Need advice for front loaded horn 4x12".

[Hayk]

I have 9x Paudio SN12b speakers that I used for aerodynamic experiment.
I want to built a pair of 4 drivers front loaded horn with bass reflex.
My question is, the 4 drivers should be in column or in square as the bellow picture?
I will use a high frequencies horn cut 250hz.

 

[norman bates]

Well, you are ballpark with a mass corner near 300hz.
A bit of squish (say 2:1 compression at the throat or more), you can go a bit higher before rolloff.

I think a square would be better, but my buddy djk (rip) ran 4 b&c 12" 12pe32 b&c in a vertical stack 150hz-1khz (a bit of squish at throat), but that was for a band for 20'+ listening, think 100' basically.

I'd ask this over at diyaudio.com under the multi way forum.

 

[Tom C]

I have 9x Paudio SN12b speakers that I used for aerodynamic experiment.
I want to built a pair of 4 drivers front loaded horn with bass reflex.
My question is, the 4 drivers should be in column or in square as the bellow picture?
I will use a high frequencies horn cut 250hz.

Magnificent.

 

[Hayk]

I am learning the hornresp software, to see what size of front horn is needed to reduce the FR to 30-35 Hz as the Mms is only 80gr with very low Qts0.16.
At low frequency, with much shorter than the quarter wavelength, a mass of air in the horn, vibrates in piston added to the diaphragm.
14 years ago when I bought these drivers, there was a European site on internet using it in pairs ,front loaded horn, for this application, it is still available for €175. The brand has disappeared last year.

 

[Flaesh]

to reduce the FR to 30-35 Hz

It's almost easy. No BR is needed. And placing the mouth of the horn in the corner is helpful!

The driver parameters are not accurate, but this is not important

 

[Hayk]

Thanks for the example, s1=444, this is compression ratio of about 5, is it?
I have a picture from Paudio catalog should be the correct parameters.

 

[Flaesh]

I've already corrected it according to the picture in the starting post. This is nothing compared to the construction of a pair of such horns))
Where are you planning to install them? Hoping for 1/8th the space is a bit optimistic.

 

[Hayk]

With an exponential horn of 60cm long and mouth 5 times the throat without compression, the resonance falls to 37hz. It needs a BF to reach.

 

[Flaesh]

I don't understand what you're talking about. What's a "BF"? A 60cm horn—like the photo in the start post?

 

[Hayk]

These are the parameters I used.
How to add BF duct to the back volume, 150 liters?
Edit sorry BR not BF.

 

[Flaesh]

BF is BR, bass reflex? May be select Compaund horn.

I wasn't interested in such constructions, I haven't had resonators at home for 20 years. It would be better to read Hresp help.

I think the 100 Hz region with your short horn will be much louder than, say, 40-50 Hz from a BR. But upper bass can be fun !
For home use, add a wall of subs below and a good waveguide with a large format driver above.

 

[Hayk]

I first ran it as BR then added a horn, it worked.
The level, 106db is what I get with closed enclosure but at 300hz, horn and BR extended to 40hz.

 

[Flaesh]

That's right, that's how it works. I answered hastily and without thinking yesterday. What range will this be used in and what will be used at higher frequencies?