Can you identify these Altec 846B's

[HarryN]

I just bought these 2 pair of speakers, and both pairs were supposed to be 846B's. They certainly look the same, and I noticed picking them up that the back panel was different on each pair, which in my haste I attributed to them possibly being different years models of the same thing. The look of everything as well as the weight seems the same, except the ones that say Altec 846B have foam under the tweeter horn and on the sides of it, and the other pair has all wood. The tweeter control is different also on the back panel. But, they all 4 had the same grills, and same enclosures, as far as I can see. They are all glued together on the back the same, so there is no getting into them without major wood working. The woofers look indentical, as do the horns, except for their color. The Altec labeled speakers have the horns black, and the others are a blue color.
I have attached some pictures of the two types. Any know what I ended up with? They are certainly in pristine shape for being 35 years or more old.
4720547204472034720247201

[Art J.]

Their were 5 versions of the 846B according to the reference page.

http://www.lansingheritage.org/images/altec/reference/1975-drivers/page06.jpg

You will have to dig deeper inside to find out which you have.
Maybe you can report if you hear a difference between the pairs.........





:)

[Progneta]

That theres a Valencia :) ...by looks in the pics. What are the dimensions?

[HarryN]

The dimensions are 26-1/2" wide, 19-18" deep, and 29 -3/4" tall- on their feet. My woofer is 15" so it looks like the Altecs are the first one above the 846U unfinished, or 5th from the top of the list, as my crossover says N800-8K.

My problem now that I have, is that the Heathkits work great. They blow away my KLH 9150AK's that also have a 15" woofer. I never knew what people were talking about using words like "stage" and others to describe the sound difference, but these things are like sitting in the front row of a concert. They also, when you crank the volume, are twice as loud as the KLH.

However, the horns of both the real Altecs are blown. I took one apart, and it has the 806-8A horn, and the smaller of the 2 caps was blown apart. I hooked my speaker wires directly to the horn, hoping the cap was the problem, and no sound at all. I have ordered new, they say, Altec diaphrams from a speaker store here in FL, and should have them tomorrow.

After I ordered them I read where several of you have modified these crossovers to be better than original, and for all I know there are better fixs for the horns, as well as adding another higher frequency tweeter. Maybe I should put this in another thread, as I now don't care if they are real Altecs or Heathkits, I just want them to sound as good as I can get them.

Who can tell me what I should do to get the best sound out of these. At this point I can solder, but reading electrical drawings and understanding a lot of the terms here are over my head. I tried to take the driver apart, and can't get the inner parts to separate. I figured when I got the new parts I would know better what to force apart.

Here is a picture of how far I got just taking the nuts off, and 6 screws. The rest of it doesn't want to easily come apart, so I haven't forced anything yet. Also here are 2 pictures of the crossover. I put the end that blew out of the cap back in for the pictures, but it is clear what blew by the white crap that came out.

[Progneta]

Hey,
I would recommend recapping these. Simply buying some new caps from Partsexpress. I like their 1% poly caps. Since you only need two, why not get the best :)

Also, When you put the new diaphragms in, make sure you cleaned the gap really good. Over time, the tend to get crap in there that can make things sound funny. Also, those diaphragms domes are literally as thin as aluminum foil. Be very careful when you install then. There are pins that you line up and the diaphragms sits right there. If you don’t know how to take apart the driver, I would find someone who knows how. Bill at GPA (greatplainsaudio.com) will whip this babies back to day one.


I would recap and add new frams. This is the easiest and cheapest way to get these babies running full speed. If you still dont like the sound, I would maybe look at tinkering with the crossover. I always like a 12-1600 hz crossover. Then you can take the loading cap off the driver and put a sound absorbent material like felt glued to the bottom of the driver cap.


My guess is after you replace the caps (which are solder and play) and fix the drivers, you will be very happy.

-G

[HarryN]

Well I don't know how to take apart the driver. I had emailed GPA and Simply Speakers, and only SS wrote back, so I ordered from them. How hard can it be to get them apart? I have a small machine shop in my place, and have built all kinds of stuff. Not knowing where the diaphram is in the picture I posted leaves me at a bit of disadvantage. Is it just a matter of a couple of wacks with a dead blow hammer to loosen things up, or do I need to take the screws that hold the wires on out also? I took out the 2 on one terminal, but they didn't seem long enough to be holding anything together.

What about the 2 coil looking things? What are they called, and do they go bad? They look just like a simple coil which I would think is either good or bad depending if a wire shorted or not. Not like a cap that could degrade in time.

Thanks for your help.

