Classic Hifi Care

I am confused, can anyone explain this chart to me. It shows capacitors and resistors. I always thought capacitors were used in crossovers. This chart shows capacitors for tweeters and resistors for woofers. Thank you. Bill

https://www.diyaudioandvideo.com/Tables ... /1stOrder/

William wrote: ↑Thu Jul 18, 2024 7:25 pm I am confused, can anyone explain this chart to me. It shows capacitors and resistors. I always thought capacitors were used in crossovers. This chart shows capacitors for tweeters and resistors for woofers. Thank you. Bill

https://www.diyaudioandvideo.com/Tables ... /1stOrder/

Bill,
The chart you posted uses inductors and capacitors.

Is there another chart you're looking at ?

The reason you see capacitors only used in crossover networks is because those setups only control the crossover frequency of the tweeters. The chart you posted gives the values for crossover networks that crossover both high and low frequencies. They would use high pass filters and low pass filters. If you want more high frequencies, you use capacitance, if you want more low frequencies, you use resistance. Most Magnavox stereos wire the woofers directly to the amp, then use a crossover network using a capacitor for the tweeters or horns.

My posted chart is the chart I was referring too. I guess I have never seen resistors used in a crossover before. The VM801 main unit has three speakers. 12", 8", and the tweeter. The tweeter has a capacitor which would be normal but the 8" has a 5-ohm wire wound resistor installed from the factory when this unit was built. It lists both the resistor and the capacitor in the parts list of the genuine VM schematic. Looking at the chart, a 5-ohm resistor is not listed but a 4.7-ohm one is. The VM and the Sam's schematics both say the 8" speaker is 4-ohm's so 4.7 would make sense to be close to the 5-ohm that the factory used. According to the chart that makes the cut at 130Hz which does not make sense to me. Why would they be that close to the woofer bottom end frequency. That makes that poor 8" speaker almost a woofer. I would think they would want it to be more of a mid-range speaker instead of a small woofer. I am confused.

Bill

A wirewound resistor is going to act like a choke, a reactor. Are you sure it's not just a choke, which are common in crossovers?

Chris Campbell

It is wirewound, the VM schematic calls it that and it looks like the square/rectangular sand block thing.

Bill

William wrote: ↑Sat Jul 20, 2024 1:52 pm It is wirewound, the VM schematic calls it that and it looks like the square/rectangular sand block thing.

Bill

I suspect that it was carefully chosen for both resistive and reactive values.

Chris Campbell