Quick bass reflex port question...

[revans]

Ok so I got the values from WinISD. Vb was 4.2 litres (but I put in 4.16875 litres as that's the volume of the enclosure I've already built). Fb was 81.94Hz.

I chucked those values into the Vented Box section of Unibox (which, surprise surprise cleared up my port length). I guessed by Pin you meant Nominal Power as it was the only variable watts related thing I could find. I set Nominal Power to 5W and began to move it up while checking the cone excursion graph.

Despite your words about 'slowly', it ended up going in big jumps as the peak only ended up touching the xmax line at 155W (is this okay?). In any case, the bottom of the graph is apparently 82.3Hz - which seems right - does this mean 82.3Hz is the lowest frequency I should place a filter at?

[infinia]

The graph looks good, but the power s/b around 15W not 150W.
Check Rs value in external components area. s/b inductor Rdc value in fraction of ohms


Anyway. looking at the graph the high pass filter (HPF) corner frequency should be placed somewhere around 70 Hz.

[AndrewT]

not much bass from this vented box driver!

[infinia]

Originally posted by AndrewT
not much bass from this vented box driver!

That's why this isn't in the subwoofer forum me thinks. Not too much danger of air turb for a 4" driver.

[AndrewT]

I'm not referring to sub-audio frequencies.
Simply bass frequencies.

[infinia]

Originally posted by infinia



for a 4" driver.

Hi Andrew
It's fs ~70ish Hz

I think a 5 - 6.5 incher would dig alot deeper for not too much bigger size.

[revans]

Well Rs was 0.2ohms, so I'm not sure what's going on there - but anyway, I guess I'll put in the filter at ~70Hz.

Ah well, now to find out how to do a high pass filter.

Thanks to everyone who replied for your help , espc. Infinia and Andrew