The Vintage Altec Codex

[Sancho22]

Looks superb! Amazing job! Enjoy and keep us posted

[junker]

Thank you sir! For low power levels the 1st order - 1st order series crossover is definitely a cool way to go. The tricky part was using an auto former instead of a 16 ohm L-Pad but I did something to properly integrate the auto former. It's breaking in nicely. Similar to Vandersteens in that toe-in to point directly to the listener results in crazy good imaging. I'm at 6 on the auto former and its sounds very balanced. My buddy is getting the mod tomorrow to put on the other pair of boards so I will have more feedback soon. Thanks!

[Sancho22]

Could you guys tell me how best to remove the old insulation?
I have the denim based new insulation, but did not have a chance yet to replace the old.
Did you guys replace it for better isolation or heath reasons or both?

[junker]

There are just a couple big staples per insulation panel, and you can use pliers to pull those out. I'd just take them out to the trash and then vacuum out the inside of the speaker being careful not to breath anything yo might kick up.

I replaced mine for a couple reasons including it's not fun to work around, and I wanted a bottom surface that I could set a crossover on. Better isolation is tricky... more is not better. It's better to start on the light side and go up from there as it's very possible to over damp and suck the life out of it. My 604s are using less than this right now but will adjust upward as required. Best to follow Altec and cover one of each parallel wall: rear, side, and bottom. Another trick to put a patch above the horn body on the ceiling to stop those reflections and clean up what leaks out of the ports to the sides of the horn.

Go to Home Despot and buy a staple gun and staples deep enough to go through your insulation and maybe ~5mm into the wood.

[Sancho22]

Awesome thanks! Do you know by any chance what size staples did you use?
I have teh same speakers and isolation so likely will be OK to use teh same stuff you already tested. Many tahnks again for all you extremely helpful posts!

[junker]

Sorry I used German natural wool felt in 10mm (Filzfelt) and think I used 14mm so I don't think that will help you much.

[junker]

Just finished painting trim on the 604s.

[Sancho22]

Actually it did help. I have this thick 1.8" denim which means I would need just a few mm longer staples...
What did you use for satining the 604 - looks reallu beautiful!

[junker]

Tried and True boiled linseed oil.

[Sancho22]

Should have known!