Perhaps after rotating the driver 180º, you tilt back the enclosure about 30º (to contain the goop within the surround) and use a hair dryer to assist the migration. It may have off-gassed too much for that to work but it's worth a try. I have seen what happens when solvents get involved in inexperienced hands. Not going to say the drivers were ruined but he never took the grills off again.
hello,
I have two 421-8LF. Which voice of theater is suitable ? I seem to remember it was combined with mantaray horn.
thanks
I have two 421-8LF. Which voice of theater is suitable ? I seem to remember it was combined with mantaray horn.
thanks
don't know myself, but someone will want the specs:
http://www.lansingheritage.org/images/altec/specs/components/421-8lf/page1.jpg
http://www.lansingheritage.org/images/altec/specs/components/421-8lf/page2.jpg
http://www.lansingheritage.org/images/altec/specs/components/421-8lf/page1.jpg
http://www.lansingheritage.org/images/altec/specs/components/421-8lf/page2.jpg
Since these are musical instrument woofers with virtually no power handling [~1.27 mm], not the best choice for HIFI/HT apps, but these were the most common combinations [1233 - 1236]: http://www.lansingheritage.org/images/altec/catalogs/1978-mi/page04.jpg
http://www.lansingheritage.org/images/altec/catalogs/1978-mi/page05.jpg
Don't recall the Mantaray as an option with the 421 series, only seen them paired to the 300 & 800 series woofers, but you can use whatever horn/driver/XO combo you prefer and tweak to 'taste' in room.
GM
I think they were also used in the 1233 and 1234. Their power handling was much greater than their HiFi counterparts. At least the ones I have are.
EDIT: I see GM already posted MI speakers they were in.
EDIT: I see GM already posted MI speakers they were in.
The closest your going to get with the plans is the 828. I haven't seen a 828C plan that the specs call out that GM posted. It may be just be a minor difference.
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I may have spoken out of turn but I saw no difference in the cabinets other than the 1236 was 3/4" material and my 828's are 5/8".
Thanks fellows for theses informations. Have you also seen internal pictures or close up that can help ?
Not a lot to see that you can't decipher from the drawings. Many like to foam fill the cavity between the horn flare and the side wall but aside from that, the only thing I suggest is to narrow the port gap to about 50% of what they show unless you plan to use these outdoors or in a very large room.
thanks fellows for links and tips. I saw mentions of fiberglass in plans but purpose is not clear for me. Any clue ?
I don't remember ever seeing one with fiberglass construction. Inside for sound damping, sure.
It's dangerous for humans, not speakers 😀 sorry, I couldn't resist. You don't have to use fiberglass, there are alternatives. Rockwool, denim, etc.
Can be if there's little/no airspace behind the driver, so loosely covering it with cheese cloth allows packing open weave insulation completely around it, though really dense cotton such as Denim Jeans needs to allow some room for it to 'breathe': Altec Heathkit legato 2-15 inch horn & driver
GM