Hi Simon5!
Most folded horns for professional use have a very small rear chamber and a compression chamber in front of the driver with a thight passage, and a very short horn. Since this is the way most companies make their horns, I call this traditional horn loading.
The Avalanche 18s x-max gives this driver the opportunity to move around five times more air than a typical 18" horn driver.
If you then have a very small rear chamber, the cone displacement will be damped extremely hard when you give the driver some power. The pressure differences in the small chamber would be significant and this gives you a different frequency response at different drive levels. With other words a lot of distortion.
The compression chamber in front alter frequency response of traditional drivers, and will alter frequency response even more of a large x-max driver. A thight passage will work as a whistle. When you blow softly there is almost no sound other than your blowing and when you blow harder it starts resonate when you reach a certain threshold.
A short horn will make the driver go bananas as soon as you try to play frequencies with longer wavelenghts than the frequency where one fourth of the wavelength match the length of the horn.
A traditional horn like I described it, would need 18" parameter values like this to work properly:
X-max: less than 8mm
Qts: lower than 0,3
BL: higher than 25
One example of non-traditional horn loading would be a large rear chamber or no chamber at all, a throat without a compression chamber, and a long enough horn. If your horn is long enough it will do all the damping as people try to make compression chambers do, and it will even do it close to linear. Then your horn will have the same frequency response at all power levels.
Ohhhh, low sensitivity on those long stroke woofers, I think we have to put them in horns some day
What do you think Simon5?
Not a traditional one of course...
Most folded horns for professional use have a very small rear chamber and a compression chamber in front of the driver with a thight passage, and a very short horn. Since this is the way most companies make their horns, I call this traditional horn loading.
The Avalanche 18s x-max gives this driver the opportunity to move around five times more air than a typical 18" horn driver.
If you then have a very small rear chamber, the cone displacement will be damped extremely hard when you give the driver some power. The pressure differences in the small chamber would be significant and this gives you a different frequency response at different drive levels. With other words a lot of distortion.
The compression chamber in front alter frequency response of traditional drivers, and will alter frequency response even more of a large x-max driver. A thight passage will work as a whistle. When you blow softly there is almost no sound other than your blowing and when you blow harder it starts resonate when you reach a certain threshold.
A short horn will make the driver go bananas as soon as you try to play frequencies with longer wavelenghts than the frequency where one fourth of the wavelength match the length of the horn.
A traditional horn like I described it, would need 18" parameter values like this to work properly:
X-max: less than 8mm
Qts: lower than 0,3
BL: higher than 25
One example of non-traditional horn loading would be a large rear chamber or no chamber at all, a throat without a compression chamber, and a long enough horn. If your horn is long enough it will do all the damping as people try to make compression chambers do, and it will even do it close to linear. Then your horn will have the same frequency response at all power levels.
Ohhhh, low sensitivity on those long stroke woofers, I think we have to put them in horns some day
What do you think Simon5?
Not a traditional one of course...
The triaxial idea is indeed a cool one.
But at the given dimensions it is definitely necessary to take care of time-alignment. And the delays involved are that large that you'd have to do it digitally.
Even without any mid- and high-frequency capabilities this thingie could be used as the ultimate neighbour-annoying device !! Ever tried to feed it 20 Hz at high power during the night ?
Regards
Charles
But at the given dimensions it is definitely necessary to take care of time-alignment. And the delays involved are that large that you'd have to do it digitally.
Even without any mid- and high-frequency capabilities this thingie could be used as the ultimate neighbour-annoying device !! Ever tried to feed it 20 Hz at high power during the night ?
Regards
Charles
Hi AndrewT!
When the horn is full sized, a rear chamber is not necessary as long as you make the throat the right way (small compared to Sd). In fact the circumference does not need to be full sized, but the length always has to be. You make the best conditions for the driver if you use L >= wl/2 and use a hp filter below. If you're not going to drive the horn at full power you will get excellent results setting the hp filter half an octave lower.
In such a horn Qts<0,4 works great and produce tremendous amonts of low bass without making it a mudbath. This gives you the opportunity to use double spider drivers with extreme x-max.
The only drawback with this kind of designs is poor sound quality when you set your lp filter to high.
It may sound like a cracy way to design horns not to have a rear chamber, but my first experience with such a design was three years ago when I built a 4 meter long horn and tested it before the back plate was properly attached. The backplate fell off and smooth massive hifi bass came alive. It was awsome and I did not belive my ears. I compared them with some 18" horns from one of the large manufacturers, and thy made the 18" horns sound like a TV speaker.
Then I heard about Bassmaxx and got some theory about their boxes and tried to make a friend of mines company to import a box, but they rather imported foam cannons, so I have actually never seen or heard the boxes. And the Bassmaxx guys haven't got stands at Frankfurt or Plasa, so I guess I have to go over the sea to see and hear them. I'm really curios on how their flares look like since they told me it is a hybrid with a tractrix ending. I guess they have the most experince with horns without rear chambers, so you should contact them if you want to know more about it.
To Simon5: If I calculate a new throat, they should sound great and have more SPL than the PHL driver in the octave from 9-18 Hz.
When the horn is full sized, a rear chamber is not necessary as long as you make the throat the right way (small compared to Sd). In fact the circumference does not need to be full sized, but the length always has to be. You make the best conditions for the driver if you use L >= wl/2 and use a hp filter below. If you're not going to drive the horn at full power you will get excellent results setting the hp filter half an octave lower.
In such a horn Qts<0,4 works great and produce tremendous amonts of low bass without making it a mudbath. This gives you the opportunity to use double spider drivers with extreme x-max.
The only drawback with this kind of designs is poor sound quality when you set your lp filter to high.
