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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. 

3.

 

You will now be able to see the stock crossover unit mounted to the rear wall of the 
speaker.  Now is a good time to take a picture of the stock units, wire orientation, etc., in 
case  you  ever  want  to  return  the  speaker  to  its  stock  configuration.  Your  new  Echo 
Mountain boards use the same pad numbering convention (E1, E2, E3, etc.) as the factory 
boards for simplicity and ease of rework. 

4.

 

Unscrew the six Philips head screws that secure the mounting plate to the rear wall of 
the speaker and set them aside in a safe place.  

5.

 

At this point, you’ll need to disconnect the wires going to the crossover unit in order to 
be able to remove it from the cabinet.  There are two options for this: de

-

soldering the 

wires at the PCB (difficult because of the limited access through the woofer cutout), or 
snipping the wires at the PCB (and then de

-

soldering the small bits of remaining wire once 

the unit is removed).  We strongly recommend the latter method, as it’s much easier, and 
there is enough slack in the wires to allow for this.  Snip the wires as close to the PCB as 
possible (they should all be accessible from the top side of the board). 

6.

 

Once the wires are de

-

soldered or cut from the PCB, you will need to remove them from 

the strain relief “clamp” that is adhered to the crossover mounting plate.  This strain relief 
apparatus doesn’t look the same on every model, but usually consists of adhesive, a zip 
tie, or both.  The adhesive is brittle enough due to years of age that it can be easily broken 
and removed.  Don’t worry about damaging the strain relief clamp, as you’ll be replacing 
it later with an adhesive

-

backed zip tie mount and zip tie, but do take care not to damage 

the wires. 

7.

 

At this point, the crossover assembly should be free of the speaker, and you should be 
able to remove it through the woofer cutout. 

8.

 

Repeat steps 1

-

7 above for the other speaker. 

Removing Factory PCB from Crossover Unit 

1.

 

Place the crossover unit on your workbench, and carefully release the PCB from the four 
snap

-

lock  plastic  terminals  by  gently  (gently!)  pinching  on  the  tabs  with  a  pair  of  non

-

marring pliers or your fingers.  Do this to one corner at a time. 

2.

 

Once the PCB is free of the clips, locate the red and black wires connected between the 
crossover binding posts and the PCB, and de

-

solder these wires from the PCB (leaving 

them connected at the binding posts). 

3.

 

Locate the two wires coming from the inductor mounted on the crossover plate to the 
PCB, and de

-

solder these wires from the PCB. 

4.

 

The factory PCB should now be free of the rest of the crossover assembly; set it aside. 

5.

 

Repeat steps 1 through 4 above for the other crossover unit. 

 

Summary of Contents for JBL 4425

Page 1: ...JBL Model 4425 Charge Coupled Crossover User Manual echomountainaudio com echo mountain audio altadena california...

Page 2: ...E 14 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 D...

Page 3: ...specs home speakers 1993 k2 s5500 page10 jpg http www lansingheritage org images jbl specs home speakers 1993 k2 s5500 page11 jpg http www lansingheritage org images jbl specs home speakers 1993 k2 s5...

Page 4: ...sting snap lock PCB clips An example of a completed crossover installed in the factory crossover housing is shown in Figure 3 Note that the default configuration uses the factory inductor for the woof...

Page 5: ...5 Figure 2 PCB bottom side view...

Page 6: ...pendix A and on Solen s product page Components of the same type and rating from other manufacturers may be substituted at the user s discretion but it is the responsibility of the user to measure the...

Page 7: ...s close to the PCB as possible they should all be accessible from the top side of the board 6 Once the wires are de soldered or cut from the PCB you will need to remove them from the strain relief cla...

Page 8: ...sidue with a swab and isopropyl alcohol 2 Insert and solder the small 0 25W resistors RC1 RC3 RC5 RC8 on the top side of the board Clean off any residual flux residue with a swab and isopropyl alcohol...

Page 9: ...rint so trim off the excess length leaving enough to pass through the board and allow for a solder fillet on both sides 3 Now that you ve trimmed off the excess leads to the desired length you ll need...

Page 10: ...enter it and then remove the protective layer on the exposed side of double sided tape Place the battery and clip down on the right side of the crossover assembly mounting plate choosing the location...

Page 11: ...neath the PCB You can push pull the wires through your semi tightened zip tie loop until you have everything dressed properly and then tighten it fully and snip off the excess length 4 Align the assem...

Page 12: ...12 Figure 4 Completed crossover installed in speaker cabinet as viewed through woofer cutout top of image points towards top of speaker...

Page 13: ...6 2 uF PA Series 250V Solen PA620 2 4 C5A C5B Capacitor 8 2 uF PA Series 250V Solen PA820 2 4 C8A C8B Capacitor 16 uF PA Series 250V Solen PA1600 2 4 L1 Inductor 1 0 mH Air Core Solen S201 0 1 2 R1 R...

Page 14: ...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 40 35 30 25 20 15 10 5 0 20 200 2000 20000 Magnitude...

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