Please some advice on my onken cabinet build with altec 416b woofers

[Mrmonster11]

Hello Lads,
I had posted before on Altec 515B cabinets, but since then I have changed directions, as I came into a pristine pair of Altec 416B woofers, and have decided on building a pair of full size Onken cabinets for them with my 288C drivers with the German Jabo conical horns sitting on top.

I am contracting with a cabinet maker to acquire the wood and do the cuts, as I do not have a table sayw that can do the precision cuts needed for a tight build, and his big shop saws can do. He will also cut out the speaker hole and drill all the screw holes for me. I will end up with a "kit" that I can assemble in my garage.

I need to make final decisions on the build before wood hits saw.
He can get 13 ply Baltic Birch plywood in a high quality form. I can order 3/4" or one inch thick sheets, The problem is that one inch sheets adds $40.00 per sheet over the 3/4" That's $240.00 extra to the total cost of the six sheets needed for a pair of cabinets.

So the question is, IS 3/4" adequate? or does one need to stick to the Hiagra 25mm or 1" thick sheet stock? is the 1/4" extra going to make that much more difference in the end?

Next is insulation. Following the Hiagra build, it appears he is using lambs wool felt applied only on the back and upper 3/4's of the sides of the baffles.
I see from Onken build sites on the web, that many new builds are using a full insulation with an additional back insulation of what appears to be audio grade foam sheet. except on the ports of course

And lastly, does the Onken box box sound best flat on the floor, on a plinth or riser, or even casters? My house has wood floors with area rugs, and my current floor speakers are the Sansui big 5500 the large mid horn filled version. These are on a 3 inch plinth and produce a very good full bass even on the bare floor.

Any Onken builders or speaker experts in the crowd, I could use some input on these questions before I start writing checks.
Thank you,
Donald Bowman

[stephane RAME]

The scan text and original plans in french of the audiophile magazine.

http://www.audioheritage.org/vbulletin/showthread.php?27401-Onken-Dual-15-quot-quot-Onken-W-quot

Stéphane

http://audioheritage.org/vbulletin/showthread.php?11750-My-new-Loudspeaker-Systems-%96-Great-Plains-audio

[Mrmonster11]

Stefan,
Thank you,
I have all of them and more, but they do not address the issues I am asking about.
As per insulation other than lamb's felt, 3/4" versus 1" thick plywoof etc.
Thank you,
Donald

[Mr. Widget]

Other than listening to Onken designs a few times I have no DIY experience with them. I have built quite a few other designs however and I would definitely spring for the 1" material. In my own projects I typically use a 3/4" MDF layer laminated to a 3/4" birch-ply layer... this gives an extremely well damped yet rigid panel.

As for the acoustic damping material, I don't know where you will be able to source "lamb's wool", but the damping material and amount of it will affect the sound. Luckily with a large woofer hole, it is rather easy to make adjustments after the enclosure is built. My personal favorite acoustic damping material is 1" non-shedding fiberglass insulation or Sonex foam. The Sonex is rather expensive, but is really outstanding.

As for plinths, risers etc., to some extent that type of adjustment is room dependent. I think you will have to experiment.

Sounds like a great project... don't scrimp on a couple of hundred bucks on the front end, down the road, that amount will seem rather trivial.

Widget

[dkalsi]

t... don't scrimp on a couple of hundred bucks on the front end, down the road, that amount will seem rather trivial.

Widget


-Ditto

[Mrmonster11]

Thanks Lads,
I guess I will have to bite the bullet on this, as this is going to wind up at around $1200 for wood and labor, might as well spen the other $250.0 for the 1" birch.

So onto insulation, as Lab felt can be found, it is almost untouchable in price. I am quite sure that there are better products.
I am adding a photo of the interior of a recent Onken build from a Frenc site. Just photos of the build, no text.
You can see the insulation that was added to the interior, can anyone comment on tis?
Plus here is a photo of the finished build from the same site.

