diaphragm for RCA MI-6306?

[jewel942]

Hi all,

I have an opportunity to purchase some (open) RCA MI-6306 speakers. They look like old stadium-style PA speakers.

Are these worth anything? Are replacement diaphragms available?

Thanks and regards~

Larry

[Earl K]

I have an opportunity to purchase some (open) RCA MI-6306 speakers. They look like old stadium-style PA speakers.

Are these worth anything? Are replacement diaphragms available?

- Clearly, they are nice paperweights without diaphragms .

- The 630x series of RCA drivers, date from the 1950s' to 60s .

- I own a single RCA 6304-C coupled to a round exponential horn ( which is @ 14" across )

- I don't know if new diaphragms are still available ( I highly doubt it ) . RCA sold off ( or closed down ) its' Consumer & Pro division decades ago ( I believe the Euro based company ,Thom[p]son owned the consumer division for a while ) .

- NOS diaphragms do seem to appear on eBay every couple of years .

- The diaphragm is based on a lightweight linen weave , impregnated with a phenolic plastic .
- My 6304 measures well out to 12K ( & is solid down to about 800 hz ) . The HF rolloff slope is an almost perfect 6 db per octave march downwards / making HF compensation easy to design ( a simple 1.2 uf cap did the trick ) .

- RCF ( Italy ) made ( or makes ) a compression driver that is a modern equivalent ( if you want & need HF extension from a phenolic diaphragm ).
- The RCF model number is the "N481". It's a lot easier to obtain & maintain .

<> Earl K ( I hope some of this helps )