Open Baffle Experience

@johnnycamp5 wrote:  "I should be more specific - Are all OB open back tweeter? I thought some had forward only directivity . So the heavy drapes question was more for the mid range and bass frequencies."

Yes, some open baffle speakers have rear-firing high frequency energy and some do not.

@johnnycamp5 again: "7’ off front wall is always why these types of loudspeakers (dipole) are “non starters” for me... I’ve always been attracted to horns for their controlled directivity.

"But man that open spacious sound of OB is hard to beat if set up right…just a whole different flavor of goodness."

Very interesting.  Ime that goodness depends on having an adequate reflection path length for the backwave energy.  Linkwitz recommends a minimum of 6 milliseconds (approximately 6 feet total, corresponding to about 3 feet distance from the wall.  I shoot for 10 milliseconds delay (corresponding to about 5 feet from the wall), based on the writings of Earl Geddes and David Griesinger.

I'm into both dipole speakers (as a dealer) and horns (as a manufacturer), and agree with your observations about "the open spacious sound of OB".  So my horn speakers usually have user-adjustable rear-firing horns which are angled up-and-back, such that their reflections bounce off the wall and off the ceiling before reaching the listening area.  This way they can be placed within a foot or so of the front wall and the reflection path delay will be in the 10 milliseconds ballpark. 

My approach would not work well with heavy drapes behind the speakers, as they would absorb the high frequency energy.  Imo it is desirable for the reflection field to have approximately the same spectral balance as the direct sound for a variety of reasons, which I can describe if you wish.

Duke

OB question I’ve never got an answer on;

Can an OB speaker be utilized in a “small room” (14’x12’x8’)???

3’ out from front wall is not a non starter in my world. Im certain my corner horns (the baffle face) are likely that far out from the corner (apex) so there’s that.

@audiokinesis I for one would love to hear your description of why the equal spectral balance…but I don’t want to high-jack the OP. 
I believe It certainly pertains to the question “open baffle experience “

I don't see why not.  They could be three feet from the front wall and you could sit around 8 feet from the plane of the speakers with three feet or so behind you.  It may not be ideal but could work.  I would treat the front wall with mostly diffusion and the wall behind you with absorption.  Also maybe control first point reflections but open baffle does not radiate much sound to the sides.

I'm no expert so maybe someone else has experience.

@audiokinesis 

Also a benefit of many open-baffle speakers is that the backwave has essentially the same spectral balance as the frontwave, and heavy drapes would selectively attenuate the short wavelengths (high frequencies), degrading the spectral balance of the backwave.

You cant have it both ways. The spectral balance you refer to is nothing but polar response. The polar response of an open baffle is unpredictable at best and horrific at worst.

Oh boy oh boy.  Can’t wait to hear the impending beat down coming to kenjit from someone who actually knows what the hell he’s talking about. Hee hee.

@johnnycamp5, here are four reasons why I think the spectral balance of the reflections should be similar to the spectral balance of the direct sound:

1. Timbre is more natural when the reflections fully support the first-arrival sound. Where the reflections are spectrally different from the first-arrival sound, they can skew the perceived timbre towards that difference. Also a rich and spectrally-correct reflection field inherently supports good timbre (as long as it decays neither too quickly nor too slowly), as is demonstrated by the acoustics of a good recital hall or concert hall.

2. If there is a significant spectral discrepancy between the first-arrival sound and the reflections, the ear/brain system has to work harder to correct identify the reflections. This is because the ear/brain system looks at the harmonic structure of all incoming sounds to determine whether they are reflections or new sounds. The more the overtones in a reflection differ from those in the direct sound, the harder the ear/brain system has to work to correctly classify them as reflections, and over time the additional "CPU usage" can result in listening fatigue.

3. The effective in-room signal-to-noise ratio can be degraded if the overtones in the reflections become inaudible before the rest of the spectrum does. (This can also be caused by excessive in-room absorption attenuating the short wavelengths moreso than the longer ones.) Once the overtones in the decaying reflections have become too weak for the ear/brain system to recognize them as reflections, they cease to be "signal" and become "noise". The net result is a raising of the effective in-room noise floor and a corresponding reduction in dynamic contrast and liveliness.

