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Altec Model 9 Series II Woofer Info Please

I

incredibleh

Member
Hello All,

I recently scored a pair of ALTEC 12" woofers that were removed from a set of Model 9 Series II speakers. They are in very good shape and I'm looking to make my own vented cabinets for them, in a 3-way speaker build. I have been able to find a lot of the info I need to get started, minus a small few. I'm hoping someone can help with the rest.


What I do know

33785 is my woofer (also used in the Santana II, Stonehenge II, and model 15)

Model 9 Series 2 cabinet dimensions:
26 1/2"h x 17 1/2" w x 15 1/2" d = 3.2 cubic ft (3.1 cubic ft in the Santana II)

The model 9 Series II woofer was crossed at 800Hz, but crossed at 2500Hz in the Santana II.

What I don't know

What is the optimal cabinet volume for this woofer (for lowest decent Hz)?

What is the port diameter and length in the original cabinet?

Are the cabinets this woofer was installed in open inside, used baffles, or was divided into separate compartments? If separate compartments, what would the estimated volume of the woofer compartment be?

What is a good crossover point for this woofer? Can I cross as low as 300Hz? 500Hz? Or will it be completely out of nominal range that low?


I know there's a lot of people who've tinkered and done custom builds with this woofer, so I'm hoping someone might have the answers I'm looking for.

Thanks in advance,

Adam
 
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All i know about this is that the Altec 15 is a 2 way so, the internal volume is all for the woofer, if you substract the horn mid/tweeter's volume.
Other's will chime in but this is a great woofer, herd some Altec Nine's and !.
If you can measure the T/S parameters of your own woofers, with a Woofer Tester or such, you could optimise the design's volume and port dimensions.
Good luck with that :rockon:
 
Thanks for your reply. I think I'll be approximating the volume like you said. Info on these woofers is kind of scare, in terms of parameters anyways. There's enough info about Altec's speakers using it to get started for sure.

Cheers
 
Since you don't know the T/S specs its best to go with a known good cab volume like mentioned above. At least you know that will sound decent.

I'm not positive about how Altec had the cabinet constructed for those speakers you mention, but if they're anything like their other speakers its probably just a simple well braced box. The model 9's didn't have a horn so no separate horn cab or anything

If you can't find anyone to measure the port for you, you might have to guesstimate from pictures and get it in the ballpark. Looking at pics it looks like about a 3"x4" or 3"x3" port

Concerning crossover frequency you can go as low as you want, depending on what you will be pairing it up with. Most people prefer crossing the Altec 15" under 1200hz but the 12" is alot more flexable. I have some 12" Altec 414b woofers that I run full range and then add a horn in around 5khz.
Are you doing horns with these woofers or staying with cone drivers like Altec did with the model 9?

Good luck with your project!

Edit: Maybe someone like GPA (great plains audio) can give you help with the specs. If they carry recone kits for your woofer that is.
 
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Thanks for your comments. I will not be using horns, I have a set of mids that I love (NOS API mids from Mirage 750's) and a choice between vifa or seas tweeters, they have the same footprint so I can experiment with which one I like most.

I was thinking of crossing the woofers over at either 300Hz or 500Hz, hopefully that's not too low for such a sweet old girl....

Thanks again,

Adam
 
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I have altec Lansing nine series 2...
My ports measure 2 3/8" (inside) diameter by 3" long.
I've only refoamed the mids, have never opened them up...
 
I sold stereo's back in the late 70's. We sold much of the typical lines. We would have sold alot more Altecs if they could have kept us supplied. A major problem with Altec. All I can tell you is the 9's didn't cost much more a pair than the HPM 100's, but they mopped the floor with them. That was almost unanimous with every one that walked in the door. But hell we couldn't get but maybe 10 or 12 pair a year, compared to a unlimited supply of HPM 100's.
 
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