wondering why no COMMERICAL OB speakers available

[joe3rp]

I wonder why there are no OB type of speakers being sold commercially? What is the reason?

The closest thing would be the Carver Amazing, the planar speakers (magnepan/Ml/Apogees/Innnersound) and the PHY (open backed - w/ resonant enclosure)

I understand the reason for limited production of Hi-efficiency Horn Speaker, folded horns and Voigts. It is the massive size and complication of the enclosure construction...which can make it expensive.

But from the looks of the OBs in this section ... though the Altecs/WE are NOS ... they seem to be of no exotic construction ...small magnets ...4-12 inchers... And the baffle construction - can be shipped knock-down like IKEA furnitures. The simplicity of the flat baffle can result in really nice finishes ...real solid wood, exotic veeners, plexy ...can't modern speakers manufactures make OB- frinedly drivers.



Is there a room type this speaker is looking for ?

[setup1]

I wonder why there are no OB type of speakers being sold commercially? What is the reason?

Yes there was the 1950s Wharfedale SFB3.


Then in the 70s there were partial OB type speakers like the Dalquist DQ10 but the bass driver was enclosed.

My guess is the main reason why there are no full range OB speaker in commercial production is because there's a great danger of overdriving and frying the voice coils with power being so cheap nowadays using silicon technology.

Back in the old days when power was expensive speakers were designed to be more efficient [lighter paper cones/easier to drive] Given the same size, alnico magnets have much greater flux density than a ceramic equivalent. Now that power is cheap driver cones can be made out of polypropylene, kevlar or other synthetic materials which are heavier in mass.

Typical SPLs remain the same in a listening room so whether or not we've come a long way from pre 1960s audio ideals or just went sideways is the question.....

JE

[Hyperion]

I think there are several probable reasons why OB speakers are not in favor anymore:

1.) they require higher sensitivity drivers which require larger magnets and lighter/larger cones which are more difficult and more costly to manufacture; and which cost higher to loudspeaker manufacturers if the drivers are sourced elsewhere.

2.) OB bass is unsuitable for most solid state amplifiers. They do not complement lean overdamped harmonically deficient bass.

3.) OB speakers tend to be much larger than ported designs. They have wide shallow baffles which can be visually and spatially obstructive in most living rooms. Note the popularity of deep narrow speaker baffles (which result to more impressive bass extension but rather poor tunefulness and quickness; as well as more pinpoint imaging).

4.) OB speakers sound a tad like ESL being dipoles, they have an airy ambient sound that can however sound weak compared to horns and ported designs (having similar sized bass driver/s) especially when it comes to bass SPL and macrodynamics. OB speakers tend to be great for classical and various types of acoustic music but hardly ideal for anything that got synthesized or electric bass that are meant to be played through horned or ported enclosures.

5.) OB speakers usually cannot be placed close to walls.

6.) Manufacturers cannot hide the contents of the speaker in an OB design. In short, it is much easier for end users to estimate the cost of manufacturing the speakers - meaning the manufacturers cannot make a large profit from them. OB are also very easy to rip off - and there is even no need to open up the speakers, no need to experiment in damping materials, no need to invalidate warranties etc.

[red76]

Joey,

Have you visited the Blackforest Audio Site or FAL Japan? They produce the "Helix to Heaven" and "Harp" using Fertin fieldcoil 8" in tall curved OBs, and field coil woofers in Jensen type boxes for the lower end... The other is from Japan by FAL... And another one is OEM Supravox models acrylic OB's only available in the UK. It is designed (and owned) by that prolific German/Brit diy'r (helpful in sharing but grumpy and dismissive to novices!)

http://www.jlbcreations.com/Fertin/
http://www.fal.gr.jp/




With Jensen/Onken FC subs....


FAL Ai (parang pridgider?)

I almost forgot, Gilmore Audio is into it too .. Albeit without FR drivers, only large ribbons and woofers and sensational marketing tactics. Remember the Gilmore Girl from last year's CES? Donald North Audio also makes an OB woofer ONLY, for their Sequence speakers.

Other stuff are all diy projects or kits (Linkwitz-Riley dipole, for mids and highs only)..

BTW, Wharfedale has diff OB models, and some with cone tweeters firing on top... But the cool things is they pioneered the sandfilled plywood panels way before Phy-Hp! I have the vintage review in Classic Hifi (HFN&RR supplement)...

