L77 Upgrade - Fostex FT207D

[Zilch]

With two-pole crossover, LF & HF:

[soulstreamer]

What type of circular adapter for the tweeter rim do you use? Also, where to get the crossover parts?
Thanks, Tom

[dmac]

Hello,

I was wondering if anyone has tried to build this crossover? The examples that I have seen all seem to be missing parts from the drawing. I would like to try this with the Fostex tweeter, but so not understand the missing parts. Any experience would be great.

Thanks,

Dmac

[mike256]

I am sorry to hear of Mr Zilch's passing. My condolences to his family and friends. Mr Zilch's use of resistors in the crossover circuit shown on this thread appear to be beyond the scope of my speaker book (Loud Speaker Design Cookbook, 5th ed). Could someone please comment as to the function of the resistors in this circuit, so that I can search on that and try to understand it?

Mike in Phoenix

[Earl K]

I am sorry to hear of Mr Zilch's passing. My condolences to his family and friends. Mr Zilch's use of resistors in the crossover circuit shown on this thread appear to be beyond the scope of my speaker book (Loud Speaker Design Cookbook, 5th ed). Could someone please comment as to the function of the resistors in this circuit, so that I can search on that and try to understand it?

Mike in Phoenix

RL1 + RL2 represents the DC resistance of the coils ( inductors ) that Zilch used in his design ( IOW, they are not separate resistors ).

[mike256]

RL1 + RL2 represents the DC resistance of the coils ( inductors ) that Zilch used in his design ( IOW, they are not separate resistors ).

That makes sense, thanks. And R3 would be adjusting the impedance of the lpad, speaker combination, I presume.

[Earl K]

That makes sense, thanks. And R3 would be adjusting the impedance of the lpad, speaker combination, I presume.

Yes, R3 modifies the 8 ohm Lpad down to a working circuit impedance ( for the HF leg ) of @ 5.7 ohms.