Jean's closed cabinets

Jean has sent the below pictures for publication.
He has built the HPD 385 (first generation, not the A-type)
15' Dual concentric's in 200 L home brew enclosures.
They are closed, air tight cabinets made of waterproof plywood.
The crossover filters are also first generation HPD filters.
He has modified the crossovers in 2000 as explained below.

In the year 2017 Jean did upgrade #2 and you can read below whats it all about.








My serials ^

You see the double flanel layer between the double plywood layers of the bracing; total 38 mm.

Due to applying new switches; I had to buy new control knobs; also vintage; ^
I still have the originals of course; detail gold plated binding posts for wire and/or banana plugs.


Saying goodbye to the foam surround cones; before leaving to Tannoy Holland.^


Detailed view of the HE surrounds. V



Some detailed foto’s of the newly applied Audyn MKP QS caps, ^
also visible the new switches. V

Speaker connection to the filter is simple 2.5 mm˛ copper wire ^

Modified x-over with new switches, 2nd modification, 2nd replacement of the 2 switches ^


 Before the protection is applied, visible here is the kit for
preventing airleaking along the “nuts and bolts”. V


Protection preventing dr baileys longhair entering the cones space; ^
material is also used as suction line filter in exhaust hoods in a kitchen.



Cabinet filled with dr baileys longhair. ^                    View without speaker cloth. ^

New linen cloth ^

Detail Dual Concentric® horns ^


At last the new HE cones with aluminum voice coils of course, without the dustcaps,
which are separately packed; 150 watts average power capability;
not visible of course the new HF domes; at last two speakers which sound identical after 40 years!!

The Graphs: V


The crossover of the HPD 385 ^

© All Copyrights ON9MMK®, Hans Hilberink & Jean Croux, α 2003, 20-05-2019.