Putting a switch in tweeter's circuit

[presscot]

I've successfully developed circuits for my tweeters with three modes; 1, 2, and 3, as shown in the picture. I have a three-position switch with 4 pins. I'd like to use this switch as a selector for each mode of tweeters; mode 1/2/3 = position A/B/C, respectively. Please help me to create the signal path for them. Many thanks in advance

 

[tuantran]

You may need a 4 position switch

 

[tuantran]

Please see the attchment

 

[chrisng]

If D1 and D2 could be one tweeter with or without a resistor in series, then this is my suggestion to reduce parts count (230uH || 177uF = 100uH):

 

[MarcelvdG]

Just a warning: with a break-before-make switch, you could momentarily load your amplifier with a 6.8 uF-230 uH LC series tank during switching. That would lead to a very deep impedance minimum. If your amplifier oscillates because of that, you might even blow it up. What's worse, you might also damage your hearing.

With a make-before-break switch, you only have to ensure you don't short the amplifier during switching

 

[chrisng]

If this is a break-before-make switch, do not switch it while the amplifier is powered!

 

[presscot]

So, how can I know the type of switch?

Here are photos of the switch. It’s actually used in the passive crossovers of car audio speakers: ADS 320is. I’ll use their PCB and switch for the project.

 

[chrisng]

how can I know the type of switch?

Using a multimeter set to resistance setting, connect probes to switch terminals 1 and 3 or terminals 2 and 4 via alligator clips. If you get a momentary low resistance reading when switching, it is a make-before-break switch.

 

[presscot]

I've been trying so hard for modifying @chrisng 's diagram since the tweeter used is only one unit--D1, D2, and D3 is the same thing.

And I've successfully created signal path for 2 modes which are mode 1 (third-order circuit) and mode 2 (second-order without a resistor). However, I've failed to create mode 3 (second-order with a resistor).

Therefore, please help me to build signal path of mode 3 (second-order with a resistor).

 

[Audio>X]

This is an interesting although rather ODD thread.
Given the response curves you have provided, I would pick your preferred (2) VS (3) curve, and then use a TWO position switch 🙂

 

[chrisng]

the tweeter used is only one unit--D1, D2, and D3 is the same thing.

If this is the case, you will need an additional DPDT switch to connect the tweeter to the crossover (please note that D3 has the opposite polarity to D1 and D2 in the original design).

By the way, before turning on the power amplifier, be sure to switch the tweeter to the corresponding crossover when using it, and do not switch it when the power amplifier is powered on!