Horn Size

[jwatts]

I am trying to design a bass horn for the sub with the following parameters.

\\Revc = 4 ohms (Single Coil 2 ohms)
\\Fs = 33 Hz
\\Zmax = 44.56 ohms
\\Qes = 0.52
\\Qms = 5.65
\\Qts = 0.47
\\Le = 2.52 mH (at 1 kHz)
\\Diam = 206.38 mm ( 8.13 in )
\\Sd =33450.61 mm^2( 51.85 In^2)
\\Vas = 24.70 L ( 0.87 ft^3)
\\BL = 14.85 N/A
\\Mms = 146.65 g
\\Cms = 157.19 uM/N
\\Kms = 6361.81 N/M
\\Rms = 5.40 R mechanical
\\Efficiency = 0.17 %
\\Sensitivity= 84.24 dB @1W/1m
\\Sensitivity= 87.54 dB @2.83Vrms/1m
\\Xmax(In) Peak to Peak = 1.17
\\Vd ft^3 = .035
\\Inverted Cone Volume ft^3= .04
\\Magnet and Cone Volume ft^3 = .09
\\Mounting Hole ID 9-1/4(In)
\\Mounting Depth 8 Inches (In)
\\Continuous Power 500 Watts RMS
\\80 oz Double Stacked Magnets

The result of this calculation yields the following.
Throat Area=42.51 cm^2
Mouth Area=13996.55 cm^2
Length=570.67 cm
Rear Chamber Volume=8.2 Litters
Lower and upper corner roll off frequency is 29-150Hz

Are these values correct or are they extremely large. How can I shrink it down some?

[GM]

Greets!

Using Leach, I get a bit larger specs, but the design isn't viable IMO since it has such a high compression ratio (Sd/St). With its low Vas and relatively high Qts, it's just not a good choice for either a FL or BL compression horn.

GM

[jwatts]

What about this twelve. Is this a better suited choice for a horn?

Revc = 4.1489 ohms
Fs = 35.5216 Hz
Zmax = 35.5411 ohms
Qes = 0.8036
Qms = 6.0807
Qts = 0.7098
Le = 2.3762 mH (at 1 kHz)
Diam = 254.0000 mm ( 10.0000 in )
Sd =50670.7504 mm^2( 78.5398 in^2)
Vas = 51.1113 L ( 1.8050 ft^3)
BL = 12.7749 N/A
Mms = 141.6356 g
Cms = 141.7366 uM/N
Kms = 7055.3384 N/M
Rms = 5.1987 R mechanical
Efficiency = 0.2748 %
Sensitivity= 86.3901 dB @1W/1m
Sensitivity= 89.2417 dB @2.83Vrms/1m

[zobsky]

Originally posted by jwatts
What about this twelve. Is this a better suited choice for a horn?

Qts = 0.7098

probably worse .

look for something with an Qts of 0.2 something and Fs in the 30 - 40 Hz range, depending on what your goal is.

[GM]

Greets!

No, it's Qts is much higher than the other one, which was already too high.

GM

[Tehrasha]

Assassin 12

Try this one in your calculations and tell me what you get.
It does have a high Sd, but the Vas and Qts are better than the two you have listed so far..
Unless they dont have the power handling you were hoping for. This is the driver I have been considering for my Insanity horn.