kenratboy Posted June 9, 2004 Author Share Posted June 9, 2004 Cool, Canadian rednecks! - the cell phone adds a nice contrast. Does it work well? I would love to make one. Quote Link to comment Share on other sites More sharing options...
michael hurd Posted June 9, 2004 Share Posted June 9, 2004 The ABS gun works ok, but you always want more. There are plans in the works for another one, only this time schedule 40 PVC, with a larger chamber, and a longer barrel. This gun will have an electonic ignition module from a barbeque ( 1.5v battery powered ) and also use propane as fuel. Quote Link to comment Share on other sites More sharing options...
InnovaZero Posted June 9, 2004 Share Posted June 9, 2004 ---------------- On 6/8/2004 9:55:14 PM fire pinch wrote: Well, the Tumult is one of the if not the most powerfull 15 inchers in the world and I have it! 34mm of LINEAR one way xmax! Quite a lot more capable than the best Sunfire. I never broke any enclosure with it yet when it was pushed to its limit if this can make you more confident! This is truely a myth! Ive never heard of another Tumult user broking his enclosure while the sub is playing at a loud volume. ---------------- That is unless Bob Carver decided to design a 15" woofer, I don't think the Tumult would reign anymore Too bad this prob. won't be a reality. Quote Link to comment Share on other sites More sharing options...
picky Posted June 9, 2004 Share Posted June 9, 2004 On 6/5/2004 10:20:56 PM Colin wrote: ----------------------------------- Dont forget that 5Hz road vibrations continually stress the sub box, cars arent stiff as a racing bike, they flex, shake and vibrate ----------------------------------- Colin has hit the nail on the head here. In automotive design and manufacturing, because all vehicles ARE flexible (they have to be or they would shake themselves apart) we test the entire vehicle on shaker tables to determine all of the body and chassis' nodes including trying to keep all harmonics noticable in the interior well below the 32 Hz level. Thus, (in theory) vibrations are rendered inaudible by most people. Remember, I said IN THEORY! It is also noted at which frequencies actual distruction takes place. Hence, Michael Hurd's mention of the mounting bolts of subwoofers actually enlarging their mounting holes, etc. The rolling chassis is a much more complex system then first realized by most. They must stay flexible or the vehicle's occupants would be more easily killed at much lower speed crashes than they are due to the energy of the crash being unloaded onto the occupants, rather than having the body and chassis twisting and distorting to absorb the crash energy. A big, heavy very stiff truck frame is more dangerous in a crash to its occupants than is a flexible frame. Both frames can be equally strong, it's just that one has been designed to collapse upon impact. Early inventors were up against an insurmountable task in making their chassis and body designs structurally sound on the road without the use of today's modern testing facilities. Ever wonder why a ship has round portholes and doors with rounded corners? It's because of the harmonics present from just running the ship's engine and moving it through the water would cause any of the openings to tear at the corners. Yes, even the steel plate would tear! Corners are considered to be "stress points". Early cars with their sharp corners would have steel body panels literally rip just from moving down the road! Although, errant squeaks and rattle will always occur from things becoming loose, this is why today's vehicles are no so much more quiet than the vehicles made just 10 years ago: Harmonics! That is, they remain quiet until a large, unplanned-for, electric vibrator (sub) is placed into an area of the vehicle that had already been rendered quiet through testing. Then, all hell breaks loose because a completely new set of harmonics has been introduced and the vehicle buzzes like a buzzsaw! -Big surprise? -NOT! Quote Link to comment Share on other sites More sharing options...
kenratboy Posted June 9, 2004 Author Share Posted June 9, 2004 Picky: Great stuff! I know about how complex vehical chassis are (anyone eho underestimates anything mechanical or electrical needs to be 'educated' on design and engineering), but the whole harmonics bit is new to me. Very cool stuff. Quote Link to comment Share on other sites More sharing options...
fire pinch Posted June 9, 2004 Share Posted June 9, 2004 ---------------- On 6/8/2004 10:06:23 PM mike stehr wrote: ***So would that be 68mm peak to peak? ***Yeah, but there is a good chance you'll find user's that broke the sub from playing the driver itself too loud. ---------------- Yep, this means 68 mm peak to peak! Do you means "the enclosure" broking because of the driver which plays too loud?? Well, I'll tell you when my Tumult enclosure will broke, I will even make a post on the Klipsch forum when this will happen. But Im sure that this will not happen, as I pushed the Tumult to its limit a few times and 75% of its limit several times. Even at 75% (approximative) of its limit, it is more loud and displace more air than a lot of woofers out there! The subs which brake must be poorly built, OR you just heard a great myth! Quote Link to comment Share on other sites More sharing options...
mike stehr Posted June 11, 2004 Share Posted June 11, 2004 Nice Potato cannon Mike. Watch out, soon you'll be building a real cannon of some sort. A buddy of mine and his brothers did, that was fun! Quote Link to comment Share on other sites More sharing options...
MD1032 Posted June 11, 2004 Share Posted June 11, 2004 >>What's funny is that you would think a sealed enclosure would have the most internal air pressure, but this is not the case. In fact, a vented (ported/bass reflex) enclosure will have up to 3 times more air pressure exerted on it then a sealed enclosure which happens at the tuning frequency of the port. Pretty neat, huh?!<< Wow! That's really interesting. So, could I theoretically just seal up my PM4.1 box then? At least I'd get rid of that darn port noise! Quote Link to comment Share on other sites More sharing options...
Rdmarsiii Posted June 11, 2004 Share Posted June 11, 2004 I tried it once. Didnt like the results. Cut the volume by like half. Oh, and its hard typing with super glue on your fingers. Speaking of vibrations, the port on the 5.1 sub came loose, it took forever to find out what was making the funny noise, so i finally found it, and super glued it shut, but in the meantime, super glued my finger, lol. Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted July 12, 2004 Share Posted July 12, 2004 No exploding sub boxes here, but while in a High School 'Kiss' tribute band we once blew the top off of a PA cabinet with some hastily prepared pyrotechnics. set off the smoke alarms in the apartment clubhouse, the Fire Dept. came and everything. VERY COOL! What scares me is putting all the subwoofer crossover electronics and amplifiers in the same massivly vibrating box as the sub! I know they can 'shake-test' the components, but it has got to reduce the life expectancy of the electronics. Has anyone ever made a (non-commercial PA) sub bin with separate electronics or how is this issue handled? Are the electronics in a sealed box shock-mounted or what???? Quote Link to comment Share on other sites More sharing options...
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