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"
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.
Old style(60's) on the left, new style(70's) on the right.
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.
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.Originally Posted by Coendert2011
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
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).
The slightly smaller smooth units weigh about 2,550 gram or 5,62 lbs.Those are 804/806/807 motors NOT 802/808 motors.The lighter, smaller and smooth units do seem to have a little less output, yet sound fine nevertheless.
In a 802 casing?
As I understand the 804 etc casing is even smaller....
That's the rub, at 5.62 lbs it ain't an 802/808 of any kind.In a 802 casing?
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
Not externally, it's alnico slug is a bit smaller.As I understand the 804 etc casing is even 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
Last edited by bowtie427ss; November 9th, 2011 at 10:06 AM.
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