Onken Enclosures

[kevinkr]

Please keep your posts technical and avoid personal attacks which are a violation of forum rules. Anyone posting technical criticism within the Forum rules is free to post in this or any other non-commercial thread.

[EBA]

Hello GM,

All the answers are on the FORUM Mélaudia / haut parleur / thread optimisation des grandes ONKEN de mélaudia page 2 / pages 3,4....

For the optimum QTS for bass reflex inclosure it is M. KOISUMI shaw the tread, but it is in french ( google translate ). And the web side about that is in japonese, but very good.
And shaw the théorique calculation of the B15 EX at 12,5V and 7,5V, QTS 0,142 and 0,238 and shaw the curves. No comment. And when you listen to the difference is big ( is possible for me in live, i just modified the voltage of the field coil ).
Shaw in this thread the différents T/S of the 416-8ABC, 515B,C,8LF,G, SUPRAVOX speaker and B15EX and the comments of me and JLMC.
Another parameter, M. KOISUMI modified the 416-8A with low fs=22hz and a QTS=0,27 N=6,35, but i think he wanted N=5,7.

If you will not anderstand the totality, i try to translate for you what you want.


Cdt.

EBA

[EBA]

Helmuth,

I posted my curves and i'm not aggree with you about yours curves. But i listen the moderator and i stop this discuss. it's not a good discussion.
I'm repeat the EMINENCE DELTA 15 is a good speaker and the B15EX to. Is the pincipal.

Cdt.

EBA

[EBA]

Hello GM,

For the optimum Bass Reflex QTS of 0,25 it is easy to check this information with the DATAS BASE speakers Dominque Pétoin ( google ). Dominque have a big base with a lot of speakers past and new with the possibilties in a few clicks to calculate the parameters for differentes combinations of volumes and bass reflex, horns, helmotz,OB, close, possibilities for each speaker with his limites.
IF you take for example the B15EX 12,5 V electromagnetspeaker, you shaw immediatly for differents volumes the Thiel alignment. And for this speaker with a QTS of 0.14, it isn't possible to have a good alignment.
But You take the same whith 7,5V and a QTS=0.238, you have the best aligment possibilities in BASS REFLEX.

You can realise this exercice with all the speakers of the base, you have the same résult with a middle QTS 0.25 or low 0.18 and lower.

The lower QTS are more according with the horn systems. Please take the B15EX 12,5 V and do the same exercice with the horn calculate possibilty. I didn't calculate but i am shure this speaker is accordind for horn system.

Cdt.

EBA

[Helmuth]

Originally Posted by EBA

Helmuth,

I posted my curves and i'm not aggree with you about yours curves. But i listen the moderator and i stop this discuss. it's not a good discussion.
I'm repeat the EMINENCE DELTA 15 is a good speaker and the B15EX to. Is the pincipal.

Cdt.

EBA

Your simulation shows 3-4 dB more, I have good experience with Winisd results so do not doubt them.

I understand your choice on your own data, with use of room gain it can become close to flat and near the 100dB level.

[EBA]

Hello Hemuth,

I charged winISD and i learn the different possibilties. I simulated the exately ONKEN 360 enclosure with, it's more importante, the good events. 6 / 0,28X0,05X0,405.

I am not had the same result but it's a good think. I used the phase curve and group delay curve for the optimisation of my ONKEN.

The instruction of JLMC at this topic is clear. For the group delay the best curve is without bump and the flatter possible and it the same for the phase curve.

It's very very difficult to get this result. For me i shuted down the efficiency to 95,6 db. But i have best curves SPL, Phase, and delay group.

And i doesn't a run to the efficiency, 96 db is suffisant. See the attached file.

I listen this new position and i will post in this thread the mesurement curves with ARTA.

Cdt.

EBA

[Helmuth]

Port size is important for Onken alignment I did not see different results for simulation small or big. When you change port size then in the box window the tuning frequency will also change in winisd.

In practice the sound is boomy from a to small port I know from my projects.

To play with the cutoff characteristic you can simulate the influence of the series resistance of the passive filter or with active place a series shunt to get the optimal result. It will change the total Q = Qts.


Also you can ad mass to the cone to lower Fs and this can be also a way to tune a driver for your application.

And you can ad your lowpass filter it will raise the groupdelay in the simulation. The low Fs of your driver helps a lot to keep the groupdelay low when tuned to Fs, you showed that in your simulation.

[EBA]

Thank's HELMUTH,

I study that. The modern word enter in my home. Is cool.

I don't have a passif crossover is a DCX modified. But i try to play with résistance série of my SE 845.

I don't have see your group delay of your nice project and for me i change the 850TI by a 2482, PR950 and ad a tweeter. With this confirguration you have the possibility to cut the DELTA 15" arround 350HZ. It's importante because the all 15" driver have a bad response under 300 hz, it Is mecanique and depend of the cone expention.

I work.

Cdt.

Eric

[DrBoar]

Regarding onken style boxes. Have anyone noticed vibrations in the sidewalls? I built some and expected that the bracing in the port slots would turn the sidewalls to a very rigid matrix. However, I find that the sides vibrate more than both the braced back and the unbraced top and bottom panels?