best beyma woofer for Onken?

[kevinkr]

Hiraga..

 

[tinitus]

since it has to be Beyma, how about the Studio woofer

http://www.beyma.de/fileadmin/seiten/download/pdf/Beyma_2011/15B100R-GH.pdf

 

[GM]

Works for me! A little above the Av = 0.75*Sd min. [~0.78*] and n = 6.34, this one does it using the popular six vent layout.

GM

 

[Pano]

....and even then the original driver used was modified by the author.

Which Author? I've sent time with the Big, Little and Mini Onken, I don't remember any that had modified drivers. Maybe it was one I don't know?

But as I recall, there was little or no damping inside the cabinet

There wasn't a lot of damping volume, but the damping was done with 100% wool felt. I used some in other cabinets, too - it's expensive! Jean Hiraga had sourced a thick felt normally used in hospitals to prevent bed sore for immobile patients. In the larger boxes, a curtain of the felt was hung about 2/3 of the way back, in addition to the small amounts on the walls. It didn't seem to take a lot to work well. Good thing, in view of the cost.

 

[Eldam]

Kind-of....Sort-of....Onken-Overtime
Onken ported MLTL "Onken-on-the-floor"

Jean Hiagra
"The chosen solution here accepts a load of much smaller speaker volume (around 190 liters, instead of the usual 350 liters required for a 15 in. woofer) without experiencing a sharp decrease in sensitivity over the low frequencies, none of the usual sound colorations when a large woofer is associated with a load of small volume. This goal has been reached successfully thanks to the merging of several means : no back-chamber/throat (decompression) but a tuned load (BR) thanks to a laminar vent situated under the speaker itself, to adequate filters and, finally, proper internal padding on wooden walls made of an optimized sandwich of plies.”

The laminar vent looks like the Supravox 'baffle compensé" : you can set up easier and more average during the development.

I don't know about the shematic of Hiraga speaker 604 but look like near a onken but radiate on the floor... sort of BR like Proac and BR of the 80s' ?

Is an Onken nearer than a bass reflex or a quarter wave box ? Ok the tunel is not 8 inch in an Onken but I read somewhere than the long tunel of the quarter wave box make them not so reactive with bass and Hiraga is one of these men who are not joking with the quality of the mid bass attack & sound quality imho. Some use AUDAX rca 15" fiber glass here because data are near of some onked JBL driver. But too expensive at 400 euros !

 

[Eldam]

Which Author? I've sent time with the Big, Little and Mini Onken, I don't remember any that had modified drivers. Maybe it was one I don't know?


There wasn't a lot of damping volume, but the damping was done with 100% wool felt. I used some in other cabinets, too - it's expensive! Jean Hiraga had sourced a thick felt normally used in hospitals to prevent bed sore for immobile patients. In the larger boxes, a curtain of the felt was hung about 2/3 of the way back, in addition to the small amounts on the walls. It didn't seem to take a lot to work well. Good thing, in view of the cost.

Is the wool felt important in relation to another fabric like underfelt carpet (underlay) or Dacron fiber or...any syntetic fiber used in sleeping bag ?

Velvet wool for coats used in the Dalquyst OB is always an good idea ? Any fabric with long fiber like lamb wool like Linn speakers (marketing & global warming proof ?)

 

[GM]

Is an Onken nearer than a bass reflex or a quarter wave box ?

Some DIY Onken alignments I've seen on-line qualify as a two-stage [stepped] inverse tapered TQWT, but all the originals I'm aware of are all simple reflexes.

With the drivers available today, multiple vents typically need to be very long to get a ~ Av = Sd, so I prefer to morph them into a true inverse tapered TQWT, which tends to measure, perform better overall, though one guy put fake vents on his to get the Onken 'look'.

[ML]TQWTs are inherently better damped due to its 1/4 WL loading of the terminus[or separate vent], so yes, it's less reactive and can be designed to be ~reactance annulling same as a compression horn, though at the expense of reduced ~flat gain BW.

Not many 'free lunches' in audio design.

GM

 

[DrBoar]

Locating thick felt can be a challange. Saddlers have such felt, if you can not find such a craftsman then find a store that sells riding equipment they sure can give you directions.

In Sweden we have a chain of stores selling car and DIY stuff, the felt is quite compact and stiff and cost about a dollar per sqare feet. What ever store that sell autosound and or panel damping/insulation could have similar products.
Ljudisoleringsfilt - Biltema

 

[Eldam]

Thanks GM for inputs.

I imagine the difficulty to set up a MLTQWT speaker to find the good shematic for the QW an the good fill in for the damping to choose the total Q of the speaker... not a beginner task !

I would have the pleasure to hear once in my life a good Onken, a good big closed box and an W OB bass box à la Linkwitz (Q=0.5?) in a same day!

I have two speaker with the concept of the kef 104/2 and Boston 400L, the bass I heard with an Onken was far better...but far bigger box too (difficult in a normal living room)

Sorry about the 15" driver i talk about : it is not Audax but Davis rca15 : interesting because datas near old JBL driver some loved to used to with Onken when no Altec could be find. Beyma is loved by Audiophile here too.
I saw with the Hiraga 604 speaker that it could be possible to source clone driver in your country (but without the expensive today Alnico). If it is nearer of a vented than a MLTQWT, we could imagine than the design is close to a pasta lunch box (like a sort of inverted pyramid with a flat top) with a cube on it : the narower base near the floor and the larger on top near the driver for the beginning of the QW... so with the box on it the width of the tunel is increasing when it arrives to the base of the speaker and it is like a big Scanspeak flowport because it's resistive ?
Electro magnet speaker could be a way to set up easier than rebuild heavy & expensive box !

Sorry to be off topic.

 

[Insanoff]

Maybe Selenium?

A guy I new once had a pair of Onken-Focal speakers that used Focal 10C02 woofers in an Onken enclosure. If I'm not mistaking they had high Vas and very low Qts. Such drivers are not easy to find anymore, that's true.

I'm going to use "Selenium 15PW3-SLF" driver for Onken. It has Qts=0.61. What do you think, does it make sense to use it?

http://imageshack.us/a/img713/2303/xap9.png
http://imageshack.us/a/img405/1521/ktgg.png
http://imageshack.us/a/img834/6479/m99r.png

 

[grandville45]

I have one of the sm115's In one of my Altec A7 cab's and it sounds very good in there, I think the cab's are around 10.5-11 cf? The other cab is the original reconed from GPA 416-8c, together they sound great! The beyma has more rumble down low, but the altec has a better sound to it overall IMO