[oz_audio_todd]

Ummm.. yeah, what is baffle step, why does it need compensation, how do u compensate 4 it and if its done properly will the design sound wrong with a different shape baffle?
Ta 

[rajesh]

Good question. Even I'm looking for answers here.

[JohnR]

In a nutshell, a woofer radiates in all direction at low frequencies, and forwards only at higher frequencies. Because of this, the anechoic on-axis signal level measured at low frequencies will be 6 dB less than at high frequencies. So this needs to be adjusted for in the crossover; typically less than 6 dB adjustment is used because woofers are used in real (reflective) rooms not anechoic chambers.

The frequency over which this transition occurs is determined by the size of the baffle. So changing the baffle size will make the compensation built into the crossover "off" by some degree.

[Danny Richie]

Very good John.

Just another way to think of it is that with the woofer radiating in an omni fashion in the lower regions then half of the woofers output went the other way (away from you).

In a typical mini-monitor this starts happening at below about 800Hz. So it starts loosing output below that. Make the baffle wider by a few inches and push the range of loss down to below 600Hz... Mount the speaker is a wall and you have no loss. It all radiates in from the wall forward. 

[FullRangeMan]

Any cone driver radiates sound in positive acoustics phase to front, and negative to rear, when positive and negative sound waves meets there is a attenuation of x dB according the cone size.

In a 15inches cone woofer it lose 18dB per octeve below 60/65Hz, in a 8 inches driver it attenuates under 120Hz.
So a huge baffle is need to help.

[richidoo]

I found this article helpful to explain the concept in simple terms, plus basic math formulas to help size the baffle.

http://www.trueaudio.com/st_diff1.htm

[Danny Richie]

Any cone driver radiates sound in positive acoustics phase to front, and negative to rear, when positive and negative sound waves meets there is a attenuation of x dB according the cone size.

In a 15inches cone woofer it lose 18dB per octeve below 60/65Hz, in a 8 inches driver it attenuates under 120Hz.
So a huge baffle is need to help.

You must be talking about open baffles.

[planet10]

A whole section of articles on baffle step:

http://www.t-linespeakers.org/tech/index.html

dave

[FullRangeMan]

You must be talking about open baffles.

Yes, it is correct, I misunderstand the topic, sorry.