Bright High End Speakers = Bad Room?

I find that the most natural and comfortable to listen to speakers are the ones that employ some subtle version of "The BBC Dip".

Highly revealing, spacious, well done lower slope crossovers, fast, tuneful, all of it, with a slight BBC Dip. Clean and warm, as the mix demands. A properly done BBC Dip, in my design experience....has the lowest part of the dip centered around 3.5khz and then goes back up again, and is about 2db deep, overall, as a best potential compromise.

And then it’s good all around and it can play all day, at any volume. From soft to break the windows levels...

Everything else that might be off.....is generally just bad equipment choices. (It is a multistage learning curve and individually committed to as an act --same goal, and very probably a different path for each person)

This graph has it as being slightly exaggerated but warming up to being ideal.

This would come down to personal preference and likely room response as well. For me, I am not a big fan of this design technique, though the reason to implement it, to invert the peak in the Fletcher-Munson equal loudness countours and "soften" the sound makes sense. From a methodology standpoint, it is similar to the "loudness" setting that boosts bass response at low volumes where we have poor sensitivity to bass. It is sneared at in audiophile land, but there is a solid reason to do it when you can’t turn the volume up.  I would not be surprised if there was a variation in the level of dip in the loudness contours from person to person.

teo_audio1,177 posts10-31-2019 11:52amI find that the most natural and comfortable to listen to speakers are the ones that employ some subtle version of "The BBC Dip".

Highly revealing, spacious, well done lower slope crossovers, fast, tuneful, all of it, with a slight BBC Dip. Clean and warm, as the mix demands. A properly done BBC Dip, in my design experience....has the lowest part of the dip centered around 3.5khz and then goes back up again, and is about 2db deep, overall, as a best potential compromise.

@teo_audio

This means you should never think that a studio monitor speaker is even remotely suitable for neutral and balanced home use. They are emphatically not.

B&w, pmc, atc, kii audio, etc many are used for both. 

@teo_audio 

That curve is about what I normally do with digital eq to "tame" my loved ATC 150asl somewhat. Maybe up to 4db around 3,5 khz where they cross to the tweeter. Except for a flat response in the bass.....

Can't really agree that most pro monitors are especially exaggerated in the highs (above 8 khz). Maybe they are just not rolled-off and a little more direct in their dispersion. Most often they have controls to take down/roll-off the treble. NS-10 of course very special. Made only to work with the mids.

Teo_audio wrote: " I find that the most natural and comfortable to listen to speakers are the ones that employ some subtle version of "The BBC Dip"."

Agreed - a bit of dippage centered somewhere between 3 and 4 kHz does seem to correlate with long-term fatigue-free listening.

One way of seeing the BBC Dip is "inverting the Fletcher-Munson peak", as atdavid so eloquently described it.

But here’s another way of seeing it: The BBC dip is right smack where the bottom end of most tweeters is, where most tweeters have an off-axis pattern flare. The result is a net excess of energy in this region (the off-axis energy perceptually adds to the on-axis energy), and the BBC dip is one way of addressing that.

One day I was curious about whether the BBC dip would be subjectively desirable if there were no off-axis energy flare to compensate for. My designs are constant-directivity over much of the spectrum including that region, so I dialed in some gentle dippage centered between 3 and 4 kHz. What I heard was educational to me.

Yes the speaker became more forgiving, but the harmonic richness was degraded. There was something obviously missing relative to having smooth response through that region. The loss of something quite desirable - timbre and texture and a natural-sounding richness - caught me by surprise.

So while the BBC dip does invert the Fletcher-Munson peak, I have come to believe that its primary raisin d’etre is to compensate for that off-axis energy flare at the bottom end of the tweeter’s range. And if that flare isn’t there, ime the BBC dip would be a step in the wrong direction.

One thing that peak in the Fletcher-Munson curve DOES tell us, in my opinion, is where the stakes are the highest.

Duke