Onken Enclosures

[Pano]

Thanks GM, that's the kind of info we need!

Here is a thread form last year that has some more info.
Onken thread

I know the Onken W and the Focal mentioned in the 1st post.
The W was VERY impressive! Double 15" drivers in a double wall sand filled enclosure. Very pure bass, and plenty of it.

I hope to can pull some good info from the French articles jamikl sends.

[Pano]

OK, looking back at some of the old Onken threads I see the GM is all over them. He seems to be the Onken Guy!

Just read the 1977 Jean Hiraga original article and Phillppe Vibou's 1982 case building article. Neither give formulas. Jean just says "build it like this, or it won't work" and Phillippe gives details and photos for building the case.

One of the great qualities of the Onkens I heard was the amazing Nantex plywood. Philippe mentions how hard it is (was) to work with. I can vouch for that. In '86 I rebuilt a pair of Altec A7s for Jean Hiraga using Nantex plywood. (My favorite speakers of all time) It was the hardest damn stuff I ever saw. Like cutting and drilling granite! But it sure was neutral. No box sound at all. Magic. Sure wish I could find wood like that now....

[el`Ol]

One example:

The Eminence Legend 151 with Fs 82Hz makes 34 Hz in a 360l Onken with Port length 31cm and port crossectional area 85% Sd at Onken alignment.

[Pano]

Originally posted by el`Ol
The Eminence Legend 151 with Fs 82Hz makes 34 Hz

Cool! I also ran the spreadsheet on the Selenium 10PW3-SLF 10". Looks like it might work.

[GM]

Originally posted by panomaniac
Thanks GM, that's the kind of info we need!

I know the Onken W and the Focal mentioned in the 1st post.
The W was VERY impressive! Double 15" drivers in a double wall sand filled enclosure. Very pure bass, and plenty of it.

OK, looking back at some of the old Onken threads I see the GM is all over them. He seems to be the Onken Guy!

Neither give formulas.

One of the great qualities of the Onkens I heard was the amazing Nantex plywood.

Greets!

You're welcome!

Onken Guy? Well, if so, only around these parts.

The formulas were in a French magazine article, l'Audiophile?

The Onken W is a very straightforward BR, with its main claim to fame being the sand filled double wall construction. Lining a 19 mm Baltic Birch plywood cab with 3/4" drywall will suffice. It's the dual Altec 416 woofers that makes this cab 'sing'.

I've never seen the Nantex, but I've used both 1" no-void marine grade and Baltic Birch and both cuts like it's made of iron, so I wonder if it's basically like either of these.

GM

[GM]

Originally posted by el`Ol
One example:

The Eminence Legend 151 with Fs 82Hz makes 34 Hz in a 360l Onken with Port length 31cm and port crossectional area 85% Sd at Onken alignment.

Greets!

Did you sim it? You'll have to stuff the vents solid to get rid of that peak, so might as well build a sealed cab and save yourself the extra woodworking.

GM

[GM]

Originally posted by panomaniac


Cool! I also ran the spreadsheet on the Selenium 10PW3-SLF 10". Looks like it might work.

Greets!

The Selenium's Qts is a bit high too. Remember, if a higher Qt driver doesn't sim well in a BR, the Onken's large vent area will only make it worse.

To keep the vent length <35 cm, I had to use n = 7 and only 75% vent area.

GM

[tinitus]

Hi guys, please try and calculate/sim this 18" BMS driver - I think it might be perfect for Onken box

http://www.bmspro.info/index.php?sho...286&id=5049386

[el`Ol]

Maybe for an Onken sub that just has to go 200 Hz long ports are not a big problem. In my simus with smaller drivers the peaks start at 400 Hz. I still have the free version of MJ King`s BR sheet.

[GM]

Greets!

Me too, but it doesn't matter. Think about it, the vent's pipe resonances will still be there, comb filtering with the mains, and since they will be higher in amplitude and probably further away, it will probably be much more audible. Of course if the tuning and/or peak power applied is such that the vent(s) is never energized fully, then this is moot and why a tuning that either isn't too close/at a major fundamental or damping the vent is a good plan.

GM