One of Altec's most scarce, mid 1950's 12 inch vintage BiFlex driver. You've probably seen the 412C Biflex speaker before -- the rarer B is a find! While essentially the same, in specification, the older B version -- that is the 1950s paper is harder, and efficiency some higher, from the earlier times at Altec -- and all around crisp, clear detailed driver...Excellent for low & medium power tube amplifiers. Overall build quality of early / mid 1950s Altec is quite high.
Sought after not only for their relative rarity; the B version is the one to look for as it represents the one of the very few BiFlex drivers that has a lower excursion, in other words... they are faster. Originally designed for tube amps, they have higher efficiencies and sweeter mid range than the later BiFlex models -- the 412B was often paired with the rare 3000A tweeter -- and will work well with lots of high performance super tweeters, like T35s, 350s, and ribbons too. Most speakers of the later decades, had more exascerbated bass and too much excursion capability -- thus losing the sheer detail these 412B's have! They perform well, to the very extended HF region -- and yet still have a nice low con resonance, I tested each of these at around Fs = 70 cyc.
These partucular Altec 412B's came from a rare situation, a very old institutional installation, and were kept beautiful in tightly sealed cabinets, saw very little use, and always in climate control --- All original condition, gently kept many years since their installation around 1956.
Check out Exhibit A,B & C -- you'll see what a nice pair of early units they are .... See exhibit A, for the beautiful cones, and D,E, & F for detailed reports showing what a wonderful, matching pair this is. Surely the prettiest, best matched and most througly inspected pair of early, vintage BiFlex you'll see anywhere for sale. Buy them now as they will sell quickly. The cones are original, both have matching number (see exhibit F). Unit # 1 has a slight paint scratch, and both units have slight stains from the special Dampening compund that is normal for their age... see exhibits A, C, and D....
The have been fully swept, down to 20 cyc -- to 20,000cyc…. and have perfect function, and good & MATCHED sounding on the bench. Excellent response, clean and clear, well centered. They sound very nice on the bench, free air and will perform well on open baffles.. Both coils were near perfectly mathced calibrated DCR and Impedance sweep showed excellent response on both drivers (see included reports in exhibit D,F, G) .
Top-notch, as new function no rattles, no buzzes-- totally distortion free.
Essentially a totally full range speaker, 12" speaker with lots of clean, powerful .... they are some of the most versatile 12 inch drivers you could ever choose....and if you run low powered tube amps. The center surround, activates at around 1000 cycles -- giving that uncommon succulent mid range, and quite nice highs (for a 12"). For a single unified cone, in a 12" driver the Altec 412 series gives an astonishing frequency response ... all with out the problems of crossovers and tweeters.
This pair jumped to life with less than a watt each, and filled my office with music, during an extensive listening test... .
See the detailed technical reports reports below, these were fully swept 20 thru 20,000 cycles, and I heard no problems. they sounded wonderful.
ORIGINAL CONES.
Both units, dated , and coded, from 1957. Coils are close production, same year, and week of production. The impedance sweep curves and // DCR results are a near perfect match (see exhibit D) -- all results. You could not find a better matched pair anywhere. They are the real McCoy, all original from the mid 1950s, USA.
Original cones are a perfect match, with Altec#s matching, erfectly centered and the surrounds are still suppling tacky just as they were, when produced almost 60 years ago.
If you have a nice tube setup, and are searching for high efficiency vintage drivers -- early Biflex are often overlooked and they sound great – and you rarely see mid 50's versions. With 100% original, perfectly centered, cones and in great condition -- quite scarce. The surrounds are supple, supportave, quick and still tacky --- showing just a little dust and lint from all of those years in the cabinet. Even the the paper of the 412B is thinner and harder --- this gives a very fast, crisp and detailed soin in comparison to to the later "accordian edge" 1960s-70s drivers.
Philosophically speaking it's very tough to find a 12 inch driver made by Altec or JBL of the vintage era that covers so many potential applications in the homes of tube oriented, DiY & collector audiophiles. Open baffle would do well, or a sealed ported box for those who want lots of bass. Single ended amps, utilizing low and meduim power tubes would do very well with these.
These early 12" drivers represent a type of product Altec only shortly made ... quickly left past as they moved towards high powered full excursion speakers of the 60s, 70s, and 80s. This era gived the best of both worlds, both detail, sweet midrange, and and quite nice HiFi bass.
They have excellent voicing, and should be great for delicate instruments or if you love silky jazz, or need superior vocals. The edgewound aluminum voice coils and powerful alnico V magnet with a tight gap, and extremely rigid molded cones ensure that these speakers have super detail – more so than many of this era --- just like you would expect from a high-quality, heavy driver of the day.
They will sell quickly. Please seeing my 100%, five star feedback from happy overseas customers.
All speakers are professionally packed in heavy double box with full protection, and shipped out ASAP after payment has been received.
Give them a try, as the more collectors get to hear these and other such pretty & quite useful old drivers --- prices will continue to climb -- -and you'll find them quite useful in your HiFi pursuits.
You won't be disappointed with these and they'll be carefully boxed in a double box for super safe delivery. Will be shipped EMS express with full tracking info emailed after payment. Please see my excellent 100% five-star feedback on all vintage audio items. Fast dispatch, excellent safety & communication always.
Your happiness is assured (please see my feedback, both here and at HiFiTown website)
