9:00 Pacific Time-MYTH BUSTERS take on the challenge of trying to break glass with a home made subwoofer. They make a sub out of tar paper, ect.. and it is over 6 feet long. They even put it into a car. Its an all new episode, so clock onto the Discovery Channel at 9:00 Pacific
Replies (11)
ttocs on 08/16/2006 13:23:57
they should have richard clark on there then.
lilschtive on 08/16/2006 14:43:42
Yeah i just saw it on a commercial. im not sure if they are trying to break windows, but its god a LOT to do with car audio
swez on 08/16/2006 18:59:39
I'll call this one "BUSTED" before the show begins. making a sub that can break glass, requires a lot of power and exceptional design of the sub and enclosure.
Transfering that much sonic energy to any transducer, (Speaker) takes more than a little backyard monkey-tree work. This is especially true of automotive grade glass compounds.
If I miss this episode, (Likely) tell us how it worked out OK?
Swez
MrBrownstone on 08/16/2006 20:52:27
You won't actually break the glass from the woofer..you'll break it from the frame around the glass bymaking it flex. You can, however, pop out a windshield from it's seal....if it flexes enough.
Not sure what they are trying to prove, but that show does have an awful lot of holes in it's 'science' .
swez on 08/17/2006 12:11:17
OK, I managed to stay up and watch this one. (1:00 - 2:00 AM)
Jamie and Adam fabricated a cone made from wedged pieces of Aluminium, welded them together and formed a wide ange cone some 51" in diameter.
The also fabricated a surround using an tire inner tube and then used a push rod cam system to move the cone up and down with the crank shaft output from the cars' transmission. Pretty interesting ideas used here, but hardly a standard speaker cone. More like a large pressure transducer.
They also sent one of their guys to Florida for a big DB Drags event and learned what SPL Heads need to do, in order to hit high numbers. In a nutshell, the report was basically to seal and dampen the vehicle as much as possible. This keeps air pressure in the vehicle at its peak ability and hense, we get huge SPL numbers.
The woofer was fabricated and installed in an old Mercedes sedan. They removed all the interior stuff, built a baffle board to mount the sub and then connected a Cam lever to the cone and driveshaft. There are 3 notes this sub will play... 1st, 2nd and 3rd gear RPM speeds off the PTO. (Driveshaft)
Well, they even had a DB Drag Judge on hand to observe and test SPL. The results were less than stellar in one aspect. The car did not fall apart, no windows were broken and the only thing that did fail, was the cone surround used. It could not take that kind of X-max w/o linear motor supports. The surround just delaminated from its glue points and the sub fell apart.
MYTH was Busted or in my thinking, inconclusive in this test. The sub managed to generate 160.? dB of SPL at ~16 Hz. This pressure wave knocked the moon roof window out of it's tracks and pressure was lost to a point, the cone just fell apart. Basically, poor structural supports were used and the cone was not moving in a true linear path. That's what ultimately tore the sub apart.
If they had used a linear actuator to drive the cone and fastened the surround with some hardware that would not fail like the glue did and sealed all leaks... Ie: Weld the moon roof in place, I think it would have worked.
The trick here, was not so much SPL levels attained, (Pretty good number here) but the method used to generate SPL. (Poor mechanical design) If the moon roof did not fail and the cone could withstand the excursion and perhaps a range of higher frequencies were employed, my guess is that the windows may have indeed "fallen out" or door jambs would have given way.
Yes, I do watch some of the Mythbuster's shows. Mostly to see what goofy ideas these two guys come up with and how they reach a given inclusion. However, the real show piece on this program is Kari Byron. She's a "Hot & Sweet" spicey meatball who's not afraid to get her hands dirty either.
In this program, the Myth was not really busted.... just the plan and methodolgy used were very flawed. Nuff Said!
