OB origins ?

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Scott L

  • Jr. Member
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OB origins ?
« on: 22 Jun 2017, 12:24 pm »
Greetings fellow members. I am trying to establish how far back in time this OB craze first started. Please understand, I am not asking about the original history, because I do understand that if you go back far enough in time, all speakers were at least "open backed". Who was it that started all this OB business with respect to igniting the level of popularity we see today, among DIY'ers?

Or, at least please post your very first exposure to OB, when/where it was, and why you liked it so much. Thanks !

ebag4

Re: OB origins ?
« Reply #1 on: 22 Jun 2017, 04:30 pm »
The Darkstar thread here on AC ( http://www.audiocircle.com/index.php?topic=19253.0 ) started by Dmason many years ago started my journey into OB.

Best,
Ed

JohnR

Re: OB origins ?
« Reply #2 on: 22 Jun 2017, 04:39 pm »
I remember reading about the turn of the century people raving about a RadioShack driver mounted in a piece of plywood. I tried it and it was awful. However it piqued my curiosity and a bit later discovered LinkwitzLab.com which at the time had only his Phoenix project on it. I didn't build it but learned a great deal from reading it.

As for origins, there have been various commercial OB speakers over the years including some designed by Linkwitz e.g. Beethoven. A historical timeline would be truly awesome if anyone knew of one published.

matevana

Re: OB origins ?
« Reply #3 on: 22 Jun 2017, 04:52 pm »
I think you'd have to give credit to the Quad ESL57 and Wharfedale SFB from the 50's, though I agree that many newer designs (Linkwitz,John K,MJK) have done a lot to promote interest more recently. The internet also played a role in helping to level the playing field, by promoting more fringe DIY concepts.   

On the commercial side, Jamo inspired a lot of DIY projects, circa 2005 maybe?



« Last Edit: 22 Jun 2017, 06:46 pm by matevana »

mcgsxr

Re: OB origins ?
« Reply #4 on: 22 Jun 2017, 09:58 pm »
I first heard a set of large Maggie's around 24 years ago.  I was amazed by the form factor.  And the price.

The combination of Dmason and Planet10 started my journey as documented in the Darkstar thread here.

I later owned 2 sets of Maggie's. 

I currently don't own OB speakers but don't rule them out again in the future. 

Chicken Man

  • Jr. Member
  • Posts: 22
Re: OB origins ?
« Reply #5 on: 23 Jun 2017, 02:46 am »

If I remember way back then, G.A.Briggs produced his Wharfdale 'sand filled baffle' (as mentioned above) which first involved me with the concept of O.B.   I have his book 'Loudspeakers' somewhere, I bought a few of his loudspeakers like the 12" RSDD, the infamous 8" RSDD (the worst loudspeaker I have ever bought.....'ever' ). I was never really satisfied with the sound of any of them no matter what I did. That 'boxy' sound was almost impossible to get rid of.

In the end I finally gave the 8" pair away for free with the sale of the 12"RSDD's, I do feel for that poor soul that bought them though, DIY loudspeaker design is a learning curve for everyone ........there are no exceptions, frustrating as it is. 

I then moved into open baffle design about 50 years ago, the fullrange driver seemed to be the way to go, no crossovers thank goodness. I soon found out that baffle size and speaker diameter made a difference, a real difference to the sound.
No 'boxiness' but a pronounced midrange and a lacking of any deep bass. What's going on ? Not another learning curve to this hobby.

Of course for the DIY'er then there was little driver information available apart from a basic impedance value and the manufacturer's frequency response of the driver on an unspecified baffle size. I had no realized baffle shape,driver placement, baffle size, baffle construction all had an influence on the final frequency response, let alone polar response. It was almost like 'the dark arts' of the loudspeaker industry was purposedly being hidden from the DIY'er in order to keep it a closed shop for loudspeaker manufacture.
   
These days with computers and the available measuring software the DIY'er has a chance to get past the guess work and the almost compulsive tweaking of components to finally get it right most of the time. Open baffle has opened up a world of sound quality and clarity that was once muffled away inside a coffin made to hide its parts and drivers. 

