First post: Questions regarding ALTEC 612 enclosure - DIY

Hello,

This is my first post on this Altec forum.

I am about to build myself a pair of Altec 612 enclosures for my Altec 604 E?s.

I have found a blueprint of one of the Altec 612 models on net. The blueprint is attached with my markings on it.


My questions:

1. Will I need a bass tube for the bass port in the 612 enclosure ? - or will the opening be enough in itself.
The reason why I ask is because I found a picture of the inside of a vintage Barzilay cabinet that did have a bass tube.

2. I also did find a picture of a DIY 612 enclosure that had a frame on the inside of the cabinet that is not shown completely on the Altec 612 blueprint.
Will I need to build this frame ? - if I do can someone give me a hint of how it looks like from the top view.

3. I do not get what the purpose of the wood piece that goes across inside the whole enclosure on the blueprint - could someone please explain.

4. I did also find the original blue/grey color code - but it is not possible to mix - at least not where I live. Does someone out there have a updated color code for the original blue/grey paint ?


I will appreciate all the help I can get.

This cabinet is the 612C variant.
1) No you don't need a tube the port is 3/4" the thickness of the plywood.
2) That is a 3"x 3/4" wide brace that goes from the front to the back of the cabinet..I have posted some pictures of my 612C's on this forum somewhere I'll see if I can locate them.
3) That is also a brace on edge diagonally from top to bottom corner and it is reversed on the other side of cabinet.
4) Battleship gray should get you there,or pretty close.

Here's the original if you want to go with what the Beatles used [among many others], though you may want to experiment with some inserts of the smaller vent areas of later versions:

GM

Here are a few photos to show you the braces inside of the cabinet.There is a diagonal brace on the back and two side panels.Also don't forget the bevel on the speaker opening.

http://www.hostboard.com/forums/hbmc...2012/11/21.jpg

http://www.hostboard.com/forums/hbmc...2012/11/22.jpg

http://www.hostboard.com/forums/hbmc...2012/11/23.jpg

http://www.hostboard.com/forums/hbmc.../2010/12/1.jpg

Why is the speaker hole beveled?

Quote:

---

Originally Posted by VolvoHeretic

Why is the speaker hole beveled?

---

When dealing with full range drivers.It reduces the eigenmodes faster... (Courtesy of GM)

http://www.hostboard.com/forums/f700...ml#post1801858

Hi again people !

Thank you all so much for your help !


ALTEC BEST: Just found the dictionary definition on bevel: in simpler english:
you mean the angled cut on the edge of the hole for the speaker element- correct ?

GM: thanks! - will definitely use this as a sketch for the front part of the cabinet.


I have two more questions:

1. Can I use 19 mm MDF for this enclosure? - or is there other materials that you recommend?
2. How much filling should I use inside this enclosure - or should I just cover the walls inside of the cabinet with damping material (carpet) ?


Greetings from Norway.

Quote:

---

Originally Posted by Tralalalala

Hi again people !

Thank you all so much for your help !


ALTEC BEST: Just found the dictionary definition on bevel: in simpler english:
you mean the angled cut on the edge of the hole for the speaker element- correct ?

GM: thanks! - will definitely use this as a sketch for the front part of the cabinet.


I have two more questions:

1. Can I use 19 mm MDF for this enclosure? - or is there other materials that you recommend?
2. How much filling should I use inside this enclosure - or should I just cover the walls inside of the cabinet with damping material (carpet) ?


Greetings from Norway.

---

Welcome Trlalalala!!! How funny I was just listening to a song with Trlalalala... Anyone no what it is??? What type of music do you listen to? What do you want out of your 604's? There are some more modern disigns that might work better for you... As far as materials I would use void free baltic birch easy to work with and sounds great!!!

You're welcome!

Any void free ~5/8" [15 mm_if going vintage] or ~3/4" [19 mm] plywood, Birch, Apple, marine grade.

GM

Just to make things more confused...

I once had an early 612 or 620 (forget which, been awhile) that had diagonally placed rigid fiberglass like the 618 photo below.

This stuff looks like Owens Corning 703 with a coat of varnish or lacquer to make it stiffer.

I'm wondering if that "brace" is there to hold a fiberglass or mineral board damping panel and not for cabinet reinforcement...or maybe it is the mineral wool panel itself!

The early cabs had very little internal damping material. In general, I have found that less is more with Altecs....add until the boom goes away. Too much and the liveliness is gone.