4. Reflections are the carriers for the reverberation tails on the recording, which in turn convey the venue ambience. If the overtones in the reflections are too weak, the venue acoustics are no longer effectively presented and the "small room signature" of the playback room is more likely to be perceptually dominant.

@soix, I don’t think kenjit has raised a legitimate issue so I won’t waste everyone’s time by replying.

@kenjit Im guessing dipoles can be measured in half space or an anechoic chamber (more or less like most other loudspeaker topologies.)

But measurements are all only generalizations of response anyway,  without the boundary interference of the things we all listen within called "rooms".

For me its how the loudspeaker makes one "feel" while listening...not what the polar response might be.

Lets ask ASR lolololol

Lets ask 

@audiokinesis thanks 

When I first set up my open baffle system, I used GIK absorber/diffusers behind the speakers on the front wall. These are absorption panels with a plate mounted on the front with various holes. They are supposed to absorb low frequencies and scatter higher frequencies. I found that these deadened the sound too much and reduced the depth and airiness of the soundstage. 

I replaced these with Quadratic Residue Diffusors from ATS and these made a huge difference for the better. 

These kind of "discussions" always end with some people showing their ignorance about how the real world works.  

"A four-dimensional space ( 4D) is a mathematical extension of the concept of three-dimensional or 3D space. Three-dimensional space is the simplest possible abstraction of the observation that one only needs three numbers, called dimensions, to describe the sizes or locations of objects in the everyday world."

kenjit-

Enclosed speaker radiation into space is compromised by baffle step.  

The Schroeder frequency defines low frequency propagation in rooms driven by transducers that radiate into 2 pi space.

Dipole speakers by design are much less susceptible to Schroeder frequency effects because they essentially remove the floor, ceiling and wall interactions adjacent to the baffle.

I was present (an exhibitor) at RMAF when Danny Richie debuted his open baffle speakers.  Pete Belasco has a song called "Deeper" that has 808-drop effects in the mix.  Their center frequency is 21Hz.  Those drops caused everyone in the room to look around in disbelief as their pants legs flapped from the LF wavefront transients and bass that was tactile as much or more than auditory.  The lows hitting the chest was startling!

I have heard the GR speakers that Jaytor has.  They are, as he says, stunning in the way they communicate (and this is important) EVERY GENRE OF MUSIC!

As a retired recording engineer with more than a little street cred I know what instruments are supposed to sound like:  ie., a double bass or contrabassoon radiates into 4 pi space.  So does the human voice...

My friend's Boulder driven Magico M3 are great at reproducing pop, electronica, ambient, etc.  They do not reproduce low frequencies produced by acoustic instruments as well as the GR open baffle speakers.

Obviously, you have never heard a properly designed open baffle speaker.  There are a lot of so-so designs that frankly suck, just like there are box speakers.  As another opined - people without real world exposure that make statements about things outside of their universe of experience are speaking out of their ass.

Just sayin'.  Over and out >>>>>>>>>>>>>>

GR-Research offers a model called the NX-Studio which are designed for applications where the speaker can't be placed at least 3ft from the front wall. These are a two-way design with an "open-baffle" planar-magnetic tweeter and sealed woofer. The cabinet has an angled panel behind the tweeter which deflects the back wave up through an open top, so the rear wave bounces up and off the ceiling. 

These aren't quite the same as a full open baffle, but in a smaller room, they project a nice spacious soundstage. They don't play super low so a sub is required if you want deep bass. I have a pair in my bedroom system (13' x 15') and they sound very nice with an open-airy sound. 

In response to Kenjit's post about me above:  For the record there are two apparently very different sides to the story, but imo this thread is not the place for either side.

It is important to mention that Audiokinesis and I had a disagreement initially about speaker design but then he started making ad hominem attacks on my character. Its not clear whether his opinion of my character has influenced his opinion about my views on speaker deisgn or vice versa but there is some correlation.  So keep that in mind when reading his responses to my comments as there may be some bias.

This is akin to a butcher having a disagreement with a surgeon about how best to remove a tumor.  Substitute “knowledge” for “character” and you might have something here.  Jeez. 

