need Manifold 2 x 18 cabinet plans

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djmarvellous

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Joined 2007
djk

djk

R.I.P
Joined 2001
What drivers do you have available?

Unless you use the original drivers, the plan is worthless.

You don't need a plan to build these. All you need do is put the two baffle boards far enough apart to allow for mounting clearance. Figure out the back volume and the port size required for your drivers. That determines all the other dimensions.
 
djk

djk

R.I.P
Joined 2001
The original EV design is a 6th order equalized alignment.

A 2 cu ft 2nd order sealed box with an F3 of 30hz can only be 0.18% efficient (84.55dB).
A 2 cu ft 4th order vented box with an F3 of 30hz can only be 0.36% efficient (87.56dB).
A 2 cu ft 6th order vented box with an F3 of 30hz can only be 0.90% efficient (91.54dB).

As we can see, the 6th order alignment is about 7dB more efficient than a sealed box, and 4dB more than a simple ported box.

0.312 is the optimum Qts for 6th order for box size vs efficiency vs bass extension.

If you can give me the T/S parameters on the drivers you're considering I can give you an idea of what can be done with them.
 
djk

djk

R.I.P
Joined 2001
This is the way I build my manifold boxes, not that much wasted space.

PPSL.jpg


With a pair of 15s it's only about 1 cu ft, the net interior volume is on the order of 8 cu ft, port is tuned to 31hz (low B on a five-string bass).
 
D

djmarvellous

Member
Joined 2007
Just about ready

Been ocupied by other things and my job
but now Im ready to build these babies:smash:

Im Going to be using Beyma 18G50 Speakers

here are the parameters:

Brand Beyma
Model 18 G50
Description Die cast aluminium basket. Paper cone. Plasticised cloth surround. Edgewound alum. flat wire voicce coil.
Range / type woofer
Typical use PA
Recomended enclosure Box size 80 / 200 Liters
Series PRO LF
Manufacturer Beyma
Order nr
Production status Active 2003
Nom. diamerer [inch] 18
Vas [Liters] 212
Qts 0,325
Qes 0,334
Qms 12,05
Fs [Hz] 40
Sensitivity [dB] 98
Max Power [W] 800
Power definition W AES
Lower freq [Hz] 25
Upper freq [Hz] 1500
Rec. Filter freq [Hz]
xmax [mm] 9
Moving mass [g] 170
Disp area [m2] 0,132
Disp Vol [cm3] 1,18
xdamage [mm] 40
Air gap [mm] 11
Coil height [mm] 25
Coil diameter [mm] 114
Cms [mm/N] 93
Rms [N*s/m] 3,54
Magnet weight [gr]
Magnet height [mm]
Magnet diameter [mm]
Magnet material - Ferrite
Re [ohm] 6,1
Z [ohm] 8
L [mH] 2
Bl [Tm] 28,8
Magnetic flux [Wb]
Flux density [T]
Outer diam. [mm] 460
Bolt circle [mm] 438
Nr of bolts [Nr]
Cutout [mm] 415
Weight [Kg] 14
Height [mm]
Depth [mm] 210
Driver volume [Liters] 13
Frequency SPL / Z

would these make good drivers for this enclosure?

Could someone please give me the dimensions off all
the boards needed to build this enclosure? (I find the plans confusing) :confused:

Thanks In Advance.:confused:
 
B

bjorno

R.I.P.
Joined 2005
Hi,

FYI, The manifold and the suggested Beyma 18 G50 drivers using the layout of djk:s posted picture (post #11) simulated in a 310 Liter (red color plots) ported box, drivers on the front baffle, picture 1(2) to 2(2).

Using the same box but reducing the internal volume to 250 L (black colour plots) where the volume occupied by the manifold and drivers is arbitrarily set to be a loss of 60 L.

At last: A probable impact on the front side driver output from the slot and baffle load, marked with blue colour and blue plot using a separate simulation from MJK: s BLH_Sections_3_21_07[1] program sheet.

b

1(2)
 

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