My 'Moon-Onken'

[Godzilla]

Great pic of the building in process! Neat box!

I bet they sound nice!

 

[Bigun]

Hi,

The holes in the brace allow for a nearly direct path from the driver, but there's a bit of a dog's leg in it.

Mounting is done with the screws that ship with the driver, they seem to server well and since I don't have a chamfer bit for my router it doesn't cause any inconvenience.

I need to fit some poly batten in the things so I can glue on the 'lid'...

 

[Bigun]

Great pic of the building in process! Neat box!

I bet they sound nice!

Thanks for the words of encouragement. So far, the first pair built sound very nice. But I need eventually to add the sub-woofer to fill out the low end (as per the design) then I'll know whether the complete 5.1 set up is going to serve or not.

 

[Bigun]

Progress at last, the front 3 Moon Onkens, sans cups & drivers...


The first pair have broken in now and have a semi-permanent place on top of my PMC floor-standers. Anyone want to offer me a good price for my PMCs!

 

[Bigun]

The drivers finally came in and I've been able to finish off the last 3 Moon-Onkens. The second pair sound awful. I've gotten used to the first pair which have over 200hrs now and the fresh drivers sound terrible in comparison.


Here's they all are...

 

[GM]

Cute little buggers. Interesting about the break in differences. There's no excuse for it in a general purpose driver.

GM

 

[c2cthomas]

Cute little buggers. Interesting about the break in differences. There's no excuse for it in a general purpose driver.

GM

Fostex = a lot of break-in. 200 hrs at least. (That's what my 167's took - heck for the 1st 40 hrs I had to crank 'em to about 60% just to get the darn things to start moving!) Plus you need to figure out how long it gonna take to do some speaker and basket treatment on the buggers.

Bigun - I like your style and most am tempted to knock some of these together for surrounds. Very nice job!!!

Have you considered BudP's EnABLE treatment?

 

[GM]

And why I consider such drivers as 'broken' once 'broken' in, needing either a rebuild or used for target practice, so should only be used in apps that keep them 'as is' over time once 'broken' in after a few hours at excursions high enough to audibly hear them leave the VC gap's 'sweet spot'. Obviously, this philosophy is anathema to this forum, so 'color' me done on the subject.

GM

 

[Bigun]

Bigun - I like your style and most am tempted to knock some of these together for surrounds. Very nice job!!!

Have you considered BudP's EnABLE treatment?

Thomas, thanks for the kind words, makes a big difference !

I am thinking about some cone treatments and have had some advice from Dave (planet10) on that topic. But it's not a high priority. Going with the full eNable is a strong possibility because I'm always curious. But I might get distracted by moving on to some amplifier building. I am only just starting to investigate my options for that and was most interested in the 'Krill' thread you participate in but I've no idea if this is the best way to go.

Good news is that I find the Fostex drivers improve drastically in the first few hours, after that the rate of improvement slows down quite a bit.

 

[gaust]

I love this design!! but I had a few questions before I embarked on something similar. I have some 4" drivers and I have used the dayton woofer tester to meaure their T/S parameters. After being inspired by this design I tried plugging the numbers into the onken excel spreadsheet that is linked to in this thread. Anyway the upshot was that this driver was (vastly) unsuitable for use in an onken. My questions therefore are

1. Did you you use the onken calculator for designing these speakers?

2. Is it possible / advisable to make an 'onken-style' bass-reflex cabinet that is not a true onken?

3. Are there any advantages to this 'onken-style' cabinet other than the reinforcement of the side panels?

Unfortunately I do not have the T/S parameters that I measured with me at work, but I do remeber that the Vas was quite small (3L) so I will probably start a new thread when I have the parameters to hand and ask about suitable cabinet types for these drivers.

Thanks,
Jon

 

[Scottmoose]

I'm not Dave et al, but...

1/ No. Onken's were only the second reinvention of the distributed vent system idea that stretches back to the original BR patent. You don't have to use it's strictures.

2/ See 1/

3/ Is entirely dependant on the alignment as a Fonken is almost the reverse of the original BR / Ultraflex / Onken concept.

 

[chrisb]

I'm not Dave et al, but...

1/ No. Onken's were only the second reinvention of the distributed vent system idea that stretches back to the original BR patent. You don't have to use it's strictures.

2/ See 1/

3/ Is entirely dependant on the alignment as a Fonken is almost the reverse of the original BR / Ultraflex / Onken concept.

and it's certainly too late to rename the (Planet10) design

 

[Scottmoose]

Besides, it's a good name.

 

[planet10]

1. Did you you use the onken calculator for designing these speakers?

2. Is it possible / advisable to make an 'onken-style' bass-reflex cabinet that is not a true onken?

3. Are there any advantages to this 'onken-style' cabinet other than the reinforcement of the side panels?

1/ i'm not sure how Bigun actually derived the design ( he did use the Fonken as a reference), but the Fonken was done with no consideration of "official" onken calculations

2/ ie all the Fonkens

3/ Yes. The inherent side panel rigidity is very important side effect, but the prime rationale is to create a high aspect ratio port -- ie effectively putting a resistor in series with the port making the BR less sensitive to the fact that TSP change as you alter the drive (as well as the fact that typical driver parameters have a range of 20-30%).

dave

 

[vinylkid58]

Unfortunately I do not have the T/S parameters that I measured with me at work, but I do remeber that the Vas was quite small (3L) so I will probably start a new thread when I have the parameters to hand and ask about suitable cabinet types for these drivers.

Use WinISD to model some boxes. Just add your drivers TS numbers to the existing database and you're all set.

Jeff

 

[Scottmoose]

Sadly, that's not going to work too well, as it can't account for the vent aspect ratios' affect on the response.

 

[vinylkid58]

True, but it's fun to play with for regular BR alignment.

Jeff

 

[chrisb]

Besides, it's a good name.

it wasn't my intention, but it is certainly another multi-purpose F word

there are no bad words, just the intentions behind them

 

[planet10]

Sadly, that's not going to work too well, as it can't account for the vent aspect ratios' affect on the response.

I don't know of any modelers -- except maybe Martin's -- that considers that, I use experience to modify the modeled response into what to expect (ie i model till i get a curve that looks a specific way, build and revise as needed)

dave

 

[GM]

The only program I've seen that can do 3D acoustic loads was a ~$5500 intake/exhaust designer.

GM