Mondrian inspired open baffle + RCA 501S1

I won this 12" co-ax on eBay back in late '07 for a little over $100. There were only a few bidders and I was the only one based in the USA, the rest were in Japan. Had a feeling this might be a sleeper... 

When the package arrived I checked the condition of the capacitor with an LCR meter which turned out to be healthy. If it was leaky, I would have searched for a paper in oil cap that would fit in that very same clamp for authenticity and good sound.

I mounted it on an open baffle for testing and it turned out to be a very fine sounding speaker. It does not have the boogie factor of the Altec 605B Duplex instead, it is refined and coherent like an Altec 755A. After a couple of weeks I carefully packed it up and waited for another unit to be listed....never saw another sample. 😞

Click here for a review by none other than the esteemed JGH (who found it a bit bright*) in the December 1956 issue of High Fidelity!

*Sorry Gordon, but I disagree...😆

A special driver deserves a nice looking baffle

Staring at bare plywood for over 10 years can get boring even if the sound is good.😊 For a quite a while, I've had this idea lurking in the back of my mind of combining the aesthetics of my favorite period in art and architecture with DIY audio projects.

Piet Mondrian's Composition II in Red, Blue and Yellow, 1930 turned 90 degrees to the right ;)

After a few days wielding a brush, cans of paint and masking tape....

Architects, Music and Hi-Fi

Music at home

Frank Lloyd Wright was known to have equipped his luxury home projects with a grand piano. When I visited Fallingwater some years ago I vaguely remember seeing a Fisher 50C preamp tucked inside a wall mounted console but no grand piano. Perhaps this was because it was designed as a weekend home for the Kaufmann family of Pittsburgh. 

The following are scans of how architects approached music reproduction in homes during the first half of the 20th century.

Charlotte Perriand's Modular Cabinet was part of a Bachelor Pad concept presented on behalf of Le Corbusier in Brussels, 1935 - looks like a  ~ 6" fullrange speaker, AM radio/phono amp + an early electric turntable? And it seems like acoustic feedback was not yet a major consideration in those days ;)

Walter Gropius living room in Lincoln, MA

Click on picture for a larger view of the hi-fi components right of center as well as the coaxial speaker further right (infinite baffle?).

Case Study House #9 by Charles and Ray Eames + Erno Saarinen for John Entenza, 2-way horn speaker system built into a wall, Stephens Trusonic drivers?

Living room of the (Julius) Shulman House,1950 by Ralph Soriano. Cool Jensen DU201 to the right ;)

Pierre Koenig's living room - lots of LPs and I see a Luxman CL35 preamp on the equipment rack + a pair of speakers housed in lowboy cabinets.

Eames Three Way

This is an interesting picture of a Charles Eames/Stephens Trusonic collaboration sent by SixCats! What's that other intriguing speaker in the background, buddy? 

Robert Stephens was part of the Shearer Horn project before starting his own company. I have seen a few Stephens drivers and the quality of construction is comparable to an Altec or JBL. But I never saw or heard this particular speaker system which according to a brochure in Hi-Fi Lit contained a 15" woofer in a folded horn chamber, compression driven 10 cell horn midrange + super tweeter. It is a rare piece and probably samples have been snapped up by mid-century modern collectors long before audio aficionados became aware of the sonic virtues of vintage equipment.

Keener eyes will notice that the Eames Trusonic E3 share the same wide baffle aspect as Pierre Koenig's lowboy enclosed speakers. I have a gut feel Koenig's speakers are actually E3s distorted slightly by a wide angle lens or that's just wishful thinking? ;)

The point is, after years of fiddling with speaker enclosures and open baffles I have come to a conclusion that the prevalent narrow and tall configuration of modern speaker designs does more harm than good to the sound. Gifted architects like Charles Eames and Pierre Koenig probably knew better then...

Visitors' Open Baffle redux...

A few years back I uploaded a webpage of OBs built by visitors to the old site. Since then I've received a couple of emails with very interesting image attachments of vintage (DIY?) OBs. 

Vintage DIY?

...obviously inspired by G. A. Briggs venerable design. 

Commercial model?

...seems a bit wider, more squat....

Was this an original logo or just pasted on a DIY project?

Intended to be hung on a wall?

To those visitors who sent me these pictures, I lost your contact information. If you see this blog please send me a message so that I can give you proper credit, thanks!

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...

Crooked frames in a Barnack?

I've had this problem for years and have read modern film cassettes are 2-3mm shorter causing the image to slant and/or intrude into the sprocket holes in early Barnacks and clones. With a packet of
 stick-on green felt pads sitting in my drawer, I stuck one in the base plate lock and it worked! I did it to all my Barnacks which had this issue.


Not my original idea, credit should go to this post.

SU HS4

There have been quite a few procedures done to my '82 Mini which I forgot to document on digital camera. Let's back track a bit...

Safety first!

 Brake lines were bled and refilled with fresh fluid. Brake shoes were thick, master and wheel cylinders were working fine so I just cleaned all the drums, adjusted  the shoes (one full wheel turn) and made sure no air got stuck in the hydraulic line.

Pedal pressure was good for a non-servo brake system and the car maintained a straight line on hard braking.

 My dad's initial enthusiasm to test drive the car was curbed upon hearing rattles. All the swivel joints were on their last shims and duly replaced following this preparation procedure from Mini Addicts. The shot steering rack was another major rattle contributor. Haynes manual at hand, this site and the assistance of a mechanic, Gilbert, who never handled a Mini in his life; we managed to get a brand new steering rack in place in less than four hours in my drive way.

The car is already fitted with Hi-Lo adjustable suspension, coil springs + Koni Classic shock absorbers which lowered the ride height below practical road use in Manila. Standard length KYBs replaced the Konis and Hi-Los adjusted to original ride height.

Brakes, steering and suspension sorted, engine is next....

Radiator removed, cleaned, cooling system drained until there were no signs of rust colored liquid circulating from the water jackets.

I thought the engine was always running too rich and I could not adjust the carburettor for consistent mixture.

 To my dismay the throttle body had a crack, probably caused by an ill-fitting/home made cardboard gasket and over tightening the two intake manifold mounting bolts.

Epoxy steel + DIY gaskets from true gasket material tied me over for a few months....

...meanwhile I scouted eBay and snagged this older SU HS4 for $30. It probably came from a junked Austin America (Austin/Morris/MG 1100/1300). I also ordered an SU repair kit, needle, float, gaskets and etc.

I stripped/cleaned the eBay acquired HS4 and combined the best parts available from both units.

Overhauled SU HS4 to the left ready for installation

I reverted to a non-Waxstat type jet upon confirming with Seven Enterprises that it offers slightly more efficient performance. Since my 998cc engine came with an LCB exhaust, I fitted a new AAU needle. Easily done since it has the self-centering/spring loaded type piston.

The engine started on the first crank but it started to rain ;(
Fine tuning of mixture and other minor adjustments saved for another day....

Icing on the cake - K&N filter for the stock air-box ;)