Four months ago I picked up my HPD's. At first they were kind of dull sounding. I then updated the crossovers with Solen Caps and Mill resistors. This was a vast improvement over what I was hearing.
My mid still seemed to sound a little off, so I added some more foam and a couple pounds of polyfill to the enclosure. That fixed that problem, but now I was lacking bass.
After a couple months of listening, something was bothering me about the sound of the speaker. Vocals sounded a little nasal and the tone wasn't just right, so I upgraded the caps again, this time to Sonic Caps. Thanks again for the tip Jesse.
I knew for a while that I should have new cabinets built. Besides the fact that the Tannoy cabs were on the small size for a 15" driver, they were made of fibreboard with very little bracing.
Using parameters from Tannoy, I drew up a design in WinISD, and printed them up for a buddy of mine who's a carpenter.
The new cabs were made of 3/4" MDF all around, with a extra 1/2" sheet on the front. At the bottom of the driver a 3/4" thick shelf was installed. Parts Express 3/4" Sonic Barrier was uses on the back wall behind the driver, 2.5" acoustic foam was used on top, with 1.5" foam for the rest of the enclosure. Two 4"x4.75" Precision Port tubes were used per enclosure, tuned to 35hz.
Internal wiring from the binding posts was some kind of braided Kimber Kable, this was upgraded to Goertz AG2 cable, the same cable I'm using from my amp to the speakers. Internal wiring from the crossover was upgraded a month or two ago with some silver hybrid copper cable from Ben. I have two silver inductors made of Goertz silver cable, once I can figure out how to do it neatly, I'm going to unroll the inductors and use them from my crossovers to my drivers.
As for finishing them, I'm going to have to wait till my back and neck get a little better, they're easily over 100lbs. The plan so far is to use a piece of 1/4" MDF from the bottom to 1" below the driver. I'd like to make it appear that it's real wood, preferably redwood. The rest of the enclosure will be painted black. The rest of the face will be a matte black (like the old cabs), the rest of the cabinet will be gloss black.
As for the sound of the new cabs and re-wire, wow! I had to check to make sure my sub wasn't on. Bass is deep and plentiful, mids are clear, highs slightly crisper. Soundstage between the speakers rival's my SDA 2B's.
Now for the pics.
Yes, I know they're ugly as sin right now. But the sound coming out of them more than makes up for it.
If you made it this far, thanks!