Bandpass box for 9515 anyone?

[Joe X]

Well here's some modeling feedback for your reference:

Box type: series tuned 6th order bandpass.

Front chamber: 5 net, port: 100 square inches of port area, 5" in length ( 59.8Hz).

Rear chamber: 2.5 net, port: 22.56 square inches of port area, 19" in length ( 32.8Hz ).

Power: 1000W rated RMS.

Cabin gain modeled as: 12 dB / octave rise downwards in frequency, +3dB @50HZ.

Theoretical frequency response:

Ports airspeed:

Finer red line is for rear chamber port.

Cone displacement:

Comparison with a ported box 4.2 net @36Hz 67 square inches of port area:

So it would seem like:

1) the 6th will help with bandwidth rather than peak SPL. Probably a narrower bandwidth design would help more with SPL.

2) rear chamber port airspeed is on the high side and may be some compression. Unless this is intended some more port area is suggested.

3) cone displacement is fine, SSF to 25Hz is suggested.

[Triticum Agricolam]

Joe X, he is running on a 5k amp.

[Joe X]

I just went for 1000W as at that power level modeling could still be half accurate, it may not come as a surprise (to you) what happens to the port airspeed of the rear chamber at 5K:

[zanekeimigdesigns]

How accurate are these models that a program such as win comes up with? I know there are variables but are they pretty dependable or?

[Joe X]

Well these softwares won't model well enclosures with design issues (for example your rear chamber port area chokes not much above the 1000W I used for the example above), also, more accurate result will be obtained at low power levels (for many reasons) and by using measured cabin gain at the location of interest, say the head rest, the wind shield, any power or signal issues are not modeled of course.

But anyways there's always some infos to gather, as I pointed out the rear chamber port looks like is not functioning well at your intended power levels also your design looks like is not providing increased peak efficiency for you which is what you may be wanting for numbers. These are the kind of infos modeling may help you with.