• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

HF roll off trend?

Roy_L

Active Member
Joined
Sep 24, 2019
Messages
197
Likes
123
Location
Haifa, IL
It seems to me that in recent years there is a trend to roll off the highest frequencies in some speakers for some reason.
It was most notable for me with a pair of Wharfedale Lintons I've recently owned; They sounded OK, but a 5db~ boost in the 12-16Khz region really brought them to life.
This is also backed up by the Linton's measurements. I've had similar experiences with newer models of Dynaudio among others, making me think that there is some pattern to this. Anyone knows what might be the reason? (Just guessing- something to do with directivity/off axis response?)
 
Last edited:
Well how were the measurements done? I'd expect a boost around 12-16 khz to bring in more airiness to the sound. As for the measurements you want the slight slope for in-room measurements like with REW. Such a slight slope would measure near flat in anechoic conditions for the 0 degree measurement point. So it is a measurement artifact.

As for whether this is a trend I don't see that it is a general trend, but there have always been voicing one way or the other for many makes of speakers.
 

I think we can say that the Harman target is proven to be the preferred choice for most listeners for most music, but the fact we have speakers like B&W *and* speakers with HF roll off means that there is still a *market* for speakers with different flavors…
 
Yes, look at the estimated in room response.

1726910069050.png
 
With my Lintons I've added a shelf of 2.5 db, centre frequency 8,000 Hz. This is something I can turn on/off with a click, but I find the sound is more realistic on many recordings.
 
The Lintons are great and by far the best value I've encountered in recent years.
Easy recommendation for audio enthusiasts who don't want to pay an arm and a leg.
However, for my preferences, they must have some HF boost to really sing.
 
Harman's curve showed people like a speaker that measures flat at 1 meter but the listening is actually further away. As you move further away the high frequencies lose energy quicker causing the roll off.

Until much of the preferences research many people would EQ their system to be flat at the listening position. What they found is this altered the sound and it no longer sounded natural. We recognize when something sounds unnatural. For instance let's say you first meet a person for the first time who has a cold with nasal congestion or a sore throat. We recognize that this is not their normal voice whether we are standing next to them or across the room, even though we have never met that person and don't know what their voice sounds like. They found that EQing to flat at the listening position can often make the sound unnatural.

That being said, everyone's room and situation is different, there is nothing wrong with EQing to your preferences.
 
I got this explanation of the graphs in most common use from https://acousticfrontiers.com/blogs...is-response-theory-and-measurement-techniques :

"Listening window, early reflections, sound power – the Harman approach

Harman’s are the inventors of this approach that includes multiple plots intended to describe the on axis, early reflection and late reflection contributions of the speaker to what we hear.. They measure speakers at 10 degree resolution in 360 degrees horizontally and vertically around the speaker in an anechoic chamber to generate the following type of chart.


The data in this chart is smoothed at 1/20th octave and has a frequency resolution of 2Hz. In this chart the following measurements are shown:


  • Listening window = average of on axis, +/-10 degrees vertical and +/-10, 20, 30 horizontal speaker frequency response.
  • First or early reflections = average of the floor, ceiling, front wall, side wall and rear wall speaker frequency response. The side wall contribution, for example, is the average of +/- 40, 50, 60, 70 and 80 degrees horizontally.
  • Sound power = the sum of all sounds radiated by the loudspeaker in all directions. The sound power is the speaker’s contribution to late reflected sounds in a room.
  • Directivity Index (DI) = the difference between the on axis curve and the sound power or first reflections curves"
Harman's approach derives from work done by Dr. Floyd Toole, who published this book:


It can be purchased here:

This thread (here at ASR) may help explain the gradual decrease in treble response inherent in some measurement methods.


Jim
 
A while ago I took my Lintons to a football field to measure them:
IMG_3184.jpeg

(thats my father in the photo)
I did both MMM and multiple points for L and R speaker. Distance approx 1.7m from front of speaker.
L/R MMM are an average of 5 MMM measurements
LA/RA Avg is the average of 5 sweeps windowed.
IMG_3651.jpeg

EDIT: SPL@100Hz approx 90dB, @4k approx 80dB sorry for cropping
 
Last edited:
Hello @dweeeeb2,

Thank you for sharing your measurement efforts in a football field!
Very nice to know your father was/is very much cooperative in your audio endeavors.:D
Just for sure (to me), in your SPL diagram, would you please include the Y-axis dB scale numeric numbers?
 
Harman's curve showed people like a speaker that measures flat at 1 meter but the listening is actually further away. As you move further away the high frequencies lose energy quicker causing the roll off.

Until much of the preferences research many people would EQ their system to be flat at the listening position. What they found is this altered the sound and it no longer sounded natural. We recognize when something sounds unnatural. For instance let's say you first meet a person for the first time who has a cold with nasal congestion or a sore throat. We recognize that this is not their normal voice whether we are standing next to them or across the room, even though we have never met that person and don't know what their voice sounds like. They found that EQing to flat at the listening position can often make the sound unnatural.

That being said, everyone's room and situation is different, there is nothing wrong with EQing to your preferences.
Good explanation, I didn't realize that. I guess I'm somewhat out of the norm, although not by much (I'm not really into "bright" speakers).
 
Yes, look at the estimated in room response.

View attachment 393732
Thanks.

The 12-16kHz region is roughly between the two dots below.

1726941442230.png


When I try to picture a full 5dB boost of that area I struggle to see how that fixes a problem that is apparent in the measurement data. On the contrary - in this representation the 12-16kHz area particularly looks like it's better left untouched.

What am I overlooking?
 
Thanks.

The 12-16kHz region is roughly between the two dots below.

View attachment 393871

When I try to picture a full 5dB boost of that area I struggle to see how that fixes a problem that is apparent in the measurement data. On the contrary - in this representation the 12-16kHz area particularly looks like it's better left untouched.

What am I overlooking?
Lol, the 12-16 kHz region! I don't think I can hear anything above ~9.5 kHz!:cool: Unless it's something that sort of activates one's skin and you can sense it.
 
Back
Top Bottom