Looks like she gots a wee warm in there. Did the inductor lead actually break?
Also, what is that black thing at the bottom of the middle pic?
Also, what is that black thing at the bottom of the middle pic?
It would appear that one or both ends of the inductor coil have become detached from the crossover board.
I suggest you remove the plastic tie and the black plastic wrapping in order to locate the soldering points to which you may reconnect the ends of the air coil.
Comparing the board with the one in the other speaker of the stereo pair may help.
I suggest you remove the plastic tie and the black plastic wrapping in order to locate the soldering points to which you may reconnect the ends of the air coil.
Comparing the board with the one in the other speaker of the stereo pair may help.
No. Inductor lead is intact.
Black thing is the plastic wrapper over the inductor.
Any idea why there is that glob of glue on the side of the inductor and why is was glued to the bottom? Some hack fix?
If some of the wire has unravelled from the coil former, simply wind it back on. There should be no need to replace the inductor.
Even if the wire which is coiled round the former is slightly shortened by having to remount the inductor this will have an insignificant effect on the inductor value.
To measure the value of the inductor you need a multimeter with an inductance scale. You would measure the inductor in the 'good' speaker.
Even if the wire which is coiled round the former is slightly shortened by having to remount the inductor this will have an insignificant effect on the inductor value.
To measure the value of the inductor you need a multimeter with an inductance scale. You would measure the inductor in the 'good' speaker.
Glue is possibly to hold the inductor coil in place, from unraveling, or to hold on to PCB.
May be an age related glue failure.
Like Galu implies, not super important or critical, just take his advice.
May be an age related glue failure.
Like Galu implies, not super important or critical, just take his advice.
Remember to use a new plastic tie when reinstating the inductor.
I shouldn't think glue would be necessary if the plastic tie is pulled tight.
As to why the inductor became dislodged, such events are usually the result of a speaker having been dropped onto a hard surface.
I would certainly inspect the other speaker of the stereo pair in order to check the condition of its air inductor.
I shouldn't think glue would be necessary if the plastic tie is pulled tight.
As to why the inductor became dislodged, such events are usually the result of a speaker having been dropped onto a hard surface.
I would certainly inspect the other speaker of the stereo pair in order to check the condition of its air inductor.
My first blush response was "Sproing!"...
Others have given you good advice as to what to do and how. I bet that is a rod-core, either steel or ferrite, due to shape alone. The glue, wrap, and tie were for keeping the windings adhered and for mounting. Electrical tape works, but at these voltages so does duct tape which can also take the heat.
Others have given you good advice as to what to do and how. I bet that is a rod-core, either steel or ferrite, due to shape alone. The glue, wrap, and tie were for keeping the windings adhered and for mounting. Electrical tape works, but at these voltages so does duct tape which can also take the heat.
I agree with you and soundchaser - an air core inductor would be lighter than a rod-core inductor and therefore not so likely to be dislodged by a fall.
How much benefit to replace that with a 1.65mh Jantzen air core inductor although I'm not sure how I would make it fit.
Depends on the quality of the overall speaker I suppose - which make and model is it?
P.S. Did you find out that your damaged inductor is 1.65 mH by googling?
P.P.S. If you did substitute an air core you would have to match up the series resistance with that of the ferrite core.
P.S. Did you find out that your damaged inductor is 1.65 mH by googling?
P.P.S. If you did substitute an air core you would have to match up the series resistance with that of the ferrite core.
Last edited:
Very little benefit, at the power levels where the iron core would saturate, the woofer's harmonic distortion would be so high it would mask hysteresis distortion.
As noted by @Galu the dc resistance of a replacement should match the original. If you introduce more dc resistance, it will likely attenuate the bass response (assuming it is in line with the woofer in the circuit).
For example, a 1.65 mH ferrite core inductor like that may have a dc resistance of around 0.10 or 0.30 ohms (even with 18 or 20 ga wire).
A 1.65 mH air core inductor would probably need to be made from 12 or 14 ga wire to have only 0.10 or 0.30 ohms.
In addition to the larger size, the cost would be much greater.
Based on your pictures, I'd be inclined to fix it and re-secure it as others have noted.
For example, a 1.65 mH ferrite core inductor like that may have a dc resistance of around 0.10 or 0.30 ohms (even with 18 or 20 ga wire).
A 1.65 mH air core inductor would probably need to be made from 12 or 14 ga wire to have only 0.10 or 0.30 ohms.
In addition to the larger size, the cost would be much greater.
Based on your pictures, I'd be inclined to fix it and re-secure it as others have noted.