Swez
MrBrownstone on 08/18/2006 17:24:26
myth busters? or Nut Jobs...you decide.
they should have used 55-65Hz and would have had better results.
swez on 08/18/2006 17:57:59
Depends on the show topic.... in this episode, definitely a couple of hacks and loose Lug Nuts.... especially Adam.
Jamie is my fav of the two. He's very logical, level headed, a deep thinking Phlegmatic and well educated . His bio suggests a very calculated personality with well researched methods in his tool bag.
Adam, on the other hand, is a total "free spirit" kind of guy. He's a very inventive/intuitive Sanguine. He can see fun in any experiment and probably the life of every party. His boisturist persona gets into a room before he even come in the door.
Yeah, 50-70 Hz., would have been a good target range to shoot for, if the mechanical drive (motor system) part of the transducer was designed correctly. This one had way too much side play and slop.
Swez
Ash on 08/19/2006 06:00:31
Sounds like to me there may be a new budget subwoofer manufacturer in the making. Pyramid better get their act together!
GRIN
swez on 08/19/2006 07:45:24
Hardly... this one probably cost thousands of dollars to fabricate and install. There was no finese or a high degree of egineering or design skills in this project either.
If I had to guess, this was one way to poke a stick in the eye of serious and amature SPL guys. There's a lot of serious work that SPL Comp guys put into their projects. This was more a spoof than any thing else.
Swez
PS Ash, How'd your brake job come out?
Ash on 08/19/2006 09:51:39
Yeah, I could imagine the cost of parts & labor on a silly project. All they had to do was the let SPL guys do the work with some used equipment. It would probably have been a better test.
Actually the brake job went along very good. The first side took a little longer than anticipated because the rotor was rusted onto the hub. After a few sprays with PB Blaster (great stuff!) and a few taps of the ole hammer.... voila! The other side was a cinch. Two new rotors, pads, and hardware... 60- 70 bucks. Can't beat that! And no injuries to boot. Brakes are smooth and stops on a dime (well maybe a quarter... SUV's ya know). GRIN
The water pump job was quite simple as well. Now all I should have left is to overhaul the flux capacitor....
swez on 08/19/2006 15:57:49
Yep, better check the flux capacitor and the Kanutten Valve too. Kanutten Valves only last 130-150 KMiles. In that truck, you're pretty close, so hit that one too.
FYI: You need a special tool to romove and change the Kanutten Valve. They can be rented at most good car parts stores. I think it's called a Do-jigger tool.
Here are the steps for that Blazer:
1. Go get the right size Do-jigger tool (25, 40 or 55mm)
2. Lossen the engine mounts
3. Raise motor upward 2.5" with a good hydrolic jack
4. Use Jam Blocks to keep engine from shifting
5. You only get access to the K Valve via the driver's side wheel housing (tire and rim must come off)
6. With your Wunder Bar, pry upward on the Dangler Do-dad and then insert your K-Valve tool over the outer housing of the K-Valve. (Be sure to remove the clip & wire sensor lines)
7. Now, use a 1/2" drive socket wrench and a 54" extension rod to remove the K-Valve (This is reverse threaded, So... lefty tighty, loosy Righty)
8. If you cannot get it loose after applying 325 ft/lbs of torque, break out your Pb Blaster and let it soak for 15 mins. and try again (You may need the "Big Boot" to break the thing loose
9. Once you have the K-Valve out, Inspect it for wear and corrosion
10. If either is noted, throw it out and get a by-pass valve adapter plate to replace said K-Valve
11. Even if the K-Valve looks good, toss it anyway (use option 10)
12. Cut off sensor wire connector and ground it to an easy location (That sensor light will never come on again) Whew... that's a relief
13. Re-assemble in reverse order
NOTE: If the spark plugs have not been changed in a while, might as well do that while you're here. Plugs #3 & 5 are dang hard to get out from any other position. Just make sure the engine lift is high enough to get a socket and extensions into that location.
The steering arm linkage is in the same location. Now is the time to replace these plugs as it is utterly impossible, (Stupid GM Engineers and Designers) to get at these plugs any other way. Got all that? GRIN
OK, have a nice week cussin this one out, MAD SAD MAD
Swez
Replies (11)
ttocs on 08/16/2006 13:23:57
they should have richard clark on there then.
lilschtive on 08/16/2006 14:43:42
Yeah i just saw it on a commercial. im not sure if they are trying to break windows, but its god a LOT to do with car audio
swez on 08/16/2006 18:59:39
I'll call this one "BUSTED" before the show begins. making a sub that can break glass, requires a lot of power and exceptional design of the sub and enclosure.
Transfering that much sonic energy to any transducer, (Speaker) takes more than a little backyard monkey-tree work. This is especially true of automotive grade glass compounds.
If I miss this episode, (Likely) tell us how it worked out OK?
Swez
MrBrownstone on 08/16/2006 20:52:27
You won't actually break the glass from the woofer..you'll break it from the frame around the glass bymaking it flex. You can, however, pop out a windshield from it's seal....if it flexes enough.
Not sure what they are trying to prove, but that show does have an awful lot of holes in it's 'science' .
swez on 08/17/2006 12:11:17
OK, I managed to stay up and watch this one. (1:00 - 2:00 AM)
Jamie and Adam fabricated a cone made from wedged pieces of Aluminium, welded them together and formed a wide ange cone some 51" in diameter.
The also fabricated a surround using an tire inner tube and then used a push rod cam system to move the cone up and down with the crank shaft output from the cars' transmission. Pretty interesting ideas used here, but hardly a standard speaker cone. More like a large pressure transducer.
They also sent one of their guys to Florida for a big DB Drags event and learned what SPL Heads need to do, in order to hit high numbers. In a nutshell, the report was basically to seal and dampen the vehicle as much as possible. This keeps air pressure in the vehicle at its peak ability and hense, we get huge SPL numbers.
The woofer was fabricated and installed in an old Mercedes sedan. They removed all the interior stuff, built a baffle board to mount the sub and then connected a Cam lever to the cone and driveshaft. There are 3 notes this sub will play... 1st, 2nd and 3rd gear RPM speeds off the PTO. (Driveshaft)
Well, they even had a DB Drag Judge on hand to observe and test SPL. The results were less than stellar in one aspect. The car did not fall apart, no windows were broken and the only thing that did fail, was the cone surround used. It could not take that kind of X-max w/o linear motor supports. The surround just delaminated from its glue points and the sub fell apart.
MYTH was Busted or in my thinking, inconclusive in this test. The sub managed to generate 160.? dB of SPL at ~16 Hz. This pressure wave knocked the moon roof window out of it's tracks and pressure was lost to a point, the cone just fell apart. Basically, poor structural supports were used and the cone was not moving in a true linear path. That's what ultimately tore the sub apart.
If they had used a linear actuator to drive the cone and fastened the surround with some hardware that would not fail like the glue did and sealed all leaks... Ie: Weld the moon roof in place, I think it would have worked.
The trick here, was not so much SPL levels attained, (Pretty good number here) but the method used to generate SPL. (Poor mechanical design) If the moon roof did not fail and the cone could withstand the excursion and perhaps a range of higher frequencies were employed, my guess is that the windows may have indeed "fallen out" or door jambs would have given way.
Yes, I do watch some of the Mythbuster's shows. Mostly to see what goofy ideas these two guys come up with and how they reach a given inclusion. However, the real show piece on this program is Kari Byron. She's a "Hot & Sweet" spicey meatball who's not afraid to get her hands dirty either.
In this program, the Myth was not really busted.... just the plan and methodolgy used were very flawed. Nuff Said!
Swez
MrBrownstone on 08/18/2006 17:24:26
myth busters? or Nut Jobs...you decide.
they should have used 55-65Hz and would have had better results.
swez on 08/18/2006 17:57:59
Depends on the show topic.... in this episode, definitely a couple of hacks and loose Lug Nuts.... especially Adam.
Jamie is my fav of the two. He's very logical, level headed, a deep thinking Phlegmatic and well educated . His bio suggests a very calculated personality with well researched methods in his tool bag.
Adam, on the other hand, is a total "free spirit" kind of guy. He's a very inventive/intuitive Sanguine. He can see fun in any experiment and probably the life of every party. His boisturist persona gets into a room before he even come in the door.
Yeah, 50-70 Hz., would have been a good target range to shoot for, if the mechanical drive (motor system) part of the transducer was designed correctly. This one had way too much side play and slop.
Swez
Ash on 08/19/2006 06:00:31
Sounds like to me there may be a new budget subwoofer manufacturer in the making. Pyramid better get their act together!
GRIN
swez on 08/19/2006 07:45:24
Hardly... this one probably cost thousands of dollars to fabricate and install. There was no finese or a high degree of egineering or design skills in this project either.
If I had to guess, this was one way to poke a stick in the eye of serious and amature SPL guys. There's a lot of serious work that SPL Comp guys put into their projects. This was more a spoof than any thing else.
Swez
PS Ash, How'd your brake job come out?
Ash on 08/19/2006 09:51:39
Yeah, I could imagine the cost of parts & labor on a silly project. All they had to do was the let SPL guys do the work with some used equipment. It would probably have been a better test.
Actually the brake job went along very good. The first side took a little longer than anticipated because the rotor was rusted onto the hub. After a few sprays with PB Blaster (great stuff!) and a few taps of the ole hammer.... voila! The other side was a cinch. Two new rotors, pads, and hardware... 60- 70 bucks. Can't beat that! And no injuries to boot. Brakes are smooth and stops on a dime (well maybe a quarter... SUV's ya know). GRIN
The water pump job was quite simple as well. Now all I should have left is to overhaul the flux capacitor....
swez on 08/19/2006 15:57:49
Yep, better check the flux capacitor and the Kanutten Valve too. Kanutten Valves only last 130-150 KMiles. In that truck, you're pretty close, so hit that one too.
FYI: You need a special tool to romove and change the Kanutten Valve. They can be rented at most good car parts stores. I think it's called a Do-jigger tool.
Here are the steps for that Blazer:
1. Go get the right size Do-jigger tool (25, 40 or 55mm)
2. Lossen the engine mounts
3. Raise motor upward 2.5" with a good hydrolic jack
4. Use Jam Blocks to keep engine from shifting
5. You only get access to the K Valve via the driver's side wheel housing (tire and rim must come off)
6. With your Wunder Bar, pry upward on the Dangler Do-dad and then insert your K-Valve tool over the outer housing of the K-Valve. (Be sure to remove the clip & wire sensor lines)
7. Now, use a 1/2" drive socket wrench and a 54" extension rod to remove the K-Valve (This is reverse threaded, So... lefty tighty, loosy Righty)
8. If you cannot get it loose after applying 325 ft/lbs of torque, break out your Pb Blaster and let it soak for 15 mins. and try again (You may need the "Big Boot" to break the thing loose
9. Once you have the K-Valve out, Inspect it for wear and corrosion
10. If either is noted, throw it out and get a by-pass valve adapter plate to replace said K-Valve
11. Even if the K-Valve looks good, toss it anyway (use option 10)
12. Cut off sensor wire connector and ground it to an easy location (That sensor light will never come on again) Whew... that's a relief
13. Re-assemble in reverse order
NOTE: If the spark plugs have not been changed in a while, might as well do that while you're here. Plugs #3 & 5 are dang hard to get out from any other position. Just make sure the engine lift is high enough to get a socket and extensions into that location.
The steering arm linkage is in the same location. Now is the time to replace these plugs as it is utterly impossible, (Stupid GM Engineers and Designers) to get at these plugs any other way. Got all that? GRIN
OK, have a nice week cussin this one out, MAD SAD MAD
Swez
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