. I have testes and think there is a slight increase in SQ, but expectation bias does come into play so don’t take my word for it :slight_smile:

Download from here (you need to register on the forum): https://www.avnirvana.com/resources/rew-windows-installer-requires-java-7-or-java-8.15/


(Larry Megugorac) #228

Anders,

I use a separate HP Amp, The Oppo HA-1, and the “Listen” circuit it totally separate from my Speaker listening set up other than they both share the same MAC Mini source as RoonServer. I am hoping I can just find a shortcut to turning on and off the Convolution filters between HP and Speaker listening…:stuck_out_tongue_winking_eye:


(Noel) #229

Thanks Magnus - will try it out tonight if not in the next few nights when I can get some free and quiet time. :slight_smile:


(Lars ) #230

@Magnus

Great tutorial for room correction!

I have a questions regarding REW using its eq function:

Aren’t the filters (IIR) generated by REW minimum phase? I use this kind of filters to do room correction to 200Hz max. Obove this frequency I think it’s better to do room correction with FIR filters which are linear phase.

With rephase you are able to do room correction with fully linear phase FIR filters. The big adventage of these filters is that you can adjust level volume independently from phase so these filters do not have any influence on the phase ( no phase shifts…)

Since REW has an export function for rephase it’s possible to transform these filters from minimum phase to linear phase. The preview window in rephase shows you the result of the correction and this fits around 98%.


(Magnus) #231

Yes, it is possible I think, but I think you need to to some tricky manual modifications in RePhase to gain anything which is why I didn’t include it in the guide. Just importing measurement and creating the filters in RePhase does not accomplish anything.

But I am not experienced in RePhase, so feel free to experiment. There is a guide on the net where REW and RePhase is used.


(Lars ) #232

You can import the filter from REW directly to rephase.

I spent the day working with rephase. I imported the measurement from REW and created the filter (all linear phase). I did not use the REW eq function but it would be possible to do so.

The rephase output file 64 bit IEEE stereo (.wav) can be used with roon without any problems.

I attached my REW screens with before and after results. The “loudness” from 20-200Hz was done by myself via filter, all is shown in var. smoothing

Is it possible to load a filter for each loudspeaker? I made a correction for both of my front speakers but I don’t know how I can assign filter “left” to left speaker and filter “right” to right speaker. So in the end I worked with the stereo signal…


(Magnus) #233

I don’t know how to do stereo filters in RePhase, but send a email to the creator of RePhase, Thomas Drugeon (email: thomas.drugeon@gmail.com ), he should know. I chatted with him earlier, but according to him regular room correction should be done with minimum-phase EQ only.

He also explained that importing measurement and EQ-correction from REW and create the WAV filter from RePhase would not yield any improved SQ compared to do it all in REW. But maybe your way will be an improvement over REW.

Your correction looks nice though, although I would not want to be your neighbour when you measured (120 dB at 30-40 Hz :slight_smile: )


(Lars ) #234

I will do so thanks for the contact.

I don’t agree that room correction should be done with minimum-phase only. Just look at Dirac which uses mixed phase correction (IIR minimum phase + FIR linear phase).

As long you stay with minimum phase in REW an rephase too of course there will be no improved SQ. But when it comes to linear phase I think there will be improved SQ.

Imho linear phase filters are always better than minimum phase filters but I’m not a pro so maybe I am wrong…

Yes, the test signal was a bit loud :joy: that’s right…

I think I’ve found a way to do stereo filter but have to test that first…


(Larry Megugorac) #235

Theirry from HAF, uses two different roots to Room Correction …with and without crosstalk and the two Convolution filters do sound different as you might expect. I really like the results! I do also enjoy what Dirac does to my room using the Mini DSP DDRC 88, though I want to eliminate the hardware and just use SW for Room correction.


(Nicholas) #236

First: Thank you for this guide! The attention to detail and screenshots are great for this newbie to room correction and REW.

Second: I’m going to try this this weekend, and have a question about this specific bit in step #14 in your instructions:

What do you mean by this? I don’t currently use any parametric EQ settings in Roon, aside from just experimenting with it. Otherwise, I’m hoping I use all the frequencies my music puts out in Roon. :slight_smile:

Thanks again, and in advance.


(Larry Post) #237

I believe I can answer for Magnus, by each frequency he means each sampling rate, i.e. 44Khz, 48Khz, 192Khz, and so on. Roon will then auto select the correct convolution file to match the rate of the file being played. If it doesn’t find a match, it’s still smart and will upsample the filter to match but it’s best to supply it will all the rates you use. Just export all the rates REW allows and you’ll be good.


(Magnus) #238

Correct, I should probably change frequency to sample rate in the guide.


#239

I came to step 4 in the first post and realized I need some pink noise. Is this download OK to use ?

I don’t even know if there exist different quality of pink noise, or how important that file is ?
Probably Roon should have a pink noise generator built in ?

EDIT:
I’m not able to past the correct link. I like to past the website, not the file. Maybe now…
" https://archive.org/details/TenMinutesOfWhiteNoisePinkNoiseAndBrownianNoise


(Alex) #240

Use the Pink Noise PN generator built into REW to set your levels, as shown in the picture under step 4.