Best horn 50 – 450: U horn?

[rick57]

I’m looking around for the best kind of horn for about 50 – 450 Hz.
I have very low Qes JBL drivers suited to cover that range (fs 50 Hz, Fhm of 590 Hz).

Straight horns are simplest, and I could live with their length (if downward firing into a concrete floor); but integration is harder with a mouth near floor level, esp. crossing at 450 Hz.

I just came across the “U horn”:
http://hem.passagen.se/sajberrapid/50hz.html a 50 Hz Hyperbolic Exponential horn, from Mattias in Sweden.

I might try to contact him to see how he input some parameters into Hornresp, but first ~

I haven’t seen anything like it – does anyone have a suggestion for a better way of covering that range in a horn/ see any disadvantages?
Or read about any other U horns??

Thanks

 

[DorinD]

Why not choose Edgard's "Show-Horn"?
A copy of the B.Edgar article here:
http://www.volvotreter.de ->Downloads
My clone re-calculated for 70Hz here:
http://www.hi-fi.ro/fhifi/viewtopic.php?t=5278&start=0
Cheers,
Dorin

 

[rick57]

Folding geometry - U horns

Hi
(I can’t read Romanian, but thanks). The Show Horn etc ~

I’m trying to really optimise the upper range of a bass horn (my JBL drivers Fhm is 590 Hz), up to at least 500 Hz. The Show Horn was a new benchmark in 1988, but I’m trying to see if some refinements have been done since then ~

Eg the Show Horn article has the theory, but I wonder if the 90 degree turns in the SH might reduce transient response above 300 Hz, compared with curved turns like in a “U horn”?

Edgar acknowledged that he had to compromise the SH with a quasi 180 degree bend, presumably because he wanted it to be portable. Apparently the University Classic doesn’t have that compromise, but if IIRC it was lot bigger.

http://hem.passagen.se/sajberrapid/50hz.html.
Any thoughts on this, curved turns or any other U horns?
Any disadvantages (other than trickier building) in curved turns?

Thanks

 

[rick57]

BTW Dorin,

just looked at the pictures - the cabinets look superb!

Cheers

 

[DorinD]

BTW Dorin,

just looked at the pictures - the cabinets look superb!

Cheers

Thanks!

To optimise the upper response of the basshorn you have to pay attention to the front chamber formed by driver's cone and throath of the horn and maybe use a phaseplug. Your intended driver (590Hz for 2*Fs/Qe) is excellent and worth the effort to try any method to get usable output up to 500Hz (maybe 600).