9846 plans wanted

[arawak1969]

Searching for a legible set of assembly drawings for the 9846's.
All help is greatly appreciated.

[moldyoldy]

With varying published dimensions for the A, B, and biamped, that's kind of a crapshoot. As a factory-built monitor, plans may have never been released. All I know of is this;
http://www.lansingheritage.org/image...ign/page22.jpg

[arawak1969]

I have an old set from my Dad and I guess I will have to get them reproduced.

He had ordered the kit for the biamp model back in the early 70's and all that remains is the plans and the biamps.

[moldyoldy]

arawak1969,
That's some very encouraging news. I've also looked long and hard for these plans. The 9846 was a well-respected design, and still has several devotees, some like me who have all the components just waiting to be installed. If you could scan them you could upload them to this thread on enclosures;

http://audioheritage.org/vbulletin/s...ead.php?t=3166

If that isn't possible, I'd gladly pay the postage, do the scanning and upload and return them to you immediately. PM me if you desire.

After lots of page-flipping comparison, it appears that the 1233 plans from AN11 in the library are very close, and could be adapted with the correct dimensions and omitting the ports. Still be better to have the real McCoy, though.

[Art J.]

Hi gang, I will help out if I can but things have been incredibly
busy here and projects are on hold. Besides just the box, the
9846 has that bump out in the front to make the driver offset
exactly a half wave at the 500hz crossover point. More later
if time allows. Art

http://webpages.charter.net/artj/9846216.JPG

[arawak1969]

Hi gang, I will help out if I can but things have been incredibly
busy here and projects are on hold. Besides just the box, the
9846 has that bump out in the front to make the driver offset
exactly a half wave at the 500hz crossover point. More later
if time allows. Art

http://webpages.charter.net/artj/9846216.JPG

Two quick questions:
1. What are the differences between the 802-8A and the 802-8g drivers?
2. Why do you have your 9846's on a platform?

Thanks.

[arawak1969]

Do I need the attenuator if I am biamping?
Can I substitute a newer driver (802-8g) for the original and how will it affect the sound?

[Art J.]

1. What are the differences between the 802-8A and the 802-8g drivers?
Others would have to help you there. I have no issues with the 8a's

2. Why do you have your 9846's on a platform?
That's the way I got them.
They were sent to a cabinet maker for the stands and finish to match the
auditorium stage they were displayed on. I prefer them up anyway.

Do I need the attenuator if I am biamping?
Its up to you. I still prefer using it for near-field listening.

[moldyoldy]

Two quick questions:
1. What are the differences between the 802-8A and the 802-8g drivers?

Here lately, about $150 each!

The only signifigant difference is the phase plug, 8as had a metal annular ring, 8gs had a plastic radial called Tangerine. While the Tangerines are considered superior, this doesn't mean there's anything wrong with the others. The original stock diaphragms differed naturally, due to the time produced, but are fully interchangeable with any other 1" Altec 'fram with the following exception; 8as that still have original rear covers and screw-terminals on the 'fram are "old-style", so to install the later (and current) new diaphragms with spade terminals, you'll need to either adapt or update to new-style rear covers/wiring (about $20 at GPA).

Other than original diaphragms, the 808 series fits the same description, As with annular plgs, Bs with Tangerines. Same motor assy.

[arawak1969]

I am currently running a pair of Altec Santiago's with Altec 771 biamps.
What do I need to do to convert my 808 drivers to 802's and can I then run them at the 500hz crossover like the 9846's?
Can I add a material such as Dynamat to dampen the 811 horns and reduce the ringing?
I added a graphic eq over the last week and have been very happy with the improvement around the attenuator frequency of 1Khz. I bumped the LF output up 6db on the biamps and the system is starting to sound a lot better.

I will be scanning the plans over the next couple of weeks and will let you know once they become available.
Cheers

[moldyoldy]

With 808s vs 802s, the diaphragm you use is the difference, 802s use aluminum, 808s originally used Symbioteks, which were replaced by Pascalite. Although the old Symbioteks gave up some response for power handling, the new Pascalites are a big improvement, so the difference now is largely subjective and small.

Either 808s or 802s can be run at 500Hz, but only on a horn that will handle it, and not the 811, which is an 800Hz horn. Yes, you can add external damping to the horn if you feel it's needed. If it's only an issue when you thump them or read user forums, just stop thumping them and ignore the forums.....

+6dB's a lot of LF boost, especially for a 771 biamp. In stock configuration, they should play pretty darn flat without EQ. It's possible you may need some caps replaced in the 771s, or maybe relocating the speakers to suit the room modes better, which I'd try first. It's generally considered better practice to attenuate the objectionably louder bandwidth to acheive tonal balance than to boost the other, for less distortion and greater wideband SPL. This is one reason why most Altec EQs were cut-only.

