Help with Tannoy 385-hpd

[LordJim]

Hi folks,

could use some help here. i bought some tannoy hpd-385s and bought some used cones on epay, as well as an original hard edge surround kit from some guy in england. my mother came visiting from germany and the surrounds and some rt-909 spares got lost at customs :sigh: .

Anyways i managed to fit some hard surrounds on the speakers, build some ported cabinets and was actively bi-amplifying them with a pioneer d-23 crossover, sansui au-717 and a pair of luxman b12s. since i'm a bit short of money atm, i have to sell the pioneer and probably some other speakers that i have.

A friend of mine told me he had some diy crossovers, that used to be installed in some tannoys, and told me i could have them for free. i installed them, but the sound isn't very good, and i suspect they might not have been for tannoys alltogether.
i attached a pic, maybe somebody who knows about crossovers could give me a hint if these are ok for the speakers, or might give me some ideas of how i could improve them (maybe using some of the components installed), since it's pretty hard to find parts where i live. the big air coil is 4mh and i measured 2ohm dc resistance, the small coil is 0.7mh and 1.3 ohm. the big capacitor has 10uf and the small one 4.7uf, the resistor is 8.2 ohm 5w.

any suggestions appreciated.

cheers
ingo

 

[audiozaz]

A crossover pretty much has to be designed for a specific driver, preferably in its specific enclosure though not always as critical. Generic textbook crossovers and those designed to work on a different speaker will rarely give good results. I'm sure there are lots of known designs out there for such a classic driver.

az

 

[LordJim]

thanks audiozaz, yea i think you are right. I have looked around on the web and found some crossover plans for this driver. my main problem is that it´s very dificult to find parts here. quality caps or inductors are basically impossible to find. shipping to venezuela is also a big mess

i found this diagram from moxtone lab website.

they designed this crossover to work with a diy berkeley size cabinet. the cabinet i build is slightly bigger. something between berkeley and arden. the values of some of those components seem to be close. the big coil 4.7mh vs 4mh (would this difference make a big change?) and the small coil can be from 0.5mh to 1mh (if i read this correctly). the 10uf cap matches from the old crossover and 4.7 is fairly close to 4.4.

i should be able to find the remaining resistors and caps. tweeter atenuator will be harder to find. this probably sounds a bit naive from my site, but i´m just trying to build something, that sounds somewhat good, until i´m able to find some better parts.

 

[LordJim]

here's a picture of the cabinet. i will make a better front baffle when i have time. i used 18mm mdf and covered it with wood veneer. it's the first time i build a speaker cabinet, and the place where i bought the mdf made the straight cuts and i did all the rest by hand. jigsawing those holes by hand was a pain in the back.