Tannoy HPD 385 diy cabs

Here on this page you will find a full story of the construction of
Leon's HPD 385 speakers in his new diy cabinets. He included photo's below!


Leon reports:

I was already addicted to the lush sound of Luxman, when I had my first Tannoys, the Lynxes.

But no matter what I improved on the cabinets, wiring, amplifiers, I was not really satisfied. I was always had the feeling something was missing.

I saved up some money to have Hans make some custom crossovers for the Lynx, but I started thinking... if I sold the Lynxes and put the extra money together, I could maybe afford some 12 inch HPDs.

I read a lot about the HPDs, while a lot of people prefer the Monitor Golds, my eye was set on the HPDs because of bass-extension. Yes, I like some extra bass :-)

The only problem was, every time a set of HPDs came up for sale, I was always too late or the price was beyond my budget.

In may 2017 I found some 15' HPDs for sale in Belgium, but they were in bad shape according to the seller. The seller send me a video of the speakers and told me that the woofer surrounds needed repair. So I called Hans for advise and asked him if it was a good deal and take the risk of driving 8 hours (one way trip) to buy them.

Hans lives in Belgium and he needed the Berkeley Cabinets, so Hans offered me a really sweet deal : He would buy the HPDs and keep the cabinets so he had time to make his new cabinets for his MG15s. He would also repair and bring the HPDs up to spec.

Luckily he needed to be in the neighbourhood of the seller visiting his daughter and he bought the Berkeleys. I was in luck.

The crossovers were already recapped with sonicaps and the problem with woofers was not as bad as expected. Hans ordered new plugs from Ebay that were fitted to the crossovers and the complete speaker units were shipped to my home.

I couldn't wait to hear them ! I first played them without any cabinets and i was amazed.

Then the hard part for me started : building cabinets.

I had some pieces of countertops that i used under the Lynxes, so that would be my starting point. 44 cm wide and 50 cm deep. To get to approximately 200 liters, they had to be 130 cm high. The size of a (small) refridgerator :)

In my conversations with Hans, he explained to me how to tune the bassport with Winisd and how to apply damping and what kinds of wood to use and the required minimum thickness of the panels used.

The best was Baltic birch plywood, but my budget did not allow it, I settled for 25mm plywood for the sides and 38mm of MDF for the front and back.

Now the challenge was to get all this together in a way I could do it myself. My solution was to glue and screw the panels from the inside, so no screws would be seen from the outside. The backpanel would be fitted last.

The front panels were routed so the driver would remain flush with the front panel. I painted the front panel eight times to get a nice even black color. I was so curious on how they would sound that I ran a few listening tests without fitting the back panel.

The hardest part for me was routing the holes in the backpanel to fit the crossover. But finally I succeeded. I bought some plastic plumbing pipe to experiment with the bass-reflex, but Winisd was right. A 10 cm hole with a length of 11,5 cm. They are tuned to 26Hz.

For damping I used the advice Hans gave me : 3 layers of acoustic foam on the backpanel and 1 layer on every other panel. Bracing and inner construction is with oak I had laying around.

They are not the prettiest Tannoys you will ever see, but I made them myself and I am a very happy Tannerd. The speakers still amaze me with their sound quality and accuracy. They can tell you if the recording is good or not so good at all, or what amp you use. Especially the human voice is something the Tannoys can reproduce like no other speaker can that I ever heard.

Thank you Hans for your hard work and for the help !

Leon Waarts.   




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ON9MMK - Hans Hilberink & Leon Waarts, 31-01-2018.