problem with ported box volume (Pionner subw)

[lalieno]

Hi, i have a subwoofer Pionner TSW 1040C and i want to make a ported box for it.
Using different software (WinISD) i obtain a volume for a flat response of about 30 liter while Pionner suggest to use a smaller box of only 18 liter (see attached).
Maybe if i use a larger box i damage the speaker?
Pionner 1040C spec:https://www.pioneerelectronics.com/pio/pe/vgn/images/portal/cit_3424/49032TS-W1040C_200012301332368370.pdf

differente response diagram (green pionner box, red my larger box)

 

[snappyturtle]

pioneer recommends based on in car and max power. what does excursion look like in the new box with rec'd power?

 

[lalieno]

i want to use it not in car but at home. what is "rec' power"?

 

[mashaffer]

It is not uncommon for manufacturers to recommend boxes that are underdamped in order to get an exagerates thump. For fidelity the larger box is preferred and will not damage the driver. Of course over driving the sub (esp below fb) will damage it no matter how you tune it.

 

[Think]

If you make it even bigger, you get a nice low end roll off (curve more like sealed), nice because it is compensated by room/car gain, and you end up with a flatter curve.
If you design it flat, big change it will sound boomy as the lower frequencies gain more from the room. For outdoors, flat is fine.

 

[Brian Steele]

It is not uncommon for manufacturers to recommend boxes that are underdamped in order to get an exagerates thump.

It also increases mechanical power-handling capability in the passband (excursion is reduced because Fb is higher).

Then there's the question of the effect of semi-inductance on the actual response curve.

 

[lalieno]

thANK YOU

 

[GM]

FWIW, a 'classic' BR [Vas/1.44] tuned to Fs: Xmax limited to ~24 Hz/150 W. Note large [125 mm dia.], long vent to get vent mach down to ~20 m/s.

GM