Jeff Markwart crossover for 605b

[vincin]

Greetings!

Had just completed the 605b phase correct xover on Jeff's site (the one without the EQ). Im a complete electrical novice, I dont understand how the xover works, but the result has been fantastic!!!

ok, a couple of questions if you could spare a little time to help:

1) for the low frequency section, Im using 4.5mH Solen inductor, instead of 4.6mh as in Jeff schematic. Is this ok? or not?

I couldnt find the exact value, hence picked the nearest.

2)Im using the standard Solen fast caps, and after a few days breaking in they actually sound ok. Should I try to bypass them with small caps, or replace them with those boutique Hovlands, Mundorfs etc...

Thanks & regards,
Vi

[jmarkwart]

Vi,

Glad to hear you like the filter. I believe it sounds even better with the Mid Freq EQ circuit added.

Your Qs:

1)A 4.6mH inductor versus a 4.5mH increases the low pass F3 point slightly but should have little, if any, audible effect.

2)I always preferred the sound of a single cap to one bypassed. A small bypass is cheap though, so why not try it and see what you think?

Jeff

[vincin]

tks Jeff,

Regarding the low pass, is there anything I can, or should do to compensate the reduced low pass ie: increase / decrease the cap C2 value etc..

Also I've just found out today that I have the aluminum voice coils, **** ! if I change the basic xover to the one with MF EQ, is there anyway to still use the 2.5mh inductors? really dont want to order another pair of inductors, the shipping cost to this part of the world is very expensive (would cost more than the parts).

Pls excuse me for the newbie questions.

Tks & regards,
Vi

[jmarkwart]

Vi,

I wouldn?t change the caps to different values. Solen inductors are rated at +/- 1%, but their MPE caps are rated at +/- 5%. Unless you have carefully measured your individual components, you will not know whether you are increasing or decreasing the error, plus, such small changes are unlikely to be detectable on normal program material in a home listening environment anyway.

My advice on your 20275 HF diaphragms would be to call Bill H. at Great Plains Audio and order a pair of new 16 ohm voice coil/diaphragms. That?s what I did when I was working on this crossover about 3.5 years ago, and the top end frequency extension with the new diaphragms on the 605s was very pleasing. You can always sell the old ones on Ebay.

Jeff