8,8 meter basshorn "6090 Monster" - Page 3 - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 17th January 2005, 08:00 AM   #21
diyAudio Member
 
Join Date: Dec 2004
Location: Drammen
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...
  Reply With Quote
Old 17th January 2005, 09:20 AM   #22
diyAudio Member
 
Join Date: May 2002
Location: Switzerland
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
  Reply With Quote
Old 17th January 2005, 09:39 AM   #23
diyAudio Member
 
Join Date: Dec 2004
Location: Drammen
Digital delay is a must have when you play with real size basshorns, indeed

20Hz at night....hmmm that is an ugly trix..he he

Ever tried a supertweeter on your neighbours dogs?
  Reply With Quote
Old 17th January 2005, 10:34 AM   #24
jdybnis is offline jdybnis  United States
diyAudio Member
 
Join Date: Jul 2004
Location: Pasadena, CA
Ha! Here in california we worry about earthquakes. It would be like shouting "fire!" in a movie theater...

I could just imagine all my neighbors running outside, and then the next day trying to figure out why nobody else they know felt the BIG ONE.
  Reply With Quote
Old 17th January 2005, 11:39 AM   #25
diyAudio Member
 
Join Date: May 2002
Location: Switzerland
Quote:
Ever tried a supertweeter on your neighbours dogs?
Cool idea !
Unfortunately our neighbors don't own a dog. But I might try a piezo tweeter on their cats !!!!!

Regards

Charles
  Reply With Quote
Old 17th January 2005, 04:34 PM   #26
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
are you saying that the conventional rules re high BL and low Qts and rear chamber are not necessary when the horn is full size (C>=wl) and length(L>=wl/4)?
regards Andrew T.
  Reply With Quote
Old 17th January 2005, 05:10 PM   #27
simon5 is offline simon5  Canada
diyAudio Member
 
Join Date: Nov 2004
Location: Québec, Québec
Quote:
Originally posted by Skramstad
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...
It's a very good idea, I wonder how it would sound in your big basshorn.
__________________
DIYaudio for President !
  Reply With Quote
Old 17th January 2005, 09:42 PM   #28
diyAudio Member
 
Join Date: Dec 2004
Location: Drammen
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.
  Reply With Quote
Old 17th January 2005, 10:24 PM   #29
simon5 is offline simon5  Canada
diyAudio Member
 
Join Date: Nov 2004
Location: Québec, Québec
Hehe then maybe it's a good solution to have my 8.2 Hz organ note played at reference levels... or not?
__________________
DIYaudio for President !
  Reply With Quote
Old 20th January 2005, 09:56 AM   #30
akb1212 is offline akb1212  Norway
diyAudio Member
 
Join Date: Nov 2003
Location: Svelvik
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
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Anyone know some decent free SPL meter software & "white noise"? Spasticteapot Multi-Way 18 6th October 2011 09:05 PM
&quot;Monster&quot; Cable vs Monster Vintage MonsterVintage Everything Else 0 18th October 2004 11:35 PM
A Monster "carcase" for sale jackinnj Solid State 3 29th May 2002 11:34 PM


New To Site? Need Help?

All times are GMT. The time now is 09:57 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2