Does Onken Bass Cabinet sounds more open & less boxy

It is more a case of how well designed 7 executed the box is. The only thing an Onken brings to the table are the inherently well braced double sides. They still need to be adequately braced.

I borrowed the vent configuraion for my miniOnkens (not an “Onken” alignemnt but my own). I go to some effort to design the boxes so that they are not boxy sounding.

Tad-Ken-visualization.png


dave
 

sumotan

Member
2013-10-16 4:18 pm
Thank you kindly Dave. Wow that's some heavy bracing work. The reason that I'm asking is that I've noticed Onken cabinets are generally big in volume which leads me to my question. Is cabinet stiffness the be it all, for me still a question mark cause a good buddy of mine has a pair of Watt/Puppy though cabinets are super tough, there is still some muffiness in the sound at higher play back levels.

Many thanks again
 
The Onken is very resonant in that the vent's combined harmonics comb filtering with the driver's output is loved by many, though for folks like me that prefer a more accurate [some say 'dry'] reproduction they wind up stuffing them to 'taste' to make them somewhat aperiodic.

Note the peaking at tuning and 'mountain range' response up to ~ 1 kHz on pg. 4: http://www.planet10-hifi.com/downloads/Hiraga-Onkens-English.pdf

This cab is n = 6.34, what is normally used, but IME the pioneer's Vb = Vas/1.44 recommendation [n = 5.7] except tuned to Fs is a better choice overall with Dave's falling more in line with what I'd build WRT vent design.

GM
 

sumotan

Member
2013-10-16 4:18 pm
Thank you again GM. Like many of us in DIY along the way I've collected some speakers & am now thinking about what to do with them. Lol. I especially like the Coral 10F-60 over the Flat 8B that I have. Test them in an OB sometime back & the 10F-60 sounded very good. Strangely I notice that vintage speakers are never quoted with TS specs. Looks like I've to learn how to measure the speakers to get the specs.
Lastly with a wide baffle, is BSC network still mandatory for a 2 way set up ?

Many thanks GM
 
Volume depends on the driver used. Onkens often have large drivers with huge Vas that need big boxes. It is not inherent.

If you can push any potential resonances up above the bandwidth of the woofer — even just get it up high — then it becomes next to impossible to excite by playing music thru it.

That it best acheived with high stiffness & suffient bracing. The cabinets do not need to be heavy (relative to their volume).

dave

dave
 
Thank you kindly Dave. Wow that's some heavy bracing work. The reason that I'm asking is that I've noticed Onken cabinets are generally big in volume which leads me to my question. Is cabinet stiffness the be it all, for me still a question mark cause a good buddy of mine has a pair of Watt/Puppy though cabinets are super tough, there is still some muffiness in the sound at higher play back levels.

Many thanks again

Hmm, to me, 'boxy' refers to 'hollow' sounding, which is dealt with internal damping.

Bracing, mass loading is about ensuring the driver is adequately supported to work at peak mechanical/acoustical/electrical efficiency, so it's about taking the box out of the reproduction signal chain as much as practical, but no amount of bracing will damp out 'hollowness', it will just shift it up in frequency, reducing the amount of damping required [a good thing], though the amount shown in the rendering is overkill unless the panels/'skin' is thinner than the norm.

IME, 'muffiness' is due to heavy stuffing densities with [over] damping increasing with increasing power.

Mass loading is where it's really at though when it comes to getting the most detail out of a speaker, so while the matrix bracing may be overkill, it adds mass and in general a 15" woofer cab requires several hundred lbs of [total] mass to become near enough inert as one skeptic found: Mass Loading ALTEC A7 VOTT 825 enclosures - drlowmu - High Efficiency Speaker Asylum

Percentage wise, even more for a metal horn: High Efficiency Speaker Asylum

GM
 

sumotan

Member
2013-10-16 4:18 pm
Thank you again Gents for the tutorial. Assuming that we have a speaker that can be use on either Onken & Blh cabinets, which would you guys prefer ? I'm more into open sound & thanks to you GM my ML now sounds more like full Esl then a hybrid.

Thank you both
 
Strangely I notice that vintage speakers are never quoted with TS specs. Looks like I've to learn how to measure the speakers to get the specs.
Lastly with a wide baffle, is BSC network still mandatory for a 2 way set up ?

Many thanks GM

You're welcome!

Nothing strange about it, but that's a history lesson and I'm about typed out, but even when manufacturers started posting them they were often wrong and this is still more of a problem than it should be, so always best to measure, especially old drivers left setting around for decades like me.

At ~ 26" it's often unnecessary when near a wall and by 30" it's normally only necessary if the driver is already rolling off, so the width I recommend for out in the room or low tuned cabs such as EBS or low Qt tuned to Fs.

GM
 
Thank you again Gents for the tutorial. Assuming that we have a speaker that can be use on either Onken & Blh cabinets, which would you guys prefer ? I'm more into open sound & thanks to you GM my ML now sounds more like full Esl then a hybrid.

Thank you both

You're welcome!

Hmm, if the driver's suited to Onken [reflex Qt], it's not suited for BLH [sealed Qt] without significant EQ since we want a low acoustic XO down where our hearing acuity isn't too good, i.e. rolls off at a low baffle step frequency.

Cool! :up: :D.

GM
 
Again,
we want a low acoustic XO down where our hearing acuity isn't too good, i.e. rolls off at a low baffle step frequency.

......and preferably far enough down in amplitude to be in the noise floor [signal to noise [s/n] ratio = -25 dB] + 10 dB [-35 dB total] to make sure we can't hear any out of phase comb filtering through the acoustic XO BW, i.e. driver/horn is perceived as a single large coincident driver. Unfortunately this is an unrealistic goal unless designed for prosound high power apps since we need up to a ~2.0 Qts and the huge horn required to squash/shape its response as required.

If we use standard T/S then, we start with the driver's upper mass corner Fhm = 2*Fs/[Qes' or Qts' depending on who you ask, though most DIYers just use published Qts], so for a 40 Hz Fs/0.3 Qts vintage spec driver = ~267 Hz, but it would have been designed for a ~matching impedance [low DF] amp that ~doubles Qts, bringing Fhm down to ~135 Hz where it needs to be to roll off to ~200 Hz and as amp power increased, driver Qts rose to offset it, hence the need nowadays for sealed Qt drivers since most folks use very high DF amps.

Qts' = Qts + any added series resistance [Rs]: HiFi Loudspeaker Design

GM
 
for what is is worth - I built the mar-ken trapezoid speakers with Daves (planet 10s) design and the Mark audio 85 dollar drivers and I have to say they are a really impressive they hit way way way above their weight class. The enclosures are complex enough to keep the woodworking side interesting. no crossover - I have been working on other speakers for a several months now and just scratched the surface of speaker design. I have come to realize the order of skills in increasing difficulty maybe medical doctor, rocket scientist, particle physicist, speaker designer.

Just for the record I mean no disrespect to any of the above skill sets. It is a fact that the more you learn about speaker building the deeper you dig into the whys. the physics and math are really complex and there is a lot of conflicting information. Just measurement alone is a lot to learn. Not to mention what happens to the sound after it leaves the speaker. I think that is why almost everyone says build a kit for your first build.
 
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