I now have a pair of 604-?? in M600 Maestro units, questions at bottom.

My observations:
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- Rear Label:
ALTEC LANSING THE MAESTRO SERIES
Loudspeaker System M600 8 Ohms
ALTEC LANSING CORP., OLKA. CITY, OK MADE IN U.S.A.

- No rear HF cover. I am not sure what to call the plastic housing otherwise, but it holds the diaphragm to the mag with 3 screws.

- HF Diaphragm marked with:
26420 (so we assume it's a 26420 pascolite)
32980
91 31

- Xover: MODEL N604-8A (stamped: 8167 ?)
- on woofer cones: 035400
- on woofer frame: Instead of the expected green (e.g.) "AL 70" in-a-square QA symbol, I see what appears to be: (green) "PI 15" in a circle.

- From a copy of an M600 spec sheet, it spec's :
R604-8L recone kit
16" coaxial loudspeaker 50-03-026768
N604-8A
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...direct or tangentially related quotes from Altec forum posts RE 604-8L:
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01)
"The M-600 uses the 604-8L. It is a K with a higher LF power voice coil and uses the Pascolite Alluminum H.F. Diaphragm. That ought to be confusing enough fo now, Jim."

02)
"Incidentally, these improvements and T/S's are exclusive to the ICONIC Model 704-8A - the 604-8L off by ALPro is NOT the same speaker, nor does it share these characteristics (and it's more expensive)."

03)
Altec 604-8L
HF horn: 60h40v "Manta Ray"
X-over:
Power:
Impedance: 8 ohms
Weight:
Magnet: Ferrite Ceramic
Response:
Frame: cast frame dark grey paint
Cone: paper cone with an "accordian edge" cloth surround
comment: a K with a higher LF power voice coil
uses Pascolite Alluminum H.F. Diaphragm

04) from: http://www.altecpro.com/pdfs/vintage...%20Summary.pdf
"604-8K" (K)
N1500-8A (L)
LF = 12 dB/oct
HF = 18 dB/oct

604-8L = Same as K with new crossover network, hand-built for Altec Lansing Professional by Great Plains Audio, USA

05) "ALPro is (or already has) dropped the 604-8L from their product line. They have always been made by GPA in OKC, but they are different than the 604-8H-II he makes now."

06) The "L" was nothing but a late "K" with all of it's flaws and is no longer being made.
ALPro has dropped everything from it's line that is not made in China, including the 604.
The 604-8H-II is a redesign of the 604, taking it back to what it was, yet making it better in several ways.
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My questions are:

a) do I have a 604-8k, or a 604-8L ?

b) What are the flaws mentioned in (06) ?


thanks for any input!



*Small pics should be posted in a moment...