Chrisfromthepast
Well-known member
- Joined
- Mar 5, 2018
- Messages
- 269
Hi GroupDIY,
I hope this little repair will be enlightening to members besides being a passive crossover network, this puzzle still has the possibility of requiring homewound inductors, or some discussion of the best electrolytics for a crossover design…
On the bench are (4) EAW JF50 nearfield speakers, 2 of which have radically different phase and frequency responses than the other 2.
The only thing I have to go on is the 1 sheet marketing material. EAW might come through with a layout.
When I’ve been down this road in the past with wedges and traps, I was able to get the crossovers out and lift one side off the turret board connection, and measure every component to brute force and save time.
This is a tight little package, and I can’t quite get the whole thing out, or have an easy time lifting the components inside the box.
So, I need a little help thinking this through.
The marketing suggests a 4th order crossover filter, and I know from the test trace that the 125hz 6db filter at the bottom works fine on all of them. The problem seems to be in between the woofer and the mid range driver. Im guessing an inductor melted, but which one? Inside is a rainbow of wires, and a user facing 4 ohm to 16 ohm switch complicates the maze.
I have no schematic or layout, but can say a little about the topology I learned from sweeping the speaker and probing the terminals unloaded.
One of the 5 inch woofers has a high pass at 125 and is open on top, while the other acts as a midrange driver.
Is this 4th order crossover with silk dome on top, and 2 identical 5inch “woofers” that are at different pick points in the crossover a common topology that I can google?
I hope this little repair will be enlightening to members besides being a passive crossover network, this puzzle still has the possibility of requiring homewound inductors, or some discussion of the best electrolytics for a crossover design…
On the bench are (4) EAW JF50 nearfield speakers, 2 of which have radically different phase and frequency responses than the other 2.
The only thing I have to go on is the 1 sheet marketing material. EAW might come through with a layout.
When I’ve been down this road in the past with wedges and traps, I was able to get the crossovers out and lift one side off the turret board connection, and measure every component to brute force and save time.
This is a tight little package, and I can’t quite get the whole thing out, or have an easy time lifting the components inside the box.
So, I need a little help thinking this through.
The marketing suggests a 4th order crossover filter, and I know from the test trace that the 125hz 6db filter at the bottom works fine on all of them. The problem seems to be in between the woofer and the mid range driver. Im guessing an inductor melted, but which one? Inside is a rainbow of wires, and a user facing 4 ohm to 16 ohm switch complicates the maze.
I have no schematic or layout, but can say a little about the topology I learned from sweeping the speaker and probing the terminals unloaded.
One of the 5 inch woofers has a high pass at 125 and is open on top, while the other acts as a midrange driver.
Is this 4th order crossover with silk dome on top, and 2 identical 5inch “woofers” that are at different pick points in the crossover a common topology that I can google?
