|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
50.82.78.85
I've been looking at inductors for my ML Scenarios, and found Litz inductors by Solen. It looks like a smaller gauge wire braided to achieve whatever awg they are after for the winding. I've also been looking at copper foil inductors, and found Jantzen that offer copper foil wax coil. So I guess I have two questions, first, does the wax add any benefit over no wax, and is copper foil superior to Litz?I was informed that the DCR and inductance of new inductors needs to match what is currently in place. Is matching the DCR and inductance for the drivers involved, or is there another reason? The crossover uses different resistors then I am accustomed to seeing, pic included. They are 1ohm 20 watt buggers. Do I need to use another 20 watt resistor, or will a 12 watt Mills for instance work and not cause problems?
Thanks for any and all help,
JCarney
Edits: 10/27/22 10/27/22Follow Ups:
Inductors are kind of a '3rd rail' issue.
First? If power handling is an issue, use aircore. Iron core will saturate and 'distort'.
Matching DCR / Inductance IS an issue. The Magnepan Mod guys who go after stock crossovers LOVE to change the 0.4ohm DCR inductor for one 1/2 that in resistance. But that's only going to make maybe a 1db difference....Given that the inductor is in series with a 4ohm driver.....give or take.
The change in driver balance is MINOR, perhaps.....
This is for the MG1.6. New Maggies use series crossovers and are designed to be DIY-Proof.....
More important, IMO? Inductor have the same number of TURNS per Layer as Layers.....This makes an inductor in which the coil is SQUARE in cross section. Adjusting for size of wire, length of wire AND core size can result in this 'theoretically perfect' dimension......
And Finally? IF multiple inductors on the crossover board? Should be AT RIGHT ANGLES as much as possible. Standing up? Laying down? At a 90degre ot either of the above? They will otherwise COUPLE in an unpredictable manner.....
If you want to just get a grip on these issues? Find an online inductor calculator and run some 'thought experiments'.......I did so and evolved an inductor using STOCK PVC pipe as a core AND with the same number of layers as turns AND within 5% of stock DCR and it was Aircore and NOT iron core. I think I ended up with 14ga wire...while stock was 16ga.....I've got the spreadsheet here SOMEWHERE.....
Too much is never enough
Thank You pictureguy, very much appreciated. I chickened out on replacing the existing inductors. I decided that was bit above my pay grade trying to figure out the numbers. Now I know a bit more than when I started and that will help here and in future goofy projects I get myself into.
Thank You to all who responded.
JCarney
I can't do the math EITHER.....and don't know the formulas, anyway.
But you might find a few usable calculators online.....and than keep a spreadsheet of results?
Something like the link may be useful...?
Too much is never enough
Thank You pictureguy, you are a helpful good guy and I appreciate you taking the time to help me.
JCarney
Hello:
I suspect that the wax may be a sort of damping treatment for the
inductor, but not sure.
Really good foil and Litz inductors should both be pretty good; I
don't think any difference would be worth worrying about.
Matching the DCR and inductance to the OEM components helps to insure
that the crossovers will work properly with the drivers.
Your speakers are efficient (89dB), so the resistor rating might depend on how loud you play music (which would dictate the peak current the resistors might see). If you want to be sure, you could parallel 2 Mills 12 watt resistors with 2 ohms each. Then you will have 24 watt capability.
DCR and inductance directly affect the crossover points as the are designed as part of a network to filter frequencies. That resistor is sized at 20 watts to handle the current continuously without melting down. The fact the maker choose one that size tells you a good amount passes through it. Don't throw away your old parts away, just in case.
To all:
Given that the speaker in question has an 89 dB/watt sensitivity, most of the time the power running through the 1 ohm resistor will likely be considerably less than 20 watts. Paralleling two 12 watt resistors of 2 ohms each gives you an equivalent 1 ohm resistor with a 24 watt capacity. This exceeds the 20 watt rating of the original unit, so all is good. In a parallel circuit of 2 resistors of equal value, the current will equally divide between the two; in this case a maximum of 12 watts per resistor, or 24 watts total when in parallel.
...for your input and detailed explanations, all very helpful to me since I'm not the sharpest knife in the drawer. I've decided to not change out the inductors, and I am going to use Mundorf MResist resistors that are similar in design and a 20 watt rating like the designer used. I'll only be replacing 5 of the 8 parts. 3 capacitors and two resistors. Good idea to hold onto the original parts, I will follow your advice and hold onto them.Thank You,
JCarney
Edits: 10/28/22
Thank You fastcat, I really appreciate the answer. It answered my questions and confirmed what I suspected about the DCR and inductance working with the drivers. I've got a big ole smile now because I get to order parts now that I'm confident in my choices.
Thanks again,
JCarney
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: