[jaypeecee]

Hi Folks,

This is my very first post on AudioCircle. Hello to all you audio enthusiasts out there!

What are the advantages/disadvantages of OB vs. closed/vented box loudspeakers? OB seem to be gaining popularity and Siegfried Linkwitz obviously favours the dipole speaker approach. But what is the collective view?

Thanks in advance.

JPC

[matevana]

For starters you have to be willing to have them located about 1 meter from the wall behind them, and probably a slightly greater distance from any other adjacent wall in the room. They will not "pressurize" most listening rooms with copious amounts of bass, but instead will provide very discriminating low frequency information that is often obscured by boxed designs. No "one note" bass lines here. 

That being said, they really don't do anything wrong. A well designed system will produce a very open, transparent sound stage with typically less negative interaction (room nodes) than most other types of design. Stereo imaging should be good with sometimes a slightly more diffuse presentation and full of natural reverberation. Because of this, acoustic music tends to really shine while music with lots of compression may sound thin. 

Do yourself a favor and listen to as many systems as you can. Many people get the OB bug after listening, and for them (me) there is no turning back. 

[JohnR]

jaypeecee - what are your current speakers? Do you make your own speakers?

[Poultrygeist]

The only advantages I see in box speakers is cosmetics and in many cases a smaller footprint.

[nullspace]

I've recently switched from open baffles to ported boxes, and here's why: I wanted a simple (i.e., no bi-amplification), moderately efficient (>93db/1W) speaker.

My experiements have led me to conclude that fullrange (say, 30Hz and up) and a minimum of efficiency are mutually exclusive in the open baffle universe. The straightforward ported box + compression driver and horn combo have been a staple in the high-efficiency camp of audio since the beginning.

Regards,
John

[django11]

Right now I have sealed speakers and an open baffle sub.

I guess I prefer this for the reasons matevana has stated.

[FullRangeMan]

Cone drivers release a + acoustic wave to front and a - acoustics wave to back, when these sound waves meet there is a loss of 4 to 5dB in comparison to a boxed driver.

15'' drivers begin to attenuate 18dB/octave at 60/65Hz(8'' drivers around 120Hz) so is need use a wide baffle.
The + and - acoustic waves form a much better soundstage than a monopole loudspeaker if there is free space around.

[galyons]

Typical cone/box speakers sound boxy.  Much of the expense is trying to minimize the interior standing waves that contribute to the boxy sound and the cost of making the boxes "pretty furniture".

All too often, IMO, more of the cost of box speakers goes to address these two parameters than the quality of the drivers and crossovers.

Since the late 90's I have used Gallo Nucleus Solo's.  Spun aluminum spheres, 6.5" main driver and a proprietary "capacitive" tweeter.  No crossover. No box sound.  To me, the best of both worlds, panel speaker openness with pinpoint imaging and the dynamics with which planars struggle.

I have often been very impressed with the realistic and relaxed sound of OB's.  I have been working on a design of an OB for efficiency.  (I am just finishing 300B SET monoblocks @ about 7 watts per side).  The design is a variation of Martin J. King's published OB study project using  8" Audio Nirvana cast drivers and Eminence Alpha 15 woofers.  I am bi-amping with tubes.  I am at the end of several months of crossover listening and almost ready to go to my finished baffles. The short take.  I am really happy with the sound of the OB's, even in their "mule" baffle stage.

I listen to mostly acoustic music, female vocals, jazz and classical.  The sound of these OB's is simply compelling.  They don't have quite the detail of the Gallo's, but I need much more power to run the Gallos. (GTA monoblocked SE40's or Rogue Magnum 150's)

So, after this long post, I think that speaker choice needs to be a combination of household acceptance factor, amplification and musical tastes.

Cheers,
Geary

[-Richard-]

Hi JPC ~

For me designing my own Open Baffle speakers with the indispensible help of our audiocircle forum community was and continues to be a learning experience.

Before I became involved with experimenting with OB's I was a "passive" consumer limited to reading reviews and visiting audio shops to "experience" the plethora of commercial "brands" all of which are targeted to specific price points.

It does not take long to realize that our perceptions are being manipulated by the illusion that the more expensive models or brands are what we are supposed to imagine is what we long for... we stretch our budgets to try to purchase the "best" that we can... knowing full well that we will still hunger for that higher priced model... which has been reviewed with a prose that gushes with superlatives that sends our blood racing through our veins.

Working with the DIY OB paradigm will teach you how to listen... you will learn to listen for the first time to qualities in sound reproduction that is de-coupled from price... de-coupled from hype... from the idea that the expensive or highly rated speaker has the qualities one should dream about. Instead you will develop a "critical" sensibility that will reflect in not only how you listen to music... but how every "commercial" speaker sounds after that.

Admittedly, the OB paradigm will not satisfy everyone... nor should it. There is no reason why you should not reject what I am saying as yet another form of hype... the difference in what I am sharing with you and the hype you read in the commercial magazines, or e-magazines is that you can test these suggestions very easily with a little bit of time and a small investment in drivers.

It is about learning by doing for yourself. Then your wish to gather feedback by consensus will be seen as a kind of treading water... or standing on the edge of the lake and wondering if you should jump in. Jump in!!!! And see what happens. Then right a post here that shares your experiences with all of us. Perhaps we may have suggestions for you that can increase the pleasure of listening to your OB's... that is how this community works.

Best of luck to you in your search for musical pleasure and integrity.

With Warmest Regards ~ Richard

[Poultrygeist]

Richard you are gifted in the way you express yourself.

[jimdgoulding]

Good show, all.  This is a conversation I can easily understand about the subject and has me interested in OB.  I'd love to see one as plain and direct about planars vs. closed box speakers (what I own) but that's beside the point.  I'd love an increase in the volume of space and true sounding low bass in my room.  I would rather not lose the 3D imagery and seperation of instruments I am getting, however.

Matevana, what speakers are you using?  Are they the ones pictured?  Thanks.

[Tyson]

One thing you normally get with OB speakers is bigger drivers.  This makes a difference in the midrange, as larger drivers sweep more air effortlessly, which gives power and authority to voices.  Higher efficiency also tends to give you a "jump factor" with dynamics that normal box speakers don't.  Bass is another area that OB speakers excel - unless you are willing to go with multiple subs ala Geddes or Audiokinesis, then box speaker bass just can't really match OB's for bass in a normal room.  OB's just physically interact less with the room in the low regions, giving cleaner and better bass.

The last area I think OB's excel is soundstage.  If you can get them 1 meter from the side and rear walls, there is nothing like an OB to give a large, open soundstage, even if your space is small.  Sounding big in small spaces is a special quality that OB's have that box speakers are hard to match.

[matevana]

Matevana, what speakers are you using?  Are they the ones pictured?  Thanks.

I have two sets currently and both are DIY. The Hestia which is outlined here: http://www.audiocircle.com/index.php?topic=108003.0 is a bi-amped three way design-on-a-dime. Each side prices out at < $100 for the drivers. The detail and resolution are amazing. I listen to them all the time and never get tired.

The 2nd build is detailed here http://www.audiocircle.com/index.php?topic=102300.msg1036443#msg1036443 and uses Usher 9950/B&C Neo 10"/ Usher 8137a and is similar but prices out much higher. The power handling is greater and therefore serves as the front L/R of a five way home theater system. Plays at slightly higher SPL's than the Hestia but not any better for music. In fact, I think I prefer the Hestia overall. 

[jimdgoulding]

Thanks, gents.  When and if I replace my speakers you'll be hearing from me again.  I think my room could be a good host for the design. 

[versus rider]

 I disagree with you my friend, I now use an open box rather than a flat baffle but in essence it is a folded baffle with a top, obviously all baffles have a bottom, its called the floor. Mine are placed approx 500mm from the back wall, admittedly they are not close to the side walls but one is close to a television and the other a table. Its only my opinion and that of audiophool visitors that they sound very good. By having an open box I get full on room filling bass with all the open baffle loveliness but a flea powered set won't give you that, I use SS for the bass, and set's for the mid horn and Raal ribbons.Of course there is more than one way to skin a cat. Takes your choice.

For starters you have to be willing to have them located about 1 meter from the wall behind them, and probably a slightly greater distance from any other adjacent wall in the room. They will not "pressurize" most listening rooms with copious amounts of bass, but instead will provide very discriminating low frequency information that is often obscured by boxed designs. No "one note" bass lines here. 

That being said, they really don't do anything wrong. A well designed system will produce a very open, transparent sound stage with typically less negative interaction (room nodes) than most other types of design. Stereo imaging should be good with sometimes a slightly more diffuse presentation and full of natural reverberation. Because of this, acoustic music tends to really shine while music with lots of compression may sound thin. 

Do yourself a favor and listen to as many systems as you can. Many people get the OB bug after listening, and for them (me) there is no turning back.

[Rocket_Ronny]

Biggest differences are:

-Open baffle has a more tube like, airy, soundstage and presentation. Boxed speakers are more like solid state amps.

-Open baffle has no box coloration. Good boxed speakers greatly reduce this and can be very enjoyable indeed.

-Open baffle is a lot easier for DIY builds, construction wise. 

-Open baffle speakers need lots of space behind them, or good dampening on the rear wall, behind the speakers. For that matter, all speakers benefit from space from walls for soundstage realism.

Rocket_I can go both ways, but prefer open baffle most times_Ronny

[077 tweeter]

I use a JBL D123 12" extended range,with a JBL 077 tweeter for the extreme high end. There in an open back cabinet,that has sides and top, with no sound absorbing material on any surface. It has a open airy sound of a true open baffle,but with more bass. In my opion, a great sound.- RUDY

[jimbones]

Hi JPC ~

For me designing my own Open Baffle speakers with the indispensible help of our audiocircle forum community was and continues to be a learning experience.

Before I became involved with experimenting with OB's I was a "passive" consumer limited to reading reviews and visiting audio shops to "experience" the plethora of commercial "brands" all of which are targeted to specific price points.

It does not take long to realize that our perceptions are being manipulated by the illusion that the more expensive models or brands are what we are supposed to imagine is what we long for... we stretch our budgets to try to purchase the "best" that we can... knowing full well that we will still hunger for that higher priced model... which has been reviewed with a prose that gushes with superlatives that sends our blood racing through our veins.

Working with the DIY OB paradigm will teach you how to listen... you will learn to listen for the first time to qualities in sound reproduction that is de-coupled from price... de-coupled from hype... from the idea that the expensive or highly rated speaker has the qualities one should dream about. Instead you will develop a "critical" sensibility that will reflect in not only how you listen to music... but how every "commercial" speaker sounds after that.

Admittedly, the OB paradigm will not satisfy everyone... nor should it. There is no reason why you should not reject what I am saying as yet another form of hype... the difference in what I am sharing with you and the hype you read in the commercial magazines, or e-magazines is that you can test these suggestions very easily with a little bit of time and a small investment in drivers.

It is about learning by doing for yourself. Then your wish to gather feedback by consensus will be seen as a kind of treading water... or standing on the edge of the lake and wondering if you should jump in. Jump in!!!! And see what happens. Then right a post here that shares your experiences with all of us. Perhaps we may have suggestions for you that can increase the pleasure of listening to your OB's... that is how this community works.

Best of luck to you in your search for musical pleasure and integrity.

With Warmest Regards ~ Richard

Richard, that is exactly how I feel. I never have enough money to afford what I like (sound wise). I am new to OB design and I like it because I am building and learning and spending my money at a much slower pace 

[jimbones]

Biggest differences are:

-Open baffle has a more tube like, airy, soundstage and presentation. Boxed speakers are more like solid state amps.

-Open baffle has no box coloration. Good boxed speakers greatly reduce this and can be very enjoyable indeed.

-Open baffle is a lot easier for DIY builds, construction wise. 

-Open baffle speakers need lots of space behind them, or good dampening on the rear wall, behind the speakers. For that matter, all speakers benefit from space from walls for soundstage realism.

Rocket_I can go both ways, but prefer open baffle most times_Ronny

Ronny,

I am new to OB speakers, just finished builing up a pair of Lambda's (Parts Express Forum) and you mention that the area behind the speakers the wall should get some acoustic treatment. Could you explain? I want to know what I need/should do.

Thanks, lots of great info/idea's here.
Jim

[-Richard-]

Hi Jimbones ~

From time to time Deborah and I go to audio shops to listen to
this or that highly rated box speakers... just for the fun of it...
and to see if our 'listening' ear has changed. One's listening...
one's sense of the "real" in reproduced music does change over
time and this is one way to get a sort of reality check (another
way to is to change amps... which I have done recently and which
has indeed changed my listening habits for me... I intend to write
about that soon). Deborah is not particularly interested in audio as
a technology... as long as the music has something of that ineffable
quality of being able to take flight and involve us emotionally,
she is very happy.

It is the music that Deb loves. So when we visit audio shops I am
very keen to find out what she thinks. Ever since we began to listen
to our Open Baffle Speakers, about 7 years ago, Deb's perception
immediately hears the constrained 'boxy' non-musical sound of
boxed-speakers. She does not like them.

What I have found is that if one has patience and is willing to work
with the Open Baffle paradigm... which means voicing them to
your taste... you can get them to sound quite wonderful. No
commercial speakers I have ever heard... and I have heard
hundreds of 'commercial' speakers, including the top rated audio
celebrities with gushing superlatives dripping from the pens of
enamored audio scribes... can come close to my Open Baffles
for bringing the music to life... detail, holographic spatial cues,
immediacy, the penetration of the 'air' of the room which
simulates a live performance of un-amplified music, depth
of tone, texture and so on.

What happened to me is that after working in the Open Baffle
paradigm for a while, I began to 'hear' what commercial
speakers actually sound like... and they all sounded/sound
limited in some essential way... especially in the sense of
sounding flat and directional. It is the difference between
hearing a newly built musical instrument compared to one
that was built centuries ago... the older instruments have
that special resonance that gives another dimension to the
music played on them... Open Baffle speakers sound like
that to Deb and I.

Also my experience regarding the question of needing space
behind Open Baffle speakers seems to be different from
many of our Audio Circle friends. I live in a manufactured
home, my simple Open Baffle panels are around 3 feet from
the front wall of our home which is mostly glass and a hard
thin surface material. There is an accordion-style window
shade that covers about half the windows on the bottom at
all times. In other words, my home reflects what is normally
considered a poor surface for the back wave to have to
contend with. But the music is quite wonderful... sometimes
I even pull the speaker panels closer than 3 feet... to 2 feet
from the front wall... and the sound is still quite acceptable.

I suspect that the reflection of the back wave from the hard
surface of the wall to the front may be helped by the hard
surface. There is a rug on the floor that the speaker panels
rest on... and that may help to keep both the front and back
wave from traveling with too much energy. I am not saying
that some form of intelligent acoustic treatment would not
further refine the sound... it very well could. I am only
suggesting that perhaps working simply, even with the
limitations of what one has, may be enough to have a
very satisfying musical experience with one's Open
Baffle speakers.

Thanks for sharing your experiences with us... please
continue to share your insights with us.

With Warmest Regards ~ Richard / Ojai, California