Sure but your looking at a box the size of a phone booth. If you want high efficiency into 2P1 space you need a large horn or at least four of the one your reading about. If you model it in hornresp and use the mutiple box option you get this in 2Pi with four boxes.
Mark
Mark
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THe graphs I just posted are for four pieces on the TRIO12 Front loaded Horn in this thread. So it is a huge box. 27 cubic feet each. Stacked up as a quad with all the mouths setup close to each other in a wall type configuration.
So each box is 16" x 32" x 92". Each box uses a single TRIO12 driver and with the 200 watts input you get the wonderfull SPL in the graph.
Horns rule!
Mark
So each box is 16" x 32" x 92". Each box uses a single TRIO12 driver and with the 200 watts input you get the wonderfull SPL in the graph.
Horns rule!
Mark
I was interested in a project like this and posted as much in my thread on "getting the last octave in horns" http://www.diyaudio.com/forums/subwoofers/189005-getting-last-octave-horns.html and was given a pointer to this thread. I really like the idea of this approach bet where I run into trouble is though I have the room for a sub of this size or even larger (garage is behind the listening room) I do not have enough room in the listening room to use acoustical positioning to compensate for the delay and I am unwilling to introduce digital delay lines (or any other kind) to my mains so I suspect I will have to be content with a different approach until I can afford a house with a longer listening room or where I can position the horn outlet next to the seating position.
Many people have listened to different types of music and I have never heard one comment about loss of tunefulness or timing. In fact it is the other way around. The comments are how musical and realistic it sounds. Me thinks the group delay idea is exactly that. A concept that is not as bad as the simulations predict.
Well I have to admit that I haven't had an opportunity to hear one in person but was concerned about higher frequency components like transients arriving 20mS or so before the low freq. fundamental. I am glad to hear that you have not found this problematic. It encourages me to give it a try even though I have heard others who have claimed problems with it. Perhaps if the crossover is low enough and steep enough it won't be a problem.
Well it's good to read a comment like that. Far to many people have opinions about something they have never listened to or built.
This particular horn will work up to about 120hz. Recommended crossover is at or about 80hz. The higher the order the better. A third order is the recommended minimum.
Group delay does exist. It is just that the effects are highly exaggerated. Arrival times of tones that are in the 12 foot plus wavelength are not that quick in the first place. The speed of sound is a relatively finite value under most normal indoor conditions. The arrival time of a lower note is by simple definition of the start to the end of one wavelength a longer period of time the lower the note frequency.
What you will notice with a horn is the ability to keep up with the music, not the other way around.
A tapped horn is a different animal altogether. I personally do not quite like the resultant group delay it generates. It ends up having a more distorted wooly sound reminiscent of an unaligned vented enclosure. Not as bad by any means, just not as clean and as quick on the transients as the front loaded horn.
This particular horn will work up to about 120hz. Recommended crossover is at or about 80hz. The higher the order the better. A third order is the recommended minimum.
Group delay does exist. It is just that the effects are highly exaggerated. Arrival times of tones that are in the 12 foot plus wavelength are not that quick in the first place. The speed of sound is a relatively finite value under most normal indoor conditions. The arrival time of a lower note is by simple definition of the start to the end of one wavelength a longer period of time the lower the note frequency.
What you will notice with a horn is the ability to keep up with the music, not the other way around.
A tapped horn is a different animal altogether. I personally do not quite like the resultant group delay it generates. It ends up having a more distorted wooly sound reminiscent of an unaligned vented enclosure. Not as bad by any means, just not as clean and as quick on the transients as the front loaded horn.
Like laser beam no?
Directional?
Well remember that a horn is a device that controls the expansion of a pressure wave off of a drivers cone. So at the mouth or close to it there is a great deal of directivity. In fact one meter SPL measurements are nearly useless. There has not been enough distance out in the wild world to get a proper expansion that close. But that changes in about 6 to 8 feet from the mouth. This is frequency dependent. Upper bass which is the bulk of what we get anyway integrates with the room fairly close to the mouth.
The most interesting thing I can say about good horns is that they have an unusual ability to completely fill a room. Their directivity can be put to great use and effect if you understand what can be gained from it.
For instance. One horn properly placed in a room can suffice for anything that you will want to hear reproduced. One subwoofer with a conventional cone box setup can fill a room but find me one that can math a front loaded horn. I haven't found or designed one that is cost/size competitive.
