Which inductors??

[sootshe]

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.

Thanks,

John

[djk]

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.

In
general:

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.

[sootshe]

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.

In

general:

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.

djk,

I'm building an ALK AP12-500, so my question is really whether to upgrade the parts quality by using better quality inductors & caps? This will be used in a set of custom LS with Crites C1526 woofers & GPA 399 mids.

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.

[djk]

The Qts on the Crites C1526 is low enough that I would not worry about the DCR of the woofer inductors.

"
Surely if I do this it can only improve the sound quality??"

The more expensive inductors are a waste of money in this design, and will not sound any better. Buy the 1dB step autoformer.

"I've heard such rave reviews about the North Creek Audio inductors that
I'm finding them hard to go past."

Ho-hum, another major breakthrough.

The difference in response at 400hz is 104.85dB vs 104.4dB for 0.25Ω DCR vs 0.50Ω DCR, the 0.5Ω DCR actually has more output below 60hz than the 0.25Ω DCR inductor does.

I find a M6 laminated low-carbon steel inductor to be fine for woofer use, and will not saturate until levels far beyond 500W. I would use an air-core for HF use, 16g or 14ga at most. The 16ga CFAC is the same price as the 14ga Solen at MAD, $32. The lower resistance of the Solen will make a very small difference well below 500hz.

I believe in good parts, but I like to be frugal as well.

DCR=0.164Ω http://www.madisoundspeakerstore.com/steel-laminate-15-awg/steel-laminate-2.5-mh-15-awg-inductors/

[sootshe]

The Qts on the Crites C1526 is low enough that I would not worry about the DCR of the woofer inductors.

"

Surely if I do this it can only improve the sound quality??"

The more expensive inductors are a waste of money in this design, and will not sound any better. Buy the 1dB step autoformer.

"I've heard such rave reviews about the North Creek Audio inductors that

I'm finding them hard to go past."

Ho-hum, another major breakthrough.

The difference in response at 400hz is 104.85dB vs 104.4dB for 0.25O DCR vs 0.50O DCR, the 0.5O DCR actually has more output below 60hz than the 0.25O DCR inductor does.

I find a M6 laminated low-carbon steel inductor to be fine for woofer use, and will not saturate until levels far beyond 500W. I would use an air-core for HF use, 16g or 14ga at most. The 16ga CFAC is the same price as the 14ga Solen at MAD, $32. The lower resistance of the Solen will make a very small difference well below 500hz.

I believe in good parts, but I like to be frugal as well.

DCR=0.164O http://www.madisoundspeakerstore.com/steel-laminate-15-awg/steel-laminate-2.5-mh-15-awg-inductors/

So....sounds like I should just stick with the standard inductors that Al has used in this design............................15 #sledgehammer for the 2.7 & Solen #12 for the 2.4.

What is the 1db step autoformer & is it superior to the 3619 that I already have?.................thanks from a novice in crossover design for your help......looks like you've saved me around $800 in inductor costs....................Found the 1db step autoformer on Bob's site....the 3636. So how is this superior to the 3619 apart from the finer gradation of control?

[djk]

" So how is this superior to the 3619 apart from the finer gradation of
control?"

I doubt there is any substantial difference other than the finer steps, but it is critical to have the fine adjustment capability.

[sootshe]

" So how is this superior to the 3619 apart from the finer gradation of

control?"

I doubt there is any substantial difference other than the finer steps, but it is critical to have the fine adjustment capability.

Thanks.

[sootshe]

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