Large Advent Crossover Modes

[Guest markjohnson22]

Planning to replace crossovers in 4 Large Advents (73 & 74 vintage) with all new components including mounting board, binding posts etc. I replaced the caps about 2 years ago. Based on what I saw then (cheap switch, margional air core, etc.) and my desire to use them in normal mode only I would like to delete the selector switch and related increase and decrease components. The crossover wiring diagrams I obtained from various posts are somwhat confusing. Does anyone have the following:

Diagram of a "normal" mode only application (what componets and where they are located in the circuit).

Origional Values of the required parts (caps, restistor, inductors).

Thanks in advance for your comments.

[Carlspeak]

>Planning to replace crossovers in 4 Large Advents (73 &

>74 vintage) with all new components including mounting board,

>binding posts etc. I replaced the caps about 2 years ago.

>Based on what I saw then (cheap switch, margional air core,

>etc.) and my desire to use them in normal mode only I would

>like to delete the selector switch and related increase and

>decrease components. The crossover wiring diagrams I obtained

>from various posts are somwhat confusing. Does anyone have the

>following:

>

>Diagram of a "normal" mode only application (what

>componets and where they are located in the circuit).

>Origional Values of the required parts (caps, restistor,

>inductors).

Yes, I have values I measured on a job I did where I built a totally new crossover for a customer who wanted to retain all the same compnents but replace them with new ones.

Attached is a picture of the upgrade. If you want to eliminate the switch, follow the schematic I've drawn in the second attchment. To make life easier, I've included the Parts Express P/N's to order.

Good luck.

To save money, you really don't have to replace the 3 inductors. They are simply coiled copper wire on a spool. Saving them allows retention of the original designer's intent regarding the inductance values and resistance of those non-deteriorating components.

Remember, it's all about the music

Carl

Carl's Custom Loudspeakers

[Guest markjohnson22]

Thanks Carl, can you confirm if the HF inductor (not shunt inductor) is required in "normal" mode. It was my understanding it functioned in "decrease" mode only.

Thanks again.

[Carlspeak]

Can't say with 100% certainty as I don't have one available at this time to confirm with. However, I'm almost certain the normal mode incorporates a basic second order xover design, in which case, the HF inductor is not needed. Just the cap, resistor and parallel inductor.

Carl

Carl's Custom Loudspeakers

[Doug G.]

This is correct. In the normal mode, the series inductor is shorted across by the switch. The series capacitor (16uf), series resistor (either 4 or 3 ohm, depending on vintage), and parallel inductor remain in circuit.

Doug