To horn or not to horn

@larryi --

My speakers are 99 db/w efficient. The midrange compression driver has considerably higher efficiency, which is why I have an L-Pad to reduce its output to match that of the woofers. I really like the sound of the 713b driver.

My local dealer, Deja Vu Audio (Northern Virginia), builds custom systems around such vintage drivers as the 713b. Recently, they reconditioned two 713b drivers (attached to 32 horns) and put them into a cabinet which is a clone of the Western Electric 753 cabinet. They installed woofers that are suppose to be clones of the Jensen drivers used in the original 753 speaker. Because the 713b does not go as high as the 713a driver used in original 753s, a horn tweeter was added, which makes it not quite a clone of the original design. This speaker was installed into a wall unit, so in that sense, it was very much a "bookshelf" system. This is a terrific compact system--dynamic, clear, harmonically rich and musical sounding system. It is right up there with another compact system built by Deja Vu that employed a Jensen M-10 fieldcoil driver and a tweeter.

Great. What's the origin of those 12" alnico drivers? The WE 12025 multi cell horn looks to be sturdily build, which bodes well for suppressing material resonances. I gather the WE compression drivers must be quite old - potentially 70-80 years? It's a testament really to how well these things were made (way) back then, and the sonics they deliver. 

The high eff. bass drivers of yore meant for horn loading aren't really made today. With straight sided paper diaphragms that light, voice coils that relatively small in diameter, short in length and low excursion though fitted with powerful magnets - all of which leads to low-ish power handling but very high sensitivity, and not least excellent performance in a horn (resulting in even higher sensitivity) quite unlike anything heard today really, in a very good way.

Direct radiation with bigger high eff. drivers (12" on up) is a very capable solution (but still no match compared to a proper horn-loaded system here), not least in duals per channel like we use in our respective set-ups, and it also potentially offers a very nice dispersion pattern match to the horn above at the cross-over. It's core physics, really, and exposes how modern speakers by and large are a poor expression of functionality. They realized the physics part as a macro parameter a century ago, which has since given way to convenience and being dictated by interior decoration. 

phusis,

I don't know who made the 12" drivers I have.  They were part of a system made by an Italian firm named Strumenti Acustici Precisione which put them in a Jensen Onken cabinet.  I bought the speakers about 18 years ago, and then later changed out the horn driver for the Western Electric horns.  This was easy to do because the horn drivers in the original speaker just sat in a cradle on top of the woofer cabinet.  My replacement midrange horn setup actually looks better than the original horns in that system because they have a width identical to that of the woofer cabinet (24").  

The woofers in my system barely move at all.  I like the sound of such old school woofers with pleated paper surrounds.  They may not go very deep but they behave well and deliver clean sound and natural "tone."

The 713b driver is quite old, I believe someone told me it was made around 1939.  I think it is one of the best sounding compression drivers made, but, it does have some limitations.  First, it does not go quite as low or quite as high as some other Western Electric drivers.  Also, it has a 4 ohm impedance which makes it harder to build a suitable crossover when using other drivers of higher impedance.  These drivers come up once in a while on eBay and other such sites, but, finding a well matched pair is quite difficult.  When a matched pair from a reliable source does come up for sale, the price is quite exorbitant these days.

I am so glad that  i took the horn plunge in 2008 because they are truly amazing on the reproduction of any kind or type of music but you have to get one made prior to 1965 to truly hear a good one.

Yes 

I am so glad that i took the horn plunge in 2008 because they are truly amazing on the reproduction of any kind or type of music but you have to get one made prior to 1965 to truly hear a good one.

1965 you say? No good ones after that you say?

Well I say I’m sitting here listening to a pair manufacturerd in 2020 and they sound sublime.