Thanks,
Donald

[stephane RAME]

http://www.ispra.net/audio/

You have to use wool felt 10mm

Stéphane

http://audioheritage.org/vbulletin/showthread.php?11750-My-new-Loudspeaker-Systems-%96-Great-Plains-audio

[Mrmonster11]

Stephane
Thank you, but it appears you are using a totally different design with your speakers, you have a double wall with felt between the wall. I am building an original Onken for the Altec 416B with an exterior HF horn.

Also the Ispra.net site you posted, is the same site I posted my attachments are from showing a non felt insulation.
Thank you

[jf65]

hello,
don't be afraid to experiment for yourself, for instance i did not put felt but thibaude (cheap carpet underlay made of scraps of felt) and no second isolating panel behind the driver, i felt that it muffled the sound. Another change is to make the rear panel of the box removable instead of the front one: you don't see the screws and since it holds the driver i think it's better.
Mine are on casters, they are a little away from the floor, but the main reason is their weight if you need to move them because they're heavy.
Best regards,
Jean

[Mrmonster11]

Hello Lads,
Thanks for the information.
I was able to get a reply from Manuel that did the photo build site at Ispra.Net - Alex Patak Audio (http://www.ispra.net/audio/)

He reports that his build was from 25MM "phenolic Beech" plywood, and the insulation was 10MM unbleached wool felt. the best results were from directly on a heavily carpeted floor.

I guess I will go the purist route on this, just need to find the extra dough to commit to this project.

The only thing I can find no definitive answer to is the Altec 416A or 416B choice, While Hiagra wrote that "he did not care for the sound of the B, there was no other reflection as to why.
I have not found anyone so far with experience with both the woofers to expound on it.

But, for now, I have a near new pair of 416B woofers,, in the future I could indeed try the A, as it would not be too hard to swap woofers, at most just making a new front board, and of course finding and buying a pair.

Anyone out there with both versions of the 416 that can comment?

As for amps, I own a Pioneer Spec 2, and Spec 4, a pioneer Sa 9100 and a Sa 9800, plus a number of 70's receivers.
I will be looking for a tube amp soon, just not sure what to look at that is within a reasonable price.
Thank you all.
Donald Bowman

[jf65]

hello Donald,

i don't think that directly on the floor or 10 cm higher on feet or casters can make a big difference seing the frequencies involved, but i often read that it's better to leave some air below the speakers.

As for the altec versions, i have the C and very satisfied by it, a friend had the B (Alnico version) in Onken box and i always found the bass a little muddy - after some years of trials of many kinds he has moved to other speakers. maybe the drivers , being a little old , had lost their magnetism as it is sait to happen to alnico. If i had to start now i'd buy a 416-8C at Great Plains Audio and be safe for the next 30 years (i bought mine new in 1982 - a few years before Altec stopped, so if you buy an old one it will be at least 30 or more for the B or A series).
IMHO there is an oversized magic aura around Onken boxes ;), they are only bass-reflex as demonstrated by J. mahul in l'audiophile with ports on the side like Jensen speakers (it's often called Oken-Jensen).
Their superior quality lies in the fantastic driver, the good wood, the big volume and the big vented area. Koizumi did many other boxes: Onken W with 2 drivers with just 2 holes as vents, another one like the A7,... I'd be curious to to know if someone has made just a box of the same volume and same ports area and lenght but in one piece below the driver and compared it to the original :confused:- maybe i'll do it someday.

By the way, do you intend to make them yourself or have them made? They are very easy to make if you buy the plywood cut at the good dimensions .
best regards,
Jean

[rusty jefferson]

Hey Donald,

Looks like a nice project.

I think the 1" ply is a good move, worth the extra expense. Wish I had used it on my DIY cabinets instead of 1" MDF. I wasn't aware of it's superior properties at the time I started.

I am a big proponent of plinths under speaker cabinets, especially large woofer and subwoofer cabinets. The set-up under mine are pretty pricey, but I don't see any reason you couldn't DIY them also. I don't think the material is as critical as the mass in applications like this. The thicker and heavier the better. I'm using cone shaped feet between the speakers and plinth, and also between the plinth and the floor. The difference in quality of bass between the speakers sitting on the floor directly, and sitting on the feet/plinths is nothing short of amazing.