@reimarc Those 521's are beautiful. I've never heard them, but have a spare 4x10HD and 12-ch amp and intend to build them one day.

@audiokinesis +1

I’ve never had the pleasure to hear open baffle speakers, but I’ve seen plenty of reviewers saying they loved them. Even Steve Guttenberg, for "entertainment value" has switched from his beloved semi-permanent on loan Klipsch Cornwalls to PureAudioProject open baffle speakers.

My issue is of course I simply don’t have a room to do OB speakers right. My living room is only 13’ x 25’ x 8’, and of the 25’ only about 21’ are "useful", not devoted to acting as a de facto hallway.

So for those of you who can enjoy them bon appetit! Those Spatial Audio X4 look killer.

Moonwatcher….I would note that your room is not really an issue for open baffles as long as you can have them 3-4’ out from the wall and as long as you match the woofer size/bass output to the room. 

After owning Vandersteen speakers I clearly decided that open baffle speaker isn't in my taste of performance.

Ferguson Hill FH001 Acrylic Horn Open Baffle speakers 

The Holy Grail of Speakers ?!

 They have Dealers here in the USA now

Unless you are prepared to use a sub.....Open baffle are not a good Idea....I have 2 pair and rarely hook them up anymore.

After owning Vandersteen speakers I clearly decided that open baffle speaker isn't in my taste of performance.

Unless you are prepared to use a sub.....Open baffle are not a good Idea....I have 2 pair and rarely hook them up anymore.

Yes open baffles are not right.

I respectfully disagree.  I own the Spatial audio x5 open baffle and their woofers are powered and include DSP and a level control. I also have two rel subwoofers and have tried using them with the X5s and they detracted not improved the bass.  The bass is much better without the rels.  I'm getting flat response to 32 Hz without the subwoofers and very good extension to the upper 20s according my stereophile test cd.

Sure I have heard open baffles with weaker bass but it depends on the open baffle speaker design and woofer implementation.  The X5s are a little different in that the bass is powered and the output controlled by the end user but this just adds flexibility.

In my opinion open baffle bass is faster and more detailed than a boxed subwoofer bass but again that is just my opinion after having lived with and heard many very good box floorstanders and subwoofers such as the Rel.

So here is kind of an oddball question.

Would OB speakers do well in a demo/hotel room?

OB Dont do well in any kind of  room, demo/hotel room included

I just heard Spatial X? at the NYC show in a medium-sized hotel room and they sounded really good with LTA electronics.  Definitely one of the better sounds in the show for me. 

I own a pair of Linkwitz "Orion" loudspeakers mated with Burmester amps, pre and DAC and can't imagine a more open and natural sounding speaker.  If bass is on the recording it is heard in full bloom.  The very complex crossover network is crucial to their performance.  Two Peerless woofers, SEAS mid and tweeters in each cabinet fill my "Great Room" with glorious sound.  Mine have the rear-facing tweeter as well and placing them about 3' from the wall produces a perfect soundstage.  I owned Linkwitz's "Audio Artistry" Dvorak for years and compared them with the Orions prior to selling the Dvoraks.  I could happily live with either. I was skeptical about open baffle speakers, too, but am now a true believer. YMMV

@soix They were almost certainly the X4's, which is what Spatial has been using recently at shows, coupled with the LTA ZOTL40+ integrated.  Earlier in this thread I posted a video of that same combo at the Pacific show.  Because of supply issues and other factors, Spatial's offering is now down to just two models, the M4 and the X4.

I heard the Spatial X4s and Linkwitz LX521s at Pacific Audio Fest, and both sounded excellent. IMHO, the X4s were the best sounding speakers under $10K, and the Linkwitz were among the top rooms at the show (not my favorite, but certainly among the top 10).

I believe the best open baffle experience is a single full-range driver accompanied by a superior active sub woofer unit. This provides the best of all worlds: a cohesive sound for the majority of the musical content, and a proper power/driver size for the really low frequencies. It's the right tool for each job, and provides the greatest flexibility in choosing the amplification scheme you prefer.

It's not enough to eliminate the sonic horrors of the box - you must also eliminate the problems introduced by multiple drivers and crossover networks. My setup includes Voxativ full-range drivers and a 300W REL sub that reaches below the range of human hearing. I've used this with everything from low-watt 300B SET amps and modest power EL34 amps, as well as higher power solid state amps. Sound quality is extraordinarily clear, transparent, open and realistic. Result is an engaging listening experience. 

“Unless you are prepared to use a sub.....Open baffle are not a good Idea....I have 2 pair and rarely hook them up anymore.”

In my rooms, dual subs (at minimum) are a given… before I even decide which mains I’m going to use.

If all your running is a pair of left and right mains in an average room (with four walls, a floor and a ceiling) and the addition of a couple subs makes  the overall bass response worse…then I’d say you most certainly have either the gain or crossover frequency (or both) of the subs set  too high.

This is only if your in a typical room and therefore have the expected boundary interference.

If you move outside, or even half outside the rules (physics) change

Obviously the degree of room treatments can change the game somewhat, but I still always use both (multiple subs and room treatments) for that clean, tight punchy bass goodness…

For those of us who have owned both box and open baffle speakers at high price if that means something to Kenjit . Not just listened to them at an audio show Open Baffel do a much better job at delivering and a sonic image. Kenjit you should expand you narrow experience before you make unqualified statements.

Kenjit you should expand your narrow experience before you make unqualified statements.

But, that’s his specialty and sole reason for being.  My guess is he isn’t allowed to leave his padded room enough to get out and actually listen to anything.  Also notice he never discloses what’s in his system.  Hmmm.

"Also notice he never discloses what’s in his system."

- It's whatever the day may bring  ❓

But, that’s his specialty and sole reason for being.  My guess is he isn’t allowed to leave his padded room enough to get out and actually listen to anything.  Also notice he never discloses what’s in his system.  Hmmm

He may have more than one system?

This whole discussion has all been about open baffle merits, referencing the Linkwitz designs. What’s been totally missing from the discussion is the merits of active amplification. All of the Linkwitz designs use active amplification. Very few, if any of the various muy expensivo hi-end designs use active crossovers. In many ways, active crossovers are as significant to the Linkwitz designs as is open baffle.

I’ve been running my Orion set for 16 years and still love them. Every time I think about doing something else, I sit down for a serious listen to my rig and fall in love again. The LX521 really is a step up, but not so much that I’m willing to leave my Orions. They are my "forever" loudspeaker.

This whole discussion has all been about open baffle merits, referencing the Linkwitz designs. What’s been totally missing from the discussion is the merits of active amplification. All of the Linkwitz designs use active amplification. Very few, if any of the various muy expensivo hi-end designs use active crossovers. In many ways, active crossovers are as significant to the Linkwitz designs as is open baffle.

Linkwitz was a stalwart proponent of active speaker designs long before DSP crossovers and equalizers were even available.  He also designed his speakers for excellent on and off axis response, an art lost in many high end makers today.

I wanted to talk in this thread about the general limitations and benefits of open baffle designs and how they compare to boxes or even other line sources.

The LX521 is a standout in my mind because it is a 4 way, allowing for fine tuning of the horizontal polar response, but having to use 4 channels per speaker is a big no for me.  😁

What do you think the active part of Linkwitz designs brings others lack?

@johnnycamp5

I used to think as you do about "needing" sub/s. I have Emerald Physics 3.4s OB 12" woofer with 1" concentric tweeters. Since owning them for almost 2 years now I felt the need for sub/s, BUT, I did 2 things recently that flipped my script

1. I upgraded all my cables with Ali-Express Odin 2 and Odin Gold which is HUGE in regards to everything, but especially to lows -mids

2. I’ve had a Solid Steel vertical rack for 15+ years. Just this week I came across a local deal and bought a solid maple table top (5 x 2 x 2"), and I am FLOORED what it does for everything, but especially the bass

hth

I had too much experience with open baffle speakers, i had Diesis Audio open baffles before and they are the bes t op's imo, open baffle is very hard to find perfect place to set the speakers and everybody has an opinion like open baffle is easy to drive you need just some watts for them that the common mistake and wrong , open baffles plays all the room and you must drive them with good amplifiers produces good current except watts...

