Who Cares About Linearity

[BassGoBoom]

OK please excuse the clickbait title. Kind of a newbie to room correction. I just used WiiM’s room correction on four different room setups (see EQ curves attached) using a Dayton Audio iMM-6C mic on my iPhone. Much different results from the internal iPhone mic. But…I had no idea how “severe” the corrections would be. I’ve used no room treatments, and let’s assume my speaker placements are reasonable and subs (where relevant) are placed to best deal with peaks/nulls. Are these typical? Looking at other sample corrections on-line, they seem not atypical. If so, it seems to render the quest for perfect linearity that dominates speaker reviews a bit, eh, superfluous? Yes I get that a smooth linear response can be EQ’d more effectively, but with such “bumpy” real-room outcomes, it seems you’d often be far better off shopping for speakers that counter the major room impacts rather than obsessing over linearity! E.g. if the room is going to bury the high-end, better to start with a bright speaker and so on….

 

[fquails]

Mine is similar, although I limited the allowable max gain to 6dB, and I limited the allowed freq range for correction to just 20Hz - 4kHz. Personally, I would adjust the gain settings for the 20Hz range to almost zero. Do your speakers or the music you listen to even go that low? May not be worth over extending your speakers' capabilities with that much gain.

 

[Everett T]

OK please excuse the clickbait title. Kind of a newbie to room correction. I just used WiiM’s room correction on four different room setups (see EQ curves attached) using a Dayton Audio iMM-6C mic on my iPhone. Much different results from the internal iPhone mic. But…I had no idea how “severe” the corrections would be. I’ve used no room treatments, and let’s assume my speaker placements are reasonable and subs (where relevant) are placed to best deal with peaks/nulls. Are these typical? Looking at other sample corrections on-line, they seem not atypical. If so, it seems to render the quest for perfect linearity that dominates speaker reviews a bit, eh, superfluous? Yes I get that a smooth linear response can be EQ’d more effectively, but with such “bumpy” real-room outcomes, it seems you’d often be far better off shopping for speakers that counter the major room impacts rather than obsessing over linearity! E.g. if the room is going to bury the high-end, better to start with a bright speaker and so on….

Just a note, "perfect" linearity isn't the goal in room You want a rising response from high frequency to low. The low frequency is especially important to the sound.

 

[levimax]

The human brain has evolved over millions of year with very advanced "signal processing" allowing us to "hear through the room". What the MIC picks up and what we perceive are not the same thing. That is why you want speakers that have been measured to be linear in anechoic conditions, even though the room messes with the sound waves your brain can figure out what the speakers are actually outputting for the most part. For "DSP room corrections" only use DSP to knock down the big "peaks" below ~ 300 Hz (which people are sensitive to) and leave the rest alone especially "dips" which are usually not possible to fill and are not audible. To get a feel for what we actually perceive use "Psychoacoustic Smoothing".

 

[Keith_W]

I would strongly advise against doing any correction above 200-300Hz unless you are 100% confident you have obtained a clean measurement of your speaker. There is a very strong chance you will ruin the sound if you do that.

 

[10PSPMemSticksForMiku2007]

Digital equalization is very useful but you need to keep in mind the what your speaker physically does. . You'd need a real monster woofer to be juicing +12db at 20hz with no ill effects. I would definitely turn that down or off. Even with the boost it may not really be doing anything at 20hz due to rolloff or room nulls.

All you can do with EQ is attenuate your signal proportionately to compensate for the acoustics you have. It can not change the acoustics. You should be very happy if you can get +-3db from your target. +-6db is not that bad.

You already are using up more headroom than that for your bass so you might as well use high shelf too. Buying different speakers to get a brighter tone makes no sense here.

You do have a point in that the anechoic conditions speakers are measured in don't exist for most people, but that's why we do need EQ. Even if you get a speaker with perfect treble response in your room, bass indoors always needs adjustment. The bass extension, sensitivity, distortion, and radiation pattern may be more important than being perfectly linear sans EQ. This stuff is all related though. Having a linear response and phase is really good to begin with.

In my opinion, the best way to enjoy speakers in an untreated room is to get narrow directivity with waveguides and position the speakers pointing right at you, and listen to them as closely as you can. Around 1 meter is good. I additionally hang blankets over my computers speakers folded so they are 12 layers of fabric thick, and extend about 6 inches in front of the speaker. Not as good as proper room treatment but helps with high frequency reflections around the wall and desk quite a lot.

I would strongly advise against doing any correction above 200-300Hz unless you are 100% confident you have obtained a clean measurement of your speaker. There is a very strong chance you will ruin the sound if you do that.

I second this. OP's graphs really make me question his measurements. Why boost 2k for one and cut for the other?
I EQ my treble way more than the conventional wisdom here on ASR suggests but my adjustments are no more than +-4db.

 

[wwenze]

I think the word you're looking for is "flat", not linearity

And to address the solution, if you have a room that has a random frequency response, you don't fix that by buying a speaker with random frequency response.