Room curve - already applied to recording?

[JoachimStrobel]

I need to warm up an old topic - room curves.
I have read a lot about it and understood most of it.
So, what happens in case music is recorded with close-up microphones. Does the recording/mastering engineer add a room curve already, i.e. damps high frequencies (and adds reverberation for the music hall feeling)? And if I do this again with my EQ I get a double dip? Or does he/she master the CD flat forcing me to either have good loudspeakers where the azimuthal frequency spread takes care of the room curve, or I force one via EQ?

 

[Wayne A. Pflughaupt]

There kinda is a room curve “baked into” recorded music, in that the monitor speakers are set up for the room they are in. In other words, they have a room curve. A good engineer recognizes this potential issue and will demo his recording on a number of systems in different environments. Nevertheless, there is no standard for music, which is why some recordings sound brighter than others, or have weak bass, etc.

There is no need to “re-eq” a recording. Just set up the curve your room requires, and EQ a recording if needed via the tone controls.

Regards,
Wayne

 

[JoachimStrobel]

Wayne,
That implies restricting REW or Dirac to 500Hz max and not messing with the higher frequencies which would require a room curve or otherwise they are EQd flat.
For Stereo that seems ok. For a 5.x system however it does make sense to room EQ the full range to have a uniform sound field at the sweat spot. Multichannel music appears as Stereo with pseudo room ambience and as full 5 channel discrete sound with ?a lot of direct sound. Would such recordings need a room curve?

 

[Wayne A. Pflughaupt]

It makes no sense to me that a curve would be dedicated to certain playback material. A room curve (aka house curve or target curve) is compensation for the room, not the playback material.

Some recordings may need EQ to correct deficiencies, but that’s not the same as a room curve. Maybe this will explain:

System Calibration vs. Program Compensation: Will a...

www.hometheatershack.com

Regards,
Wayne

 

[JoachimStrobel]

Wayne,
Let me take another view:
My decent loudspeakers were build with a room curve in mind. I could “see” this room by putting my loudspeaker in a anechoic chamber averaging a 360 deg measurement. My room will alter that room curve, but if I knew it, I could EQ it back.
In real live I do mit know that perfect curve my loudspeaker designers had in mind. But I do not want to EQ them flat either. So what do I do? (Other than hanging my speaker on a crane and measure outside?)

 

[Wayne A. Pflughaupt]

The thread linked below covers pretty much everything about house curves, including theory and how to set up one that’s proper for your room. Basically, a house curve is compensation for, and specific to, the room. It doesn’t matter the speakers in use. Bass-heavy speakers may need the lows dialed back to achieve the desired curve. Conversely, small bookshelf speakers may need a boost at the lower frequencies.

House curve: What it is, why you need it, how to do it!

www.hometheatershack.com

Regards,
Wayne

 

[JoachimStrobel]

Wayne,
Thanks a lot for your answers and links. I read them all. Given the inperfections of filters I still believe that there good but also bad in EQing speakers to a room response curve. I gave it a try and yes .. it is good but leaves room for improvement. While I enjoy the crisp sound field, it lacks a bit a natural flavor to it.
I did follow F Toole’s book with its room curve suggestion. It has essentially two: One for the average listener and one for the experienced one, having a 2-3dB stronger dip for high frequencies. Any comments from your side on that?

 

[Wayne A. Pflughaupt]

The trick to manually EQing full-range, especially above about 2-300 Hz, is being able to recognize what issues can be EQ’d and which shouldn’t be attempted. Basically, you’re looking for the larger and / or broad peaks in response, as those are the most audible. Dealing with those will typically get the most audible improvement.

Also above 2-300 Hz, left and right filters should be matching. Mis-matched filters will have an adverse effect on imaging.

In addition, using graphs smoothed at 1/3 or at most 1/6 octave are best, as they give a better visual representation of what you’re actually hearing.

Here’s an old thread that’s a good case-study in full-range EQ.
Spridle’s Experiment

Sorry, I can’t comment on Toole’s room curve because I have not seen his book. You can try both curves and go with what sounds best to you.

Regards,
Wayne

 

[JoachimStrobel]

Many thanks Wayne

 

[JoachimStrobel]

Just to wrap this up:
I felt always a bit uneasy with the many options REW has and the complete freedom in the target curve. I believe that I could potentially do more harm then good.
So I went with Dirac Live and upgraded my Nanoavr HDA.
In Dirac I started with the Auto-Target curve, which is a fine thing as it looks at each speakers response and adjusts them to a “Toole alike” curve. Good for a start and even at the full frequency range it did a great job optimizing low frequencies but keeping the higher ones together. I then added a bit if Bass boost to those target curves. I guess Dirac is conservative in not assuming too much amp power for low frequencies correction.
I am not sure if there is a copyright on those target curves, otherwise I will post them later.

 

[JoachimStrobel]

... attached is a merge of Dirac's and Toole's room curve