Common sense, very narrow OB is close to no baffle in one direction; rear wave below 1khz start to wrap around interfering destructively with the front wave. One can use folded wings to expand the effective open baffle width (OB-U), to reduce the wrap-around and even (help) to angle the backwave so the 3-4m-roundtrip-delayed wall-bounce came back to the listener more constructively (post #99). My against-wall foot-of-bed OB-U angle-bounced rear wave up toward the ceiling, the wall being part of the speaker enclosure.
A personal choice which s fine. But that doesn't make it better - it's just something you WANT.
You recognise your speaker ADDS a LOT?
The membrane adds a lot (of problems mostly). Magnest system, the whole moving system adds unlinearities and restrictions.
The horns you use ADD directivity and unlinearity.
So when you leave your speaker as it is ... it already ADDED A LOT to your voice.
The art of speaker building is not adding more but getting the speaker to add as little as possible! And show the whole spectrum we can receive with our ears.
Sometimes there are plenty of components needed to add LITTLE to the music.
You probably LIKE what it added in first place ... then just stick with it, totall fine. But be aware your speaker adds a ton to the original signal.
p.s.: What music do you hear that you are only interested in the human voice reproduction? I can imagine the speakers you show are pretty good in that specific frequency range and you achieve that goal!
I find this thread interesting. I've been a fan of OB, (had a full size OB before with Eminence Beta 15 woofers and Visaton B200 fullrange).
But, as I have changed residence, new domestic conditions dictated the new kind of... boxes?
Well, at first I got back to bixes, as it was the most "logical" thing to do. But, soon I missed that OB sound.
So, still no place for 15" woofers (space being limited to 10 " or so).
So... I got some old JBL speakers cheaply. And they played cheaply. But, at least the box was good, and it fit the space requirements. Then, after a while, I replaced the JBL woofers with Monacor SPH250-TC. It was a straight drop-in replacement and I closed the BR port. With the second order crossover at around 250 Hz, it plays very nicely.
Then the idea was to make a Waw wich I did. While not bad... I still missed the OB sound.
That is, until I took a handsaw and literally cut the box.
Then, experimented with various fullrange speakers...
Currenly using some old Siare fullrange. Until I get something better.
But hey it works!
There are two areas for future improvement:
1. Better fullrange speaker
2. Ripole instead of a bass (closed) box...
But, as I have changed residence, new domestic conditions dictated the new kind of... boxes?
Well, at first I got back to bixes, as it was the most "logical" thing to do. But, soon I missed that OB sound.
So, still no place for 15" woofers (space being limited to 10 " or so).
So... I got some old JBL speakers cheaply. And they played cheaply. But, at least the box was good, and it fit the space requirements. Then, after a while, I replaced the JBL woofers with Monacor SPH250-TC. It was a straight drop-in replacement and I closed the BR port. With the second order crossover at around 250 Hz, it plays very nicely.
Then the idea was to make a Waw wich I did. While not bad... I still missed the OB sound.
That is, until I took a handsaw and literally cut the box.
Then, experimented with various fullrange speakers...
Currenly using some old Siare fullrange. Until I get something better.
But hey it works!
There are two areas for future improvement:
1. Better fullrange speaker
2. Ripole instead of a bass (closed) box...
Attachments
Yes @vkung - I made the exact same observations as @Sonce wrote in its last post.
By the way, it's closely related to the laws of basic physics of sound propagation, in the sense that the size of the baffle prevents the acoustic short-circuit occuring between front and rear faces of the cone speaker, which reduces neatly - not to say nearly null - the bass extension of the system.
Below some documents giving explanations of this acoustic short-circuit phenomenon - sorry, some are in French :
From SoundPractices / Claudio Bonavolta website :
From the book "Les Haut-Parleurs" de Jean Hiraga :
From the tlhp website ( https://www.toutlehautparleur.com/charge-acoustique-enceinte#:~:text=Le BAFFLE PLAN&text=Soit L la largeur de,a lieu à 114.5 Hz. )
Let L be the width of the plane baffle, and C be the speed of sound, the acoustic short circuit occurs at the frequency F=C/2/L.