Harry

[Progneta]

the diaphragm is underneath that black cap. simply take a small flat screw driver underneath to separate and say hello to the diaphragm.

[scott fitlin]

When you install the new diaphragm, be careful when you are screwing the diaphragm in place, REALLY I MEAN BE CAREFUL the pull of the magnet will pull a screwdriver right into the aluminum dome. IF you can or already have one, use a non conductive screwdriver.

When you get the back cover off the driver, and you removing the old blown diaphragm, you will see how strong the magnetic pull is.

[HarryN]

What's wrong with this picture? The diaphram looks perfect to me. What else could make the horn not work at all?


47269

[scott fitlin]

Just because the diaphragm looks fine doesn't mean it is. A tiny burn on the VC is all it takes.

[Guy in WNY]

Go to You Tube. Search for speaker repair, or voice coil replacement, or horn repair - whatever gets you in that area. Watch the videos of voice coil replacement. Notice the special care taken to clean out and keep clean the gap. After a coil (or diapraghm) has toasted, there can and normally is some debris in the gap. You MUST REMOVE THIS DEBRIS! You don't want to take the chance that some will rub your new coil and mess up the sound. So be very clean.
Oh, and watch out for the magnet. It is very strong. You don't want to get a finger tip pinched somehow - it really hurts!:o:

[louped garouv]

What's wrong with this picture? The diaphram looks perfect to me. What else could make the horn not work at all?


47269

often with altec small format diaphragms,
the failure mode is the two small wire leads on the
other side (side not shown in your pictures) of that diaphragm will break...


FWIW, GPA is considered to produce the nicer of the diaphragms for altec drivers, as they have the tooling....

and they will install and remag Alnico magnets for 'free' when you buy the
diaphragms if you mail them in for service...

also good to note that GPA seems somewhat notorious for not really being
the best at answering their emails... phone calls seem to do much better
at their shop from my understanding....

[scott fitlin]

often with altec small format diaphragms,
the failure mode is the two small wire leads on the
other side (side not shown in your pictures) of that diaphragm will break...


FWIW, GPA is considered to produce the nicer of the diaphragms for altec drivers, as they have the tooling....

and they will install and remag Alnico magnets for 'free' when you buy the
diaphragms if you mail them in for service...

also good to note that GPA seems somewhat notorious for not really being
the best at answering their emails... phone calls seem to do much better
at their shop from my understanding....YES and I will attest to this, as I always called Bill on the phone, and he always took my calls. Email, according to everyone has always been the less successful method of contact.

Aending the driver in to GPA IS a good idea as OLD alnico's can do with recharging the magnet.

[Altec Best]

Yes call GPA you will get a much quicker response than email the wire leads on the other side where the dome is is where they break 99.99999% of the time this is where I have found the break in all of mine.I have included some pictures at the bottom of the diaghram there should be some #'s if they are original and they are 806-8A's they should be 23744's don't throw them out.I've had them repaired before.They are the "lite" diaghram the best sounding IMHO the 34647's are just as good though.Also in the other picture check the leads at the top of diaghram I have a Pic of that too to show you what to look for.Regards ~ John

If you can cancel that other diaghram order I would and order them from Bill at GPA they are the only place in the world still manufacturing OEM diaghrams for Altec Lansing !!;) Also IMO you won't like the sound of the cheap replacement diaghrams that cost $40 chinese specials ,GPA's are $90 with free recharge of Mag's but the sound is worth it IMO.And treated right they should last you a lifetime.There replacements will be part # diaghram 34647

[Altec Best]

Email, according to everyone has always been the less successful method of contact.



Yes with GPA being a very small shop email replies suffered, but Todd White the Altec User Board owner has since taken over the email handling at GPA so that should improve very soon.:)

[HarryN]

You were right. Once I got them apart, one had both the wires broken, and the other one only had one broke. I did throw them out, and then thought about it when I got up this morning and pulled them out of the garbage, undamaged luckily.

Simply Speakers had what they said were real Altecs for $112, and imports for around $80. I bought the Altecs, and they are number 26420. I had to drill out the hole for the 2 pins, as it wasn't quite large enough, but I got them in and they sound good to me.

Does the placement of the 2 wires have any affect? It didn't seem to have a positive or negative side, since both wires hook to the aluminum diaphragm. I hooked 2 Radio Shack type capacitores that were 4.7 that I had together in series, wire nutted them to where the 8uF had blown, and I am back in business, until I can get the right ones from Parts Express.

Hooked all 4 up to my new to me Harmon Kardon amp ( 75 W x 7 @0.07%) last night with the KLH's, and cranked it up full. With 6- 15" woofers, I am not sure if I will need a sub-woofer.

