Altec 32343 Network Divider

**bowtie427ss** · April 24th, 2011, 10:47 AM

Oh i'm no expert here VOTT, but i am familiar with the 9849's as i've owned a few. AFAIK, the 9849 is the only speaker that was factory equipped with the 32343 XO, and the 23746 compression driver. Apparently the 23746 was made with both annular metal and radial plastic(tangerine) phase plugs, i think member RonSSS has examples of each. I currently have 9849-8D's with annular metal phased 23746's, those drivers "look" like an 802-8G with the same new style rear cover and rough cast exterior surface except they're the shorter body and smaller magnet of the 806. Here's a pic of one of my drivers from a while back.

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**voice of the theater** · April 24th, 2011, 11:23 AM

Originally Posted by bowtie427ss

Oh i'm no expert here VOTT, but i am familiar with the 9849's as i've owned a few. AFAIK, the 9849 is the only speaker that was factory equipped with the 32343 XO, and the 23746 compression driver. Apparently the 23746 was made with both annular metal and radial plastic(tangerine) phase plugs, i think member RonSSS has examples of each. I currently have 9849-8D's with annular metal phased 23746's, those drivers "look" like an 802-8G with the same new style rear cover and rough cast exterior surface except they're the shorter body and smaller magnet of the 806. Here's a pic of one of my drivers from a while back.

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Allen, does that look like your h.f. driver? (click to enlarge the photo) It looks similar to me but hard to tell from the angle and lighting of your (Allen's) photo. If that's your driver, I'd still recommend 414's since they were selected by Altec engineers to work with that h.f. driver and your crossovers.... As I mentioned before, your speakers would be very similar to Altec 9849's (which are great speakers) in (well made) home made cabs. With those woofers you'd have an amazing pair of speakers.....

Originally Posted by Corona Blue

The cabinet is well made from 3/4 inch birch ply and its outside dimensions are: 24" (H) x 16.5" (W) x 12" (D) with a 3/4" vent across the lower part of baffle board.

Allen

**Corona Blue** · April 24th, 2011, 10:43 PM

Wow! Thanks so much for your kind help guys!! I spent this afternoon deriving the schematic. Have a look and see if it looks right to you.

I haven't had time to put a meter on VR1 to verify its value. I suspect it is around 100k. (04/25 UPDATE: VR1 is 7 ohm/50 or 100 watt component) And I don't know the values of the inductors. If anybody knows this stuff, I can update it. Once we know it's right, feel free to add it to the documents lib.

VOTT- yes, that does indeed look like the same HF driver! Sorry about those blurry snaps... batteries in the cam were dying so auto focus was dodgy... I will attempt to get some clearer shots tomorrow... for now... just put yer glasses on! :-)

Let me know and thanks again.

Allen

:thankU:

**Earl K** · April 25th, 2011, 07:29 AM

Thanks so very much for this Allen !

I'm always very thankfull when someone takes the time to expose the workings of an older network such as this . We all benefit by these efforts / so thanks again !

Does it look right ?

- Yes, electrically your layout is very workable ( when designing for an @ 1500 to 1600hz acoustic crossover point ) .
- The component layout ( visually ) on your drawing is fairly unconventional ( & may confuse untrained eyes ) / but it's the eletrical layout that matters here .

FYI ;

L1 & L2 could be in the neighbourhood of 1.2 mH for a standard "B2 filter" rolloff ( B2 = 2nd order ButterWorth filter ) .
L3 ( at that location ) would need to be @ .075 to .20 mH to function properly and do anything of importance to the HF filtering .
VR1 should be a standard type 8 ohm variable Lpad ( 100 watt ) .
The values of the capacitors do "ball-park" to where I would expect them ( ie; knowing the components somewhat , as well as Altecs' standard approach to dealing with the FR curves of those components ) .

- It would be nice to have your layout confirmed by a second set of eyes on another network ( before declaring this all correct ) .

<> cheers EarlK

**Corona Blue** · April 25th, 2011, 11:51 AM

Thanks EarlK-

If anybody would like to modify the schematic, I can email them the source file which was done in TinyCad (shareware/freeware). It would be great to have it laid out so it would be clear to anyone. My thought in the lay-out was to clearly show the two sides of the network, but better is better!

Just PM me or send an email!

Best,

Allen

**Corona Blue** · April 25th, 2011, 08:07 PM

Here are some clearer pics of the horn and driver... don't know if this will help you identify it or not. Let me know if you need me to do anything to identify these. I'm not all that familiar with what I am looking for on this.

The driver is painted with black wrinkle finish paint. The horn feels like heavy carbon plastic and it mates to the driver with a fiberboard gasket that is about 1.5mm thick.

Let me know what you think and if there's something else I should look at...

Thanks again,

Allen

**RonSSS** · April 26th, 2011, 03:37 PM

Looks like the 806 style driver. Hard to say exactly what it is until you take it apart and remove the fram. Or look down the throat and see what kind of phase plug is in there. Tangerine would be orange.

Looks like the drivers were subjected to moisture.

I don't think the horns are Altec.

Ron

**RonSSS** · April 26th, 2011, 03:47 PM

The caps you have there are original. All altec crossovers from that era used those black caps with red ends. So I don't think anyone had changed values. I'm betting the blowed up one is the shunt cap that goes across the woofer. Which means someone really cranked the volume!

I don't think you would gain anything by replacing the resistors. They certainly shouldn't be getting hot.

Is that JBL woofer some sort of high powered deal? If someone had these up loud enough to pop that cap, I wonder how the hf fram survived?

I have a pair of the 9849's and I hate to adnit that I've never listened to them......

Ron

Originally Posted by Corona Blue

Hi Earl K-

Thanks for the link and for looking around for the schematic. I looked before I posted. I must commend you guys for having such a nice library of documents!! Very handy!

The resistors I saw all looked like 10w ceramics... going from memory here... 2 x 5ohm in series and an 8ohm. I will verify how they are wired.

I'm just wondering if it might be worth changing out the ceramic resistors for non-inductive 25w (finned aluminum) resistors that I can bolt to the box for extra cooling. These would have the additional benefit of being much smaller than the huge ceramics.

The 18uf cap that exploded was installed right up against one of those ceramic resistors. I can't imagine the heat would have done it any good. I have no idea how long it was like that. I have not used these speakers much since I have had them.

I was hoping to have a look at a schematic of the network to verify if it has been altered. Just wanted to know. If I get a free hour, I will attempt to derive it for the group.

Best,

Allen

**Corona Blue** · April 26th, 2011, 04:16 PM

I had a minute to revise the schematic of the Divider Network... just some clean up really. I wanted to show the logical correlation between the Zobel filter in the LF and the LR filter in the HF sections. And I added in the extrapolated inductor values as provided by Earl K. If you have additions or corrections, please advise, and I will do so.

I will re-post on Wednesday with some measurements of the horn driver. One question: If I choose to remove the rear cap, do I need to be careful about anything in particular? What to I need to be wary of?

Thanks!

Allen