Heresy I - How do I update them?

[rholling424]

I have 2 pair; 1978 Walnut and 1979 Birch. I'm told new capacitors and something about a motor board might be in order. I have the Type-E wiring schematic but little knowledge of how to use it. Does anyone have a kit? Screw on backs are a dangerous thing in the hands of a tinker!

[muel]

Bob Crites crossover repair kit... if you don't mind soldering. He sends instructions along with the kit. Best $35 I ever spent!

His CS-1 project looks interesting too... lots of information on the forum if you do a search.

[rholling424]

Thanks for the lead!

[Groomlakearea51]

A suggestion, in order of greatest noticeable difference:

• Replace the capacitors (BEC has the caps and it's not that difficult if you can solder anything)
• Make sure the back is sealed. Over time it "leaks". Use 1/4" speaker gasket tape from parts-express. Check the braces themselves and make sure there are no "gaps". That will noticeably improve the bass. You should also seal the joint between the motorboard and the cabinet braces with a good caulk. You can also use woodworkers glue.
• Consider either new diaphragms for the K-77's, or BEC's CT-125's.
• Consider new K-28 woofers (as in the H-III's) or BEC's CW-1228's
• Usually the K-55's (Atlas PD5VH's) are ok. Given the age, new diaphragms will help. You can always replace them, but they are "pricey".
• You can experiment with a different mid range driver (D250-X), but should use an E/4500 crossover with CT-125's to take advantage of the CT's extended frequency response.

Hope that helps.

[H]