For example, for a plane baffle 1.5 m wide, and a sound speed C of 343.4 m/s (at 20°C), the short circuit takes place at 114.5 Hz.
From the website : https://www.boom-mastering.com/single-post/enceintespart3
T
Last edited:
To be honest with you.. I do not think the panel is matter. It is the horn matter. Once you have the horn 98% of sound is from the front.. The placement of the speaker is easier..
I use 650mm in the shows and 1280mm at home. The difference is huge for bigger horn. According to Filip from AER, he told me 2000mm horn is
another level
Please read the comment of Filip from AER
Please refer to below Google translation in English:
Dieses Horn setzt neue Maßstäbe die in der Lautsprecherkonstruktion bisher völlig unbekannt sind. Die Grenzfrequenz und die Größe des Horns entspricht einem 2x 2 m großen Horn und entwickelt eine Kraft und Wucht die normale Horn Lautsprecher und auch Groß Hornsysteme wie Kinderspielzeug erscheinen lassen. Die Klangwiedergabe ist leichtfüßig, die Bass Wiedergabe leichtfüßig und federnd, die Hochton Wiedergabe fein und bruchlos aufgelöst, da der Mitteltonbereich ultra- kräftig und dynamisch, der Bassbereich kolossal wie noch nie gehört wiedergegeben wird, mit einer enormen Durchschlagskraft dass es einem im Körper durch und durch fährt. Die Fülle bei der Instrumenten-Wiedergabe ist unerreicht. Durch den geringfügigen Anteil an indirekt Schall ist die Wiedergabe außergewöhnliche natürlich, es klingt weder nach einer geschlossenen Box noch nach einem Hornsystem noch nach irgendeinem anderen Kompromiss, sondern die Wiedergabe ist absolut umwerfend natürlich. Durch den über 95 % über das Horn abgestrahlten Schalldruck ist das Horn Aufstellungs-unkritisch und liefert Klangerlebnisse wie wir sie selber bisher noch nirgendwo gehört haben. Herausstreichen möchte ich noch einmal die enorme Wucht die dieses System entwickelt und den kolossal hohen Wirkungsgrad, der andere großen Systeme um mindestens 10 dB übertrifft, bei stärksten Bassschlägen stehen die Membranen völlig still, da die Schwingungsenergie vollständig an die Luft übertragen wird und mit enormer Wucht zum Hörer abgestrahlt wird. Ich bin der Auffassung dass diese Art von Hörnern die Lautsprechergeschichte völlig neu schreibt und weiterhin schreiben wird und ich kann jetzt sicher sagen dass nahezu alle bisherigen Basshorn-Konstruktionen misslungen oder absolute Fehlkonstruktion sind. Wer das nicht glaubt soll sich selbst durch Anhören ein Bild davon machen. Es ist absolut umwerfend was hier erreicht wurde. Filip Keller
Google translation:
This horn (
Please refer to below Google translation:
Dieses Horn setzt neue Maßstäbe die in der Lautsprecherkonstruktion bisher völlig unbekannt sind. Die Grenzfrequenz und die Größe des Horns entspricht einem 2x 2 m großen Horn und entwickelt eine Kraft und Wucht die normale Horn Lautsprecher und auch Groß Hornsysteme wie Kinderspielzeug erscheinen lassen. Die Klangwiedergabe ist leichtfüßig, die Bass Wiedergabe leichtfüßig und federnd, die Hochton Wiedergabe fein und bruchlos aufgelöst, da der Mitteltonbereich ultra- kräftig und dynamisch, der Bassbereich kolossal wie noch nie gehört wiedergegeben wird, mit einer enormen Durchschlagskraft dass es einem im Körper durch und durch fährt. Die Fülle bei der Instrumenten-Wiedergabe ist unerreicht. Durch den geringfügigen Anteil an indirekt Schall ist die Wiedergabe außergewöhnliche natürlich, es klingt weder nach einer geschlossenen Box noch nach einem Hornsystem noch nach irgendeinem anderen Kompromiss, sondern die Wiedergabe ist absolut umwerfend natürlich. Durch den über 95 % über das Horn abgestrahlten Schalldruck ist das Horn Aufstellungs-unkritisch und liefert Klangerlebnisse wie wir sie selber bisher noch nirgendwo gehört haben. Herausstreichen möchte ich noch einmal die enorme Wucht die dieses System entwickelt und den kolossal hohen Wirkungsgrad, der andere großen Systeme um mindestens 10 dB übertrifft, bei stärksten Bassschlägen stehen die Membranen völlig still, da die Schwingungsenergie vollständig an die Luft übertragen wird und mit enormer Wucht zum Hörer abgestrahlt wird. Ich bin der Auffassung dass diese Art von Hörnern die Lautsprechergeschichte völlig neu schreibt und weiterhin schreiben wird und ich kann jetzt sicher sagen dass nahezu alle bisherigen Basshorn-Konstruktionen misslungen oder absolute Fehlkonstruktion sind. Wer das nicht glaubt soll sich selbst durch Anhören ein Bild davon machen. Es ist absolut umwerfend was hier erreicht wurde. Filip Keller