@mwatsme could you send me link to plans for your speakers? I think this is exactly what I am looking for in my listening space.

LXmini plans are available here:

Phoenix open-baffle sub plans are free from Linkwitz Labs website, here:

https://www.linkwitzlab.com/woofer.htm

The specific Phoenix[alt] version I built is here:

https://www.linkwitzlab.com/woofer3.htm

I made a slight alteration (think it was 1/4" taller?) to fit built-in Hypex FA-123 (could also fit wider FA-253), and you can build a pair of the subs with one (4’x8’) sheet of wood.

While searching for that file, I also found the in-room measurement (used REW and Omni Mic)...

right on thanks

Since both "russbutton"and "eric_squires" both mentioned the active crossover in Linkwitz designs, I thought I might elaborate on my last post.  I was fortunate to be good friends with one of  Linkwitz's collaborators on the "Orion" loudspeaker.  He was nearby and I frequently visited as he tinkered on improvements to the design. Siegfried had signed off years prior after deciding that he'd taken the "Orion" to its limits but my friend continued to work painstakingly at them nontheless.  On every occasion the work centered on changes in the active crossover.  We all are familiar with companies that promote their careful matching of components during the build and how significantly that care can impact performance.  Well --- he had a substantial stock of components and hand-matched them before putting them into service, hence the values were as close to perfect as possible.  Every change was followed up by long, careful listening sessions.  Most changes were subtle and a few were remarkable.  I'm positive that my active crossover was altered/improved at least a dozen times over probably a 5 year period, so I can't honestly say that I have a standard Orion crossover at this point.  He was Linkwitz's builder of most of the crossovers for the Orion and as such, was intimately informed of its performance specifications.  As "russbutton" also stated, the Orions are my "forever" loudspeaker as well.

You bring up a serious benefit od dsp based crossovers

 Dabbling with qith passive crossovers is expensive as hell.  You can easily spend 5x more on the parts you don't end up using.

I have Spatial Audio Lab's X5s and I love them. They are easy to drive and I haven't even done anything really to set them up. They sound even better when the equipment behind them is improved (duh). 

@jaytor do you think the GR Encore Studios are worth the price? They look interesting but are kind of pricey when there are a lot of good speakers below $2,000.

@soix I'm thinking you heard the X4s. Right now Spatial Audio Labs is only producing 2 models, the X4s and the M4s. I think this is due to parts shortages. The main difference between the X4s and the X5s is that the X4s have a passive woofer whereas the X5s' woofer is active with a hypex amp built on. I do think the X4s (newer) may have newer speakers although I don't know how much a difference that is. 

@dz13 - I assume you are referring to the NX-Studios. I would say that, within their limitations, they are exceptional speakers. The NEO3 is one of the best drivers for upper midrange and treble that I’ve heard, particularly in an open baffle implementation.

These speakers won’t play exceptionally loud, and they don’t go very deep (maybe 65Hz) so if you are looking for deep bass, they need to be used with a sub. They also aren’t as efficient as GR-Research’s other models, but that’s true for most stand mount speakers.

I use them in my bedroom system (approximately 13’ x 15’) driven by a Purifi amp (DIY) and don’t play them particularly loud. With the jazz and folk music I typically play on this system, they are excellent - far better detail and soundstaging than the Totem Mani-2s I was using, with a sweeter sounding midrange, although the Mani-2s handily beat them in bass extension.

@jaytor  - yes I meant the NX-Studios. Thanks for the information. 

There are open baffle speakers and then there are open baffles speakers. One can’t judge all by listening to one, or even a few. Case in point: I came across the video on a preview of a review over at 6moons of Qualio Audio IQ open baffle (for the mids and highs) and I must say, if I had the room, I’d get them.

Now, his room isn’t treated and the head of Qualio admits as much, saying he’s gonna get some carpets and room treatment but the music I hear is astonishingly good, despite the echos. Here’s the video:

All the best,
Nonoise

Check out the simple system he’s using as well. I feel this system destroys a lot of audio shibboleths that we all adhere to.