C.M 

ttan98

  • Full Member
  • Posts: 541
Re: OB my builds over the years.
« Reply #6 on: 23 Jun 2017, 06:06 am »
Hi,

I remembered when I built my first OB it was when J. Clayton  owned Eminence Physics, that was more than 10 years ago.
I built a few models based on Clayton's speakers configuration, i.e. Compression driver mounted on a horn and one or twin 15" bass drivers, the sound at that time was very good very dynamic(coming from compression driver) since then I built many models over the years. I am currently listening to the model I built 3-5 years ago still sound quite good even though I use rather cheap components.

Once you listen to OB speakers you don't want to go back to box speakers.

Cheers happy listening...

Russell Dawkins

Re: OB origins ?
« Reply #7 on: 23 Jun 2017, 06:59 am »
I remember reading in a Philips Driver catalogue around 1972 their mentioning that a particular 12" driver of theirs with a cloth surround  and an Alnico magnet sounded surprisingly good in a simple baffle angled back, like the Wharfedale SFB3:



I think the Visaton NoBox  deserves mention, too, as an admirable effort by a mainstream manufacturer:
http://www.visaton.com/en/bauvorschlaege/archiv/noboxbb/index.html

Scott F.

Re: OB origins ?
« Reply #8 on: 24 Jun 2017, 12:02 pm »
Regarding the origins of OB, as best my memory allows, Quad is the first true OB speaker which dates back to 1957. The next OB that I am aware of is Magnepan which dates to 1969. After than, the next ones I remember are the Carver Amazing Loudspeaker that dates to 1986. Linkwitz didn't start doing OB until the mid to late 90's as far as I'm aware, but I could be wrong on that one.

Those are all modern commercial offerings.

Dating back into the roughly 1924, Rice and Kellog patented the first moving coil loudspeaker. Nearly all of these early offering were of OB design. Back then, they had no idea about what Novack would define in the back in the late 50's (pre-dating Thiele and Small's enclosure design parameters).

Wikipedia has articles on all of these fellows. They are a quick read and fairly insightful. I'm sure if a person really wanted to do a deep dive on the origins of OB, you could pin it down. That would make for an interesting read.

If you did the research, I'd bet you could even get it published in one of the online mags.
Any volunteers?

admin1

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Re: OB origins ?
« Reply #9 on: 5 Jul 2017, 03:47 pm »
Please continue.

Wind Chaser

Re: OB origins ?
« Reply #10 on: 5 Jul 2017, 05:43 pm »
Greetings fellow members. I am trying to establish how far back in time this OB craze first started. Please understand, I am not asking about the original history, because I do understand that if you go back far enough in time, all speakers were at least "open backed". Who was it that started all this OB business with respect to igniting the level of popularity we see today, among DIY'ers?

Or, at least please post your very first exposure to OB, when/where it was, and why you liked it so much. Thanks!

I'm not sure what you mean by "OB craze" but among DIYers I think Dmason and Hawthorne Audio in large part took the idea out of obscurity by calling attention to it.  That's where it all began for me, if you exclude stats and planners which I owned back in the early eighties.


Dmason

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Re: OB origins ?
« Reply #11 on: 6 Jul 2017, 02:47 am »
I'm pretty certain Linkwitz got it going in modern times with his designs for Audio Artistry. I would say his current designs are pretty much state of the art, and each are replete with the applied Physics, circuit design, and carefully chosen bits required to pull it off.

Myself, I mounted a pro audio coaxial on some plywood while hiding in the garage escaping a heat wave, drinking beer, and was dumbfounded.  The rest, as they say, is history.  The DarkStar design of a wideband driver augmented by a Ripol bass alignment is still a very solid concept, with a narrower profile, -as is a pair of car speakers mounted on slabs of scrap plywood.

Poultrygeist

Re: OB origins ?
« Reply #12 on: 30 Jul 2017, 10:57 am »
Don't know about the origins in modern times but the open backed juke boxes of the 40's and 50's were the best sounding speakers for public consumption. Those big wide band speakers in U frames powered by flea watt tube amps from yesteryear are similar to what I enjoy today.

A number of years ago I heard my first OB's at Ed Schilling's Hornfest. Then after reading the inspiring "Darkstar" thread I started building my own and haven't looked back. Thank you Dmason.

nicoch

  • Jr. Member
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Re: OB origins ?
« Reply #13 on: 20 Aug 2017, 06:54 am »
Bob Carver push again in 90's  with the Amazing