Early,
Please give examples. You say plenty of of vintage drivers beat the B&C DE250 but, you don’t say which…
Sorry for the long delay -- this is not a megathrough or super worthy response to your great question.. but it's a start:
Like many modern one-inch compression drivers, the B&C DE250 trades low-end response for a steeper cutoff in its operable regions, typically above 900 Hz, while extending as high as possible -- allowing huge wattage rating for continuous programs. That said, I personally run a modified (mversion of the DE250 with a special rear cap that allows it to go about 100 Hz lower with probably only 1/4 the power handling.. (to make it smoother and more vintage like) . I plan at some point to sell that part.. but the assembly is tricky.
On brand new / stock units... It’s also worth noting that the DE250 has a fairly short but vicious break-in period as well. Once it has settled down, however, it is quite smooth—possibly the smoothest sounding modern one-inch driver I’ve encountered in the past 15-20 years. Coupled with its low cost, availability, and 16-ohm impedance, the DE250 is probably the best contender I’ve seen for replacing vintage drivers in a long time. (DE250 *only* fancier models not recommended)
In contrast, a typical vintage hi-fi driver often has a much lower cutoff, well under 500 Hz in free air resonance, allowing it to play into the lower regions. In practical use with a crossover, this difference might not seem critical, but the tonal characteristics are vastly different—and this is, of course, a big deal. Comparing a really old flexible, large aluminum diaphragm driver to the DE250, you’d hear significantly more musical information playing full-range without a crossover (which, admittedly, nobody does).
Now, on to the list (in no particular order):
1940s Altec 802 B or C (16~20ohm) (by a good ways better than the newer ones)
The Altec 802 from the 1940s, or slightly newer versions from the 1950s and early 1960s, are excellent. However, anything beyond the 802C with the green paint finish is hit or miss, as Altec progressively detuned the diaphragm to prioritize power handling over speed and detail. By the 1970s, sound quality had become average. Variations exist across designs, models, and impedances, with Altec continuing to produce 16-ohm voice coils likely into the 1980s... it's confusion.
The Altec 806 green body also deserves mention -- as realistically all of the drivers in this list are going to be overpowering and require some amount of attenuation. Doing something clever like utilizing one of Altec's slightly less efficient drivers (so long as it has a good diaphragm and it will work fine. )The 806, 804 I believe and many other variants are all going to have the same machining on the face plug. So as long as you don't have any funny business going on under that rear cover – – you can use the smaller magnet drivers to just the same good results.
JBL D175
Walt and I held the odd opinion .. that the black wrinkle finish JBL D175 is standout .. it's later from the 60s and 70s and usually 8 ohm...
Our friend and expert... superuser hobbyist of Lansing/early JBL ,
@widerangesound prefers the smooth gray drivers from the 1940s and early 1950s (who could sanely disagree?, they are beautiful) . Performance-wise, all these JBLs and Altecs are comparable, capable of dropping down to around 400 Hz Fs (on bench, no load) smoothly and without terrible harshness ( if running the old diaphragms and low power 16 ~24 ohm voice coils)
Stevens Trusonic and ElectroVoice
Stevens Trusonic drivers, made with duraluminum diaphragms, are very interesting but they have a primitive phase plug design, and some models are very good as they have super nice duraluminum spun diaphragms.
Likewise early Electro-Voice drivers are also duraluminum, spun, but later models, mid 50s: onward , used phenolic diaphragms.
EV made some very, very good
sounding drivers ... and are among the better phenolic drivers, *depending on their condition.*
4. Atlas and University Drivers (threaded)
Atlas and University drivers are worth exploring if they have survived their lives wherever they’ve been reclaimed from. A lot of times, these were used in 1950s hi-fi systems, in which case they’ve been babied. However, units pulled from ballparks or other harsh environments might not be functioning as well.
5. Western Electric and IPC
Western Electric drivers, especially the very rare permanent magnet versions like those from IPC, are exceptional. Going further back into the 1920s and 1930s, you’ll find interesting cinema drivers made by companies like BUD (likely manufactured by Ballantyne) and other rebranded designs.
There are also European options, though several brands elude me at the moment. Jensen, for instance, made a line of one-inch drivers with threaded mounts, though I’m not sure if I’m constrained here to two- and three-bolt patterns.
Vintage drivers are amazing if they’re still functioning correctly and original. For reliable, high-fidelity performance with a lower cutoff point, a well-functioning Altec 802 is probably the best choice. JBLs also hold their own, giving you plenty of competition.
The B&C DE 250 actually suffers (minor) a degree the same problem as all these other vintage drivers -- I've measured six of them so far and they all test a bit differently!
Even I'm surprised that modern machining equipment and their fixed design .. does not have tolerance that Western Electric 555's had back in the 30s! Then again Western Electric wasn't working as cheap as B&C ($120 .. so cheap) so the inconsistencies are minor and are fine to live with!
