I want to rebuild a pair of Genesis loudspeakers and the original inductors are 0.63mh or 0.47mh coils of 22 gauge wire. I've found 0.47mh in 18g or 15g but not the 22g. The 15g coils are 50% more expensive than the 18g. If the inductance is the same what is the difference between the two? They are both Jantzen inductors.
I'm inclined to go with the 18g as that is closer to the original part from 1982.
I'm inclined to go with the 18g as that is closer to the original part from 1982.
The series resistance of the wire in the inductors may be a significant factor in the crossover performance.
Thicker wire is not necessarily better; the resistance is part of the design.
Thicker wire is not necessarily better; the resistance is part of the design.
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I don't think they have gone bad. The crossovers are attached to the speaker terminal plate which is broken. There is a lot of adhesive involved and I don't know if I want to, or am able to remove the inductor without damaging it. And there is only one inductor and one capacitor on the crossover so.... And the parts are not that expensive either.
I will be making new cabinets for these, because I can, and will change out the spring clip terminals with banana terminals. This is more an aesthetic exercise than anything else.
I will be making new cabinets for these, because I can, and will change out the spring clip terminals with banana terminals. This is more an aesthetic exercise than anything else.
Difficult, but not impossible: measure the resistance of old/thin and new/fat coil. Get a resistor to make-up the difference.
It is unlikely the *total* resistance is critical to 5%, so even a 20% part will not be a problem.
It is unlikely the *total* resistance is critical to 5%, so even a 20% part will not be a problem.
Heavier wire used in inductors of the same mh value is simply for higher power-handling. That's all.
Any internet buzzing and babble of different reasons is just that... babble. A..47mh coil is a .47mh whether it's made from 22 gauge or 18 gauge.
I hope that clears up your questions.
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how do you know the thickness of the magnet wire? Anyway these are very close to what you asked for(20gauges):
ERSE - ALQ Coils.
ERSE - ALQ Coils.
but I would use the 18 gauges ones( at least for the woofer):
ERSE-EQ
ERSE-EQ
ERSE - ALQ Coils.
ERSE - ALQ Coils.
but I would use the 18 gauges ones( at least for the woofer):
ERSE-EQ
ERSE-EQ
A given mh choke at a given speaker impedence will define the crossover point, period. Wire size only changes the power handling of the circuit. A heavier wire gauge will cause less "loss" feeding the woofer, effectively giving it more power/DBs, if that's what the design calls for. The "apparent" difference between 20 gauge and 18 gauge is negligable, you won't really hear a difference.
The wire size needs to be enough that the inductor doesn't cook at maximum power (well, not before the driver itself I suppose). The loss in dB will be tiny, this is really a trade-off between maximum rms current handling and cost. For an air-cored inductor the losses are resistive, but complicated by skin effect and proximity effect (somewhat higher than the DC resistance would suggest).
Crossover inductors ought to be rated by max power handling as well as inductance to make it easy for you. The symbol for the henry is 'H', not 'h', which is Planck's constant to a physicist! And yes the unit is 'henry', not 'Henry'. Units are not capitalized.
Crossover inductors ought to be rated by max power handling as well as inductance to make it easy for you. The symbol for the henry is 'H', not 'h', which is Planck's constant to a physicist! And yes the unit is 'henry', not 'Henry'. Units are not capitalized.
So in looking closely at the crossover, I was able to get it out without further damage, the cap installed is a 8uF, not a 10 or a 6.8 as listed in the published schematics. I'll take it into the lab and see if I can measure the inductor and check that value. The inductor isn't marked in anyway that I can see.
So how common is this situation, where the installed components are not what is listed on the mfg's website? I purchased these new from a reputable dealer.
So how common is this situation, where the installed components are not what is listed on the mfg's website? I purchased these new from a reputable dealer.
There's something common in manufacturing.
It's called "Design Changes" - often made during a specific "run" in manufacturing.
Perhaps they decided to change a part's value because of their own research.
I understand. But this wasn't documented anywhere on the "official" website. They list two possible crossovers, and neither of them have a 8uF cap in them. Perhaps I'll send him a photo and ask about it.
If a particular component isn't available in the required lead-time, substitutions may be made for a while (rather than stop production). Yes it may be a bit out of spec, but its a judgement call by the manufacturer - they are paying the production staff whether or not they are doing anything, and profit margins are often wafer-thin. Since these are expensive big components stocking levels will be lower, so more chance of lead-time upsets. Documentation comes as a secondary concern.