Our friend from 13Audio shares an intriguing story… “Why didn’t they make the 16a horn in solid wood 90 years ago? The Western Electric 16a horn was manufactured in steel yet the patent mentions wood, steel, or any other appropriate materials. However, steel was the only material known to have been used. From a mass production perspective, this makes sense; thousands of 16a horns were produced and many are still be around today.”
“I own an original 16a that came straight from a conference hall in Philadelphia, Pennsylvania, in the US. It stood along five others. The fact they weren’t exclusively used in theatres may explain why so many are still around today.
As is the case today, in the 1920’s, any industry envisaging large-scale production would certainly opt for the faster and cheaper : metal. The manufacturing of the 16a meant investing in tools to make the various curves and shapes, something that’s easy to write off while producing thousands. In addition, at the plant, simple welding was all that was needed to pump them out en masse. 
But crafting from solid wood?….well that’s another story.
Having just made the first 16 crafted from solid wood, I can say with some authority, this is not any easy build!
Skill and time are the necessary ingredients to see this horn come to life. Cutting, shaping, adjusting, and glue hardening times, for example, are just not compatible with any large scale industry. And the cost? Well, it becomes obvious why they choose to make the 16 in steel.
Recently, my good friend “N” was seeking an alternative to the 13a I’d made for him some years back. He has a new listening room and for space reasons needed to change his system.
The 16a was certainly the right candidate, but its metal resonating sound just doesn’t work for anyone who has grown accustomed to a big solid wood horn.
While considering various options for “N,” I learned that the 16a could (or should?) have been made in solid wood.
Never one to shy away from a challenge, I looked at this as an opportunity to create something that hadn’t been done before. Just as I had recently built the Western Electric 15 in solid wood (only one had been made in the late 1920’s) I decided to build the 16a in solid wood, which, seemingly had never been done.
Having an original on hand, albeit in metal, made the measuring and comparison of plans somewhat easy, although plotting anything this large is never any easy task.
Yet again, I came to witness that the production tolerances were to say the least, “slack.” Each side of my original 16a has discrepancies. We can actually read in some Western Electric production sheets “tolerance: as close as commercially possible”. I’m not sure this would fly in the 21st century.
I did have to imagine how they would have made this build back in 1928/9. My experience from making the 12, 13, and 15 horns from solid wood allowed me to do that.
Throats on the originals are in cast iron, and that’s what I made despite the availability of brass throats that are on the market. (Read up on throats here)
My philosophy is very simple: keep it like original. Why reinvent and why shortcut?
Okay, cast iron is technically at a totally different level to brass when it comes to casting! And one thing is the temperature : Brass 1,000–1,120 degrees Celsius and iron 1,280–1,380 degrees Celsius. You’ll find small foundries doing brass even those casting statues and art. But that’s just too easy! Go the extra mile and don’t look back!
The woodwork here is probably as complex as it gets. Beyond the craft, there is some serious planning to establish the adequate workflow. I work exclusively alone and the sheer size and awkward shapes of the horn’s sections make the build far more than just woodworking skills.
In total, the 16a consist of 411 individual pieces of wood, each hand- shaped. The 16a has some insane radiuses dues to its shallow size. This challenged my wood shaping skills and helped me take them to a new level.
How long does it take? No idea as whilst doing these builds I lose perspective on time; I just enjoy it that much!
Now, what about the sound?
I’ve always found that the 16a has limited listening capabilities. Some users attempt to dampen the thin metal walls, others claim to have a “special” torque and tightening sequence. Well, maybe. I’ve tried just about anything you could imagine and the 16a remains a thin- walled metal horn that vibrates.
This gives a very singular sound on violin or small formations, so if you’re into just that I guess it’s okay. But entering other more complex territories will leave you questioning. Lift the needle off the turntable and you’ll get an echo from the horn as the steel bounces back. Compare the 16a steel with any solid wood made horn and you’ll understand what’s so disturbing with the steel 16a.
Still, a 16a original is a valued part of my collection. Not for its sound but for what it is. It is a piece of audio history. And, it’s now installed in the 15th century medieval town where I live.
Some care to listen to the 16a in stereo. This means using the right and left channels on either side having the joined signals blend at the mono mouth. Why not. But when you understand the science behind the design of the 16a as clearly outlined in the patent where you appreciate that each side is actually half of the horn. As such, the added air columns are pretty much the same horn as the WE15b (two 555 WE15 horn). Both of the air columns add up to share the same mouth. But some enjoy it that way, so. . .
So, what does a dual 555-driver 16a horn made in solid wood sound like?
I was imagining that it would share the sound of the 12a horn (here). But I was wrong! The 16a has a far better lateral dispersion as the flares are curved sideways and not upwards. We addressed this question here when we actually put the 12 horns on the sides to get that lateral dispersion. It worked. Here we have that but done symmetrically and using 2 x 555 drivers. Just wonderful! Open easy and precise. No more metal resonance! Like the other solid wood horns I make it’s really a clean and well controlled sound wave generated by the 555 drivers. I have some sessions ahead to establish the correct settings even if of the bat it’s insanely good!
So was it worth it? Yes!
All I need to do now is get a pair and run in stereo! That’s a plan! 
This baby is off to “N” who I thank for trusting me to make this “never built” horn for his new home. I know he will enjoy the sound! Thanks “N”.
All fun…”