TheEAR Posted February 7, 2008 Share Posted February 7, 2008 Same with american machines,some became giant BBQ others...you get the picture.When you are on the bleeding edge of what is possible at that time,you will have problems. Those that never had problems never tried much,those that claim otherwise are liars So how's that for []. Quote Link to comment Share on other sites More sharing options...
Canadian_Dude Posted February 7, 2008 Share Posted February 7, 2008 $50000 is small change for a machine, you should see some heavy duty CNC machines. They make a classic saw look like a caveman device and are priced to match. The most impressive machine that I ever saw when I was just a kid was at the place where my father was the main technical...a huge press capable of several 1000 T of pressure,a HUGE mofo press. Drive under it and PRESS the big button....the motor block would end up a flat crushed piece. Im my city we have some of the world's largest metal lathes for making all kinds of stuff for the oil patches. They could fit your house on the chuck, these are ridiculous. Now my little lathe at work has only a 20" inch chuck, microscopic compared to the 20' chucks I've seen. Quote Link to comment Share on other sites More sharing options...
TheEAR Posted February 8, 2008 Share Posted February 8, 2008 Large machinery is fun...audio is more relaxing to listen to. Try listening to a big mutha torbocompressor...[:S] Ok NEWS BREAKING NEWS.!!! I am ordering ACOUPOWER 18 inchers ! Pics as they start arriving ! Quote Link to comment Share on other sites More sharing options...
TheEAR Posted February 10, 2008 Share Posted February 10, 2008 Braces.more braces done last night..after work. You do DIY..do it right. No cutting corners using a large cement pour cardboard cylinder lazy man way. [] When the four boxes start to near finishing,you will see what TheEAR subs are all about. [] High output,low distortion,true deep bass and linear across the range they cover. No phony EQ boosing here , the EQ only use,attenuation. [] Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted February 11, 2008 Share Posted February 11, 2008 cardboard tubes are quite strong, remember a circle is one of the strongest shapes Quote Link to comment Share on other sites More sharing options...
TheEAR Posted February 11, 2008 Share Posted February 11, 2008 Any Joe Blow can do a sonotube sub,and sonotubes look like $heete. A well build ,cabinet...heavy bracing and all is much stronger than a sonotube(you buy,started life as a cement pour tube). The sonotube would be more solid if it was not so thin (walls) and braced. Even HSU and SVS's best offerings are in boxes now. The tube is simply the most inexpensive way to get the job done. Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted February 11, 2008 Share Posted February 11, 2008 I tried to find a paper core tube at 20 inches wide but its cost would be exponential and much more than a wooden box. I wasquoted something 600 dollars for a 20 inch internal diameter paper core that was 1/2 inch thick. Also shipping would be another 200 dollars. I would say that paper core would be much stronger than any box. Quote Link to comment Share on other sites More sharing options...
DrWho Posted February 11, 2008 Share Posted February 11, 2008 1/2" thick?!? Why??? Dude, go with something that is 1/4 oreven 3/16 of an inch thick. Heck, 1/8" would probably be sufficient.The only thing that will be vibrating is your 3/4" end panels...evendoubling it up to 1.5" it'll be a problem. I would suggest somethreaded rod that goes through the entire enclosure and mounts to bothsides (perhaps using it as the bolts for two drivers...either bothactive or just one active....). In the meantime, your super thin paperwall tube is not going to vibrate at all - it's the weirdest thing inthe world....but then it makes sense considering that these tubes don'tflex when being filled with concrete - talk about orders of magnitudemore psi than a measley subwoofer driver will ever produce. The wallsof the sonotube don't give a crap where the pressure is coming from(concrete or air)... Anyways, the point is that the stupid cardboard doesn't flex at all. You couldn't ask for anything better... Themost complicated part of the sonotube builds is dealing with thecompounded resonances introduced by the geomtery of the internals.You're really going to need lots of absorbtion. Even if the resonancesare outta the passband, you can't prevent any driver distortions fromtriggering them - and it doesn't take much to make the resonancesaudible. Think about it...we can hear distortion that is 60dB down anddriver distortion is going to be way more than that (like on the orderof 1% at most normal listening levels). Your resonances are going toamplify that 1% distortion probably by around +6dB to +10dB...(bringingit to about 10% distortion at the fundamentals that trigger theharmonic resonances). I bring all this up because it's an issuewith cube enclosures too (except the dimensions can be chosen to offsetthe compounding of standing waves). One of the nice things aboutpassive radiators is that it keeps this nonsense inside the enclosure(well for the most part). I suppose if you wanted to be hardcore, youcould tune a classical port so that it rejects the harmonicresonances...talk about a complex problem of standing wave nodes andport geometries (not to mention making everything scale with humidityand temperature changes). While one could over build thestructural integrity of the enclosure, I think it's retarded and showsa lack of experience to do so. Eventually the distortions imparted byflexing walls are going to be swamped by other, more seriousdistortions (like cabinet resonances in this example). At which point,it makes sense to shift the focus onto engineering those distortionsout... Quote Link to comment Share on other sites More sharing options...
