Monday, June 20, 2011

Jensen Ultraflex Cabinet for 8" Speaker

Today is the end of a long weekend commemorating the 150th birthday of our national hero Dr. Jose Rizal. I can't help but wonder whether he as well as our other national heroes died in vain... I am quite confident our current president is a sincere man who wants to get rid of corruption and lead us towards progress but there are elements in government as well as sectors in our society who don't cooperate. ;o( 

But mulling over matters beyond my control is a waste of time and energy. It's best to turn time and effort towards productivity. ;o) When I lived in the USA holidays were spent building projects to avoid heavy traffic and crowded places, so...

Years ago I wrote fondly about the Jensen Duettes as SE amp friendly budget speakers. I am not abreast with current pricing on these drivers and wonder if they still qualify as budget specials?



 Influenced by the article my buddy Rofiel collected a few Jensen and vintage Japanese drivers and wanted to try a bigger cabinet so I sent him the plans below. A few months later a pair of Ultraflex cabinets built from 1/2" phenolic plywood arrived at my doorstep.


Meanwhile these Ultraflex cabinets sat in a storage bin in the attic for over a year so a week ago I dropped by Joey's shop to cut holes on the front baffle with his router.


High quality plywood is expensive and hard to find in Manila. The closest affordable option we have available is phenolic faced plywood for industrial construction.



Simple crossover using a 2uf paper in oil cap + generic 16 ohm L-pad to the RP103 tweeter. 


Damping material for top and bottom panels as recommended on page 2 of the plan. Initially I was listening without any damping material and it was fine in free space standing on glass blocks. The moment I placed it in a corner, the bass tended to boom. Since there's no Walmart (my old source for Dacron) in Manila, I cut up an old foam pillow. That controlled the bass boom but I may have to experiment further with material and amount of damping...


Bogen B62 (Lenco L70) - stock arm fitted with a Pickering 380 or Shure M7D (coils connected in series) for Stereo LPs played in mono + Velvet Touch viscous damped tonearm with GE RPX---> JE Labs/PAS preamp - Telefunken 12AX7 phono + 12SN7 linestage (only one channel used)---> JE Labs SE71A amp.


Evolution of a mono hi-fi system in the study room...

2 comments:

  1. How do you find/are you enjoying that Pickering 380, by the way?

    Justin.

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  2. The 380 is a darker sounding cartridge compared to the M7D. Better or not, will solely depend on the system context.

    IIRC, I've exchange messages with you a while back...thanks for dropping by and happy listening!

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