The horn proper does not have to be in the room. The mouth must exit into the room. With a horn that plumbs the depths there is no decor acceptance factor. It's a big ugly box period. So take the box and put it away. Place it behind an adjacent wall and cut a hole in the wall board for the mouth. Throw it underneath the stairs. Place it on it's side and build over top of it. Think hutch and buffet style cabinet. The upper shelves can be the part you pay attention to and the horn part be the base you set it on. It is plenty strong enough to support a 200lb plus guy like me.
Directional?
Well remember that a horn is a device that controls the expansion of a pressure wave off of a drivers cone. So at the mouth or close to it there is a great deal of directivity. In fact one meter SPL measurements are nearly useless. There has not been enough distance out in the wild world to get a proper expansion that close. But that changes in about 6 to 8 feet from the mouth. This is frequency dependent. Upper bass which is the bulk of what we get anyway integrates with the room fairly close to the mouth.
The most interesting thing I can say about good horns is that they have an unusual ability to completely fill a room. Their directivity can be put to great use and effect if you understand what can be gained from it.
For instance. One horn properly placed in a room can suffice for anything that you will want to hear reproduced. One subwoofer with a conventional cone box setup can fill a room but find me one that can math a front loaded horn. I haven't found or designed one that is cost/size competitive.
The horn proper does not have to be in the room. The mouth must exit into the room. With a horn that plumbs the depths there is no decor acceptance factor. It's a big ugly box period. So take the box and put it away. Place it behind an adjacent wall and cut a hole in the wall board for the mouth. Throw it underneath the stairs. Place it on it's side and build over top of it. Think hutch and buffet style cabinet. The upper shelves can be the part you pay attention to and the horn part be the base you set it on. It is plenty strong enough to support a 200lb plus guy like me.
Wow - what a horn ! Can the opening be switched?
Mark, I love your work ! It is obvious that so much effort has gone into this !
I fully intend to build this project.
A question - due to possible positioning issues in my room, could I chose to have the mouth open on the side panel (would not be completely square), or even at the top? Top would actually allow a more even expansion/exit (am I right?).
I have 10'6" ceilings, so the horn would exit and sort of corner load to the ceiling corner?
I have a pair of Soundlab M1 electrostatics, soon to be replaced with a pair of Soundlab Majestics (8'6" high) - so what's another big speaker in the room matter. Wife Acceptance Factor is so far out the door now, I may as well go the whole hog !!
As a second issue, I hope one day to build a dedicated sound room, with of course a very large built in horn sub. Do you have a plan for a slightly larger horn?
I would be prepared to go for a straight(ish) horn, perhaps driven by one or two 15" or 18" drivers. Although, if the Trio horn is as good as it reads, maybe just scale that up slightly, or double up the drivers?
The horn might be triangular section - to allow for a gradual bend from horizontal (underfloor) to coming up as a cross-corner triangular mouth that would be behind where the ESL's stand well out from the walls. (steel grate to stop me falling in!)
Am I crazy?
LAST point - I have learnt something else from this thread - there is a Perth in Canada (never knew that !). I am in Perth in Western Australia - about as far away from you as is possible on dry land !
Peter
Mark, I love your work ! It is obvious that so much effort has gone into this !
I fully intend to build this project.
A question - due to possible positioning issues in my room, could I chose to have the mouth open on the side panel (would not be completely square), or even at the top? Top would actually allow a more even expansion/exit (am I right?).
I have 10'6" ceilings, so the horn would exit and sort of corner load to the ceiling corner?
I have a pair of Soundlab M1 electrostatics, soon to be replaced with a pair of Soundlab Majestics (8'6" high) - so what's another big speaker in the room matter. Wife Acceptance Factor is so far out the door now, I may as well go the whole hog !!
As a second issue, I hope one day to build a dedicated sound room, with of course a very large built in horn sub. Do you have a plan for a slightly larger horn?
I would be prepared to go for a straight(ish) horn, perhaps driven by one or two 15" or 18" drivers. Although, if the Trio horn is as good as it reads, maybe just scale that up slightly, or double up the drivers?
The horn might be triangular section - to allow for a gradual bend from horizontal (underfloor) to coming up as a cross-corner triangular mouth that would be behind where the ESL's stand well out from the walls. (steel grate to stop me falling in!)
Am I crazy?
LAST point - I have learnt something else from this thread - there is a Perth in Canada (never knew that !). I am in Perth in Western Australia - about as far away from you as is possible on dry land !
Peter
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