Google translation:
This horn sets new standards that are previously completely unknown in loudspeaker design. The cutoff frequency and size of the horn corresponds to a 2x2 m horn and develops a power and force that makes normal horn loudspeakers and large horn systems seem like children's toys. The sound reproduction is light-footed, the bass reproduction is light-footed and springy, the high-frequency reproduction is finely and seamlessly resolved, as the mid-range is reproduced ultra-strong and dynamic, the bass range is reproduced colossally like never before, with an enormous impact that it penetrates your body drives through. The richness of instrument playback is unmatched. Due to the small amount of indirect sound, the reproduction is exceptionally natural; it sounds neither like a closed box nor a horn system nor any other compromise, but the reproduction is absolutely stunningly natural. Due to the over 95% sound pressure radiated via the horn, the horn is uncritical in terms of placement and delivers sound experiences that we have never heard anywhere before. I would like to emphasize once again the enormous power that this system develops and the colossally high efficiency, which exceeds other large systems by at least 10 dB. During the strongest bass hits, the membranes stand completely still because the vibration energy is completely transferred to the air and with enormous force is transmitted to the listener. I am of the opinion that this type of horn is completely rewriting the history of loudspeakers and will continue to be rewritten and I can now say with certainty that almost all previous bass horn designs have failed or are completely incorrect designs. Anyone who doesn't believe this should see for themselves by listening to it. It is absolutely stunning what has been achieved here. Filip Keller
2M)sets new standards that are previously completely unknown in loudspeaker design. The cutoff frequency and size of the horn corresponds to a 2x2 m horn and develops a power and force that makes normal horn loudspeakers and large horn systems seem like children's toys. The sound reproduction is light-footed, the bass reproduction is light-footed and springy, the high-frequency reproduction is finely and seamlessly resolved, as the mid-range is reproduced ultra-strong and dynamic, the bass range is reproduced colossally like never before, with an enormous impact that it penetrates your body drives through. The richness of instrument playback is unmatched. Due to the small amount of indirect sound, the reproduction is exceptionally natural; it sounds neither like a closed box nor a horn system nor any other compromise, but the reproduction is absolutely stunningly natural. Due to the over 95% sound pressure radiated via the horn, the horn is uncritical in terms of placement and delivers sound experiences that we have never heard anywhere before. I would like to emphasize once again the enormous power that this system develops and the colossally high efficiency, which exceeds other large systems by at least 10 dB. During the strongest bass hits, the membranes stand completely still because the vibration energy is completely transferred to the air and with enormous force is transmitted to the listener. I am of the opinion that this type of horn is completely rewriting the history of loudspeakers and will continue to be rewritten and I can now say with certainty that almost all previous bass horn designs have failed or are completely incorrect designs. Anyone who doesn't believe this should see for themselves by listening to it. It is absolutely stunning what has been achieved here. Filip Keller
I use 650mm in the shows and 1280mm at home. The difference is huge for bigger horn. According to Filip from AER, he told me 2000mm horn is
another level
Please read the comment of Filip from AER
