I've hit a bit of a snag with my stereo project.
I have a 2-channel amplifier from eBay, and I've been using it with 4 ohm speakers, one on each channel.
Now I planned to upgrade it with tweeters. I got a 3.9uF capacitor for my tweeters, thinking of connecting it in parallel. I got a set of tweeters of 8 ohms each.
I realized something.
Connecting my 4 ohm speaker and 8ohm tweeter (tweeter in series with a capacitor) in parallel, results in a net resistance of 2.67 Ohms and will cause a problem for my amplifier.
simulate this circuit – Schematic created using CircuitLab
It seems putting these two speakers in series will be better as it will give a net impedance of 12 ohms. But where/how can I connect the capacitor (as a high-pass filter) for my tweeter?
Any other way I could proceed with this?
I saw a method to do it in series:
But I do NOT have a low pass filter (I assume an inductor.) It would be better, because I don't have the time to procure other components 🙁
Best Answer
If you are worried about overloading the amplifier then I wouldn't be overly concerned unless you were intent on playing very loud passages of sound that were exclusively in the low to mid kHz region (not something that normal or even modern music attempts to do).
The 3.9 uF capacitor starts to "bring-in" the tweeter at a few kHz and above so if you are really worried about loading then consider putting an inductor in series with your woofer so that as frequency rises, the woofer is progressively removed from circuit. Something about 1 mH should start reducing the loading effect of the woofer from about 1 kHz upwards.
Alternatively, find one of the several web-site tools that calculates proper cross-over components values and do the job properly.
Sometimes, you just can't make a silk purse from a sow's ear