Billfort
Addicted Member
Rob - regarding Altec 604s. I have 604-8g's. Since mine are 8ohm, I couldn't use the Mastering Lab crossover without resizing the components - it was designed for the 16ohm 604Es which I believe your c's are. I understand the ML crossover is a major upgrade with these drivers as it tries to deal with the midrange forwardness of the horn by using frequency compensation as part of the attenuation circuit on the compression driver.
I thought of rolling my own version of the ML but those multi-tapped chokes and hard to find component values scared me off. A friend in the Toronto area is also building up speakers using Altec 604E drivers and has talked to a guy who specializes in custom crossovers. They are working on a ML based design using custom wound air-core chokes and decent quality caps, and from what I heard, at a decent price (Canadian dollars!). I'll keep you posted on the results.
I got the 6db level difference from someone I talked to that built his own first order crossovers for these drivers. He used Alphacore foil chokes, some flavor of poly caps and Siemens resistors - was real happy with the results but was thinking about notch filters.
I keep thinking bi-amping but the dollars make it a "later" proposition. I got to have tubes and the amps got to be SET. Tube crossover + another SET amp = big dollars.
My first step will be new cabinets (9ft3, 39hz). I've narrowed it down to 2 designs, 1 - a back vented box with 3 sloping sides and 2 - a corner cabinet with Onken style vents along the back edge (similar to attached image). I'll build these out of Baltic Birch. Initially, I'll stick with the stock Altec crossovers but I'll leave them external so I can try first orders or the ML knockoffs. Some day, maybe bi-amp.
Billf
I thought of rolling my own version of the ML but those multi-tapped chokes and hard to find component values scared me off. A friend in the Toronto area is also building up speakers using Altec 604E drivers and has talked to a guy who specializes in custom crossovers. They are working on a ML based design using custom wound air-core chokes and decent quality caps, and from what I heard, at a decent price (Canadian dollars!). I'll keep you posted on the results.
I got the 6db level difference from someone I talked to that built his own first order crossovers for these drivers. He used Alphacore foil chokes, some flavor of poly caps and Siemens resistors - was real happy with the results but was thinking about notch filters.
I keep thinking bi-amping but the dollars make it a "later" proposition. I got to have tubes and the amps got to be SET. Tube crossover + another SET amp = big dollars.
My first step will be new cabinets (9ft3, 39hz). I've narrowed it down to 2 designs, 1 - a back vented box with 3 sloping sides and 2 - a corner cabinet with Onken style vents along the back edge (similar to attached image). I'll build these out of Baltic Birch. Initially, I'll stick with the stock Altec crossovers but I'll leave them external so I can try first orders or the ML knockoffs. Some day, maybe bi-amp.
Billf