Please refer to below Google translation in English:
Dieses Horn setzt neue Maßstäbe die in der Lautsprecherkonstruktion bisher völlig unbekannt sind. Die Grenzfrequenz und die Größe des Horns entspricht einem 2x 2 m großen Horn und entwickelt eine Kraft und Wucht die normale Horn Lautsprecher und auch Groß Hornsysteme wie Kinderspielzeug erscheinen lassen. Die Klangwiedergabe ist leichtfüßig, die Bass Wiedergabe leichtfüßig und federnd, die Hochton Wiedergabe fein und bruchlos aufgelöst, da der Mitteltonbereich ultra- kräftig und dynamisch, der Bassbereich kolossal wie noch nie gehört wiedergegeben wird, mit einer enormen Durchschlagskraft dass es einem im Körper durch und durch fährt. Die Fülle bei der Instrumenten-Wiedergabe ist unerreicht. Durch den geringfügigen Anteil an indirekt Schall ist die Wiedergabe außergewöhnliche natürlich, es klingt weder nach einer geschlossenen Box noch nach einem Hornsystem noch nach irgendeinem anderen Kompromiss, sondern die Wiedergabe ist absolut umwerfend natürlich. Durch den über 95 % über das Horn abgestrahlten Schalldruck ist das Horn Aufstellungs-unkritisch und liefert Klangerlebnisse wie wir sie selber bisher noch nirgendwo gehört haben. Herausstreichen möchte ich noch einmal die enorme Wucht die dieses System entwickelt und den kolossal hohen Wirkungsgrad, der andere großen Systeme um mindestens 10 dB übertrifft, bei stärksten Bassschlägen stehen die Membranen völlig still, da die Schwingungsenergie vollständig an die Luft übertragen wird und mit enormer Wucht zum Hörer abgestrahlt wird. Ich bin der Auffassung dass diese Art von Hörnern die Lautsprechergeschichte völlig neu schreibt und weiterhin schreiben wird und ich kann jetzt sicher sagen dass nahezu alle bisherigen Basshorn-Konstruktionen misslungen oder absolute Fehlkonstruktion sind. Wer das nicht glaubt soll sich selbst durch Anhören ein Bild davon machen. Es ist absolut umwerfend was hier erreicht wurde. Filip Keller
Google translation:
This horn (
Please refer to below Google translation:
Dieses Horn setzt neue Maßstäbe die in der Lautsprecherkonstruktion bisher völlig unbekannt sind. Die Grenzfrequenz und die Größe des Horns entspricht einem 2x 2 m großen Horn und entwickelt eine Kraft und Wucht die normale Horn Lautsprecher und auch Groß Hornsysteme wie Kinderspielzeug erscheinen lassen. Die Klangwiedergabe ist leichtfüßig, die Bass Wiedergabe leichtfüßig und federnd, die Hochton Wiedergabe fein und bruchlos aufgelöst, da der Mitteltonbereich ultra- kräftig und dynamisch, der Bassbereich kolossal wie noch nie gehört wiedergegeben wird, mit einer enormen Durchschlagskraft dass es einem im Körper durch und durch fährt. Die Fülle bei der Instrumenten-Wiedergabe ist unerreicht. Durch den geringfügigen Anteil an indirekt Schall ist die Wiedergabe außergewöhnliche natürlich, es klingt weder nach einer geschlossenen Box noch nach einem Hornsystem noch nach irgendeinem anderen Kompromiss, sondern die Wiedergabe ist absolut umwerfend natürlich. Durch den über 95 % über das Horn abgestrahlten Schalldruck ist das Horn Aufstellungs-unkritisch und liefert Klangerlebnisse wie wir sie selber bisher noch nirgendwo gehört haben. Herausstreichen möchte ich noch einmal die enorme Wucht die dieses System entwickelt und den kolossal hohen Wirkungsgrad, der andere großen Systeme um mindestens 10 dB übertrifft, bei stärksten Bassschlägen stehen die Membranen völlig still, da die Schwingungsenergie vollständig an die Luft übertragen wird und mit enormer Wucht zum Hörer abgestrahlt wird. Ich bin der Auffassung dass diese Art von Hörnern die Lautsprechergeschichte völlig neu schreibt und weiterhin schreiben wird und ich kann jetzt sicher sagen dass nahezu alle bisherigen Basshorn-Konstruktionen misslungen oder absolute Fehlkonstruktion sind. Wer das nicht glaubt soll sich selbst durch Anhören ein Bild davon machen. Es ist absolut umwerfend was hier erreicht wurde. Filip Keller
Google translation:
This horn sets new standards that are previously completely unknown in loudspeaker design. The cutoff frequency and size of the horn corresponds to a 2x2 m horn and develops a power and force that makes normal horn loudspeakers and large horn systems seem like children's toys. The sound reproduction is light-footed, the bass reproduction is light-footed and springy, the high-frequency reproduction is finely and seamlessly resolved, as the mid-range is reproduced ultra-strong and dynamic, the bass range is reproduced colossally like never before, with an enormous impact that it penetrates your body drives through. The richness of instrument playback is unmatched. Due to the small amount of indirect sound, the reproduction is exceptionally natural; it sounds neither like a closed box nor a horn system nor any other compromise, but the reproduction is absolutely stunningly natural. Due to the over 95% sound pressure radiated via the horn, the horn is uncritical in terms of placement and delivers sound experiences that we have never heard anywhere before. I would like to emphasize once again the enormous power that this system develops and the colossally high efficiency, which exceeds other large systems by at least 10 dB. During the strongest bass hits, the membranes stand completely still because the vibration energy is completely transferred to the air and with enormous force is transmitted to the listener. I am of the opinion that this type of horn is completely rewriting the history of loudspeakers and will continue to be rewritten and I can now say with certainty that almost all previous bass horn designs have failed or are completely incorrect designs. Anyone who doesn't believe this should see for themselves by listening to it. It is absolutely stunning what has been achieved here. Filip Keller
2M)sets new standards that are previously completely unknown in loudspeaker design. The cutoff frequency and size of the horn corresponds to a 2x2 m horn and develops a power and force that makes normal horn loudspeakers and large horn systems seem like children's toys. The sound reproduction is light-footed, the bass reproduction is light-footed and springy, the high-frequency reproduction is finely and seamlessly resolved, as the mid-range is reproduced ultra-strong and dynamic, the bass range is reproduced colossally like never before, with an enormous impact that it penetrates your body drives through. The richness of instrument playback is unmatched. Due to the small amount of indirect sound, the reproduction is exceptionally natural; it sounds neither like a closed box nor a horn system nor any other compromise, but the reproduction is absolutely stunningly natural. Due to the over 95% sound pressure radiated via the horn, the horn is uncritical in terms of placement and delivers sound experiences that we have never heard anywhere before. I would like to emphasize once again the enormous power that this system develops and the colossally high efficiency, which exceeds other large systems by at least 10 dB. During the strongest bass hits, the membranes stand completely still because the vibration energy is completely transferred to the air and with enormous force is transmitted to the listener. I am of the opinion that this type of horn is completely rewriting the history of loudspeakers and will continue to be rewritten and I can now say with certainty that almost all previous bass horn designs have failed or are completely incorrect designs. Anyone who doesn't believe this should see for themselves by listening to it. It is absolutely stunning what has been achieved here. Filip Keller
I think there is a disconnect here.
vkung, you're talking horns. Horns act like a lense to focus the sound.
tubelectrons is talking OBs. OBs simply provide a barrier that separate the front waves from the back waves to reduce cancellation below a frequency that is dependent on the size of the baffle.
vkung, you're talking horns. Horns act like a lense to focus the sound.
tubelectrons is talking OBs. OBs simply provide a barrier that separate the front waves from the back waves to reduce cancellation below a frequency that is dependent on the size of the baffle.
You are correct.... I highly recommend to add a horn with your OB system.
In 2017, I used OB without horn in CAF. (before I used VOXATIV wood cone driver)
From 2018, I use OB with 650mm horn up to now. The only difference is the driver, BD1, BD2B, BD3B and BD5B.
