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thymanst
02-05-2010, 11:12 AM
In a moment of stupidity I order a 806 driver off that auction site that was 16 ohm http://www.audiokarma.org/forums/images/smilies/no.gif when I needed a 8 ohm 806. what threw me off was the 8.1 ohm reading the guy was showing in his picture of the driver (the driver says 16 ohm on label) whats really weird is I took out the 806 I have here and it reads 11.2 ohms (8 ohm on label) I guess I need a little guidance..........

SMKSoundPro
02-05-2010, 11:26 AM
Hi. I am sorry you consider this a moment of stupidity. It will turn out differently, I assure you.

There are are two 806's. An 8 ohm version and a 16ohm'er.

When measuring across the voice coil with a resistance meter, your are measuring the static resistance (measured in Ohms) of the coil in DC, or direct current. This will show that there is continuity across the simple coil of wire on the coil former, just like an Edison incandescent light bulb.

The 8 or 16 ohms rating of the speaker driver is an AC measurement of impedence.

The two measuremtns are two completely differant animals that do not live in the same jungle.

If you made a mistake and bought a 16 ohm driver instead of an 8 ohm'er, then put it back up for sale and keep searching for the desired impedence model you seek. Or try GPA (Great Plains Audio) with help and guidance for your quest. Maybe someone here has what you seek.

Pictures of your speakers and projects are always a help to all of us.

See, now don't you feel better about yourself? I thought so.

Keep the faith! You're doing just fine!

Scotty.

Ruediger
02-05-2010, 11:31 AM
In a moment of stupidity I order a 806 driver off that auction site that was 16 ohm http://www.audiokarma.org/forums/images/smilies/no.gif when I needed a 8 ohm 806. what threw me off was the 8.1 ohm reading the guy was showing in his picture of the driver (the driver says 16 ohm on label) whats really weird is I took out the 806 I have here and it reads 11.2 ohms (8 ohm on label) I guess I need a little guidance..........

The 806 which reads 11.2 ohms, has that been reconed with a kit which is different from the original one?

Ruediger

thymanst
02-05-2010, 11:39 AM
The 806 which reads 11.2 ohms, has that been reconed with a kit which is different from the original one?

Ruediger

I dont know if it was redone or not - I remember that JBL had some drivers that said 16 ohm but they were all 8ohm - I was hoping this was the same kind of deal - I saw some heathkit 806a drivers on auction right now that read around 14 ohms for each (8 ohm on label) - anywayI'm just trying to get a handle on the varible ohm readings

I've already got them cleaned up from these pictures and was just waiting for the 806a driver & horn to get them back to spec.

SMKSoundPro
02-05-2010, 01:09 PM
They're model 846B Altec Valencia's!

I have a lone orphan 811 horn here and quite a few different Altec 1" drivers doing nothing but holding my shop down to the ground, in case the earth's gravity thingy fails!

pm me if you are interested! These are extra parts I don't need.

Oh, I also have a original N800 crossover for these, too!

Pm me if you are interested!

Scotty.

thymanst
02-06-2010, 05:11 AM
They're model 846B Altec Valencia's!

I have a lone orphan 811 horn here and quite a few different Altec 1" drivers doing nothing but holding my shop down to the ground, in case the earth's gravity thingy fails!

pm me if you are interested! These are extra parts I don't need.

Oh, I also have a original N800 crossover for these, too!

Pm me if you are interested!

Scotty.
Thanks for the offer - I've got the two horns now, but just weird readings from my meter - I'm thinking who ever had these befor me tried to fix the one, but with a 16 ohm diaphragm, the one I just bought must be way out of spec at 8.0 - a simple question...what makes a 806a 16 ohm - is it the diaphram or is there something different with the magnet? could I make the 16 ohm 8 by putting a 8 ohm diaphragm in? - thanks,scott

I took the driver apart (the supposed 8 ohm one) and the codes on the diaphragm are PI1, 41600, 24701 & 9798346 -can any light be shed on this Diaphragm? - I'm going to take the other apart now...the other one has(the 16 ohm) has AL45 and 391035 on it - there is a difference in the 16 and 8 ohm housings, the 8ohm housing around the diaphragm has a greater circumference (but the housing with the magnets look to be the same size - the screw holes all look like they match also)

Earl K
02-06-2010, 06:56 AM
In a moment of stupidity I order a 806 driver off that auction site that was 16 ohm http://www.audiokarma.org/forums/images/smilies/no.gif when I needed a 8 ohm 806. what threw me off was the 8.1 ohm reading the guy was showing in his picture of the driver (the driver says 16 ohm on label) whats really weird is I took out the 806 I have here and it reads 11.2 ohms (8 ohm on label) I guess I need a little guidance ,,,,,,,,,

Thanks for the offer - I've got the two horns now, but just weird readings from my meter - I'm thinking who ever had these befor me tried to fix the one, but with a 16 ohm diaphragm, the one I just bought must be way out of spec at 8.0 - a simple question...what makes a 806a 16 ohm - is it the diaphram or is there something different with the magnet? could I make the 16 ohm 8 by putting a 8 ohm diaphragm in? - thanks,scott

Hi Scott,

- Regardless of the circumstances leading to you having diaphragms with different DCRs / don't lose sight of the fact that you should use drivers that are matched ( in at least their DCRs ) .
- That means ( from my POV ) , buying 2 new diaphragms from GPA .
- ( And ) since diaphragms are 1/2 the cost of GPAs drivers / you might as well bite the bullet and buy a pair of new ( 8 ohm ) 902-8a(s) . @ $ 400.00


I dont know if it was redone or not - I remember that JBL had some drivers that said 16 ohm but they were all 8ohm - I was hoping this was the same kind of deal - I saw some heathkit 806a drivers on auction right now that read around 14 ohms for each (8 ohm on label) - anywayI'm just trying to get a handle on the varible ohm reading.

