Magnepan crossover question

[Grainger49]

Adam,

IMHO an electrolytic has no place in a crossover.  It is not intended for AC, which is what an audio signal is.  But....

If it were me I would go all film caps, Dayton or Solen and bypass with well broken in KK Teflons.  Say a 0.1uF or 0.22uF for the bypass caps.

[adamct]

Grainger,

This all came about because I wanted to upgrade the stock caps to film caps. I was going to replace the inductor, too. But when I opened up the MG12s, I found the previous owner had already done that. The stock iron core inductor was upgraded to a Jantzen copper-tape inductor, the 50uf electrolytic was replaced with 20uf and 30uf Solen film caps wired in parallel, and the stock 33uf Solen film cap was bypassed/paralleled with a 10uf Crescendo film-and-foil cap. So I'm considering taking that 10uf cap out, since that is presumably changing the crossover frequency, and I trust that Magnepan picked the right values.

Paul,

To be honest with you, I don't think I remember who I bought them from!

[earwaxxer]

Ok, so Adam, this is your assingment, if you choose to accept it.... To learn what magnepan had in mind with your crossover and do them one better!

One thing I love about Magnepan. You can call them up and talk to someone on the phone. They are very old fashioned kind of mid western folk. I love that. They sent me some of their bare wire speaker terminals because I love them! Its like a nut with a hole drilled through it, tapped for a screw to tighten down the wire on both ends. I like bare wire. What goes along with that is their folksy kind of laziness when it comes to electronic hardware. You will NEVER find a V-Cap in a Maggie! They leave that up to you....

[Paul Joppa]

Non-polar electrolytics are in fact designed for AC. Not very successfully, of course. They are said to sound slightly better than polarized electrolytics even when both are polarized with DC.  It's not an experiment I have ever bothered with...  :^)

[Grainger49]

You are right, but....   they still don't sound good in a signal path circuit.  I was forgetting non-polarized electrolytics.  I don't deal with them often enough for them to remain in my brain.

[Paul Joppa]

Nonpolars have two main applications as far as I know: cheap crossovers, and cheap motor-start capacitors.

[earwaxxer]

One more point for this thread, and maybe we can lay it to rest.... Maggie crossovers are the easiest to mess with because you dont have to yank a driver to do it. What I have learned, though, is that I cant imagine ANY speaker, outside of a Wilson or Magico etc that I would feel comfortable leaving said crossover to its own. This is by far IMO the biggest bang for the buck mod you can do. They all hide cheap crap in there. They have to. Its simple economics. Thats one of the reasons I probably cant buy a box speaker ever again, because I would be forced to tear it apart not long after it was broken in.

[adamct]

Well, here is another update: I installed new stands on my MG12s tonight. I took another look at the crossover before I did. I think I misread the bypass cap on the 33uf treble cap. The label reads like this:

0.            10uf

When I peeked under the "skirt" on the MG12s, I only saw the "10uf". I didn't see the large "0." all the way over on the side.

So the 33uf cap was bypassed with a 0.10uf cap, which makes much more sense!

[earwaxxer]

makes sense... What was the brand? .. or forget it.. I 'm supposed to let it go!

[adamct]

It's a Northcreek Crescendo film and foil cap. See here.

[earwaxxer]

Update on the Mundorf EVO almum/oil 10uf in my MMG's... got probably about 50hrs on them now. They are definately "opening up". What I also noted is that they benefit from the Mundorf silver/oil "bypass". Early on there was no noticable difference. Nice "well behaved" top end and mids. Non-irritating. Natural and musical. A CLEAR upgrade from the AmpOhm paper/oil IMO. What was interesting was that the caps started out a bit "restricted" and rolled off. Not the usual nasty bright and crappy.

[earwaxxer]

Sorry, forgot to add - HOW are the EVO's better from the AmpOhm paper/oils - IMO of course. I would say that it has to do with resolution and PRAT. Tighter. More natural. I think I payed more for the AmpOhms.  Dont remember. The AmpOhms seemed to "smooth" things out compared to say Obligatto gold, or Jantzen Superior Z. The EVO's did all that with some nice added tightness and natural timber.