[Art J.]

Searching for a legible set of assembly drawings for the 9846's......................................
I will be scanning the plans over the next couple of weeks and will let you know once they become available.
Cheers

Thanks for doing that. Get the best scan you can and I can touch them up in
"Photo Shop" if needed.
Ive done that before for Model 19 plans.

Before
http://home.earthlink.net/~jmarkwart/id13.html

After
http://home.earthlink.net/~jmarkwart/id14.html

[arawak1969]

With 808s vs 802s, the diaphragm you use is the difference, 802s use aluminum, 808s originally used Symbioteks, which were replaced by Pascalite. Although the old Symbioteks gave up some response for power handling, the new Pascalites are a big improvement, so the difference now is largely subjective and small.

Either 808s or 802s can be run at 500Hz, but only on a horn that will handle it, and not the 811, which is an 800Hz horn. Yes, you can add external damping to the horn if you feel it's needed. If it's only an issue when you thump them or read user forums, just stop thumping them and ignore the forums.....

+6dB's a lot of LF boost, especially for a 771 biamp. In stock configuration, they should play pretty darn flat without EQ. It's possible you may need some caps replaced in the 771s, or maybe relocating the speakers to suit the room modes better, which I'd try first. It's generally considered better practice to attenuate the objectionably louder bandwidth to acheive tonal balance than to boost the other, for less distortion and greater wideband SPL. This is one reason why most Altec EQs were cut-only.

What are the influences that placement will have on the sound? Room is 16'x 30' and speakers are placed in the corners on one 16' side:dont-know .

[moldyoldy]

What are the influences that placement will have on the sound? Room is 16'x 30' and speakers are placed in the corners on one 16' side:dont-know .

Whoooeee! Guess I left myself wide open for that one......

In short, A WHOLE BUNCH.

Room acoustics is a subject you can spend several years to get a degree in, and what I could tell you wouldn't get you past the first week.

The most noticeable effect is usually in the deep bass. Corner placement generally increases bass, but not always. For high frequencies, minimizing sources of early reflections is important, and where you sit and listen will effect things too. You can study, buy test equipment, perform computer analyses, and go broke on room treatments. Or you can simply experiment, observing each change long enough to know if it's better, worse, or just the same. Take notes. One almost certainty with your horns is you'll need to have them near the same height off the floor as your ears (in your listening spot), and both toe'd in enough to aim right at you. They spread the midrange pretty well, but the highs are focused, sort of like a flashlight beam. When experimenting, set your tone controls on the amp flat, no boost or cut, it'll be easier to notice changes. An audio test CD or LP would be a worthwhile investment to get started. Parts Express has some.

If you wanna study, here's a start (there ain't no end);

http://en.wikipedia.org/wiki/Room_acoustics

(add/edit; If you end up building the 9846s, you'll need 511 horns)

[arawak1969]

Whoooeee! Guess I left myself wide open for that one......

In short, A WHOLE BUNCH.

Room acoustics is a subject you can spend several years to get a degree in, and what I could tell you wouldn't get you past the first week.

The most noticeable effect is usually in the deep bass. Corner placement generally increases bass, but not always. For high frequencies, minimizing sources of early reflections is important, and where you sit and listen will effect things too. You can study, buy test equipment, perform computer analyses, and go broke on room treatments. Or you can simply experiment, observing each change long enough to know if it's better, worse, or just the same. Take notes. One almost certainty with your horns is you'll need to have them near the same height off the floor as your ears (in your listening spot), and both toe'd in enough to aim right at you. They spread the midrange pretty well, but the highs are focused, sort of like a flashlight beam. When experimenting, set your tone controls on the amp flat, no boost or cut, it'll be easier to notice changes. An audio test CD or LP would be a worthwhile investment to get started. Parts Express has some.

If you wanna study, here's a start (there ain't no end);

http://en.wikipedia.org/wiki/Room_acoustics

(add/edit; If you end up building the 9846s, you'll need 511 horns)

Well I am doing the 9846 boxes and am looking for the 511's on ebay.
I am also keeping and eye out for a set of 411 woofers and 802-8g drivers. The attenuator is the one thing I have not seen and wonder if I will really need.
I am planning on scanning the plans that I have here next Wednesday and picking up the wood. I will be using marine grade ply as listed on the plans and staining to match my furniture. I will probably do some pedestals at the same time to get them to the same height as my listening chair.
Anyone have the correct attenutaors out there?