- FWIW ( to your present dilemma ) , I've ( for some time ) considered Altecs "16 ohm" drivers ( up to the end of the 802C generation, ) to actually be more of a 12 ohm variety .
- This means older diaphragms from that era should actually measure out in the area of 8 ohms.

- The introduction of the 802-8D ( saw the introduction of a properly DCRed diaphragm, @ 6 ohms ) in the 1960s .
- Concurrently ( to the 802-8D ) the diaphragm in the 16 ohm 802D had it's DCR raised ( to around 12 ohms ) .


- This is a very long winded way of saying ; you either have an aftermarket diaphragm in one of your drivers / or ( if the drivers are stock ) they come from different generations ( 1 old "B or C" type & 1 newer type "D" / these representing the 2 time periods {"before & after"} when Altec rejigged the official impedance ratings for their drivers ) .

>< cheers

thymanst
02-06-2010, 07:09 AM
thank you Earl - your info (knowledge) was exactly what I was looking for...I'll contact GPA and get the new drivers (I'll sell the old on ___) I assume the new drivers require some sort of x-over change. I'll search the forums to find what I can. thanks again,Scott T.

Earl K
02-06-2010, 07:34 AM
Hi Scott,

You're welcome .

Here are some pics that support my contention . These are from a current eBay auction # 180466090769 ( for a pair of sweet looking, Altec 802-B(s) / among other system components ) .

<> cheers

voice of theatr
02-06-2010, 08:44 AM
If you swap out the 806's for two 902's, will the stock Valencia 800 hz crossover be ideal or would it be better to use Model 19 crossovers that have a 1200 hz crossover frequency with the 902's? Also, will the 902 sound "right" in the Valencias? Doesn't it have a different efficiency/sensitivity than the 806--would that difference in efficiency/sensitivity be corrected by swapping out the stock Valencia crossover for a model 19 crossover?

Earl K
02-06-2010, 08:49 AM
If you swap out the 806's for two 902's, will the stock Valencia 800 hz crossover be ideal or would it be better to use Model 19 crossovers that have a 1200 hz crossover frequency with the 902's? Also, will the 902 sound "right" in the Valencias? Doesn't it have a different efficiency/sensitivity than the 806--would that difference in efficiency/sensitivity be corrected by swapping out the stock Valencia crossover for a model 19 crossover?

Assuming Scott has 8 ohm woofers ( stock, with 846B Valencias ) / I'd swap the original crossovers for a pair of 1201-8A networks .


>< cheers

thymanst
02-06-2010, 10:17 AM
Yep, the woofer are the 8ohm model - I emailed GPA to see about drivers and I guess I need the x-overs - will start looking...

speakerdave
02-06-2010, 11:29 AM
Differences is measurement technique can make a big difference in readings. There can be problems with the push connectors, etc. Differences in DCR are not deal killers, necessarily.

Buying new diaphragms is not a bad idea, in any case.

There are several long threads here about Valencias and their crossovers. I believe if you will read them you will find a lot of guidance, and that you can build crossovers for that speaker that will be an improvement over the original.

voice of theatr
02-06-2010, 04:15 PM
Has anyone out there ever heard one of these model 19 crossover replacements ("Crossover Upgrade Model For Altec Model 19") ? Is this company affiliated with GPA or the original Altec/Iconic? Anyone ever seen any specs or photos of these?
http://www.iconicspkrs.com/crossovers.html

"...To assure proper performance of the Iconic DN19-8U
Replacement Crossover, the values of the original
components of the factory-supplied crossover for the
Model were carefully measured and duplicated. Modern
parts with identical values were then selected to be used
in the Model DN19-8U, to assure proper audio
performance - metallized polypropylene capacitors, noninductive
wire-wound resistors, air-core inductors, highquality
wire of sufficient gauge to connect the crossover
to the loudspeaker components, and meticulous hand
assembly combine to produce an excellent
upgrade/replacement for the original crossover supplied
with the Model 19...."

I notice they also offer "Stonehenge" and "Magnificent" speaker systems and that some of their drivers have the "Tangerine radial phasing system", "mantaray horn"? They have links to GPA on their site--I'm wondering if they're affiliated or if they're "horning in" on GPA's turf (bad pun!)? BTW, I'm loyal to GPA if they're a competitor...

thymanst
02-06-2010, 05:22 PM
It looks like they are somehow related to GPA according to the fine print at the bottom - the pdf's have the same look as GPA's- I'm interested as long as they arent mega$$$ - if I can replace crossover and get 902's in there :)Heres pics of them cleaned up with new fabric - they sound good right now running off a Jolida sj502a on my lanai(68 and sunny today)