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

[Mr. Widget]

I'm not sure if super low DCR is that critical in your design, but if it is a premium quality ferrite core design can be the best choice, especially if you do not plan on extreme power levels where the core may saturate.


Widget

[4313B]

If you designed your crossover network and your enclosure volume/tuning based on ideal passive components then you want the DCR to be as close to zero as possible and that means using something like the very expensive Erse type laminated steel core inductors.

Crossover networks and enclosure volume/tuning are usually designed with parasitic passive components, usually around 0.5 to 0.6 ohms of DCR in typical series inductors. Some inductors can have up to 8 ohms of DCR (in an 8 ohm system) when used in parallel circuits.

[Sootshe]

If you designed your crossover network and your enclosure volume/tuning based on ideal passive components then you want the DCR to be as close to zero as possible and that means using something like the very expensive Erse type laminated steel core inductors.

Crossover networks and enclosure volume/tuning are usually designed with parasitic passive components, usually around 0.5 to 0.6 ohms of DCR in typical series inductors. Some inductors can have up to 8 ohms of DCR (in an 8 ohm system) when used in parallel circuits.

You mean like one of these?

These are around $20?? I was thinking of the North Creek 10# ........around $200.(DCR 0.17)

[Sootshe]

I'm not sure if super low DCR is that critical in your design, but if it is a premium quality ferrite core design can be the best choice, especially if you do not plan on extreme power levels where the core may saturate.


Widget

Yes , the original design uses a Madisound Sledgehamer 2.7.......around $15, DCR 0.168.

I was thinking of the North Creek....around $200 ...DCR 0.17. Power levels will be relatively low...using a 60 watt valve amp & listening levels fairly moderate.

Maybe overkill???

My final decision is really based on sound quality rather than anything else. I suppose I'm having a hard time coming to terms with a $15-$20 item sounding as good as a $200 item.

[Mr. Widget]

Maybe overkill???

My final decision is really based on sound quality rather than anything else. I suppose I'm having a hard time coming to terms with a $15-$20 item sounding as good as a $200 item.

That thinking has made many in the audio world, very rich.

Seriously... I am confident in a double blind test, you won't hear the difference. Now, if you were to hold the massive copper coil in one hand and the dog bone Erse in the other, you will likely hear the coppery goodness that your $200 bought you... just try not to think of it in those terms.


Widget

[Sootshe]

That thinking has made many in the audio world, very rich.

Seriously... I am confident in a double blind test, you won't hear the difference. Now, if you were to hold the massive copper coil in one hand and the dog bone Erse in the other, you will likely hear the coppery goodness that your $200 bought you... just try not to think of it in those terms.


Widget

Yes, one upmanship is a very bad thing!!

Trouble is 1 need 4 of these things, so that's $800 versus $80. I think I'll take your advice.....coppery goodness isn't worth that much,

Cheers,
John

[4313B]

Like G.T. says... it's a length of wound copper...

You decide whether you want to pay $20 for it, $200 for it, or just rip it out of an abandoned house.

[subwoof]

Way back when a few of us were putting a club system together on the cheap and we needed to run the sub cabinets passive. there wasn't a madisound or any source for large inductors so we took a very long piece of 10ga cloth covered copper wire from an abandoned conduit, a long iron weight from an old sash window, a massive black+decker drill with a very low gear clamped into a woodworking vise and made one.

While the drill turned the sash weight in it's chuck, we wound that wire ever so nice until it was as thick as your thigh. coated it with floor varnish and let it dry.

never mind the value, the DCR, saturation, etc. we wanted bass and it actually worked.

Always wondered where that went to when the place closed and became a condo...

and now I look at the pile of sash weights in the back yard from the old windows and am thinking...

sub

[Mr. Widget]

Sash weights? I'm thinking core saturation.

Years ago before high quality coils were easily obtained I bought a pale of 12 ga magnet wire... I used to wind my own coils, what a PITA. Today things are far more civilized.


Widget

[Allanvh5150]

I have always wound my own coils. Just sit down with a bobbin and a roll of wire and begin winding. Enamel wire is pretty cheap and you can get the exact value that you want.

Allan.

[DHL]

I vote for the air core inductors. Yes they are big. Yes, they are heavy. Yes they are expensive. But they sound better than iron core alternatives and I don't want to worry about exactly what power levels they might saturate at. If you need to compromise, buy some with a bit higher series resistance, as the losses due to that are more acceptable than core saturation IMHO.

I recently replaced the iron core stock JBL ones in my L212 crossovers with air core versions and the new sound is exceptional. Never going back.