Summary of Contents for Echo Mountain Audio JBL 4425
- Page 1 JBL Model 4425 Charge-Coupled Crossover User Manual echo mountain audio altadena, california echomountainaudio.com...
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Page 2: Table Of Contents
APPENDIX B: MEASURED FREQUENCY RESPONSE Introduction Thank you for your purchase of Echo Mountain Audio’s charge-coupled crossover boards for the JBL Model 4425 Studio Monitor. The set of bare boards you have received are intended for DIY build and “plug-and-play” integration into your existing 4425 monitor system. -
Page 3: The Charge-Coupled Topology
• Echo Mountain Audio Model 4425 Crossover boards • 4425 Charge-Coupled parts kit for Model 4425 from Solen (see Parts Information section and Appendix A for more details) •... -
Page 4: Overview
Overview The JBL 4425 Charge-Coupled Crossover PCB is shown in Figure 1 (top side) and Figure 2 (bottom side). The board is designed to fit into the existing crossover housing, and the mounting holes, denoted with red arrows in Figure 1, are sized to make use of the existing snap-lock PCB clips. - Page 5 Figure 2: PCB bottom side view...
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Page 6: Parts Information
Echo Mountain Audio does not support or provide specific info on custom or user- selected parts that are not on the official parts list. -
Page 7: Removing Crossover From Speaker
Removing Crossover from Speaker 1. Lie the speaker on its back and remove the woofer by carefully loosening the screws (don’t let the screwdriver slip and damage your cone or surround!) and lifting it gently out of the cabinet. 2. Disconnect the two wires (green and green/black stripe) from the woofer and place the woofer off to the side in a safe location. -
Page 8: Pcb Assembly
PCB Assembly For ease of assembly and to allow for unobstructed two-handed access to ensure that one makes good solder joints, it is recommended to follow the steps in the order they are presented. Since there are gluing and curing steps involved on the large components (capacitors and air core inductor), we recommend doing each phase of the assembly in parallel on both boards before moving on to the next phase, to minimize time spent waiting for the adhesive to cure. - Page 9 the top for a few seconds to allow the adhesive to spread underneath the part. The component will have some play in the plated through holes, allowing it to rock and back and forth slightly; adjust it so that it’s sitting upright and not tilted to one side. 4.
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Page 10: Installation Of Pcbs Into Crossover Assembly
Installation of PCBs Into Crossover Assembly After allowing the boards to cure overnight, you’re now ready to install the new PCBs into the factory crossover assembly. 1. Align the PCB mounting holes with the four snap-lock board mounts on the crossover board, and gently snap each corner into place, one at a time. -
Page 11: Installation Of Completed Crossover Assemblies
Installation of Completed Crossover Assemblies 1. Inside the speaker cabinet, strip the ends of the L-pad and driver wires that were previously snipped away from the factory PCB, twist the strands together, and tin the ends of the wires with solder. 2. - Page 12 Figure 4: Completed crossover installed in speaker cabinet, as viewed through woofer cutout (top of image points towards top of speaker)
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Page 13: Appendix A: Parts List
Appendix A: Parts List The table below shows the parts list included in the official parts kit from Solen (sold separately Solen’s website). Total Manufacturer Quantity Quantity Designator Description Manufacturer Part No. per board project Capacitor, 27 uF, PA Series, 250V Solen PA2700 Capacitor, 30 uF, PA Series, 250V... -
Page 14: Appendix B: Measured Frequency Response
Appendix B: Measured Frequency Response Model 4425 Crossover Stock (Orange) vs. Echo Mountain Charge-Coupled Equivalent (Blue) Both L-Pads at Max 2000 20000 Frequency (Hz) Measured response for the 4425 factory crossover (orange curves) and the Echo Mountain Charge-Coupled Crossover (blue curves) was obtained using 8 ohm dummy loads with an RME ADI-2 Pro FS R BE audio interface and REW software.