As to the insulation, a knowledgeable friend recommended a low bulk wool (the type used for felt) that was not yet felted, but loose. Several pounds were packaged into a small box for shipping, but then I "combed" it into a fluffy (cotton candy like) web, and filled the cabinets with it. You may just be able to see it in the picture inside the port.

I'd like to thank the forum for making the plans for these speakers available, and the members for sharing their knowledge of all things JBL and quality audio in general. I know the feet/plinth/wool fill I'm using may be unconventional, but these speakers have exceeded my expectations. They replaced two factory B-380s and are a great upgrade.

Jim (Rusty)



46661

[reVintage]

Go for the original design, there is no reason to do it otherwise. If you check the original article below you can see it should be built with 25mm/1":

http://www.ispra.net/audio/Onken/Audiophile_n2_dec1977/articulo-hiraga01.html

I built the Petit Onken (414A) many years ago and I don´t regret for a minute that I used 25mm.

[Mrmonster11]

Thanks,
After a lot of footwork and advisement, I am now committed to the 1" Baltic Birch plywood for the cabinets, and I am trying to find the 10 MM wool felt insulation.
I am still trying to find out if there is any real difference between the 416A and the 416B in this cabinet besides the personal tastes of Hiagra.
Thanks,
Donald Bowman

[Altec Best]

I am still trying to find out if there is any real difference between the 416A and the 416B in this cabinet besides the personal tastes of Hiagra.
Thanks,
Donald Bowman

Hi Don, I think the 416B sounds the best to my ears but everyones tastes are different.Since you have a near mint set of 416B's I would use them.If they haven't been dropped or ridden hard chances are they won't need recharging.And since you say they are fairly new chances are they are good to go.The 416B's came in the model 19 and they are a great woofer.If you don't like them then you could always try something different.And I would be the first to take them off your hands.:D Good Luck with your project. Kind Regards ~ John

[Mrmonster11]

John,
That's the conclusion I came to. I set the B's up with the horns and the xovers with a blanket around the woofer, and it sounds great like this, can't wait to get the boxes built.
I just need to find a good price on 10mm wool felt. for the insulation.
Thanks,
Donald bowman

[Altec Best]

John,
That's the conclusion I came to. I set the B's up with the horns and the xovers with a blanket around the woofer, and it sounds great like this, can't wait to get the boxes built.
I just need to find a good price on 10mm wool felt. for the insulation.
Thanks,
Donald bowman

Good Deal, I'm looking forward to your impression of them when complete.Post some pics too,would like to see your project.:bouncy:

[Mika K]

Greetings from Finland.

I'm newcomer at the forum here but at the moment considering to build Onken cabinets by Hiragas plans to replace the cabinets of my Altec Valencia Iconics. Love the way they represent the music but as the cabinets are pretty much original and bit worn here and there, they would need some work to be done. My room is big and as Valencias do not deliver all the goods at the lower registers have thought to go for Onken as could really use that better defined bass that this design can deliver.

Have also eyeballed that french project, so will definately follow this with great interest. So please do share your experiences!

[Mrmonster11]

Hello Lads,
For you still watching this thread, I wanted to update you.
The cabinets are almost done, and wanted to share some photos and some thoughts.

I elected to have a cabinet maker build these due to the precision cuts and assembly needed. That and there is no way you can cut a 4'x8' sheet of one inch plywood on a $200.00 craftsman table saw.
My builder has a high precision table saw that cuts to within a 1/128 of an inch, and all the cuts are laser straight with no splitting or chipping of some very expensive plywood.
I could not find Baltic Birch anywhere here on the West coast, so we used one inch Apple Ply, that has 17 plys to the sheet.

Here are a few photos of the Ginormous table saw, and some of the cabinets near finished
The fellow in the shot is my builder.
The front panel is removable, but there is zero tolerance on the fit. It has to be tapped in place, and I don't have a feeler gauge thin enough to measure the gap.