Now I need to find out what the other larger capacitor is. I looked at both of them, and the one number that would tell me is wore off them both.
They say :
TSI-7440
PA21MS75NPXTF
21?-75VNP

The 21? should be the uF rating, but I don't see an F or a u there. Does anyone know what size this is. I want to replace them both in all 4 cross-overs, just out of general principal.

Thanks for all the input. I wish now that I had waited for these last responses before I ordered my parts. Neither one of my magnets seemed near as strong as has been mentioned here. I had no trouble with stuff sticking to them at all, so they probably could use re-magnetising.

[Altec Best]

HarryN;294267
Simply Speakers had what they said were real Altecs for $112, and imports for around $80. I bought the Altecs, and they are number 26420. I had to drill out the hole for the 2 pins, as it wasn't quite large enough, but I got them in and they sound good to me.



If they were real Altec diaghrams do you think you would of had to drill them out.Those pins are the locating pins for locating the voice coil in the center of the gap.GPA's fit perfectly on those pins.;)

Does the placement of the 2 wires have any affect? It didn't seem to have a positive or negative side, since both wires hook to the aluminum diaphragm.


Yes it will if you have them reversed you will reverse polarity,Altecs mark their diaghrams with a Line 1and Line 1 is usually the Negative and positive Line 2. I would get back to the 8uF cap ASAP too.


With 6- 15" woofers, I am not sure if I will need a sub-woofer.


I don't think so, but who knows after you get everything all set up you will know if that should be an option.The amp is important too.



Now I need to find out what the other larger capacitor is. I looked at both of them, and the one number that would tell me is wore off them both.
They say :
TSI-7440
PA21MS75NPXTF
21?-75VNP
The 21? should be the uF rating, but I don't see an F or a u there. Does anyone know what size this is. I want to replace them both in all 4 cross-overs, just out of general principal.
Thanks for all the input. I wish now that I had waited for these last responses before I ordered my parts. Neither one of my magnets seemed near as strong as has been mentioned here. I had no trouble with stuff sticking to them at all, so they probably could use re-magnetising.


Yes it should be a (Callins 21uF cap) which is the roll off cap for the woofers (Bypass Cap) No music goes through it, it just removes the High Freq.'s from the woofer.So don't go crazy with expensive caps for this one.Solens are very good and priced right IMO.Good Luck with everything Regards ~ John

[HarryN]

Parts Express has a Dayton 8.2 uf for around $6, or a Jantzen for around $52. The Dayton says it is 1%, and the Jantzen says 2%. Do you think there is a difference in sound quality?

Also I took apart the other Heathkits I have, and they are 16 ohm, with a sealed box type of crossover. I was going to replace their caps too, figuring they are 35 years old also, but was surprised to see 16 ohms. And both speakers are different, although they are all Altecs.

My real Altecs have:
Horn is 806-8A
Woofer number is 50 03 030767. I can see no other number and the end of the woofer is a silver unpainted cylinder.

The others have:
Horn is 806A 16 0hms
Woofer 803B 16 ohms. The end of this woofer is painted green and is more rounded, and seems to be built in with the frame.

Should I take the crossovers apart, and replace the caps? What is the deal with running 16 and 8 ohm speakers together? I have never seen 16 ohm before.

Are these all about the same quality?

[Progneta]

Id use daytons. I have used them in several projects and they work great.

[Altec Best]

Parts Express has a Dayton 8.2 uf for around $6, or a Jantzen for around $52. The Dayton says it is 1%, and the Jantzen says 2%. Do you think there is a difference in sound quality?

Also I took apart the other Heathkits I have, and they are 16 ohm, with a sealed box type of crossover. I was going to replace their caps too, figuring they are 35 years old also, but was surprised to see 16 ohms. And both speakers are different, although they are all Altecs.

My real Altecs have:
Horn is 806-8A
Woofer number is 50 03 030767. I can see no other number and the end of the woofer is a silver unpainted cylinder.

The others have:
Horn is 806A 16 0hms
Woofer 803B 16 ohms. The end of this woofer is painted green and is more rounded, and seems to be built in with the frame.

Should I take the crossovers apart, and replace the caps? What is the deal with running 16 and 8 ohm speakers together? I have never seen 16 ohm before.

Are these all about the same quality?

The 806-8A is a great driver IMHO it is similar to an 802-8G the 806-8A came with the 23744 diaghram if it is still original.And I would keep the caps the same values that were there.Solen makes a 8 uF cap and they are around the same price as the Daytons.Solens and Daytons are pretty close in performance IMO. :)