Altec 416-8b woofers

[Mercury3]

Hey everyone,

I started to post about these woofers in my other posting for a MLTL design but decided a separate thread devoted to these woofers might be better.

I've four of these woofers and recently tested them with DATS and was quite disappointed. All four woofers tested off from what the specs are suppose to be. Two were pretty bad with the other two not as bad:

fs: qts:
40hz .56
39hz .54
30hz .3
27hz .26

I've a 416-C to test against so I know the DATS is giving me pretty close readings.

Its my thought the magnets need recharged which would explain the high qts but not the high fs.

I spoke with Bill at GPA and I've sent all four in to be reconed and have the magnets recharged. For the benefit of others I'll post the results when I receive them back.

In hind site had I known the Alnico Magnets can become weakend if over driven (what I suspect has happened to these) I might have selected the "C" model over the "B"

At any rate even if I don't end up using these 416-b's I couldn't bring myself to sell them without having them fixed first.

Does anyone have any thoughts on how much power one can safely run on these without fear of weakening the magnetic field strength? More the reason I see for running two per channel vs one. I'll be running mine with a PassLabs XA30.8 which can hit about 150 watts pk. so be about 75 per woofer pk. I do realize amps can do a lot more when driven to clipping but I don't abuse my equipment. I do however like to crank it up a bit every now and then.

Any thoughts appreciated and I'll post the results when I get these back from GPA. That way any others considering the same have access to this info. I suspect there are a whole lot of 416-b's out there with weakened magnetic fields.

Mark

[Elitopus1]

I?m curious to know the answer to this also. I drive my AlNiCo drivers with high power SS amps and don?t want to push them too hard either.

I?m curious which would happen first, mag loss or VC damage. Assuming a normal Altec/GPA VC is being used.

[LOUDER]

If it was I, and it's not I would've sent Uncle Willy just the two way out of spec 416's so we all could have seen what the difference of a remagging does since you have the test equipment. Remember the value goes down once you don't have the original cones. Plus it will save you some money. If the remagging works get the other two remaged since he'll have all four anyway's.

[bowtie427ss]

I do realize amps can do a lot more when driven to clipping but I don't abuse my equipment.

I just have to know, are you implying/insinuating that driving an amplifier to clipping is abuse?

[Mercury3]

I just have to know, are you implying/insinuating that driving an amplifier to clipping is abuse?

Would "abuse" be the wrong term? I'm a bit slow are you being sarcastic?

Anyway in home audio I would think so.

- - - Updated - - -

If it was I, and it's not I would've sent Uncle Willy just the two way out of spec 416's so we all could have seen what the difference of a remagging does since you have the test equipment. Remember the value goes down once you don't have the original cones. Plus it will save you some money. If the remagging works get the other two remaged since he'll have all four anyway's.

Good idea but I figured I prefer if they all match. I think we should be able to tell when I measure them all once I get them back. I'm a little concerned to find out.

[Elitopus1]

I’m curious how close the woofers test after GPA is done with them.

Re amp clipping: I always drove my pro amps into light clipping doing small shows for the band that I was in. And even at home when I had less efficient speakers. No amp or speaker damage ever occurred. If you drove the amps into heavy clipping I would think the speakers would be damaged first, as your nice sine wave turned into a squarish wave.
The amp should be able to handle a square wave. Hell, I’ve heard you can weld with an Ashly amp.

Lol, just thinking about it. I used to turn my amps up into clipping and then turn them down slightly.