[Hilux Rules]

Baffled by baffles, Sunk with subs: Vas

I’m new to the forum, any forum (so if I’m doing it wrong or in the wrong spot let me no). I’m learning a tremendous amount given myself a headache with all the reading I’ve been doing. I’d really appreciate any help and all suggestions on my project.
How important is the Vas when calculating box size for subs and other speakers?
When going through a wholesalers catalog came across this problem

Driver
Code P830847
Pwr 350Wrms (Conservative)
Coil 51mm 0.9mH
Zo 3.0W at 115Hz
Fs 21.8Hz
Sens’ 92.0dBm
Qms 10.24
Qes 0.37
Vas 144.2L


Kit for above driver

DRIVER P830847 X1
Box 58L (2ft) 25% Fill
Port 450mm x 90mm
Tune 26Hz
F3 32.5Hz
Loud 116dB (1M)

Manufactures specs say Vas 144.2L yet the kits box is only 60L. (this is specs for driver and a kit to suit the same driver)

Firstly the woofer box won’t suit the car (not after a doff doff system just a little more bass). Want to build one to suit. So I thought being a handy guy with some knowledge of carpentry, electronics and such I’d build up a system myself. That’s when the headache began. as I was reading up on construction , box dimensions crossovers etc. found your enclosure calculator and it just don’t add up or am I looking at it all wrong.
Doesn’t the Box Vas have to be the same as the manufactures Vas specs?

 

[Mike P.]

Code P830847

That is the code from a Peerless XXLS sub, a good choice. Box size depends on what the application is for. For car audio a box smaller then the subs Vas works because the cabin gain of the vehicle will boost the low end output. Build the box 60 liters and you will be happy with the results.

 

[Hilux Rules]

i will thanks for your reply but just for further ref how did they come up with this figure is it just a factory set thing or a calculated one? is there any ref material you no of i can look up?
thanks Laza

 

[Mike P.]

Most manufacturers recommend box sizes and tuning frequencies based on an expected performance level from a specific product.