Crossover help please

Hi folks, I have completed assembly on my 4355 clones and have all drivers mounted in the boxes and now at the final hurdle of crossover.

I have decided to go with the below schematic, I would like to get ordering parts but I am a bit confused on exact component values, for example, what dcr should the inductors be? what voltage rating for the caps and what wattage the resistors?
Can anyone advise on a good one stop shop for all components?

Please forgive my ignorance (novice on this kind of thing)

Any help greatly appreciated!!

Regards

Attachment 81628

Hello

Well a couple of things these are going to be used at home and you know how you will be powering them. Choose the resistors accordingly. I would think 10 watts would be fine but could also run 20's if you wish. As far as DCR just get inductors with as low DCR as your budget will allow. Low DCR value inductors can get very expensive especially air cores, copper is not cheap and the lower the DCR value the heavier the gage. If you go cored look at the ERSE inductors. The only place it will be an issue is with the 2.4 and .86 mH the others you should check the values but should be low because of the Inductance values. Caps Voltages I wouldn't worry to much as film caps have high ratings many Solens are 250/400 volts which is higher than you would need as an example. If you find standard values above those voltage ratings at reasonable prices go for it but don't pay a premium for higher voltage ratings you are not after all capping a tube amp.

Rob:)

thanks a mil for the advise Rob, itching to get them going now.... quite a costly effort getting the drivers together!!

Good advice from Rob!

I recently built a pair of Nelson Pass L300 crossovers. I used 14ga Erse XQ air core inductors. They were not cheap. 16ga Erse EQ inductors are about half the price of the 14ga XQs. Those 14ga air core inductors are also big and heavy and require some significant mechanical restraints:

https://s6.postimg.cc/kl8r0wkg1/JBL_...rossover_2.jpg

Keep in mind that resistors can be doubled up in parallel to get twice the power rating. For example, in the Nelson Pass crossovers, I doubled up a pair of 16 ohm 12W resistors to get an 8 ohm 24W and a pair of 20 ohm 12W to get a 10 ohm 24W.

MCM Fan -

Your crossover build pictured above is very attractive and neat looking. You did a beautiful job. I really like the "frame" you built around the upright inductor. Very nice work!

GeeDeeEmm

Quote:

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Originally Posted by gdmoore28

MCM Fan -

Your crossover build pictured above is very attractive and neat looking. You did a beautiful job. I really like the "frame" you built around the upright inductor. Very nice work!

GeeDeeEmm

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Thanks! I always like to place inductors with their magnetic fields orthogonal to each other to minimize any coupling and resulting mutual inductance.

In this case, the 14 ga inductors were quite heavy and the completed crossovers had to be shipped over 2000 miles to their eventual owner. I wanted to make sure they were properly mechanically restrained. In addition to wood glue, the vertical uprights are attached through the bottom of the main board using a pair of 2.5" wood screws. The inductors are held in place using both hot glue and zip ties.

The idea wasn't original. I've seen others, such as Toels Gravesen, do something similar.