XO parts help

[rv1890]

I was about to order the crossover parts needed to complete the 2 way seasl18/seas27tbfcg monitor on Zaphs web site. but before i place my order i need to have a few things clarified.



1) Zaph says to use steel laminate inductor of 2.2mH rating. Will an inductor that is 16ga. and 500 watt rating be the correct inductor?? http://www.partsexpress.com/pe/showd...number=027-560
Will this work??

2) Judging by the images on the website it looks like the other inductors are air core (correct me if im wrong). It states that L3 needs to be .1mH.....would this be sufficient?
http://www.partsexpress.com/pe/pshow...=260-718&DID=7

Lastly.....(sorry guys for the newb ?'s)

3) In this image for the xo schematic it says in red on top "this resistance is part of the inductor"....what does this mean?
Im also looking at the image of the physical XO and i dont see where these are wired in. Do i just wire them in series with the part thats next to it?
Heres the image.

[sreten]

Hi,

if you look at the spec for the 0.1mH core DCR = 0.2 ohm.

the red resistors in the scematic represent the inductors DCR.

In this case you want a DCR of 0.1 ohm.

http://www.partsexpress.com/pe/showd...number=255-202

is near enough.

You can see the DCR of L0 should be less than 0.3R.

http://www.partsexpress.com/pe/pshow...number=266-906

will be fine. And the other inductors should be aircored.

quoting from Zaph's page

There's a good amount of flexibility in the DCR for inductors L3 and L7,
but try to keep L0 below .4 ohms to avoid affecting the woofer SPL too much.

/sreten.

[rv1890]

Sorry . I think I had confused the links and got them backwards. I put the pic of the cap instead of the inductor. Thanks guys...i got it right now...

Sticking with the subject...what components should i be looking at if i wanted some higher grade components. any certain brands or places to shop? or does higher grade components even make that much of a difference?

[rv1890]

So does this mean that I dont need to add the resistors that are labeled in red in the schematics if the dcr of the inductor is close enough to the recommended amount??>

[googler]

Originally posted by rv1890
So does this mean that I dont need to add the resistors that are labeled in red in the schematics if the dcr of the inductor is close enough to the recommended amount??>

Exactly!

For example if you used a Goertz 14GA copper foil inductor for L3 the dcr would be .05R which is half of the specified .1R. In that case, if you wanted to stick to the values that Zaph has specified in the diagram, you would need to add a resistor after the inductor to compensate.

[rv1890]

Dude whoa!!!....Thanks a lot guys!!.....you guys have really been helping me out, and the project is almost complete.....cant wait to hear....thanks so far for everyones help!!>

[hungplu]

RV1890, could you please give me the link of Zaphs web site, also if you can I'd love to see pictures of your project(XOs and speakers)
I'm in a project of putting seas speakers together too. Thanks

[Willitwork]

Originally posted by rv1890
Sticking with the subject...what components should i be looking at if i wanted some higher grade components. any certain brands or places to shop? or does higher grade components even make that much of a difference?

Solen caps are already high quality, they are the most widely used brand in high-end commercial speakers. You can get them from Madisound or directly from Solen. They are more expensive than DIY outlets' home brands but still reasonably priced. There are of course more esoteric "Silver/Gold/Whatever Oil" available from overseas but those are insanely expensive this side of the Pond and imho are only worth the expense in first-order (6dB) crossovers when the signal is fed directly from a single cap to the driver(s). Not the case here.

As for the inductors the most obvious upgrade would be to replace the 2.2 cored unit with an air core inductor, but given the low DCR requirement your choice of air core inductors is pretty narrow. Off-hand I know of two that would meet the criteria: the 10-gauge and 12-gauge Hepta-Litz coils from Solen. The 10-gauge 2.2mH coil has a DCR of 0.24 and the 12-gauge has 0.33 which is still perfectly acceptable. These are very high quality units but they each cost $80USD and $50USD respectively, sustantially more than ferrite-cored units. I'd say it's only worth it if you listen to music at very high volume with powerful electronics, otherwise you won't hear the difference.