The REAL reasons behind open baffles 4" or less having no bass ?

[sreten]

I was indeed listening directly on axis 🙂

The problem is that people explain the lack of bass is due to low frequencies from
the back interfering with frequencies coming from the front as they are out of phase.

But in my experiment where I placed the speaker in a big rockwool pack,
which at this thickness and size have a huge absorption coefficient, and
the result was as I explained in the original post.

Hi,

Your assumption is incorrect. The rockwool will not prevent
the front and rear interferring locally around the driver.
There is no backwave for the wool to absorb apart
from the rear sound of the driver in free air.
(moreorless, a bit more to due resistive paths)

In other words it will sound pretty much exactly the same.

The rear will take the path of least resistance,
which is to simply still interfere with the front.
Consequently the size of the rockwool is inconsequential.

rgds, sreten.

 

[Cal Weldon]

That was helpful. I think that was first said in post 3.

 

[boswald]

Let's not get touchy. The point is that you did not disprove the common model. You did not isolate the front and back waves, and the result was very similar to free air response. Try this. Measure the distance from the back of the frame holes(just in front of the magnet) to the edge of the speaker frame in front. Hold that thickness over your ear and put your ear toward a woofer playing some bass signal. Better yet, face the speaker and see if there's much difference in bass between your ears.