From Madisound a 2.5 mH air core has 1.0 ohm DRC and the iron core is .164 ohm DCR. A little off from memory, but the point remains the same.
Is 1.5 Ohm coil in your system from a 2.5 mH coil? That must be a very cheap coil!
There is nothing good about the series resistance of the woofer inductor. Its like throwing away a good portion of the magnet on your woofers. You pay big bucks for BL, why try to save a few pennies on Re? Makes no sense.
Hehe but of course, pennies can not buy expensive stuffs.
Or may be I misunderstood you?
Swarky started with this:
And your first post was:
You might just posted general "clue" there, or might as well addressing to Swarky's post. But the problem is, there is "distortion" issue with iron-core coils. So, "going with lower DCR" could mean using expensive foil inductor (not saving pennies), or using iron-core inductor.
And your later post:
Can you see the contradiction between looking for low DCR and "not saving pennies"?
So in your system you choose the iron-core 0.4 ohm instead of the 1.5 ohm (which I assume air-cored) because low Re is so critical in your opinion? But it has nothing to do with saving pennies...
For me, it is a strange comprison, hence my "unusual values" comment. The iron-core is so low in DCR while the other one is so high. Is it for 3-way crossover at 200 Hz or something?
The values are unusual to me because I hve never used inductor of that high DCR. If low DCR should be prioritied over pennies, then buy Jantzen foil. If low DCR should be prioritied over anything, then buy iron-core... (assuming that iron-core could be the lowest, even tho in Swarky example it is not).
But one of my point was similar to Infinia's. There is no easy way to determine when we have to go with minimum Re (We know that low Re is good to have but there is always trade-off). There is money considertion which is not easy to calculate, there is "distortion" issue of iron-core inductors, and few others...
In summary, foil coil (very expensive) will have similar DCR with iron-core (very cheap). But which one to go? As you say, DCR difference is not critical, so now the decision is about "money" or "distortion". Which is it? Here I'm interpreting your posts as "pick either one"?
You do have it wrong. I am not concerned with price of the components only the DCR. I am not concerned with "distortion" because, as most know, after studying this problem intensely I find that there is no rational to worrying about nonlinear distortion. So you see, to me, there is no "tradeoff", just find the lowest DCR that you can find that fits your other requirements and go with that.
The crossover is at about 700 Hz and uses two 2.5 mH inductors (3rd order). Maybe not common, but it works quite well.
The crossover is at about 700 Hz and uses two 2.5 mH inductors (3rd order). Maybe not common, but it works quite well.
and how have your industry peers accepted your study and oft stated conclusion?
I'm just guessing they accept the study but ignore your more subjective conclusions.
BTW just from our limited interaction in the lounge area your conclusions are a little extreme (black n white) to my thinking
I'm just guessing they accept the study but ignore your more subjective conclusions.
BTW just from our limited interaction in the lounge area your conclusions are a little extreme (black n white) to my thinking
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I would say that the industry completely buys into the findings. I know that the engineering staff at JBL thinks that way. For example, Toole told me that he put in as much discussion of nonlinear distortion as it warranted in his book - 1 paragraph out of the entire text.
But anyways think what you want.
I don't have the time (or interest) in getting into the nuances of all these discussions so I sometimes speak succinctly. Maybe that sounds "black and white", but I can assure that I know all about the grays.
But anyways think what you want.
I don't have the time (or interest) in getting into the nuances of all these discussions so I sometimes speak succinctly. Maybe that sounds "black and white", but I can assure that I know all about the grays.
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no I meant the way you form black and white conclusions just from a simplistic statement I made recently in the lounge.
It doesn't surprise me you have made other controversial perhaps major "breakthrough" statements, but shouldnt they have been discussed in many of the other audio papers too? I was hoping you could point me to these discussions so you don't have to re-hash them in a forum.
Okay, got it. Your mentioning about saving pennies in your first post confused me but in your later post you clarified (tho I wasn't sure 100%) that you preferred 0.4 ohm iron-cored than 1.5 ohm whatever. Yes, it is a big difference and like you, I will also choose the iron-cored one...
But my options usually are between low DCR Foil versus low DCR iron-cored, so no big difference in DCR, only in money...
What if the expensive foil inductor is the lowest DCR? No trade-off? Like I said, it is never clear when the decision involves money.
And from your post I CANNOT deduce that, for you, foil and iron-core of the same DCR will sound the same (You're not black or white here).
Have you read all of my papers - they are likely the most comprehensive for this subject. If you have read those and then don't agree then I would hope that you must have some reason to exclude my data.
PS. The papers are all on my website.
Yes, I am very "value" conscious. I will not add money to a design to do something that is not an improvement sufficient to justify its cost. A judgment call that is hard to quantify. But for every foil inductor there is always a lower or equal "possibility" at a much lower cost with iron. Now is that "possibility" available, probably not and I don't make inductors. So I balance the "options".
But aren't we nit-picking here?
really that's your answer? more self promotion
your conclusions about ignoring IMD in audio seem to go against all my learning and professional experience working in communications, radios & transmitters. I wanted to see how if it was accepted by others, I doubt what you say in these forums is repeated by others on any peer reviewed papers. I'm think I'm beginning to see a trend here.
It can't do any harm, can it? Gotta be better than a ferrite.
Ferrites are IMO, the theoretically worst component in crossovers. All that measureable hysteresis.
How much better will your speaker now sound? Usually it won't matter much, because the SEAS woofer is a great big 3.8mH ferrite inductor itself.
But here, the 0.76mH bass coil is part of a resonant circuit notch at 6kHz with the 15R + 1uF tank. Which exaggerates any non-linearities IMO.
It's not going to be huge, but 0.76mH is comfortably within sensible and affordable air coil range, so why not do it?
BTW, this filter does do something to the woofer. It rolls it off more smoothly than running it fullrange. But not a huge change IMO, because the shunt has a high 27R.
Thanks Steve for the bother. I don´t´know what difference the wax and foil make to the cheaper basic wire air core apart from slightly higher DCR but, as you say it´s not going to break the bank, fortunately.
I'm seeing a trend too. You just like to insult people on the internet - must make you feel important.
where did I do that?
maybe you confused me for some else, check posts.
an inductor showing high IMDs is at the onset of saturation E.g. non-linear.
In an analog system any non-linear element is most always undesirable. It's not a "don't care item" by anymeans.
again I suspect your conclusions as stated on the internet are black and white thinking and would of been highly controversial if you made them in a peer reviewed paper.
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