Check this 620 out

http://soundup.ru/images/stories/arc...ondition-7.jpg

Quote:

---

Originally Posted by Geekstar

I once had an early 612 or 620 (forget which, been awhile) that had diagonally placed rigid fiberglass like the 618 photo below.

This stuff looks like Owens Corning 703 with a coat of varnish or lacquer to make it stiffer.



Check this 620 out

http://soundup.ru/images/stories/arc...ondition-7.jpg

---

Joe that looks like a 614 to me,which usually houses a 12" speaker.. A lot smaller than a 620 or even a 612. The driver in this photo is a 700 series full range driver 755 me thinks. A 612 or a 620 houses a 15" speaker and is twice the size of those cabs in my humble opinion..

http://altecpro.com/pdfs/vintage/Spe...net%20Plan.pdf

http://www.lansingheritage.org/image...pro/page14.jpg

Hi !

Music : difficult to say : varies a lot ... almost all genres ... it just have to trigger something.
For example I don?t like Bob Dylan very much , maybe I just have not figured him out yet... anyway: but I do love Nashville Skyline.

I still want to make the 612C cabinet with the front that GM posted.
Think I will go for 18 mm birch plywood.

Understand now that the damping of the cabinets is a matter of taste.

Will keep you up to date on how this goes.

That is the original 612 that GM posted..Just follow the plans for the 612C with the different front baffle.The original doesn't have the bevel I believe.

Quote:

---

Trlalalala... Anyone no what it is???

---

Professor Longhair? Ike and Tina?

Being from Philly. I like The Delfonics "Lalalala...means I love youuuuu..." Major Harris RIP this past weekend.

Quote:

---

Joe that looks like a 614 to me,which usually houses a 12" speaker.. A lot smaller than a 620 or even a 612. The driver in this photo is a 700 series full range driver 755 me thinks. A 612 or a 620 houses a 15" speaker and is twice the size of those cabs in my humble opinion..

---

The pic of the cab with the slanted pink insulation is my personal 618 (for 8"). I put it up to illustrate old school minimal damping technique.

The point I was making is that I had a bigger Altec cab years ago with the same damping tactic. I think it was a 612.

I am wondering if this is the sideways "thing" in the pictured old 612 plans? Doesn't seem to be a wood brace because it cuts the cab in half completely.

Altec changed their nomenclature for these cabinets over the years.
The utility cabinets used to follow a naming convention with a suffix letter A, B, C, to denote the size of the speaker mounting hole. The size of the old 612 cabinet matches that listed on the drawing posted by GM, but back in the 60's, that would have been called the 612A for a 15" speaker. But even then, the 612 was the larger of the utility cabinets (6 CF), followed by the 614 (3 CF), and the 618 (2.3 CF).

Confusing, but that is the joy of vintage! :)

Quote:

---

Originally Posted by Geekstar

The pic of the cab with the slanted pink insulation is my personal 618 (for 8"). I put it up to illustrate old school minimal damping technique.

The point I was making is that I had a bigger Altec cab years ago with the same damping tactic. I think it was a 612.

I am wondering if this is the sideways "thing" in the pictured old 612 plans? Doesn't seem to be a wood brace because it cuts the cab in half completely.

---

Understood, thought you posting it as a 612.. The thing in the old plans is a slanted brace on edge that is mounted to the side panel I'm pretty sure.They don't usually post dimensions of the insulation AFAIK. Just thickness and location bottom,one side,back panel,etc..

Here is the 612 plans.

http://altecpro.com/pdfs/vintage/Spe...net%20Plan.pdf

And the 612C plans.

http://www.lansingheritage.org/image...closures05.jpg


IMHO both these plans are of the 612C.If you look at the front view you can see another slanted brace through the speaker opening mounted on the back panel.. In my original 612C cabinets there are 3 of these braces.One on each side and one on the back panel.

Quote:

---

Originally Posted by Tralalalala

Thank you all so much for your help !


ALTEC BEST: Just found the dictionary definition on bevel: in simpler english:
you mean the angled cut on the edge of the hole for the speaker element- correct ?

---

Your Welcome ! Yes. Altec used that bevel on all of their 612C cabs.

AB:

OK, I never saw the side to side cross braces....does your cab also have a front to back diagonal brace as depicted in the middle drawing?

This 612 I once had was really old and had no diagonal bracing, only a piece of sideways rigid mineral board, which may or may not have been factory, and a little bit of cotton padding on the back and maybe the sides. It think it had a gray 603B in it. This was in the 80s which was many brain cells ago, but I remember it because of the diagonal mineral board, which is the first time I saw that.

