altec 515b cone question

[horn]

hello i am new here
i have a question that maybe someone can answer me here

i have altec a5 speakers with in the bass cabinet 515 8g someone put these in
and i will change that to the original 515 b i don't now if this is an upgrade but its original that way
now i have 3 515b units but no matching cones
i have one 21184 one 211843 and one 21184-2
is this a problem are these different cones or is it just a manufacturing lot number ?
and do they sound the same?

[Earl K]

<<<<<SNIP>>>>>

now i have 3 515b units but no matching cones
i have one 21184 one 211843 and one 21184-2
is this a problem are these different cones or is it just a manufacturing lot number ?
and do they sound the same?

I wouldn't be worry much about those ( different ) cone numbers ( the good news is, they are all bona-fide Altec numbers ) .

I'd be more concerned ( given the age of the woofers ) that their magnets may be out of spec and needing a recharge ( you'll need to search out that service on your own dime ).

The thing to do is is buy a device to measure the TS parameters ( of each woofer ), to then determine if each is up to specification ( or not ).

Ah the joy ( not ) of buying old used ( Alnico ) woofers .

[horn]

I wouldn't be worry much about those ( different ) cone numbers ( the good news is, they are all bona-fide Altec numbers ) .

I'd be more concerned ( given the age of the woofers ) that their magnets may be out of spec and needing a recharge ( you'll need to search out that service on your own dime ).

The thing to do is is buy a device to measure the TS parameters ( of each woofer ), to then determine if each is up to specification ( or not ).

Ah the joy ( not ) of buying old used ( Alnico ) woofers .

thanks do you think alnico magnets always loose strength with age?

[speakerdave]

hello i am new here
i have a question that maybe someone can answer me here

i have altec a5 speakers with in the bass cabinet 515 8g someone put these in
and i will change that to the original 515 b i don't now if this is an upgrade but its original that way
now i have 3 515b units but no matching cones
i have one 21184 one 211843 and one 21184-2
is this a problem are these different cones or is it just a manufacturing lot number ?
and do they sound the same?

21184 is a cone model number and is the correct cone. I've seen suffixes 2 through 4 and do not know what they mean, but I assume they do not exist for no reason. More Altec expertise can be found at the Altec User web site. Someone there may know the reason for them.

As for demagnetization of Alnico speaker magnets, simple age is not a concern but abuse resulting in physical shock, excessive heat or over powering can be. Visual inspection can tell you if some of these are probable and history, if you know it, can help also. We've been told by a JBL engineer that demagnetization because of excessive drive current is not a concern in woofers which like the 515b have underhung voice coils. Earl is a pro with high standards and very experienced, and since pros must deploy speakers in condition to perform as expected, no questions, remagging, if you have a local remagger, may be routine for that use. I on the other hand am an amateur and was corrupted long ago, and if I were to come across a clean looking Altec 515b, I'd just go ahead and use it.