Last edited:
Below the horn cutoff these OB horns will act just like an OB.With no loading bass will fall dramatically below this.
Basic theory says a horn of the nature of the AERs one can get an idea of how low it goes before that transition will be — wavelength of the cutoff is the circumeferance of the horn.
dave
It may sound very nice, but I am not sure (In fact I am sure that Not) if my wife would tolerate something like this in the living room.
If I had a house, and a dedicated listening-room-basement-wife-shelter, maybe...
Thus, I may appreciate those for whom it works, but not for me...
If I had a house, and a dedicated listening-room-basement-wife-shelter, maybe...
Thus, I may appreciate those for whom it works, but not for me...
Already mentioned earlier, but the upside potential is that it bears repeating:
Bipole with either 2 equal drivers, or the best front-firing mid-tweeter you can find, and a smooth mid-woofer facing the wall.
At high frequencies, they are aligned as a standard dipole, probably including some roll-off to limit beaming reflections from the rear facing speaker.
At low frequencies, the system is boxed and working as a monopole with strong bass. The hard part is the all-pass filter to rotate the phases of the drivers. A really cool thing would be an adjustment knob that varies it between full monopole action and cardioid with reduced room interaction — I think there could be a nice sweet spot in there that is even better than the figure 8 dipole pattern.
Bipole with either 2 equal drivers, or the best front-firing mid-tweeter you can find, and a smooth mid-woofer facing the wall.
At high frequencies, they are aligned as a standard dipole, probably including some roll-off to limit beaming reflections from the rear facing speaker.
At low frequencies, the system is boxed and working as a monopole with strong bass. The hard part is the all-pass filter to rotate the phases of the drivers. A really cool thing would be an adjustment knob that varies it between full monopole action and cardioid with reduced room interaction — I think there could be a nice sweet spot in there that is even better than the figure 8 dipole pattern.
Notwithstanding your thinking, width of the panel/"horn" do matter. Look at the Figure 214 from the post #124 by @tubelectron - OB in the middle has total width of 65+2x20=105 cm, which is very close to 128 cm of your AER Excenter. As you can see, below 100 Hz output is dropping. It is not just a "theory", it is a real science theory based on real life observations and backed by literally many thousands measurements (and listening, too) in the past 100 years.
But you don't need to look at the theory, see what the manufacturer AER wrote on their web-page for the AER Excenter with 128 cm "horn":
- Frequency response: 100 Hz – 70 kHz
"Excenter comes with our active Subway subwoofer for the low frequency range." (Quote from the AER web-page)
I don't want to dive in the more elaborate things about their so called "horn", because it is not a horn but a short waveguide, with no capability to reinforce the bass range. The depth of that so-called horn is only 22 cm - exactly the same as any 1000 Hz capable professional high-frequency horn!
As written by Mr. Keller about his AER horns, as pictured :
OK - so let's simply calculate :
FC=C/2L
Where :
FC=frequency cutoff of the baffle, in Hz.
C=340m/s=average speed of sound.
L=smallest dimension of the baffle, or minimal radius, in meters.
Since the baffle equivalent is 2x2m, the speaker at best is placed at the centre, so the smallest dimension is 1m
FC=340/(2*1)=340/2=170Hz
The low frequency cut off of that baffle is circa 170Hz. It means that the sound level will decrease at a 12dB/Oct. slope below 170Hz and, possibly reaches 18dB/Oct. under the FS of the loudspeaker.
The included horn pictured here by itself brings a slight curvature which extends a bit the smallest dimension, but IMHO, this would not change significantly the calculation of FC, since the lenght of the acoustic short-circuit is similar.
Now the placement in the room and its dimensions have an influence about the bass response and can potentially enhance it, but it's a case-by-case basis IMHO.
Either it's about Open Baffles or Horns, a low frequency cutoff drives to a large dimensions construction, or to the use of artifacts like angle placement to complement the missing dimensions - think folded horns like Klipschorn, among others - or use of a subwoofer system.
T