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I'm building a 500Hz crossover & confused as to which inductors to use. I need a 2.4 & a 2.7 in this design.
Research so far says that they should be the lowest resistance for the best bass performance. I looked at the North Creek Audio, but their 12# resistance is 0.27 & 0.30. I'm looking at Solen 10 gauge which have a resistance of 0.17 & 0.18. I've also heard good reports about the copper foil coils, but notice that their resistance is considerably higher.
Any advice as to the best type for the best bass performance.
Series R causes attenuation, but it is only a fraction of 1dB as long as it it less than 10% of the driver DCR.
What is more important is that series R raises Qes, which in turn raises Qts, which in turn affects the box size.
Find an online calc that allows you to figure out a new value of Qts with the added DCR of the inductor.
Do not change inductor DCR on an existing design, the box size will now be less than optimum and the HF attenuation will need to be changed.
On new designs, take into consideration the new Qts and it will not be an issue.
I'm building an ALK AP12-500, so my question is really whether to upgrade the parts quality by using better quality inductors & caps?
Surely if I do this it can only improve the sound quality??
I've heard such rave reviews about the North Creek Audio inductors that I'm finding them hard to go past.
Thanks for the technical explanation, but sorry, this doesn't make much sense to me, as a lay person with limited technical expertise.
You should at least get some info on what are called TS Parameters used in speaker design.
DJK is correct. I was initially thinking about panel speakers where things are 'different'. I have no background building or designing boxes.
Now, for the icing on the cake, parts ain't parts. Capacitors also have a slight inductive and resistive measures which also effect the final design. Inductors, as you've already learned, are resistive, too. Some resistors have an inductive aspect.
The long-way 'round, and perhaps the way to satisfy yourself, is to first build as designed with the recommended parts. THAN begin substituting.
The link is to the Cliffs Notes version and may prompt further reading on your part.
Good luck with your mods.....
Too much is never enough
John, you should really post this over on the speaker forum where there is more technical expertise.
That said, I am using the Solen 14ga. and am very pleased with them. Unless you have really powerful amplifiers and inefficient speakers then 14ga. should be fine. Don't worry about the fraction of an ohm series resistance of the chokes; you are never going to hear the difference between .17ohm and .27ohm.
Lower DCR is not always the answer, you must think of output balance.
Attached, find a link to a calculator. You can enter your parameters and get an output which'll make sense.
I urge you to 'juggle' the numbers to achieve the same number of layers as turns per layer....this will make a coil square in cross section. This is a theoretical 'best'.
I would also suggest, if you decide to 'roll your own' to consider using PVC as a core. Look up standard dimensions and choose one based on getting a 'square' coil out of it.
for my panels, which come with a 0.40 ohm DCR aircore, many people add to the bass output by going to very low dcr inductors. The panel already has such a bass peak for good reason.
You also may find that going to 10ga is sheer wacky. the coil is difficult to wind and if bought aftermarket, $$$$. Not to mention they can get pretty LARGE.
with just 30 seconds on such a calculator, i came up with the following::
Inner diameter 2"....height of coil of 1.05" and 163 turns of 12ga and nearly 13 layers of 13 turns each.....DCR? about 0.2 ohms which is pretty low.
You'll probably find the commercially made coils to come from a series of 'stock' size spidles and therefore NOT optimized.
ALSO such minute changes in DCR will produce only fractional DB changes in output.
Take the DCR of the driver, add it to the coil DCR and take a percentage. Say....a 4ohm coil and a 0.4 ohm inductor: Thats 1/11th the power being dissipated in the inductor. Not much, I'd say.
Too much is never enough
Thanks for the helpful info. I don't see myself making my own coils, so I will be selecting from the various options available commercially.
As I say, the Solen's have the lowest DC resistance so I was wondering whether they are better or not than the copper foil type.
Or is this just another means to the same end?
I have NO idea in your application....and nobody ELSE does either.
Speaker design has come a long way. Computers make first approximations much easier than the old way.
For the DIY guy? I'd say either go with a known good design / parts / the works OR be ready to do some experimentation and listening tests. This could not only be expensive but time consuming.
Too much is never enough
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