They are going to finished in Osmo clear, a German water based finish that is very scratch resistant and seals the wood deeply.
We used the original Hiagra plans to build these using his dimension exactly, even down to the number of screws and their placement in the wood and every joint was heavily glued with a high grade wood glue that becomes stronger under pressure.

I was lucky to contact Alex and Manuel who posted their build on the French site Ispra.net Audio, and he was gracious enough to help with a number of questions on my project.

They should be ready on Friday, and I am going to do the finish myself to save a few bucks, as this was a very expensive project due to the plywood and all the precision work that needed to be done. Then I still need to install the wool felt insulation. If you are still interested I will keep this up to the final testing for sound

Thanks for all you input on this project.

Donald Bowman

[Altec Best]

Looking Good Don ! If that Apple ply is anything like 1" Baltic i know it is very expensive.We can get it here easily on the east coast.But it is $190 for a 4x8 sheet.the 3/4 comes in 5x5 sheets and is $48 Wait till you have to move/carry those.:eek: But they are looking great can't wait to see the drivers mounted.;) What are you using for the HF ?

[Mrmonster11]

Hello,
Thanks for the praise.
I would have had to ship Baltic Birch in from the East, and that would have put it over $375.00 a sheet. as it is the Apple ply was $175.00 here.

The HF are Altec 288C drivers with the German Jabo conical horns, which work great in normal size listening rooms

Thanks,
Donald Bowman

[Altec Best]

The HF are Altec 288C drivers with the German Jabo conical horns, which work great in normal size listening rooms

:applaud:


Those Jabo Conicals are huge aren't they.I'm using a set of 288C's with Altec tar-filled 1005"s at the moment, they are big too.I'm doing a build myself at the moment (Custom) I'm going with dual 416B's :D with 511E's / 288's in 20 cu.ft cabs.


Regards ~ John

[Mrmonster11]

Hello,
I am using the type 50 Jabo horn which is smaller than the type 55. my horns are 21 inches in diameter.
They were a tad small on my old Altec VOT speakers, but are perfect in these Onkens
The big Altec multicell horns are great horns, but I found them to sound "tinny" in a smaller room. I found another member here that was using the Jabo horns, and he was very happy with them.
I am also using the Jabo crossovers on this setup. They worked great on testing the components without a cabinet, and I am sure they will be super fine once everything is finished.

That German Jabo guy makes some great stuff, but he is an Ass to work with on shipping and getting follow up information, like user guides and setup questions.
But I still have no problem in recommending his products.

Donald Bowman

[Mika K]

Looking good!

I have also contacted the local builder for the Onken cabinets and they are assigned on his queue. Most likely they will be manufactured next years jan-feb etc. Depends of the finish of the current projects he is having.

I have planned to fit atleast for a beginning the original Altec Valencia Iconic drivers and horns and was asking something related the xo in other thread, but no love for newcomer atleast so far. So please keep this page updated or atleast share your thoughts after the cabinet is ready, drivers and xo's in place and in action ;)

[Progneta]

I wish I had some one in Ohio that could make me cabs like that...I am looking for a stonehenge type cabinet for 2 Altec 601c's. I could make the cabs, but they wouldnt look as pro as yours! Very nice!

[Altec Best]

The big Altec multicell horns are great horns, but I found them to sound "tinny" in a smaller room.

That's why you need the Tar-filled's heavy as heck.Wrap on those(Dull as a Post) and you bruise your fingers.;) No tinny sound there.The newer Aquaplas ones aren't as damped IMO.But I think they still sound good.But how small is your room.The Multicells really need some room to breath and weren't designed for Hi-Fi/HT apps.They were designed to project sound out into a big audience(Movie Theater).


I have planned to fit atleast for a beginning the original Altec Valencia Iconic drivers and horns and was asking something related the xo in other thread, but no love for newcomer atleast so far.

