Thoughts on the Isophon H510

Hey every one! Ive been a lurker for sometime, on and off... but I finally found something that looks like it might be interesting!

So I was doing some research the other night on horn speakers and I found this one, its the "Exponential-Hornsystem H510".

http://www.lup-berlin.de/archiv/Bausatz/img/h510.jpg

The company is now under another name, and is no longer producing drivers. But I have been able find the specs for both the tweeter (KK75) as well as the midranges (BPSL65). So with any amount of luck, I should be able to match the old drivers with something new!

They are using a 2-way crossover, Not to sure if what type it is, or the cross over points. (Suppose I could decide on that.)

I know it rolls off at about 150Hz, but thats all right, I was going to meld it with a subwoofer...

Its been designed as a 4ohm speaker, but I was hoping to modify it to an 8 ohm the only problem with that is im not to sure what generation driver they were using, as there is a difference from the 1980-1984 in regards to the Qms, Qes, and Qts

Just looking for any thoughts, Or opinions...
 
Locating Drivers

So doing more research, I have only been able to find one speaker that would be a "sufficent" contender. The Dayton Audio RS75T-8, which is very close to what is being needed.

Speaker BPSL 65 Dayton Audio RS75T-8
PT# 247185 101813 RS75T-8
8 ohm 4ohm 8 Ohm

fs 150 Hz 150 Hz 164.9
Re 7.3 Ohm 3.3 Ohm 6.4 Ohm
Le 0.13 mH 0.06 mH 0.30 mH
Qms 7.2 6.2 4.7
Qes 1.2 0.9 1.1
Qts 0.95 0.7 0.89
Vas 0.014 ft^3 0.014 ft^3 0.01 ft^3
Cms 0.63 mm/N 0.82 mm/N 0.92 mm/N
Mms 1.3 gr 1.3 gr 1.1 g
B1 2.8 N/A 2.2 N/A
SPL 86 db/W/m 86 dB/W/m 82.7 dB/W/m

The only thing that I have a little hesitation with about this particuluar driver, is that its SPL is lower then the other driver, would this be a problem ?

If anyone knows of another speaker with these parameters, or somewhere that i might be able to find something let me know. Thanks!
 
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Hi,
just a brief description of what is your goal/aims ?
We use to say: much water had passed under the bridge, since then...

I would suggest to revise the whole thing : since there are three vertically
aligned sources emitting in the same range, sort of line array, they will
interact ( interference ) depending on the frequency, as they are brutally
driven in parallel, rather than gradually. So it's better to lower the crossover frequency at about 4-500 Hz and use a modern 2" fullrange...well, maybe a 3"
but you'll find issues in reproducing the super-treble range .

I would then use some 16Ω drivers, maybe arranged 2 by 2 on a square baffle
....I was designing ( actually) a triplet, being the drivers at the edges of an
equilateral triangle, and assuming some short-cuts or semplifications of the radiation phenomenon .

Surely my choice would be not to point the mouth of the horn / any other back load of the membrane frontally, or at least it has been done ad it's still doin' for things such as positioning attached to a wall, on shelves etc.

Maybe with just two drivers and a mid-tw, depending on their characteristics,
it could be done. I have one Voigt pipe done in that manner ( without the compression chamber ) with an 8" crossed at 500 Hz to a mid-tw.

Today I woke up with a Talk talk theme in my mind :p
Life's what you make it, yesterday's faded...
 
I know, technology as well as research has changed. I dont really have any goals or aims. I was just looking to build something that might look interesting and sound decent in a horn manner.

I really liked the size and the horn design on this particular speaker. I dont know much about horns, but im trying to learn....

If I were to use 4x8 ohm, wire them in series parallel, that would produce 8 ohms for me....

....Not to sure what i really should do...