picked these up last week. they don't sound too bad. but I'm wondering if doping the surrounds would be a good thing or a bad thing.
they look really dry. like there is just enough to seal them. from what I see in some of the guitar forums there seems to be a debate about "dope or not to dope that is the question".
the speaker type, they pretty much agree the other stuff.
so would it help?
ALTEC LANSING 3127 12" LOW FREQUENCY DRIVER - 8 OHM | eBay
Sonic Barbarian
Looks like it needs softening at the very least and if you can see daylight through it afterwards, then add some of the dope used on 416s, etc..
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
what do you mean by softening?
I have some of the acoustic research version.
I used it on the pair 419As I have. there was no doping on the inner ridge. sure made a difference on them.
Last edited by Phil-G; November 11th, 2016 at 11:33 PM.
Sonic Barbarian
Over time/exposure, surround doping and spider binder chemicals can dry out, raising Fs/lowering Vas, sometimes enough to completely screw-up the driver's frequency response and cab alignment.
??? Please elaborate re the 419s, though for sure all Altec driver's surrounds must be sealed/doped AFAIK, though I've known pro reconers that either put too little doping or none unless specified, paid extra for.
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
419A biflex. almost exactly like these. they didn't have anything on the second ring. they sounded flat.
now they sound closer to 420s I have. they have cymbals now. still needs a small tweeter to make up the difference. but what the hay, they sound nice.
FULL Range Altec Lansing | Am Thanh Xưa – Hoai Niệm Cũ
Sonic Barbarian
Right, bi-flexes are a mids cone inserted loosely to a larger woofer, so came doped, but the 3127 is a mid-bass woofer, so just the surround should be pliable/doped. That said, it's my understanding that some models had dust caps [DC] 'glued' on with a lossy dope to tune/roll off its beaming HF response like is sometimes done with 'FR' drivers, though no clue which models or if any for sure as I can't recall any discussion on the subject or done any re-coning of Altecs myself.
All that said, there's often some sonic benefits to selective doping using various types of materials on the diaphragm, DC, which I've done a bunch with cheap drivers, but without a frequency response to guide one, it's a tedious affair using a mechanic's stethoscope.
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
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