Fun with 802-8G’s

[EarlK]

Does anyone have the measured impedance curve of the gpa 34647 they could share?

GPA diaphragm mounted into what model Altec driver having which type of phase plug ?

With or without the loading cap in place ?

And finally, the driver mounted onto what horn ?

Each answer will effect the shape of the final impedance curve.

EarlK

PS: Here's a similar thread ( ask ) over at the Altec Hostboard Forum.

 

[Kosinki]

GPA diaphragm mounted into what model Altec driver having which type of phase plug ?

With or without the loading cap in place ?

And finally, the driver mounted onto what horn ?

Each answer will effect the shape of the final impedance curve.

EarlK

PS: Here's a similar thread ( ask ) over at the Altec Hostboard Forum.

Hi Earl,

They are currently in 802-8Ds with the metal radial phase plug and no loading cap just felt in the rear cover. I've been using them on plastic 32B and cast metal 808 horns.

 

[EarlK]

Hi Earl,

They are currently in 802-8Ds with the metal radial phase plug and no loading cap just felt in the rear cover. I've been using them on plastic 32B and cast metal 808 horns.

I've never seen anyone post a sweep of the ( Altec or GPA ) 34647 diaphragm ( mounted into an 802D ) working on a 32( a-c ) bent horn.

I think that's a flavour of impedance curve that you'll need to acquire from your own gear.

Have you already created the necessary .frd ( Frequency Response ) file ??

 

[RonSSNova]

I had a pair of 802-8D but they had no diaphragms. I sold them over on the Haven.

I have run DATS on at least 6 drivers 2 that have GPA frams. Sadly as I’ve mixed and matched frams, I’ve lost track of which drivers have the GPA units.

The DATS device is a handy tool. And not all that expensive. Perhaps you should just buy one?

To my ears, the GPA frams sounded identical to the originals. However, I bought mine from Bill many years ago when they were $75 ea. I can’t speak to the quality of the last ones that were being sold.

 

[EarlK]

@Kosinki

When I get home from travelling I'll swap a 34647 diaphragm ( out from a 802G ) into an 802D body and run my DATS to get an impedance sweep.

Since I don't have either of the horns that you mentioned, the sweeps will be done on a generic big BiRadial.



PS: I don't think anyone has ever compared the original 34647 diaphragm to the GPA version.

 

[Kosinki]

@Kosinki

When I get home from travelling I'll swap a 34647 diaphragm ( out from a 802G ) into an 802D body and run my DATS to get an impedance sweep.

Since I don't have either of the horns that you mentioned, the sweeps will be done on a generic big BiRadial.



PS: I don't think anyone has ever compared the original 34647 diaphragm to the GPA version.

Cool Thanks!