straight bass horn

[boptura]

hi,

i am considering to start building a pair of bass horns. would be happy to cover from 35-40Hz to around 120-170Hz.

available space is around 3,5mt in lenght and 1,5-1,75mq for mouth area (each horn)

if mouth area is not large enough i can switch to just one mono bass horn, reaching almost 3mq... how important is the stereo perception under the 150Hz ?

i would prefer to use high efficiency vintage alnicos, if possible, anyway which are your suggested drivers ? 12" or 15" ? how many of them ?

thanks to all !!

[Helmuth]

try horn response. There are many drivers suitable. fs/Qts=110 (indication)

[boptura]

forgot to mention that i need to be low on mouth, as i need space for the midbass and high horns above...i could use 70, maybe 75cm in mouth high (width can go as large as 4,5-5mt.)

so, in order to avoid a horn with parallel top and bottom sides, i need to be more low on throat, around 50-60 cm, and have a minimum degree of vertical expansion...

i was thinking to use a pair of 12'', one above other ...

another way could be to mount a 15'' on each side, like in the skramstad horn...

which work better ?

tnx

[Helmuth]

The bigger the mouth off the horn the higher the cut off frequency. Or the horn will become enormous in total volume.

[Helmuth]

Try this one 18"
mivoc awx18




awx

[boptura]

Helmuth, at now i would prefer remain into 12'' - 15'' range, two drivers, if possible...

attached is my first attempt to calculate the horn, i used Melhuish hypex calculator:

throat area: 600 cm2
flare frequency: 35 Hz
size factor: 2 (horn will be on the floor)
M: 0.8

width: 500 cm
height: 77 cm
lenght: 342 cm

i would prefer vintage drivers, like Altec 414, EV12M, Jensen A12.... or 15'' Altec 515, Jbl 2220, Gauss, Coral..... something better ?


tnx

[Helmuth]

Why 12 OR 15"? What is your reason for that.

When you reduce the horn troth will flatten the response and reduce the dimensions

[MaVo]

Despite it not being vintage... try Hornresp to simulate your horn speakers. You will be amazed what one can do wrong with horns if some paramters are not right. Either simulate the horn or build several ones and measure each iteration, until you find the right parameter configuration.

[tinitus]

This way of doing it is quite nice

[GM]

Yeah, given the height/XO limits, a truncated dual 15"/channel stereo version of this at minimum would be my choice, though four 15"/ channel to further shorten it and limiting the XO point to <150 Hz would be my preference.

GM