No diagonal front to back . There is a straight brace from front to back just below the driver opening,and just above the port.Check the photos I posted and that should give you a better idea.

Quote:

---

No diagonal front to back .

---

I checked out your pic. I think there are different eras of boxes in play here. Gradually they got more solid (and heavily damped), it seems.

If there is no front to back diagonal brace, then what is the diagonal "thing" in the middle drawing in the first blueprint above?

That is what I was thinking could be a mineral board damping panel. Note how it has square edges and is not connected to the walls. Can't be a sheet of ply because it would block off half the cabinet!

That is a diagonal on the back panel.There are 3 diagonal braces in the 612C. Both sides and back with a front to back brace going from right under the driver straight back to back panel look at the photos carefully you should be able to see all braces.

Yes I agree the 612 changed a few times from the Iconic (Original 612) to the last incarnation the 612C.. I think the 612C is the best and certainly is the most sturdiest due to all the bracing.. The original 612 only used cleats AFAIK... :smile2:

I'm totally following what you are saying. My question is what is the object with the arrow in this side view?

It is not connected to wall, doesn't appear to be a brace.

My "theory" is that it is a damping panel.

That is the side brace Joe ! You can see the same graphic from the front view denoting a brace.It's a brace...

Look at this photo you see that diagonal brace on the side ? :smile2:

http://www.hostboard.com/forums/hbmc...2012/11/24.jpg

Hold on..let me take another hit off this bong...slurrrrrFFF....cough cough


That's better.:biggrin2:

Think I'm getting it. The diagonal "brace" goes from front of the cab to back of the cab, as well as side to side...is that the story?

Front right corner to back left corner, for example

By George I think he's got it ! :biggrin2:

Right side diagonal goes from back bottom to top right and the diagonal on the other side is reversed. Goes from top back to bottom right ! :wink2:

Quote:

---

Originally Posted by Geekstar

I'm totally following what you are saying. My question is what is the object with the arrow in this side view?

My "theory" is that it is a damping panel.

---

It's drawn wrong in the front view to be a damping panel, instead depicting a square bar running diagonally from the lower left front to the upper right rear corners [which could be used to support a diagonal piece of rigid insulation such as duct board in lieu of damping the top, sides, back], but in AB's cab it appears to be attached diagonally across the back-plate, which makes the most sense to me from a bracing POV, so assume the drawing is wrong.

GM

Quote:

---

in AB's cab it appears to be attached diagonally across the back-plate, which makes the most sense to me from a bracing POV, so assume the drawing is wrong.

---

Yes, it is hard to correlate all of this data because I think we are looking at different eras of 612 reality. And there is something off about that first print.

A brace from front right corner to back left corner would be bracing in the dimension in which the box is the strongest and least subject to vibration, so that is kinda weird.

Anybody have an early 50s plywood 612 box to verify?

A diagonal brace on each side per ABs photo panel makes good practical sense to me. This looks like a late model particle board cab.

The basic 612 design goes way back. I posted a pic of a 40s Lansing Iconic in such a cab a few weeks ago.

I tried to find the best photos of the diagonal bracing bracing that I took of my 612C's.

http://www.hostboard.com/forums/hbmc...2010/09/49.jpg

http://www.hostboard.com/forums/hbmc...2012/11/25.jpg

http://www.hostboard.com/forums/hbmc...2012/11/24.jpg

http://www.hostboard.com/forums/hbmc...2012/11/22.jpg

http://www.hostboard.com/forums/hbmc.../2010/12/3.jpg

Joe I think you referring to the original Iconic cab (612) like this that has that old cotton batting and just cleats and angled glue blocks for the bracing.

http://www.hostboard.com/forums/hbmc...2012/11/26.jpg

http://www.hostboard.com/forums/hbmc...2012/11/27.jpg

Cool, very instructive! Thanks!


Wow I like that 3x5 Lansing horn!

What I am calling an "old Altec 612" had that kind of cotton batting and a diagonal slab of mineral wool board. No braces.

I was listing to this 808 horn version Iconic last month in the Silbatone factory. Pretty good! Those Lansing field coil woofers are really great.

Yeah, the 100x60 1508 must be really rare as I tried for years back decades ago to find a pair after the local Altec distributor mentioned them, but they remained only a model number until that photo surfaced awhile back. Wound up stacking 511s as a 'make do' that fortunately turned out fairly well.

