Any horn designers here

[jerluwoo]

I'm estatic to say that I recently recieved a pair of klipsch k55 mid horns gave (freebie) to me.These were originally part of a pair of LaScalas that had been in a house fire,the mid horns and type aa crossovers being the only surviving parts. What im looking for is a basshorn designed around a pair of woofers that i already have to use with them.They are a pair of fosgate 12's made in 93(yes I know car speakers yuk).I can give you full t/s for them and the only real size restraints on the enclosure is the ability to fit them through a door. Would like extension somewhere near 40hz to 300hz.Follow is the t/s for them.
Re=3.6
Fs=32
Qms=4.79
Qes=.31
Qts=.30
cone area Sd=.054m^2
Vas=133L
compliance Cms=.00032m/N
moving mass Mms=79grams
xmax=4.7mm
spl=94w/m
operating power pe=100w

Would also like to here some opinions on other enclosures that may match well with them.

[DIYGuy]

MY Thought would be to pick up a pair of k77 tweeters, a pair of k33 15" woofer and build the bassbin for a lascala. Did the k400 may it rhrough the fire with the k55's ?

[chops]

Also, you're going to have a devil of a time trying to match those Fosgate drivers up with the K-55's. The K-55's are rated around 107dB @ 1 watt, whereas the Fosgate drivers are rated at 94dB @ 1 watt. And I'm not sure those Fosgate drivers are a good choice for horn loading either.

If you want to go horn loaded on the bass bins, you may want to look at the Dayton PF385-8, Eminence Legend CB15, or go onto the Klipsch forum and look up forum member "BEC". He has custom drivers made for him by Eminence called CT1526 which are exact replacements for the Klipsch K-33E, except a little better. All of these drivers are rated around 97-99dB @ 1 watt and will allow you to get closer to the output of the K-55. And once you horn load them, their output will increase that much more.

However, no matter what bass driver you use, you will certainly have to attenuate the K-55 to some degree.

Good luck with your project!

[GM]

Greets!

Long story short, for reasonably low distortion and high efficiency to 300 Hz, the horn will be way too big to get to 40 Hz and be very power limited due to a high compression ratio (CR) with these drivers. Better to stick them in a MLTL (all dims inside):

L = 46.875"
L x W = 173.78"^2 (recommend 16.75" x 10.375")
driver down from top 18.875"
5" dia. x 6" long vent down from top 42"

Line the top, back, and one side with acoustic fiberglass and if the room location causes it to be too 'boomy', you can damp the vent to suit.

GM

[GM]

Originally posted by chops
Also, you're going to have a devil of a time trying to match those Fosgate drivers up with the K-55's. The K-55's are rated around 107dB @ 1 watt, whereas the Fosgate drivers are rated at 94dB @ 1 watt.

Greets!

Not really, but the trade-off is low power handling due to the high CR required.

GM

[chops]

Originally posted by GM


Greets!

Not really, but the trade-off is low power handling due to the high CR required.

GM

There's a 13dB difference there, and that's not including horn loading of the K-55. If there isn't enough proper attenuation on the K-55, the midrange is going to be very hot sounding and unbalanced.

[GM]

Greets!

Hmm, historically, Klipsch ratings are for the horns and the Leach horn design calc'd a ~13.6 dB gain, so combined with the Fosgate's 4 ohm rating, referenced to ~2.83 V the Leach horn tops out at >108 dB/m. Even if the K-55 has a higher eff., which is the norm when comparing compression driven horns to basshorns, it's still not the gross mismatch you imply.

Frankly, for HI-FI apps, if it's like Altecs, JBLs, etc., there's enough clearance in them to attenuate them down to the MLTL's ~95 dB and still work fine.

GM

[chops]

GM,

I stand corrected.

[jerluwoo]

I'll definetly agree on the difference in volume between the 2 the first time i listened to them together.I had to add a 20 ohm in series with the k55's just to bring them down near but still well above the fosgates.This was why I wanted to look into horn loading to try and match them a bit more.
I do have the k77's also but the diaphrams got cooked completely,melted down into the magnet gap and all so they are pretty much screwed.
My largest issue with buying new bass drivers of course is $$$.I dont make much and bills got to be paid.It is so horrible to have the audio bug and cant afford it but I cant get lumber for next to nothing so design that may be large but still do what I need would be no biggie.
I have not looked into a TL type setup so will look into that a bit and see what I can find.
Thanks all for the replies may need a little help on a TL design if I decide to go that way.

[jerluwoo]

Well after afew days of listening I have concluded that I am going to wait and save back for some good units to use with the klipsch.The overall sonics for the lower midrange on the fosgates are litterally nonexistant compared to the k55s which leaves me with a rather nasty tonal void between 100 and 500 hertz.Should have known anyway being car speakers made for booming and all.
I like the TL type enclosure idea after researching it a bit and will probly use some form of it after getting some good drivers.