Ideas for horn subwoofer (B&C 12PS32)

Hello everyone!.. i have this driver (b&c ps32) and i am thinking of building a sub ,specifically a horn type. I have built mth30s in the past, with great results, using ps32's smaller ''brothers'' the pz32's. I have seen martinsson's roar 12 sub plan, i find this very interesting design. I have done some reading and it seems that this design have some opposers , maybe it needs sove development maybe not, so it can reach the success of the mth30 or the tham 12, tham 15. I am open to ideas of course, since this site is a huge tank of knowledge with people that they really love what they do. thanks in advance and KEEP BUILDING....
Joined 2004
Paid Member
Hi dantonis,
First off, what are you trying to make exactly? I ask because you have presented the impossible.
A horn is very difficult to make into a sub as the mouth has to be very large. I mean house-sized large.
Second, you have presented a mid bass as a driver.
Do you want to make a bass bin?
Is this for loud rather than accurate?
Do you want another tapped horn or something different?
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Dear Cal, i bought this driver from a bass guitar player who upgraded his gear. So, my previous experience with tapped horns makes me want to build something similar. I am not expecting miracles, i want something compact one man lift. I know i have to do compromises, anyway we cannot have it all. I must consider bass reflex options also, but i' d like to know the way to take the most out of the woofer.


Joined 2003
upper mass corner (Fhm) = (2*44/.35) = ~252 Hz

min. throat (St) = ~13543/pi/252 = ~17"/43.45 cm

mean center = sqrt(44*252) = 105 Hz

min. mouth dia. = ~13543/pi/105 = ~41"/104 cm

traditional prosound tuning = 1.56*Fs = ~69 Hz


  • BC12PS32pro_horn.txt
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  • B&C 12PS32 ~69-252 Hz expo BR horn.PNG
    B&C 12PS32 ~69-252 Hz expo BR horn.PNG
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using ps32's smaller ''brothers'' the pz32's
Although the 12PZ32 has a 3" voice coil and lower thermal power handling, the gap depth and winding height are both larger. More importantly, it's Qts is much lower and BL significantly higher, so it has a much stronger motor than the 12PS32.

So for PA, using the 12PS32 I would look at the MTH30, for home use I would consider the ROAR12. At PA volume the THD might become to significant in the ROAR 12.