Magnepan 3.7 tweeter resistors

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jaylevine

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Magnepan 3.7 tweeter resistors
« on: 5 Mar 2013, 12:49 pm »
 I purchased a set of used 3.7s and they didn't have the resistors. The tweeter is a bit bright, even a touch shrill on some cuts, so I thought I'd try the resistor and purchased a couple of Mills 5w at .5 and .75ohm. Now I'm losing sleep over if I should have bought the 12w spec..... :banghead:

Does it matter or am I getting weird(er) than usual about this?

Thanks

kevin360

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  • án sǫngr ek svelta
Re: Magnepan 3.7 tweeter resistors
« Reply #1 on: 5 Mar 2013, 02:15 pm »
Relax :lol:

Let's call the ribbon 3 ohms (I think that's about right) and think about the half ohm resistor in series with it. The resistor will represent 1/7th of the load (thus will dissipate 1/7th of the total power) and it's rated at 5 watts - continuous (and that's a safety spec too). You'll cook your ribbon well before the resistor. The .75 ohm resistor will only represent 1/5th of the load, so that's safe too. If the value of the fuse is 2.5A (fast blow, by the way), the 3 ohm ribbon is protected from dissipating in excess of 18.75 watts without a resistor adding to the load (adding the resistor increases your safety margin a bit).

That's the longer way of saying that you're fine - relax.

jaylevine

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Re: Magnepan 3.7 tweeter resistors
« Reply #2 on: 5 Mar 2013, 02:30 pm »
Relax :lol:

Let's call the ribbon 3 ohms (I think that's about right) and think about the half ohm resistor in series with it. The resistor will represent 1/7th of the load (thus will dissipate 1/7th of the total power) and it's rated at 5 watts - continuous (and that's a safety spec too). You'll cook your ribbon well before the resistor. The .75 ohm resistor will only represent 1/5th of the load, so that's safe too. If the value of the fuse is 2.5A (fast blow, by the way), the 3 ohm ribbon is protected from dissipating in excess of 18.75 watts without a resistor adding to the load (adding the resistor increases your safety margin a bit).

That's the longer way of saying that you're fine - relax.

Thanks. Now I go back to worrying about something else........ :wink: