the length of low frequency sound waves? 20hz = 56.54ft
I would start to become worried about the integrety of the house, not being funny but most American houses are made from 2x4" and plaster board from what I have seen. I used to run a Cerwin Vega Stroker 18D2 in a 3.5cf box in my car(half req vol), running off a DEI 1100D (1100wrms@1ohm) and could hear the roof flexing and watch my steering wheel travel 2-3inches-I took it out after my gudgeon pins fell out of the door and my door swung past its intended range when opening it.
I'm trying to find a feature a car audio mag did where they measured on the richter scale the output from a few bass cars.
shouting is quite appropriate here
however, I have read repeatedly that the maximum possible sound pressure level in air is under 200 dB, as the air itself would ... what was it disintegrate, or the molecules would split, or something. Maybe one of you guys can straighten me out?
regards, Ben
lol, sorry cut 'n' paste!
I can't see why wavelength would have any effect - headphones work to low frequencies, and they're not given room for the waves to propagate.
IIRC, the loudest sine wave you can have is 184dB - as AndrewT rightly pointed out, you go from zero pressure to 2 atmospheres p/p. Any louder and you're effectively clipping because of the air, which is cool if you can do it.
Chris
Norman,
What you wrote is an audio myth.
A bass horn may not increase in level in the very near field, within an area approximately the horn mouth dimension, but will conform closely to the inverse distance law, loosing 6 dB per doubling of distance from one meter to 100 meters, assuming a mouth area of one meter square or less.
The wavelength a speaker produces has nothing to do with the inverse distance level reduction, and the type of enclosure makes no difference in the rate of level drop.
Your w-bin in a house is subject to peaks and nulls caused by the room dimensions, construction materials, and openings to other rooms.
Art
Art, +1
http://www.cartchunk.org/audiotopics/SmallEnclBass.pdf
edit: although the bass has to be produced by a pressure system device ie. dipole won't work below 1/4 wavelength = the rooms longest dimension
double edit: Mr. Pierce is wrong in the above pdf about BR not being a pressure device as the back-wave is inverted.
http://www.cartchunk.org/audiotopics/SmallEnclBass.pdf
edit: although the bass has to be produced by a pressure system device ie. dipole won't work below 1/4 wavelength = the rooms longest dimension
double edit: Mr. Pierce is wrong in the above pdf about BR not being a pressure device as the back-wave is inverted.
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Fun breaking stuff.... with sound
On Destroying stuff... Ive regularly knocked ceiling tiles out with tapped horns in 10,000 sq foot 10' ceiling clubs. Ive learned to look up during sound check and adjust my low cut accordingly by watching them flutter about.
During a sound lesson back in 79 or 80, I experienced what happens when 2 JBL 2" drivers powered by s d150 and the right female singer on a long sustained note will do......Shattered 40 feet of plate glass windows.
It was at "My Fathers Place" in old Roslyn New York.
The club owner was actually happy because his insurance would now pay for those much smaller windows he always wanted.
My teacher and engineer was the late great and sorely missed Wayne Ernst.
Apparently I put a keyboard bass player in the hospital with severe re-arranging of his innards. He kept complaining it wasn't loud enough. 2 double 18 and two 15+horns, less than 24 inches from his right side, 3000 watts. His intestines and colon were all twisted to the left when he went to the emergency room at the end of the night. His keyboard tones were all in the subsonic region. It was a trip watching his face and clothes flutter about
durning the gig....
The us military tested an airborne sonic weapon using 3 helicopters and horn loaded speakers. Contact wireless mics were dropped on the target, and the engineer dialed in the resonant frequency of concrete and other structures.
It took a while but..... it worked. Concrete bomb proof pillboxes would crumble to dust. Not practical in combat, but proof sustained sound can cause some impressive damage aside from the obvious hearing issues.
Car subs routinely break the welds on trunk lids etc, and that's steel on steel welded!!
With all that in mind. What the heck are you REALLY trying to do. I suspect you want your house to sound like an audio competition car driving by. In other words rattle everything outside the house. This way as the babes and
dudes (substitute your own descriptors) pass by, they will be surprised and attracted or respectful to you. If that's the case........
A few good tapped horns in the house to fill it out nicely... or a wall of DR speakers, and a couple of Concrete Dth-20 type tapped horns with car speakers in them outside the house. Cross the outside cabs over below 55hz and adjust levels until the desired "Can you Hear me comin" or "Look at ME" feel and rattle is reached. Warning: you will seriously **** off the neighbors and may do damage to their houses. If so, expect to be sued.
In some areas, over a certain spl outside the house, constitutes various legal violations. These may include "Running a commercial venture inside a home",
"Disturbing the peace", endangering the lives of others, destruction of personal propery, etc etc etc.
Have fun.
On Destroying stuff... Ive regularly knocked ceiling tiles out with tapped horns in 10,000 sq foot 10' ceiling clubs. Ive learned to look up during sound check and adjust my low cut accordingly by watching them flutter about.
During a sound lesson back in 79 or 80, I experienced what happens when 2 JBL 2" drivers powered by s d150 and the right female singer on a long sustained note will do......
Shattered 40 feet of plate glass windows.It was at "My Fathers Place" in old Roslyn New York.
The club owner was actually happy because his insurance would now pay for those much smaller windows he always wanted.
My teacher and engineer was the late great and sorely missed Wayne Ernst.
Apparently I put a keyboard bass player in the hospital with severe re-arranging of his innards. He kept complaining it wasn't loud enough. 2 double 18 and two 15+horns, less than 24 inches from his right side, 3000 watts. His intestines and colon were all twisted to the left when he went to the emergency room at the end of the night. His keyboard tones were all in the subsonic region. It was a trip watching his face and clothes flutter about
durning the gig....
The us military tested an airborne sonic weapon using 3 helicopters and horn loaded speakers. Contact wireless mics were dropped on the target, and the engineer dialed in the resonant frequency of concrete and other structures.
It took a while but..... it worked. Concrete bomb proof pillboxes would crumble to dust. Not practical in combat, but proof sustained sound can cause some impressive damage aside from the obvious hearing issues.
Car subs routinely break the welds on trunk lids etc, and that's steel on steel welded!!
With all that in mind. What the heck are you REALLY trying to do. I suspect you want your house to sound like an audio competition car driving by. In other words rattle everything outside the house. This way as the babes and
dudes (substitute your own descriptors) pass by, they will be surprised and attracted or respectful to you. If that's the case........
A few good tapped horns in the house to fill it out nicely... or a wall of DR speakers, and a couple of Concrete Dth-20 type tapped horns with car speakers in them outside the house. Cross the outside cabs over below 55hz and adjust levels until the desired "Can you Hear me comin" or "Look at ME" feel and rattle is reached. Warning: you will seriously **** off the neighbors and may do damage to their houses. If so, expect to be sued.
In some areas, over a certain spl outside the house, constitutes various legal violations. These may include "Running a commercial venture inside a home",
"Disturbing the peace", endangering the lives of others, destruction of personal propery, etc etc etc.
Have fun.
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All the whining about SPL in this thread is just lame. It's reminding me of the old AVS Dirty Harriet thread. It's easy to get this kind of output in a car, and just like in the car $hit is going to break. So quit whining and help him get it done. The aftermath will be much more entertaining than this anyway.
All the whining about SPL in this thread is just lame. It's reminding me of the old AVS Dirty Harriet thread. It's easy to get this kind of output in a car, and just like in the car $hit is going to break. So quit whining and help him get it done. The aftermath will be much more entertaining than this anyway.
Wait, what?!
The structural damage such a system will cause to a building is very very real.
Are you saying we ought to help to design a system that may flatten someone's property, potentially crushing them with it?
I sincerely hope not.
Chris
Yes - yes I am.
It's common sense vs Darwin, let the natural selection begin.
Now back in your hole!
ok i am loving the concern here and maybe this goal is not a good goal to have after reading all this information hah. how about can someone design me a box that goes to about 30 hz with a 2011 series Kicker 15" L7 dual 2 ohm. trying to see if I can get 120db+ plus at 30hz . dimensions you would have to work with would be 22"w x24"D x 60"H.. if someone could put that together I will save my house and possibly life. Thanks for the help and thanks to everyone that has posted so far. btw i would be feeding the kicker juice from a qsc 2450 so for wattage i can be at 1000rms no problem
Keep in mind that amp cannot do high power at 20hz into a 2ohm load with low distortion. That's why the power ratings are blank for those parameters in the spec sheet.
Reminds me of my 'nights out' at a place called "Earthquake Ethels"........a disco in Beaverton Oregon. I was working nights at an alternate disco as a "stripper".........Really does wonders for ones ego..."My" club was a place called "The Chase"..........I was "Mr Risque".........Made decent money & had lotsa girls at my beck & call. This one disco had floor to ceiling Phase linear amps, a dozen or so 30" Electrovoice drivers built into the walls........The system was cranked up in earnest at about 8:00....Playing the scenes on video & audio of the senserround (sp?) of the Movie "Earthquake"......the building suffered from structural damage in short order & the system was dialed back. The stack of Phase linears were never all cranked up after that.
_______________________________________________________Rick.........
_______________________________________________________Rick.........
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