Although this is Lansing Heritage in which we are here to honor Mr.James B. Lansing in his endeavors Lansing Manufacturing,Altec Lansing,JBL this forum is mostly JBL enthusiast's and has nothing to do with being a newcomer.May I suggest trying the Altec User Board for Altec questions.;)

http://www.hostboard.com/forums/altec-users-board/

[Mrmonster11]

Hello Lads,
well this long journey is almost at an end. I need to install some more of the wool felt insulation and finish mounting the 416B's to the front panel

Which brings up the question of how tight do I drive the mounting bolts to the face? any suggestions or torque measurement in foot pounds? as these have cast frames, and a very thick gasket on the face of the rim, and I don't want to crack the frames after all this work and money.
These are new old stock woofers, and were never mounted before, so that gasket is thick and firm.

Hope to be playing music on New Years Eve through them.
Thanks,
Donald Bowman

[jf65]

Greetings from Finland.

I'm newcomer at the forum here but at the moment considering to build Onken cabinets by Hiragas plans to replace the cabinets of my Altec Valencia Iconics.

hello, the original wood used by Hiraga (and me) was Nantex made of Finland birch, you are at the right place .

[Salectric]

Donald,

So how do the speakers sound in the new Onken cabinets?

Dave

[norelco]

Hi,

Since this thread are inactive for almost 5 years,i would like to chime in with some few questions regarding to well regarded Onken Builds,

1. Is it ok to use 11/8 thick Marine Plywood (over/excess of 1/8" to the 1 inch of the original design)
2. same with Mr. Donald, i have the Altec 416 8B (compare to 416 A of the original design)

Hoping for your help, since this an old thread and i assume that many people here have a lot of experience owning this legendary speaker.


Thanks & regards,

From Philippines,

Norelco

[norelco]

Posting some photo of my project, ( just finish yesterday)

http://i12.photobucket.com/albums/a201/ronaldcorrales/Mobile%20Uploads/2F675EF4-7128-4911-9B6C-5E6B5BC3A54D_zpsj6w8spll.jpg (http://s12.photobucket.com/user/ronaldcorrales/media/Mobile%20Uploads/2F675EF4-7128-4911-9B6C-5E6B5BC3A54D_zpsj6w8spll.jpg.html)

http://i12.photobucket.com/albums/a201/ronaldcorrales/Mobile%20Uploads/55D79143-CD62-413A-BC30-2C3E7B955959_zps97ibhluw.jpg (http://s12.photobucket.com/user/ronaldcorrales/media/Mobile%20Uploads/55D79143-CD62-413A-BC30-2C3E7B955959_zps97ibhluw.jpg.html)

http://i12.photobucket.com/albums/a201/ronaldcorrales/Mobile%20Uploads/9A67276C-7116-4EDF-8269-86325206CE66_zpscn3scuea.jpg (http://s12.photobucket.com/user/ronaldcorrales/media/Mobile%20Uploads/9A67276C-7116-4EDF-8269-86325206CE66_zpscn3scuea.jpg.html)

http://i12.photobucket.com/albums/a201/ronaldcorrales/Mobile%20Uploads/D45E617C-2F88-4AD6-90DE-B3B221261377_zpssnaejywl.jpg (http://s12.photobucket.com/user/ronaldcorrales/media/Mobile%20Uploads/D45E617C-2F88-4AD6-90DE-B3B221261377_zpssnaejywl.jpg.html)

http://i12.photobucket.com/albums/a201/ronaldcorrales/Mobile%20Uploads/9CE79DBB-F984-4B03-B45B-654A8934ADF7_zpsjg5zfvc0.jpg (http://s12.photobucket.com/user/ronaldcorrales/media/Mobile%20Uploads/9CE79DBB-F984-4B03-B45B-654A8934ADF7_zpsjg5zfvc0.jpg.html)

http://i12.photobucket.com/albums/a201/ronaldcorrales/Mobile%20Uploads/29A8945E-2966-4867-AAFC-10106D9D6C48_zps56t9xrca.jpg (http://s12.photobucket.com/user/ronaldcorrales/media/Mobile%20Uploads/29A8945E-2966-4867-AAFC-10106D9D6C48_zps56t9xrca.jpg.html)