Vintage pr of Polydax (Audax) HD17B25J Bextrene 17cm woofs, one new, one used

Description

Vintage pair of Polydax (Audax) HD17B25J Bextrene 17cm woofers - one woofer is new old stock (NOS) the other used
Brand:      Polydax aka Audax
Model:
HD17B25J2CP12
Cone Material: Bextrene
Surround: High Compliance PVC 1/2 roll inverted
Frame: Stamped steel
Dimension: 166mm ext diameter
Woofer hole cutout: 149mm
Key features:
-QTS
= . 41
-FS
=
29.5
-Frequency Response = 60 Hz  to 6000 Hz
-Smooth, extended midrange
-Detailed and musical sounding bass
-Ideal for small sealed boxes between 8 and 12 liters in size.
-Nominal Power 30 watts
-Program Power = 25 Watts to 75 Watts
-Ideal amps - 25 to 75 watt SS or tube amps
-Amps that bring out the best in these woofers - Tubes
-Music genres best suited to these woofers-
Classical, Jazz, Folkrock, Vocals, Acoustic Instruments
-Not suitable for head bangers and teeny-boppers
Up for sale is a pair of quite rare Audax bextrene plastic coned woofers. The right woofer with the faded looking magnet was actually NOS and never used as can be verified by the virgin, clean surface of the speaker terminals. While the left woofer with the clean magnet was briefly used with another identical HD17B that I no longer have using a 35 watt tube amp in an effort to design a set of near-field monitor speakers. The difference in DC resistance (DCR) is less than 4.6% which is well within good tolerance levels. They were both stored in their shipping boxes in an air conditioned hallway cabinet since the 1980's.
These 6" plastic woofers were the1st drivers I ever tried as a DIY hobbyist. I was extremely lucky since they do so many things right. Their sound reproduction is so musical and real in the midrange, which is also where tube amps perform so well.
The tone of these speakers sound similar to speakers designed by the British Broadcasting Corporation's (BBC) for their broadcast and recording studios. High on the BBC's list of priorities is sounding correct and convincingly real in vocals. This make good sense since all over the British Empire were broadcast studios that depended on superbly accurate vocal reproduction. BBC speaker designs are typically licensed to British speaker manufactures whose engineers often1st learned their craft while employed at the BBC. These include respected companies like Rogers, Spendor, Harbeth, Chartwell, and Graham. Furthermore, they build their licensed designs according to strict specifications often bound in 1/2" thick books that spell out all aspects of construction from the glue used to bond the surround to the cone, the DCR values of the crossover coils to the materials and construction of their cabinets.
The BBC was the 1st to use thermoplastic-coned woofers in the early 1960s in an attempt to avoid some of the problems inherent in using paper cones. KEF bextrene woofers of the 1960s like the B110 were used in lots of European speakers. Perhaps the most famous of all BBC speakers using bextrene woofers are the famous  LS3/5a mini-monitors which utilize the KEF B110s. Still in production over 50 years later and now over six times the original cost at between 00 to 00 depending on the veneers, LS3/5a's still dazzle critical listeners worldwide.
The one drawback of these bextrene woofers is that the smaller ones are low in efficiency and power handling but that has never stopped thousands of music lovers from spending their hard earned cash to own a pair of magical sounding LS3/5a's. They just know how to listen to them without damaging them. Therefore, headbangers and all those wanting to blast them at parties and bleed peoples' ears should look elsewhere.
Feel free to ask me any questions that come to mind. I can share several great crossover schematics using these 6" woofers and the  still-in-production 1" Audax textile dome tweeters.
These wonderful sounding woofers are rare and were treated with care.
The buyer pays for shipping according to his or her location.