TheEAR Posted February 11, 2008 Share Posted February 11, 2008 Cardboard is extremly strong,what is MDF ? It is a very dense type of cardboard. Show me a tube with .75 to 1inch thick walls...ah we are talking. I want a stable 200-300lbs chimney..not a 50lbs giant TP tube. [] Dense cardbord has natural absorption,take MDF for example. Great for cabinet building. Internal resonances can be reduced greatly by using tar like covering with 2-3in thick sound absorbing material.This is what I will do inside my cabinets.Even the inside of the port will be lined with a thin dense foam like material. This done you can have all the SQ or very close to a system using PR's. Overbuilding ..retarded. LOL Overbuilding is retarded when you do commercial and profit is the key,here the least expensive device suitable for the application is often the best route. For personal application overbuilding is far from RETARDED. Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted February 11, 2008 Share Posted February 11, 2008 medium density fiberboard theear..... Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted February 11, 2008 Share Posted February 11, 2008 oh btw, theear, drwho is correct as a circle is the strongest shape since it relies on the fact that all the surface receives the force evenly distributed or more evenly than any other shape thus making it very rigid. I would think the best shape for a subwoofer would be an oversized airtank with one side cut off an the other side be a hemisphere. Quote Link to comment Share on other sites More sharing options...
TheEAR Posted February 11, 2008 Share Posted February 11, 2008 Ideal cabinet,a sphere. Try to deform a sphere with equal pressure. Cylinder has its weak points,being the end caps. Sphere,now that is an idea.WHo will make the first sphere made out of dense cardboard ? A spherical sub. Someone needs to make the cabinets. Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted February 11, 2008 Share Posted February 11, 2008 a sphere is not conducive to smallest size. Also didn't B&W do something like that albeit weak and I think 10 inches? Quote Link to comment Share on other sites More sharing options...
TheEAR Posted February 11, 2008 Share Posted February 11, 2008 That B&W did build a sub in a sphere has not much to do with much else than shape.The B&W spherical is more of a toy than anything else,it uses tiny drivers in a tiny cabinet. A bit of a Sunfire with much less output down deep. Try making a sphere sub cabinet out of MDF,the process is not complicated. WIth CNC machines,but at home it would result in a grandiose waste of time. As rings would have to be cut and glued. ...now back to the DIY... I ordered my ACOUPOWER 18" ...paid,called Carlos from Acoupower. Should be done Friday and sent out. I feel likle a kid in a candy store. ACOUPOWER...yeah talk about one of the most capable drivers ever made. And quality it goes against the best of the best. PICS and more PICS the day it arrives !!! Quote Link to comment Share on other sites More sharing options...
DrWho Posted February 11, 2008 Share Posted February 11, 2008 Overbuilding ..retarded. LOL Overbuilding is retarded when you do commercial and profit is the key,here the least expensive device suitable for the application is often the best route. For personal application overbuilding is far from RETARDED. We'll have to agree to disagree then....I guess that's the difference between engineers and hobbyists [] (even when talking only about building for yourself) Quote Link to comment Share on other sites More sharing options...
TheEAR Posted February 11, 2008 Share Posted February 11, 2008 Overbuilding is not practical due to costs involved,lets remember this is not a commercial product that has to be designed to do the most with the least. And even a good engineer will agree adding the extra to be safe will not hurt you(budget will)as you know...simply I add a bit overboard. As yes this is my hobby,and I am a bit of a lunatic when it comes to audio. [] Why use a 8" bass driver when you can use a 18" ? You will move as much air with a small fraction of the excursion...and push distortion to where our hearing will not notice. Then why now a few 15" and 18" drivers in a tiny space ? Borders on insanity. OT... Overbuilding was even done and is done by some engineers,not always with the results wanted. [8-|] Take for example the Yamato battle ship who was the most capable ,largest battleship ever built.Overbuilt for its time. The result,sunk by a few tiny,puny planes ..the moral ...no overbuilding would have changed the end result. Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted February 12, 2008 Share Posted February 12, 2008 I ordered my ACOUPOWER 18" ...paid,called Carlos from Acoupower. Should be done Friday and sent out. I feel likle a kid in a candy store. ACOUPOWER...yeah talk about one of the most capable drivers ever made. And quality it goes against the best of the best. PICS and more PICS the day it arrives !!! what are the specs for it? does it rival the lms 5400? Quote Link to comment Share on other sites More sharing options...
TheEAR Posted February 12, 2008 Share Posted February 12, 2008 It is not far off the LMS-5400 18" in displacement. [] Models damn well, I may do dual EBS. 17cu ft per driver,34 cu ft ! A monster,now duals with dual 10" vents flared to 18" !!! Watch out I will go after wall cracking SPL. Duals in the Genesis Device are capable of damaging SPL levels. Cannot wait...tomorrow I will try to order more CSS,Mach 5 and Spound Splinter ....pure madness. Some are happy with 1-2 of displacement,I will surpass 100L total . Next will have to be FiCar and eD. ...after..hmmm hunting downsome LMS-5400 18" drivers.And maybe the RE XXX 18" brutes. Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted February 13, 2008 Share Posted February 13, 2008 17 cubic feet.... and how will you tune it since the port is 10 inches? nothing below 25 hertz or the thing I envision will be what 60+ inches? Quote Link to comment Share on other sites More sharing options...
TheEAR Posted February 13, 2008 Share Posted February 13, 2008 Enter the driver data in WinISD you will see. [] Quote Link to comment Share on other sites More sharing options...
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