As we all know the HPD series of tannoy speakers used a thin foam rubber surround that deteriorate after about 15 years. Initially it goes tacky and then starts to split etc...hence the need for a replacement.
The HPD series of speakers were designed for the new transistor amps and are capable of over 60Ws. To do this some petals were added to the back of the cone to stiffen it up, this led to additional mass and a loss of a couple of db sensativity compared to the previous Gold and Reds etc...
I have always sourced my surrounds from Speakerbits in Melbourne as I knew these were the correct material compared to the much thicker surrounds offered by many on e bay. They also provided them as a kit with shims, pva glues, instructions etc and could also supply new spiders and suspension units as required.
Of late there has been a chap on e bay selling complete and original Tannoy cones complete with surrounds, coils, spiders for between £250 and £300 depending on speaker. Anyone used these?
I have also seen the Tanoplas surrounds being offered for HPDs, these surrounds are the same as those on the Golds and do not deteriorate over time. I think ther were a kind of fibre impregnated rubber??????
Does anyone know for sure if these tanoplas surrounds are the same compliance as and provide the same damping factor as the correct foam runner HPD surround...in other words will they change the sesativity of the speaker?
I should add that the above is a bit of "ported history" and there is much more to the Tannoy story. I should also add that if the rubber surrounds on and HPD are at the ripped and destroyed phase, chances are the coils will have rubbed and will need replacing, the trebble horn may need work and that someone like Lockwoods may well be the best option for a rebuild. I do not know the prices charged.