[ichabod]

From the looks of these, it seems like the OBs we have are the simpliest amongst the brood. They may not be popular in the open market, but amongst dyed-in-the-wool afficionados, they seem to be favored indeed to come up with various shapes and sizes. Definitely a passion for open baffles as well.

[AudioImageLover]

I visited a place in Hong Kong. There is a DO-IT-YOURSELF OB shop (includes instruction manual) and all the materials needed. They can also assemble it for you but you need to pay around US $ 200. The photos and link are as follows;

http://www.diyhifisupply.com/diyhs_prometheus.htm

[arnoldc]

you mean pay $200 or so for SHIPPING

the speaker kit is $2,198

[bruno]

Here you go:

[AudioImageLover]

you mean pay $200 or so for SHIPPING

the speaker kit is $2,198

The salesman (speak little english) says "You pay $200 and you can get this". He is pointing to the Finish product. My understanding when he told me that, the $200 dollars is the cost of the wooden cabinet/box plus the labor in attaching the kit to the wooden box to get the final/finish product.

[ihatejazz]

The NOLA Exotica Grand Reference is OB!

[vintage_dog]

why not too many commercial OBs?

- most are big, expensive and low WAF

- also, very few have discovered SETs to need them...

[arnoldc]

you mean pay $200 or so for SHIPPING

the speaker kit is $2,198

The salesman (speak little english) says "You pay $200 and you can get this". He is pointing to the Finish product. My understanding when he told me that, the $200 dollars is the cost of the wooden cabinet/box plus the labor in attaching the kit to the wooden box to get the final/finish product.

$200 for the assembly + baffles, $2,198 for the KIT. there, total of $2,398 for the complete unit.

[ichabod]

I wondered why too. Single full range drivers of yore got the smoothness relax quality that many won't find easily.

I guess that's the "come on" why some audiophiles like their tone. Mellow and relax but still have that midrange openness to all the music. Coherence, I almost forgot, is tops.

The downside being low in WAF/MAF factor and honestly needs space and a good presentation to look at at any place you may want to put them.

But I think it's a good antidote to highstrung listening.

[ttommy]

Bastanis!

[AudioImageLover]

Nice photo ttommy.

[red76]

ttommy, that's the latest Prometheus kit from Bastanis...

Non-kit from Bastanis .... the new Apollo

[ichabod]

red76 have you by any chance heard the "corals" alnico 8 inchers. How might the sound go? Is it ringy, shouty, or mellow, sweet, and kinda extended you'd not want a tweet to go with it.

They pretty much look like those green altecs only in silver.

Thanks for any feedback.

Those speakers are quite imposing.

[ichabod]

red76 or anyone who knows more than the little that I do pray tell me. I had my R & As hooked back a few months ago on my flea powered Calrad SE amp. Then got the urged to switch to several other amps to sample their sound. Lo and behold, with the bigger amps, I noticed that one of the R & A speakers was giving off some noise and distortion. Every other amp I tested did this. I hate to hear one of these nice sounding alnico full rangers is broken. So I discontinued using them until I could figure out why. This was not the first time it happened. I remember a friend whom I lent these to had a similar observation on one of the drivers, that it got weak and distorted, a sign of rubbing perhaps. After anachrophile, had looked at it, did some quick pressing and checking, they replaced the driver and had it working and sounding good, distortion gone!

So after several days of wondering and thinking, I thought to myself that maybe something's a little strange here or I just didn't know. Yet.

So again I hooked the driver back for a short listen. Placed the driver on the floor facing me with the speaker terminals up where you can easily clip the wires. And to my pleasant surprise, I could not hear any distortion! So I quickly replaced them on my OBs for some real music playing. But to my dismay, out came the distortion again. (Some of you must have gone through something similar to understand the frustration!) By then something was starting to dawn on me. Call it intuition or a hunch. I checked back how I installed the driver and saw that the speaker terminals were situated under as against the manner I tested it on the floor where they were visible on top. I quickly checked the other speaker to my left and saw the terminals were on top. So quickly, I turned the speaker around almost 180 degrees with the terminals up, and lo and behold, it sounded louder, with no hearable distortion. I don't understand why.

Can some genius please explain?

[Doc Jr 8156]

Joe3rp,
Please Google NaO speakers by John K and The Siegfried Linkwitz Orions. Godspeed.

[amandarae]

NAO



Linkwitz Orion