Different versions of 802?

Hello all,

I am in the possession of apparently two types of 802s. One pair stemming from the 60s and one recently acquired pair from the 70s.

They both are branded as 802s, yet there are however striking differences between the two. The 70s version is 1/4 inch smaller and no less than 0.5 kg lighter (2.5 vs 3 kg for the earleir version). Furthermore the newer ones have a smooth surface and no taper.

At first I was under the impression that the 70s versions actually are 806 or something, but those seem to be even smaller.

So what is the deal on the 802?

If there is any forum that could shed light on this matter it would be this one!

Regards, Coen

Sorry for the metric notation.

Posting pictures will go a long way in helping you determine what you have.As you are a new member you may have to wait a couple days.But anyway "Welcome to the Board"

Old style(60's) on the left, new style(70's) on the right.

http://www.hostboard.com/forums/

Thanks for the welcome!

Bowtie's pictures illustrate the external differences perfectly. I have different rear caps on the rough units though. Also I ( mistakenly?) reversed the dating. I took a fait little stamp on the side of the polepiece for a date code. That suggested 60 something for the rough ones (right in the pic above) and 70 something for the other ones.

I am still curious about the weight difference. Is is due to a smaller magnet, less casing material or both?

The lighter, smaller and smooth units do seem to have a little less output, yet sound fine nevertheless.

The later 802s used a cast pot structure rather than one welded from pipe and plate stock. Dare I suggest that this was likely a cost saving measure, as with the Tangerine phasing plug? I do know that the cast pot assemblies on JBL cone speakers were begun in 1953 as a cost saving measure.

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Originally Posted by Coendert2011

The lighter, smaller and smooth units do seem to have a little less output, yet sound fine nevertheless.

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They are both rated at 15,250 Gauss and both should weigh the same at ~7 lbs, but the later 802G design has its BW shifted up a little higher to make it better overall with the M19's ~1200 Hz XO as well as do a better job of reproducing the increased HF BW output around that time. The trade-off is that the 'G' isn't as strong down low when XO'd at 500 Hz which with today's very low output impedance systems is actually a good thing overall.

GM

According to my converter 7lbs is 3,175 gram.

The slightly smaller smooth units weigh about 2,550 gram or 5,62 lbs.

They are not the 'tangerine' g version, but have ordinary circular slots. I xo around 750 hz with a second order LR.

I will try to make some illustrative photos and post them here (if possible).

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The slightly smaller smooth units weigh about 2,550 gram or 5,62 lbs.

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The lighter, smaller and smooth units do seem to have a little less output, yet sound fine nevertheless.

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Those are 804/806/807 motors NOT 802/808 motors.

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Originally Posted by bowtie427ss

Those are 804/806/807 motors NOT 802/808 motors.

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In a 802 casing?

As I understand the 804 etc casing is even smaller....

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In a 802 casing?

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That's the rub, at 5.62 lbs it ain't an 802/808 of any kind.

If there's as much as a 1/4 inch of length difference(i suspect if measured the difference is actually ~3/8 inch), one is NOT an 802/808 motor.

An 806 weighs 5 lbs 11 ozs

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As I understand the 804 etc casing is even smaller....

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Not externally, it's alnico slug is a bit smaller.

Steve Schell has posted a pic of the 3 various slugs used along with some good info on the variances recently enough that it should show up in a search here. Searching his recent posts would probably be the quickest way to find it.

EDIT: Correction, it seems that it was member Earl K who recently posted the pics. I remember Steve posting about this long prior to Earl's post. I have a great deal of faith in Steve's input here, FWIW.

http://www.hostboard.com/forums/f700...ml#post1807303

;)

Thanks for thinking along.

Imho the mystery is not solved yet. The discussion in the posted thread is about the difference between the 804a and 806a. Obviously these have the same height (length), yet different mass. I would expect these magnets to be 1/2inch less long than the 802 otherwise they won't fit in their smaller housing. The guy who sold me the units sent me pics of 802 (old style in green, same length as my unit) and 806 and there is an obvious difference in length, hence magnet length.

The only thing I can think of is that the magnet of my units has the same length as a 802 but has the inner/outer diameters of the 804. Purpously or by accident. Tonight i will make a new weight measurement to be shure of the 2.5 kg. If my theory is correct it should actually be a little more than the 806 weight ( providing published data is correct).

I have unfortunately no gaussmeter to check the gap.

Thinking of my post. The units may well be -undocumented- large versions of 806. Magnet mass is probably similar to that of the short version....

Just to make sure we're all on the same 'page', spec wise: http://www.lansingheritage.org/image...804a/page2.jpg

GM

Are there any kind of numbers on the back cover caps ? When Altec didn't use any kind of sticker/label they just stamped the model #'s on the back cap. Ex. 033952 = 802-8G, 23746 = 806-8A etc....

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Originally Posted by GM

Just to make sure we're all on the same 'page', spec wise: lansingheritage/images/altec/specs/components/802d-804a/page2

GM

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I think so. In the link of bowties last post the difference between the 804 and 806 is discussed. The conclusion was that the 804 has a smaller magnet ( smaller outer diameter) and a different phasingplug with tighter slots. The photo clearly shows that the 804 and 806 magnets have equal lenght and will fit into the same case.

I would think that one is not able to visually discriminate between both drivers with rear caps on and badges removed. One would expect the 806 to be heavier than the 804. The 802 magnet and hence casing is clearly bigger.

Data on the 806 is scarce.

Dit anyone put his 80x on the weight scale?

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Originally Posted by Altec Best

Are there any kind of numbers on the back cover caps ? When Altec didn't use any kind of sticker/label they just stamped the model #'s on the back cap. Ex. 033952 = 802-8G, 23746 = 806-8A etc....

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Nothing on the rear covers. The polepiece has a code on its side though: 391217...

I did some measuring and made some photographs I can't post yet.

Rough unit 1, 802-8D badged, without rear cover, loading cap, diaphragm and screws: 3,432 gram = 7.57 lb
Rough unit 2, no badge, same conditions: 3,313 gram = 7.30 lb

Interesting!

Extra stuff weighs 175 gram = 0.386 lb add to both to compare with below.

Length from polepiece to front for both units: 68mm = 2.68 inch

Smooth unit with all stuff attatched (to lazy to take it off): 2.866 gram = 6.32 lb

Length from polepiece to front: 64mm = 2.52 inch

So that's 4 mm of difference in length = 0.16 inch, and a weight difference of at least 3.488 (incl stuff) minus 2.866 = 622 gram or 1.37 lb (22.2 oz).

On the net the regular green 806 look quite different (my units are black).