Originally Posted by bowtie427ss
Scratch my last comment then, stocker prolly OK. I have only owned 900 Hz crossover versions, so was thinking of that. Recapping should be done AFTER the other mods. Might not be necessary.
I agree, a mid adjustment would be sweet, but the stock XO is really a pretty good one albeit a PITA to work on as it's pretty stuffed.The only thing I could suggest beyond that is a crossover similar to the Model 19 with separate mid/high adjustments. It would raise the xover to 1200 Hz but that should not cause an issue.
His stock XO's should cross at 1500hz, they even have a bit of EQ built in to help smooth and perceivably extend the HF a bit with those 806's.
Scratch my last comment then, stocker prolly OK. I have only owned 900 Hz crossover versions, so was thinking of that. Recapping should be done AFTER the other mods. Might not be necessary.
Your neighbors called. They like your music.
Hello again,
I have written two posts, but have been mysteriously logged out both times before they went through. (Wouldn't be such a big deal if I could type worth a damn.) Anyways, the 9849A crosses over at 800hz, with a top end that extends only to 15khz, per an old Altec brochure. If they had the 902-8t's in them for hf drivers, that would take them out to 20khz, and I would leave them alone. I purchased the 908-8b's for replacements. I have not been able to get them apart to check for loading caps, I don't want to pry on them and damage them.
I understand the concern about the banana plug conversion. I would definitely expect problems if the speakers were connected and disconnected often. I have them on a pair of Wharfdale diamonds, and haven't had any issues. They are also on the Perreaux amp which will eventually be used to drive the Altecs.
If the 908-8b's require a higher crossover point, I will gladly rebuild the crossovers. And the final project will be new cabinets, I have a lot if furniture grade 3/4" plywood I scored for free from work.
It would be a shame if the final product didn't look as good as it sounds.
Thanks for your input, all feedback from the audiophile legends is appreciated.
I'd double check the component values in your networks. It's possible their evolution took place in steps, possibly the 414 came along before they raised the crossover point. But, i am doubtful of this.Anyways, the 9849A crosses over at 800hz, with a top end that extends only to 15khz, per an old Altec brochure.
Can you post an internal pic of a network?
The 1975 reference guide(one of the most trusted pieces of Altec lit) says 9849A uses the 32343 network. http://www.lansingheritage.org/image...ers/page11.jpg
The 1500hz 32343/9849 network is fairly unique and fairly easy to recognize with an internal pic, also not a bad idea to inspect for broken solder joints/lugs, i've encountered more than one on this model.
It's been brought to light several times on this forum that the Altec literature is not 100% accurate, and we also have to consider that changes and revisions were ongoing, often after catalogs and brochures were printed.
One of the big advantages of the evolution into the 414 woofer would have been the 414's ability to smoothly play up to a much higher crossover point than the previous woofer in a sealed alignment. So, my logic wants to believe the 414 and 1500hz XO point came along at the same time.
Just my .02 .................
Last edited by bowtie427ss; January 5th, 2012 at 11:35 PM.
Yup agreed ! Since they are 8 ohm they are 806-8A's 16 ohm would be 806A. The 806-8A's I have seen all had the 23744 diaphragm in them.So they should have plenty of top end.Yes the first places to look are at the diaphragm and inside the crossovers.Also loose grounds/wiring.
I have no doubt when you track down the problem you will be happy with them.They should rock !
FWIW - Those montors look like 9849-8B's
http://altecpro.com/pdfs/vintage/Spe...r%20System.pdf
Careful AB, his internals are date coded 1974, and use "pipe and plate" alnico motors. 9849-8B uses all ferrite motors, introduced prolly sometime in 1979-80.
AFAIK, the history goes something like this:
9849A originals used a foam edge woofer, sealed box, and 900hz XO.
Sometime not long after their introduction(very early 70's) came the 414 and ports. The move to a 1500hz XO may or may not have happened at the same time.
Sometime late '74 or early '75 the 9849-8A was born with the newly designed cast return pots on both HF and LF sections.
9849-8B arrived circa 1979-80, and with it's new ferrite motors offered a big step up in sensitivity and sizzle at the cost of some midrange smoothness and warmth.
This is my .02 based on the info i've been able to glean over the years combined with owning multiple 9849's, temper it accordingly.
Bowtie I'm referring to the enclosures he has there.Although it says 9849A. It looks like a 9849-8B to me,they are ported cabs.
WRT the internals it wouldn't be the first time that Altec speaker systems had other internals than what it was supposed to be ! Where are you seeing date codes on those drivers ?
In the Altec Ling or LTV era is when there was the most discrepancies IMO.The 414 is definitely in the Ling era.
Sure enough they do/should, all the ported cabs are essentially the same for 9849A, 8A, and 8B. It is the driver load that makes the difference.Bowtie I'm referring to the enclosures he has there.Although it says 9849A. It looks like a 9849-8B to me,they are ported cabs.
The only date code i saw was on his crossover. The drivers are easy enough to date within a narrow range by virtue of the pipe and plate construction of the alnico motors, and black paint. By some point in '75 9849's were using the "new improved design"(think 416B and 802G) 1 piece cast magnet structures and would continue until the introduction of the ferrites in 79-80.Where are you seeing date codes on those drivers ?
I have 1975 vintage 9849-8D's, their load consists of non-tangerine(later 23746 had tangerines) equipped 23746 HF drivers which have one piece cast pots, basically an 806 with the light phragm, and 414-8C woofers which use the same 1 piece cast motor pot as the 416B.
Hello,
I have uploaded some pics of the crossovers. I have not seen any obvious problems with them, hopefully you will be able to tell what they are. Most listeners would probably be content with their sound as is, I am just hoping to get a fuller top end. I do enjoy the mid range detail they have, I listened to a Hall and Oates tune called "Out of Touch", and heard a background guitar track I did not know was there. My wife did not understand why I would be interested in "old stereo stuff" like these speakers until I put her on the couch in the living room in front of them in the dark. I played REM's Everybody Hurts, and you'd swear Michael Stipe was sitting on top of the tv that was in between the Altecs. They kind of remind me of myself, somewhat old and beatup, but still with potential.
Thanks for your advice with my ongoing project.
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