Heathkit AS-48 (JBL L-99 Lancers?)

[shnaggle]

Found a pair of these Heathkits, which I think are an off-branded JBL L-99 Lancers.

Drivers are still working, thank goodness. But rear terminals are numbered "1" and "2" -- 1 is positive?

 

[tarior]

AS-48 is for all practical points and purposes JBL L-99 Lancer. Just hook the right and left up the same way, and you'll be good to go.

 

[shnaggle]

Thanks. The surrounds are intact, but hard, not flexible. Is that normal, or need a refoam?

 

[tarior]

Refoam them.

 

[shnaggle]

I gotta figure out how to refoam these. The original surrounds aren't really foam, more like a surround that's glued flat to the outer-most ring of the cone, so removing the old surround looks a bit tricky. The bass still sounds pretty darn good. More detailed/punchy/defined than my L100 Century's.

Would these 50+ speakers need a recap? Don't know if they're oil-filled, and could be left alone.

 

[tarior]

JBL called that surround material Lansalloy, and it was supposed to last forever. It does last a long time, but it hardens over time. It's tricky and tedious to peel it off. You will be amazed at how much better they sound with proper new surrounds. I always cut the cap and shim the VC, but I also have new dustcaps and proper black lacquer based adhesive. Speaker Exchange (no affiliation) sells the Moyen 3087 adhesive in small tubes and a refoam kit with new dustcaps. The dust caps they have are a bit big, a purist might complain if they notice.
If the caps are electrolytic, then yes, replace them. If mylar or oil, leave them be.

 

[shnaggle]

JBL called that surround material Lansalloy, and it was supposed to last forever. It does last a long time, but it hardens over time. It's tricky and tedious to peel it off. You will be amazed at how much better they sound with proper new surrounds. I always cut the cap and shim the VC, but I also have new dustcaps and proper black lacquer based adhesive. Speaker Exchange (no affiliation) sells the Moyen 3087 adhesive in small tubes and a refoam kit with new dustcaps. The dust caps they have are a bit big, a purist might complain if they notice.
If the caps are electrolytic, then yes, replace them. If mylar or oil, leave them be.

Cutting the dustcap and shimming the coil -- for me, that's crossing the Rubicom.

 

[tarior]

Cutting the dustcap and shimming the coil -- for me, that's crossing the Rubicom.

It's easy. It also allows you to get the crumbled foam from the pole vent "filter" out of there.