It may sound like a cracy way to design horns not to have a rear chamber, but my first experience with such a design was three years ago when I built a 4 meter long horn and tested it before the back plate was properly attached. The backplate fell off and smooth massive hifi bass came alive. It was awsome and I did not belive my ears. I compared them with some 18" horns from one of the large manufacturers, and thy made the 18" horns sound like a TV speaker.
Then I heard about Bassmaxx and got some theory about their boxes and tried to make a friend of mines company to import a box, but they rather imported foam cannons, so I have actually never seen or heard the boxes. And the Bassmaxx guys haven't got stands at Frankfurt or Plasa, so I guess I have to go over the sea to see and hear them. I'm really curios on how their flares look like since they told me it is a hybrid with a tractrix ending. I guess they have the most experince with horns without rear chambers, so you should contact them if you want to know more about it.
To Simon5: If I calculate a new throat, they should sound great and have more SPL than the PHL driver in the octave from 9-18 Hz.
I saw the story on the news here in Norway! Funny to watch the reporter climb in to the horn during his presentation of it
And the thing is, I live 30 min drive from you Rune. I hope you answer my PM about me visiting you and have a listen
In fact there is already a small community of horn enthusiasts here already, and I think they all would love to have a look (and listen) at it.
Have you tested the thing you mentioned about using 7 Hz tones to make people loose control over their closing muscles and involuntarily let go in their pants????
And nice demonstration when they filmed the barn with the horn sticking out of the barn door playing from a distance. The reporter saying "this is real sound you are hearing...." just to clarify that it is the horn in the distance that is playing. www.nrk.no has a web-TV service and you can find it there! You have to be a member, and I'm not sure if you have to be Norwegian to register, but it is as I know it free. And it is in Norwegian.... It was in the 21:00 news on the 17. of jan.
Anders
And the thing is, I live 30 min drive from you Rune. I hope you answer my PM about me visiting you and have a listen
In fact there is already a small community of horn enthusiasts here already, and I think they all would love to have a look (and listen) at it.
Have you tested the thing you mentioned about using 7 Hz tones to make people loose control over their closing muscles and involuntarily let go in their pants????
And nice demonstration when they filmed the barn with the horn sticking out of the barn door playing from a distance. The reporter saying "this is real sound you are hearing...." just to clarify that it is the horn in the distance that is playing. www.nrk.no has a web-TV service and you can find it there! You have to be a member, and I'm not sure if you have to be Norwegian to register, but it is as I know it free. And it is in Norwegian.... It was in the 21:00 news on the 17. of jan.
Anders
What can I say? Its the horn Ive dreamed of for half my life!
Slightly similar to - Gjerstadt horn?
http://www.geocities.com/xobt/sys/sys.htm
Slightly similar to - Gjerstadt horn?
http://www.geocities.com/xobt/sys/sys.htm
An externally hosted image should be here but it was not working when we last tested it.
lThat organ note is just below what the horn can manage, but I've started on a new project called bass cannon and when that one is finished the organ pipe of yours should fit nicely
Hi akb1212, it was a funny story about the horn, but the cut and paste technology of today did not quite follow the story board of the 7 Hz story. I have not tried out the theory myself yet, but I have read a lot about infrabass science and military use of infrabass so I would like to think that it works In china they split a mob with 7 Hz tones and made almost everyone let go of something.... I'm going to try this theory before summer when I'm finished with the basscannon.
The horn does not play 7 Hz very well, 9 Hz is the absolute limit, and it is intended to use down to 16 Hz (-3dB point) when you power it up. I guess we'll try that out on February 13. with the Crown Itech 6000
It would have been fun if you brought your Basstech 7 cabinets to the event also, cause I really want to see and listen to them.
Hi MikeE!
It is quite a dream for me too
I started drawing large horns eleven years ago, and the first really big ones was the Gjerstad horns (2004), and then followed the 6090 Monster (still need some bracing).
The 6090 Monster may look similar to the Gjerstad horn from a distance or on a picture. Unlike the P-Audio BM18LF the PHL Audio 6090 is a really good horn driver. The Gjerstad horns have larger dispersion in the horisontal plane than the 6090 Monsters 40 degrees. Mainly because of the smaller dispersion, but also because of the power handling, and different throat the 6090 Monster is almost ten dB louder than the Gjerstad horn.
And because of the extended length of 1,8 meter it also goes lower.
Hi akb1212, it was a funny story about the horn, but the cut and paste technology of today did not quite follow the story board of the 7 Hz story. I have not tried out the theory myself yet, but I have read a lot about infrabass science and military use of infrabass so I would like to think that it works
In china they split a mob with 7 Hz tones and made almost everyone let go of something.... I'm going to try this theory before summer when I'm finished with the basscannon. The horn does not play 7 Hz very well, 9 Hz is the absolute limit, and it is intended to use down to 16 Hz (-3dB point) when you power it up. I guess we'll try that out on February 13. with the Crown Itech 6000
It would have been fun if you brought your Basstech 7 cabinets to the event also, cause I really want to see and listen to them.
Hi MikeE!
It is quite a dream for me too
I started drawing large horns eleven years ago, and the first really big ones was the Gjerstad horns (2004), and then followed the 6090 Monster (still need some bracing).
The 6090 Monster may look similar to the Gjerstad horn from a distance or on a picture. Unlike the P-Audio BM18LF the PHL Audio 6090 is a really good horn driver. The Gjerstad horns have larger dispersion in the horisontal plane than the 6090 Monsters 40 degrees. Mainly because of the smaller dispersion, but also because of the power handling, and different throat the 6090 Monster is almost ten dB louder than the Gjerstad horn.
And because of the extended length of 1,8 meter it also goes lower.
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