How to read kef beamwidth charts?

[No_hair_left]

How would I go about reading the beamwidth charts on the kef speakers https://assets.kef.com/documents/ciseries/Ci130QR-EDIT-NO-CROPS.pdf that suggests that these speakers have 130 degress of coverage which I find hard to believe.
have no idea what the polar charts mean either.

I am currently sitting at a 35 degree angle, does the chart suggest its good up to 40 degrees off axis?
what is going on with the massive peaks and dips?

I can also look into building a wedge type box to angle these better at the mlp (like the ascendo type speakers) as the min box requirement is only 7L and that way I wont need to cut massive holes in ceiling, have seen people build sonotube angled baffles to do this but if these speakers were built with an certain baffle in mind would it not mess the fr response up?

 

[staticV3]

The beamwidth chart likely plots e.g. ±45° as 90° beamwidth, that's the only way I can make sense of specifying >90° for a flush-mount speaker.

Still, it's weird that the speaker supposedly plays wider at -6dB than at -3.
KEF may have mixed up the graphs.

If you're interested, I could digitize the data to both confirm my suspicions and to try to convert it into a familiar Klippel-style directivity contour plot, albeit with far lower resolution that typical NFS plots.

 

[Miley_B]

Still, it's weird that the speaker supposedly plays wider at -6dB than at -3.
KEF may have mixed up the graphs.

It looks correct to me. You would expect it to get quieter further off axis, therefore with the on axis level as the reference, the point at which the level drops by 6dB would be further off axis than the -3dB width limit.

 

[staticV3]

It looks correct to me. You would expect it to get quieter further off axis, therefore with the on axis level as the reference, the point at which the level drops by 6dB would be further off axis than the -3dB width limit.

Thanks for the correction! You're completely right.

Looks like OP is not the only one who's not used to reading beamwidth charts

 

[pierre]

For the KEF CI130.2CR (not sure if it is the same), maybe it is easier to look at it like:

or

The spinorama (dont compare with a normal speaker):

 

[No_hair_left]

The beamwidth chart likely plots e.g. ±45° as 90° beamwidth, that's the only way I can make sense of specifying >90° for a flush-mount speaker.

Still, it's weird that the speaker supposedly plays wider at -6dB than at -3.
KEF may have mixed up the graphs.

If you're interested, I could digitize the data to both confirm my suspicions and to try to convert it into a familiar Klippel-style directivity contour plot, albeit with far lower resolution that typical NFS plots.

yes please.

 

[No_hair_left]

For the KEF CI130.2CR (not sure if it is the same), maybe it is easier to look at it like:

View attachment 432395View attachment 432396
or
View attachment 432398View attachment 432399
The spinorama (dont compare with a normal speaker):
View attachment 432400

the 2cr looks to be identical other the the 16mm (0.6in.) Aluminium dome tweeter and smaller depth, the 130qr has a 19mm (0.75in.) Aluminium dome tweeter, not sure if this makes any difference at all, this is much easier to understand though, looks like be stay within 40 degrees.

 

[staticV3]

yes please.

Here are the Ci130QR's Polar graphs converted to a Klippel-style Contour graph:


Pretty low res (1/1 Octave)

And here's what happens when I splice in the data from KEF's Beamwidth charts for better resolution:

 

[No_hair_left]

Here are the Ci130QR's Polar graphs converted to a Klippel-style Contour graph:

View attachment 433308
Pretty low res (1/1 Octave)

And here's what happens when I splice in the data from KEF's Beamwidth charts for better resolution:
View attachment 433309

Many thanks, that's a wild looking chart, guess I'm better off making sure they are at 30 degrees for the mlp.