Polydome K

[ducko]

Has anyone tried replacing polydome with Dynaudio D52?

I did.
I've expirienced the same problem as everyone else had with their polydome mids. Inadequate replacement offered by Vifa and Scanspeak and numerous complains regarding sound and resistance mismatch left me a little space than to go directly with Dynaudio d-52.
I replaced both mids with d-52. During that process i had to drill 4 new holes 'cause of 5mm (maybe less) mismatch in diameter.
My first impression was that d-52 is way too louder than polydomes , which is expected because of higher efficiency of 92db . Mid pot on X-over couldn't correct that even on farthest left position.
My next step was to insert 4 ohm 10w ceramic ressistor between + of midtone and speaker wire .
BINGO !!!
I've even returned mid pot to its NOM level.
That resistor calmed the mid range and the new love was born.
Guitar , vocals , piano , you name it , its all here in front of you , well positioned , unmuffled .
In my opinion this is one very well engineered bad-ass midtone speaker.

 

[ducko]

My apologies , I forgot to tell that I'm using kappa 7a with HK Citation 11/19 combo.

 

[ccheung]

Morel CDM88 auto midrange is a direct dropin replacement for polydome, 3", 4ohm, 89db. Better than those vifa 8ohm replacement IMO.

 

[MrLegit]

Cant remember exactly,but definetly here in one of the threads on AK.
There is a guy in Hong Kong that actually replaces the old yellowish stained/tarnished dome with a brand new black one.
The driver stays the same,so your impediance stays the same,just a cosmetic change in colour.
Do a search through the threads for more info.
A few vowed and chose this path with very happy results.

As for the method being discussed on this thread,it is here on other threads on AK in more detail.
How to pull the driver apart,coating it both inside and out,etc,for those who dont know.
Just dont fall for the heat trick!

Another alternative is to replace the actual dome from the original Polydome K with a newer type .1-.1-II dome.
Here you might have to relieve the positive speaker terminal connection as the housings are slightly different between the two types.

 

[Me Tarzan]

That driver will not work as it is 8 ohms, the original polydome driver is 4 ohms, you would have to do some mods to the crossover to get that driver to cross over properly and even with the mod it probably wouldn't play loud enough as the original was 4 ohm, some people buy that driver and remove the voice coil from it and attach the dome to the original polydomes voice coil and housing with good results..

Can that part be purchased separately?