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9846 and 9849 projects

The color is certainly different. Texture too.
What I noted is that the baffle board is different. On the one on the left, the woofer is closer to the horn by 0.6".
The woofer is about 0.25" higher from the bottom as well.
Design change? Or goof? :)
Left one is a later version as it had a 414-8E in it. Had the same good compression driver.

On the recone, I started the second one and am wondering.
The spider is very stiff. Has only 3 pleats. Sadly, I don't have the orig cone, but I bet the Altec was very loose.
I have a 416-8C orphan sitting here and that spider is very soft.
Simply speakers show a spider from an EV woofer same ID and OD, that has 4 pleats. It might be softer?
I would call them and ask, but they don't list a phone number.
 
Man I want to build a pair of 9849. I have all the parts for them, except my drivers are 16 ohm. I actually talked to Jeff Markwart about it a few years back. He helped me (I say help, but I didn’t do any of the work. Haha) design crossovers for the 16 ohm drivers. It wasn’t just the usual halving and doubling of caps/coils.

Your setup looks nice Ron. I wish I could have bigger speakers in the house. I told my wife if she let me bring some bigger Altecs inside I’d even let her put plants on top of them! She thought about it but said no
:whip:
 
RonSSNova said:
What I noted is that the baffle board is different. On the one on the left, the woofer is closer to the horn by 0.6".
The woofer is about 0.25" higher from the bottom as well.
Click to expand...
Hard to tell on my monitor, i can lose 3/4" just to a shadow.

My wag is that one cabinet was built by Altec in house, and the other by one of their vendors. Once upon a time i posted the name of the company who made utility cabinets for Altec, i cannot for the life of me remember that name.

RonSSNova said:
The spider is very stiff. Has only 3 pleats. Sadly, I don't have the orig cone, but I bet the Altec was very loose.
Click to expand...
I would opine that the original damper/spider should be somewhat stiff, it entirely controlled the compliance as the original cloth surround offered nothing in the way of resistance. This is why i think the foam stiffness could be partly compensated for by the use of a looser damper/spider. But, it won't eliminate the stress loading of the cone, and that will change the cone's natural break up modes.

Old JBL would add mass, but that will affect the performance in the midrange.
 
elitopus said:
Man I want to build a pair of 9849. I have all the parts for them, except my drivers are 16 ohm. I actually talked to Jeff Markwart about it a few years back. He helped me (I say help, but I didn’t do any of the work. Haha) design crossovers for the 16 ohm drivers. It wasn’t just the usual halving and doubling of caps/coils.

Your setup looks nice Ron. I wish I could have bigger speakers in the house. I told my wife if she let me bring some bigger Altecs inside I’d even let her put plants on top of them! She thought about it but said no
:whip:
Click to expand...

I used to chat with Jeff on the phone. Of course, he is a car guy, Corvette if I remember. You should build the boxes. They aren't very big.
My audio room is in the basement. I built it to be as dead as I could get it. And no wife around to tell me I can't have big speakers.
plants on top ruined many a Model 19 cab I suspect! Ha!

All the stuff I have I pretty much stumbled on for cheap. The lighter 9849 was in the newspaper classifieds. $100. The other I got from some forum member somewhere. he shipped it along with another 414-8C from Florida. He had 4 of them.

I shudder when I look at prices on this stuff today. I probably said the same ten years ago.
 
bowtie427ss said:
Hard to tell on my monitor, i can lose 3/4" just to a shadow.

My wag is that one cabinet was built by Altec in house, and the other by one of their vendors. Once upon a time i posted the name of the company who made utility cabinets for Altec, i cannot for the life of me remember that name.

I would opine that the original damper/spider should be somewhat stiff, it entirely controlled the compliance as the original cloth surround offered nothing in the way of resistance. This is why i think the foam stiffness could be partly compensated for by the use of a looser damper/spider. But, it won't eliminate the stress loading of the cone, and that will change the cone's natural break up modes.

Old JBL would add mass, but that will affect the performance in the midrange.
Click to expand...

Yeah, the time to think about the spider was before I assembled the first one. I went ahead and glued up #2. With a looser spider, you are right, it would likely overtravel the surround and that wouldn't be good.

I will throw these in the sub boxes above and see what they do.
 
Was waiting for someone to say I built a pair of guitar speakers! That was the first thought that came to my mind when I finished the first one.
 
Both 411's are re-coned. Both measure the same for Fs @ 34.75Hz.
Sadly, nowhere near the Altec spec.
These were meant for the 9846 but won't be going in there. I'll try them in my subs you see above.
At least I proved to myself that I could do a re-cone job.
 
RonSSNova said:
Both 411's are re-coned. Both measure the same for Fs @ 34.75Hz.
Sadly, nowhere near the Altec spec.
These were meant for the 9846 but won't be going in there. I'll try them in my subs you see above.
At least I proved to myself that I could do a re-cone job.
Click to expand...

What you've built is something like the original ( Alnico ) JBL 2205a that had a more HiFi Fs ( at 30hz ).

As JBL became more and more enamored with power-handling for their Pro-products they raised ( stiffened-up ) the compliance ( taking that Fs up to 40 hz ).

:)
 
They just might be fine for the subs. I have some horsepower there. The 411's dig nice and low, but are a bit slow and thumpy.

I remember a buddy's JBL speakers. Conical horn with the window shade diffuser, and a 15" woofer with a rubber surround. My God would they play loud. Very clean too.
Not sure of the model, they were in black road cases.
 
RonSSNova said:
They just might be fine for the subs. I have some horsepower there. The 411's dig nice and low, but are a bit slow and thumpy.

I remember a buddy's JBL speakers. Conical horn with the window shade diffuser, and a 15" woofer with a rubber surround. My God would they play loud. Very clean too.
Not sure of the model, they were in black road cases.
Click to expand...
411s are anything but slow and thumpy!!
 
I went ahead and put the reconed 411's in my sub boxes. An ordeal as I failed to use T-nuts in these when I built them many years ago. They have T-nuts in them now.
First thing I noticed was the bass was low in volume. I have a Kenwood KA9100 (100wpc) integrated that runs them. So, it's easy to increase the volume.
With the GPA units in there, 10w peaks on the power meters was perfect. With these reconed units, I needed 30w peaks. That's a big hit in the efficiency department.
Quite amazing actually. They seem to go low just fine.

Now that the GPA units are out, I compared the spiders. The GPA spiders have 4 pleats and are quite soft. I could also see that the GPE voice coils use edge wound ribbon, not round wire like the SS kit.

I have a spare 416-8C a buddy gave me for free. I'm going to stick that in one box and see how it does just for grins.
 
damacman said:
Wrong driver for that ...
Click to expand...
Naaaaaaaa

It was a radical departure in speaker design from traditional Altecs. In the late 60's when it was born they simply had neither the tech or experience to apply the 411 to ported alignments.

Perhaps as an effort to use up 411 stock that had been languishing in storage for several years, or simply because it fit the application, Altec chose to load the 411 in a combination mid-bass horn/bass reflex system and market it to the far east until the 411 supply ran out.

1975 was the last year Altec would put the 411 in a domestically marketed speaker system. They would continue to offer it as a raw driver until the end of the 70's.

Late production 9861's would ship with 416-8C woofers.

Circa 1983:

9861-2.jpg
 
Well, the TS parameters changed when they made them with the foam type surrounds as opposed to the rolled cloth. I measured mine before and after GPA reconed them.
They modeled quite nicely in the ported 8.5 ft3 enclosures that I built.
 
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