Flat Anechoic Measured Frequency Response Speakers

Hesson11, that is a very eductional set of curves. Thanks for posting the link.

In the 45 to 75 degree family of curves, you see that big bump between 2 kHz and 5 kHz? Unless you listen nearfield or under quasi-anechoic conditions, that bump is probably audible - and it's right smack in the region where the ear is most senstive, according to the Fletcher-Munsen curves. This excess off-axis energy in the lower treble region is caused by the tweeter having a very wide pattern just above the crossover point, and it's there on most speakers - but you cannot predict its presence from either the on-axis anechoic curve or the "listening window" curve. Kudos to SoundStage for measuring the off-axis response out to 75 degrees.

Duke

Thanks, Duke. I'm guilty of focusing too often on on-axis measurements, so it's good to get a bit of education from one as knowledgeable as yourself.

BTW, I assume most Audiogoners are aware of this, but if you go to the link below, you'll find a great many speaker reviews that feature the same kind of NRC measurements as shown for the Usher Be-718.
-Bob

http://www.soundstageav.com/avreviews_speakers.html

Duke,

The K&H O 500 measurements are absolutely stunning (although the spectral decay plot may be hiding resonances as it cuts off at -25 db)

I have read good comments about these speakers (except they do not play very loud - probably a direct result of their tremendous linearity and even dispersion - as everyone knows you can EQ down to get flat but you lose efficiency).

Do you know what they sound like? I have not heard them.

Hesson11,

I use this page. it is a list of all the NRC measured speakers:

http://www.soundstageav.com/speakermeasurements.html

This excess off-axis energy in the lower treble region is caused by the tweeter having a very wide pattern just above the crossover point, and it's there on most speakers

AHA ....now you have hit the nail on the head in respect of the deficiencies of most speaker designs and especially in contrast to the K&H O 500 you refer too, which has the most beautiful plots I think I have ever seen. WOW.