Roll off of slot load configuration

[akh]

Does anybody know a simple to way to calculate or estimate the roll off of a slot load? I feel like I have seen this mentioned before but I can't find the information.

Basically I am looking to use a slot load on an 8" midbass. The midbass will play from 80-300hz. How deep can I make the slot before I run into issues at 300hz? Any other considerations that will impact the desired frequency range?

 

[ICG]

Hornresp can do that.

 

[akh]

^Ya, I know. I am not sure I would model it correctly.

 

[ICG]

'Correctly' is a far stretch. What's 'correct' depends also on the pressure chamber form (yes, that includes the shape of the membrane aswell). The range from 80-300Hz isn't that critical though because it's just 2 octaves.

 

[Scott L]

Is the corresponding 300Hz wavelength larger than any of the slot dimensions ?

And then, depending upon what kind of driver orientation you have, ask if any
dimensions correspond to 1/2, or 1/4 wavelengths.


1130
_____

300 = 3.76 feet

 

[djk]

8's can go to 400hz in a slot if you keep it compact.

 

[akh]

Thanks for the replies.

The reason I am asking this is because I have an application where I need my output to come from a certain position. But, the drivers cannot fit there. So the idea was to use a slot to create a phantom source of sorts.

This is for midbass. I figured out how to model this in Hornresp. The interesting aspect is that it seems to add to group delay, if the sims are correct.

 

[picowallspeaker]

The interesting aspect is that it seems to add to group delay, if the sims are correct.

😱