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Frequency response + or - 1 dB ??

The technical material world is full of incredible precision - watches as a mundane example. Why can’t the best loudspeaker manufacturers create a loudspeaker with + or -  1/2 dB frequency response within the rather limited 20 to say 30,000 cps range? 
ptss
millercarbon's avatar
millercarbon
12,531 posts
 
I've got a better question: who cares?

Seriously. The sarcasm is an unintended but usefully jarring side effect. But seriously: Who cares? Take any speaker that has at any time ever been considered the best, or a classic, or whatever. Any greatly admired speaker. Can you think of one of them that the big reason it was so revered was its ruler flat response? 

I mean aside from the followers of speakers like Dunlavy who are happy to have the sound stepped on all over the place just so long as its flat. The vast majority however vote with their wallets for a whole lot of other sonic attributes. Of which perfectly flat response seems to be pretty far down the list.

So its less "why can't" than "why don't". And the answer is: Because hardly anyone cares all that much. Not because it doesn't matter. Because its just one of a whole lot of things that matter.
audiokinesis
2,750 posts
 

A powerful DSP unit can probably get you pretty close at the microphone location, but to do it right, you'd need to exclude reflections.

When I first had access to good test equipment, as an enthusiastic amateur, I built a speaker that was about +/- 1.25 dB over most of the spectrum (room size limited how low I could get good data).  I remember vividly tweaking the crossover to get closer and closer to "flat", and that as I did so, the speaker sounded worse and worse!   I persevered, having faith that everything would sound right when I finally got to the promised land.   Well, it didn't happen.  When I was done, it was a truly dreadful sounding speaker. 

I won't bore you with my quest for understanding that experience and where it led me, but let's just say that "flat" would not be my goal for a high-end home audio loudspeaker. 

@erik_squires makes an interesting observation:  "...in the room it all goes to hell."

In my opinion there are really TWO frequency responses that a designer needs to get "right":  The frequency response of the first-arrival sound, and the frequency response of the reflections.  By way of example, live unamplified instruments get both of these "right", and the result sounds pretty good.   

Duke

kenjit
1,771 posts
 
Well, it didn't happen. When I was done, it was a truly dreadful sounding speaker.
It was probably not measured properly and not really flat. Why else would it sound dreadful?
erik_squires
16,375 posts
 
Kenjit,

Would you please describe your current speaker syste, as well as any widely available commercial speaker you stan?


Thanks
audiokinesis
2,750 posts
 

"It was probably not measured properly and not really flat. Why else would it sound dreadful?"

Actually, you are right! I was only measuring the on-axis response, and ignoring the off-axis response, because back then I didn’t know any better!

But here is another critical piece of the puzzle: "Flat" sounds "thin and bright" to most people.

And a gently downward-sloping curve sounds "flat" to most people.

There’s an excellent discussion of the subject in this review of the Dutch & Dutch 8c loudspeaker, scroll down about 1/4 of the way:

https://audiophilestyle.com/ca/reviews/dutch-dutch-8c-loudspeaker-review-r739/

The author draws on an extensive controlled blind study conducted by Sean Olive and Floyd Toole, and says,

"Most participants in the study preferred a frequency response from 20 Hz with a straight line to -10 dB at 20 kHz. A measured “flat” in-room frequency response is not the preferred target, as it sounds too thin or lacking bass."

If I was designing a studio monitor the goal posts would be in a different place, and "flat" measured response might very well make sense, depending on what type of monitor it was (tracking, mixing, or mastering).

Duke


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