In this message I will illustratesome different bandpassdesigns....
(Thanks to
jsg mashed for explaining thisto me)
Whenworking outthe order of a bandpass cab;
You get 2nd order for the driver, and 2 more orders for each chamber and portyou add on.
When the chamber behind the driver is sealed, it does
not add another order.
[So the order of a sealed box "acoustic suspension" cabinet is the same as that of just the driver. This is because the compliance of the air in the chamber "merges" with the compliance of the driver and becomes one element. If you then port that chamber, you separate the two compliances because they no longer act as one. So you get an order for the port
and another for the now-separate chamber volume.]
A 4th order bandpass can look like this:
The driver and sealed chamber
Bare 2 orders, chamber
Aand theport are a further 2 orders.
Designs like this are also 4th order bandpass:
(like the Infrabass)
The drivers and sealed rear chambers
Bare 2 orders, and they fire into a chamber
Aand theport which is two more orders.
Common 6th order bandpass cabs can look like this:
Parallel6th order is when(like the X1) both chambers
A and
B are ported to the outside
Series 6th order is when chambers
B and
A are ported in series IE.
B is ported into chamber
A which is ported to the outside.
With the two above the driver is two orders, chamber
Band itsport are two more, andchamber
Aand itsport are two more.
Another form of 6th order:
The driver and sealed chamber
Bare 2 orders, andchambers
A and
Cand ports make up 4 more orders.
Designs like this are also 6th order bandpass:
Dual parallel 6th order bandpass
A couple of 8th order bandpass designs:
This one aboveis the same layout as the
Mighty dub pass
design.
This is like a parallel 6th order but both chambers are portedinto a third chamber
C.
The 8th order above is like a series 6th order but with chamber
A ported into a third chamber
Cinstead of tothe outside.
I'll add more to this later, obviously if anyone has anything to add, do so.
Jake