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

Never mind my previous post. I have deleted all REW preferences and started again from scratch. The measurements I get now are much more like I’d expect :slight_smile:

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Remember to download and use the calibration file for your UMIK (the 0 degree one) and point the microphone towards the speaker being measured.

I found this: http://arqen.com/acoustics-101/acoustic-measurement-primer/

Also, a google search turned up a good amount of information, though it is difficult to parse through it, as it is all located in various internet forums (fora?).

Hi Magnus,

Thanks for the reply. It worked out so far. Now I have put the filters into Roon’s convolution engine and when I make a new RTA measurement I get the below reults. Looks kinda weird all those spikes in the bass region right? The measurement has been performed with the Pink PN WAV file from REW saved and played in Roon. Can you think of what’s going on here?

Regards,
Martijn

Not sure, never seen that before. Perhaps excessive clipping? Does the light in Roon blink red when you play the pink WAV file?

Strange indeed. No clipping according to Roon… I’ll make some new filters and test again. Maybe I did something wrong.

Maybe try pink noise instead of periodic pink noise. Looks like comb filtering of some sort due to the measurement technique.

Thanks for helping out! Measurement looks better now, little puzzled by the 55Hz gap though haha :sweat_smile:

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You can try to “fill it up” but it might be a null node and then you will only add distortion if you try to compensate for it so then its better to leave it (acoustic treatment in your room will help though)

Yep, go with the hole, don’t correct it, no big deal especially if you have 55Hz through the second speaker.

In case of a low-frequency dip impacting left but not right channel, would it make sense to boost right channel on that frequency with a dedicated filter entry? If bass is not that directive, wouldn’t that be a smart way to compensate?

Most experts recommend no boost whatsoever.

I used Acourate, and their recommendation is to pull the target down below the dips, the calculated convolution will then pull everything down, nothing up. And don’t pull it down more than 10 dB, really deep dips or nulls cannot be fixed.

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When we remodeled a few years ago, I lost my dedicated listening space. However, all was not lost! I was able to install a quad of B&W CCM 818s the ceiling of my listening room (which is really the kitchen/family room), plus a B&W in-wall subwoofer (ISW-4). It sounds really nice.

I decided to go the final mile, and try room correction, so I bought a calibration mic, and read this thread (and several others) discussing how to build the filters.

I’m not sure where to perform my measurements from. There’s the chair I usually sit in, which is roughly centered between one L/R pair, but unlike “traditional” listening rooms, the speakers aren’t in front of me, but more over-head.

What suggestions do you all have for how to measure the room?

@AndersVinberg thanks for inputs this would sound reasonable not to boost. Do you have link to those discussions?

Now Markus reported the following:

I am thinking loud that starting with a 16bit file and ending up with 24bit output (my typical use case), you should have possibility to lower by up to 8 bits without issue. @magnus what bit depth did you start with?

My experience:

  • if you correct a room mode with a high Q filter (5 or more), limit the gain between -6dB and 0dB.
  • never apply high Q / positive gain filters
  • low Q / positive gain filters are OK, for example overall bass boost, or treble correction etc… They can be more than 6dB magnitude but if the case, it means you have quite an unbalance in your setup.

In summary :

  • high Q --> gain between -6dB and 0dB
  • low Q --> gain typically between -6dB and +6+dB (could be more in extreme cases)
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Just downloaded Acourate, pfiww looks very difficult if you compare it against Dirac or even REW. Don’t know how to start with it…

Hi,

I have had no personal experience of this software but this book appears to be the ‘bible’ for its use and is written by a respected speaker and Acourate user/reviewer. The kindle edition is very cheap (less than £7 in UK).

Yes, Acourate is difficult. But it appears to do the best job.
I had been completely dissatisfied with my results with REW, a friend recommended Acourate, and that was it. I think because it does a complete time/phase aware calculation.

Mitch’s book, referenced above, is good guidance.

There are discussions here, searchable, I don’t have links.

Can’t have Kindle Unlimited in my country.

Well buy the kindle edition then. Kindle Unlimited is for Prime customers I believe (think you get free books as part of the Prime sub)?