Never seen any rectangular Altec cab with diagonal damping like in your 618. Is the cab a factory one? I mean the local distributor use to get cabs made locally to cut labor, shipping costs and their resident engineer for whatever reason didn't necessarily have them built to spec.

GM

My 618c cab is definitely factory. The decal shot I provided for the decal project came from this box. It is an early 50s model. Very thin wood, like 3/8 ply on the sides and back. You can see that the fiberglass brackets are pained the same as the inside of the cab. I saw another one just like it on ebay that had an early 400B in it. I should have snatched it up but hesitated and lost out. I'll probably see that one in in Korea next trip.:biggrin2:

I'm having a pair of these thin wood 618s built as I speak. I intend to experiment with damping techniques using archaic materials--cotton, rigid mineral board, Kimpak, etc.

I had other later 618 cabs that were thicker plywood, gray, and had pink fiberglass on the back wall and bottom panel. The silver one in the pic has nothing on the back wall.

The old 612 box I had was darker gray instead of silver hammertone but it had an old fashioned Altec decal on it as well. That was real early 50s too with a gray Hollywood coax and it had the diagonal damping panel, so I'm wondering if that wasn't factory also. This was a long time ago and I don't remember the minute details. Actually, it might have been a 614...really can't remember. I had a lot of premium junk piled up at the time.

Clearly, many of the well known utility cab designs evolved over time. The earliest Altec versions were more resonant and minimally damped by later standards. Some of them ended up particle board and heavily damped.

When I was talking with Mr. Mukai of Western Sound Inc. about this he said the Japanese like the old boxes because they are more "easy listening" and the later ones are more "dry" or "severe."

Yes indeed that 1508 must be rare. I never saw one before, not even a picture. Did Altec make these or it is only a Lansing Mfg. Co item?

Just remembered this Lansing drawing, also from Steve Schell IIRC:

Hmm, I've run out storage space and can't figure out how to delete any of my uploads, so guess I won't post it.

POS hostboard.

GM

I have the same problem....just used up 998kb of my 1 meg allowance with that last pic. Any way to get more space?

I love to post pics to illustrate my ravings and get info into circulation.

Image Allowance Problems?

LMGTFY

Quote:

---

Originally Posted by GM

Just remembered this Lansing drawing, also from Steve Schell IIRC:

Hmm, I've run out storage space and can't figure out how to delete any of my uploads, so guess I won't post it.

POS hostboard.

GM

---

Go up to settings and go all the way to the bottom of the page on the left, Click on attachments then select the check boxes of the ones you want to delete. Then go to the bottom and tell it to save changes or something like that. I was converting mine to GIF's in photoshop, I could post about 40 then.

Quote:

---

Originally Posted by cradeldorf

Go up to settings and go all the way to the bottom of the page on the left, Click on attachments then select the check boxes of the ones you want to delete. Then go to the bottom and tell it to save changes or something like that. I was converting mine to GIF's in photoshop, I could post about 40 then.

---

Thanks!

Found my old Flickr account, so considering me and some other folks can't see these dinky little pics well enough to make the effort worthwhile I just won't use it anymore.

Circa 1940 Iconic cab sketch: Iconiccab | Flickr - Photo Sharing!

Lansing C502: C502 for D-130, 131 | Flickr - Photo Sharing!

GM

Quote:

---

Originally Posted by cradeldorf

I was converting mine to GIF's in photoshop, I could post about 40 then.

---

For those Photoshop impaired, Irfanview is free, does conversions and simple color edits, cropping etc. A neat trick- add Ghostscript plugin. Then look for a program called doPDF. It installs as a printer. So you can "print" any page to a PDF. Open in Irfanview and convert the PDF to any graphic file.

Hello,

Have drawn up a digital sketch of a 612 cabinet based upon the iconic cab sketch and the 612C blueprint.

I want to build this cabinet , but I am uncertain if it is good enough , since it is a mix of two...

The height is 29 inches as on the iconic cab ( not 29 1/2 inches on the 612C )
The bass port is as on the 612C - I just put it somewhere on the front baffle. - will appreciate any suggestions on where it should be.

One more thing: should I also make brackets in this enclosure as in the 612C?

Will make new drawings and post them after new suggestions...

PS: The height on the front baffle is wrong (the height should be 22 1/8 but is 22 7/8) - will fix it later on.

Quote:

---

Originally Posted by Old Guy

For those Photoshop impaired, Irfanview is free..........

---

+1 on Irfanview, I resemble that remark! Never heard of these other goodies, so thanks for the heads up. :Thumbs up:

GM