the baffle-step frequency

[ttvonau]

How does one determain the baffle step frequency of any given speaker design?

 

[daatkins]

Check out John Murphy's True Audio site:
http://www.trueaudio.com/st_diff1.htm

I wouldn't recomend the full 6dB of gain because a lot of the sound that wraps round the back of the cabinet will be reflected off a read wall. I think +2dB was all I needed.

Regards,
David

 

[planet10]

Also the Jason Neal article and Alex Megan's active compo circuit at http://www.t-linespeakers.org/tech/index.html. Jasons article has a formula -- f(baffle-width) -- that gets you in the ball-park.

dave

 

[ttvonau]

I'm working on a 2.5 way tower speaker consisting of two 55-1200 4.5 poly woofers from mcm and the 53-525 1" silk dome tweeters.Using the formulas that your links provided, I should bring in the .5 woofer at approximately 830hz at 6db.This seems kinda high for a 5.5 inch wide cabinet.Any thoughts on this?

 

[planet10]

I'm working on a 2.5 way tower speaker consisting of two 55-1200 4.5 poly woofers from mcm and the 53-525 1" silk dome tweeters.Using the formulas that your links provided, I should bring in the .5 woofer at approximately 830hz at 6db.This seems kinda high for a 5.5 inch wide cabinet.Any thoughts on this?

Seems about right. That is why i like to keep my 2.5 ways about 13" wide (~300 hz) or better yet, make them bipolar and you get perfect acoustic baffle-step no matter what your box shape.

dave

 

[ttvonau]

In bipolar you mean simply mounting the .5 on the rear of the cabinet straight across from the front mounted woofer.If so would the fact that the cabinet depth is 10" would there not be other unwanted effects caused by this configuration.

 

[planet10]

In bipolar you mean simply mounting the .5 on the rear of the cabinet straight across from the front mounted woofer.If so would the fact that the cabinet depth is 10" would there not be other unwanted effects caused by this configuration.

The amplitude of any re-transmission thru the cones may increase -- but the time delay would be half.

If you let the rear driver run FR you have to have the room to support it.

On the other hand any phase anomalies from rolling off the rear woofer, would be in the rear and radiating in 2 pi so you wouldn't get the comb filtering you do with a front facing 2.5.

And the big benefit -- if you tightly couple the drivers mechanically is an almost total cancellation of newtonian forces, with a subsequent increase in detail.

dave