inductor in series or not

Jump to Latest
AllenB

AllenB

diyAudio Moderator
Joined 2008
Paid Member
I'd guess so, since the existing inductor doesn't itself look like it would easily dissipate 5W.

The usual caution when doing this. During your early discovery listening sessions, go over and feel it a few times when it seems appropriate.
 
  • Like
Reactions: 1 user
T

Tubenstein

Member
Joined 2011
ianbo said:
You haven't said where you want to use the copper foil inductor. In the tweeter circuit? Or on the mid/bass?

For the tweeter, you want to keep the resistance of the trap the same as the original, so if you use the 2.24R coil, you need to add a resistor in series of around 2.2 or 2.3 ohms. If you use the foil coil, you need a resistor around 3.7 ohms.

If you use the foil coil on the midrange, you will have increased the series resistance by 0.2R. That will cause a small change in the response, notably a small reduction in level - I'd guess around 0.2dB.
Click to expand...
Can I parallel 3 x 6.8R 5w carbon resistor for 2.27R and then wired in series with the 2.24R coil?
 
I

ianbo

Member
Joined 2014
Well, it doesn't need to handle the same wattage as three paralleled resistors could. It just needs to handle the power it's going to be presented with in the circuit. In the original crossover, there's a very light gauge air core coil there - something like 29 AWG, I'd guess. I reckon that a single 5 watt resistor, sharing the load with the new coil, will be fine.
 
  • Thank You
Reactions: 1 user
E

egellings

Member
Joined 2010
ianbo said:
Well, it doesn't need to handle the same wattage as three paralleled resistors could. It just needs to handle the power it's going to be presented with in the circuit. In the original crossover, there's a very light gauge air core coil there - something like 29 AWG, I'd guess. I reckon that a single 5 watt resistor, sharing the load with the new coil, will be fine.
Click to expand...
Presumably, the resistors were sized to possibly handle that much wattage. If it's known that they will never see that kind of power, then a lower wattage rating, such as 5W, would be just fine.
 
T

Tubenstein

Member
Joined 2011
ianbo said:
Well, it doesn't need to handle the same wattage as three paralleled resistors could. It just needs to handle the power it's going to be presented with in the circuit. In the original crossover, there's a very light gauge air core coil there - something like 29 AWG, I'd guess. I reckon that a single 5 watt resistor, sharing the load with the new coil, will be fine.
Click to expand...

The Jantzen 1mH Air Core Wire Coil is AWG26, not 29AWG
 
I

ianbo

Member
Joined 2014
Yes, I know. If you read what I wrote in post #47 again, I said that the original tweeter inductor, the one with 4.5 ohms DCR, must be something like 29 AWG.

(Why did I estimate 29AWG? Because there is a Jantzen 29AWG coil available which is 1mH, 0.44R.)
 
Last edited:
  • Thank You
Reactions: 1 user
M

mboxler

Member
Joined 2011
The 1mh inductor and 4.7uf capacitor create a deep notch at around 2320hz. Any added series resistance (including the DCR of the inductor itself) simply makes the notch less deep. You may be okay without the added resistor, but there's no drawback to adding a series resistor.
 
  • Thank You
Reactions: 1 user
T

Tubenstein

Member
Joined 2011
mboxler said:
The 1mh inductor and 4.7uf capacitor create a deep notch at around 2320hz. Any added series resistance (including the DCR of the inductor itself) simply makes the notch less deep. You may be okay without the added resistor, but there's no drawback to adding a series resistor.
Click to expand...
The stock 1mH inductor has DCR of 4.5R. So the added 2.2R resistor along with the 1mH inductor (2.24R DCR) just set the DCR back to 4.5R, right?
 
You must log in or register to reply here.
Top Bottom