jason str Posted June 17, 2016 Share Posted June 17, 2016 The larger driver will use a larger cabinet making any differences minimal at best. Larger cabinets means beefier bracing as well adding more weight. Weight is a non issue. Throwing weight on a vibrating sub is band-aid fix. Hmmm... Adding weight intentionally and normal construction panel and brace weight are very different things. Not talking cardboard boxes either so don't take the comment to the extreme again, it accomplishes nothing. Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted June 17, 2016 Share Posted June 17, 2016 (edited) Adding weight intentionally and normal construction panel and brace weight are very different things. Your original comments were in response to the construction methods of Deep Sea Sound though. He doesn't just bolt on lead weights. He builds his boxes like a tank. Still vibrates a little bit. That massive 24" sub with over 6,000 watts going to it is just a lot of force. Edited June 17, 2016 by MetropolisLakeOutfitters Quote Link to comment Share on other sites More sharing options...
RoboKlipsch Posted June 17, 2016 Share Posted June 17, 2016 I'm no expert but I do think there are two very different concepts going on here. I do have tactile transducers in my couch and on a chair that I installed. The purpose of those transducers is to vibrate something ON PURPOSE, and in doing so, I am trying to achieve as much as possible. IN FACT, I was instructed to install the TTs onto boards first, and then install them onto the couch and chair. The reason for this is that by doing so, I transfer MORE of the vibration directly to the objects I want to vibrate. The board transmits the vibration better than the other materials on the furniture. Even if I didn't specifically add them to the boards first, and then the furniture, the clear instructions were to mount them onto either wood or metal. So consider that. In my basement, I have my RSW sub on the carpeted floor, on feet, and it plays great just as it is. Upstairs, I have two smaller subs playing in that theater, on a hardwood floor. I noticed, just by observation, that they were transmitting vibration through the rubber feet, onto the floor. This includes the R-10SW from Klipsch. By placing each of them onto a thick welcome mat, folded over (about 2 inches thick total), there was a considerable improvement in clarity of the sound, and it seemed to me that it was largely due to less vibration being transferred directly into the floor. SVS, a well-respected ID builder, sells a very expensive isolator, as do many others. I THINK, but do not know, the reason is what I just described, a form of decoupling the subs from the surface it is placed onto. The other part of this discussion is about cabinet design and vibration. I would think and assume that the less braced a cabinet is, the MORE vibration is can have. And to Jason's points, THIS vibration can be minimized or reduced through proper build principles. So I think bad cabinet design can very well lead to increased vibrations. It can also lead to the sub moving around, which may or may not be solved with the isolator. Does this help the discussion at all? Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted June 17, 2016 Share Posted June 17, 2016 Does this help the discussion at all? The discussion is centered around whether cabinet panel vibration or the moving driver mass is the more likely cause of subwoofers moving. Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted June 17, 2016 Share Posted June 17, 2016 (edited) Not subs but I've always thought this demo was interesting. You can tell the difference just over a crappy youtube video. Most people go the exact opposite direction on the mains though, using spikes and whatnot. Edited June 17, 2016 by MetropolisLakeOutfitters Quote Link to comment Share on other sites More sharing options...
Scrappydue Posted June 18, 2016 Share Posted June 18, 2016 As for subs that don't walk or vibrate, I expect a sub with a down firing driver would tend to vibrate less. Depends on the floor. Scrappy had one of those SVS down firing cylinder subs in his living room, which is fully suspended over the downstairs area. I thought he was exaggerating but I visited and it was ridiculous. On any big sub hit that was pretty low, the energy transferred to the floor which flexed it, A LOT. This wasn't just a small vibration that tickled No, it literally felt like the floor was going to cave in. First time I felt it I was standing up and had an innate reaction where my knees buckled and I was looking for something to grab on to. Yes it is that extreme. you should feel the floor with these two sealed 18's compared to that Svs. It really does feel like my floor is gonna cave in. Lol it's awesome! 1 Quote Link to comment Share on other sites More sharing options...
mustang guy Posted June 18, 2016 Share Posted June 18, 2016 As for subs that don't walk or vibrate, I expect a sub with a down firing driver would tend to vibrate less. Depends on the floor. Scrappy had one of those SVS down firing cylinder subs in his living room, which is fully suspended over the downstairs area. I thought he was exaggerating but I visited and it was ridiculous. On any big sub hit that was pretty low, the energy transferred to the floor which flexed it, A LOT. This wasn't just a small vibration that tickled No, it literally felt like the floor was going to cave in. First time I felt it I was standing up and had an innate reaction where my knees buckled and I was looking for something to grab on to. Yes it is that extreme. you should feel the floor with these two sealed 18's compared to that Svs. It really does feel like my floor is gonna cave in. Lol it's awesome! LOL! I wish there were a LOVE THIS button! The new and much better benchmark for subs is the floor deflection. We can call this new measurement system Plankman Parabola after it's inventor, the Plank Meister. Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted June 20, 2016 Share Posted June 20, 2016 (edited) Check this out. I can't confirm that it is correct but if it is, holy cow. So a subwoofer being fed a sine wave is apparently the same thing as what's known as a simple harmonic oscillator in physics, and the parameters can be calculated: http://hyperphysics.phy-astr.gsu.edu/hbase/shm2.html https://en.wikipedia.org/wiki/Harmonic_oscillator Using 0.05 seconds as the time constant, which is 20 hz, equals an angular frequency of 125.66370614359172 radians / second. Using this value for ω = sqrt (k / m ), or angular frequency = square root of the spring constant energy divided by the mass, where mass is 0.68 kilograms (1.5 pounds of moving mass in an 18" ultimax)... energy should equal 10738.129588385222 Newton meters. Translating that to a value that we can understand, that is 7,920 foot / pounds. Assuming I'm not missing something at least. If true, that means an ultimax cone going just one cycle, peak to peak, at 20 hz, has 1.6 times the energy as a .338 Lapua Magnum rifle at the muzzle. boom. Edited June 20, 2016 by MetropolisLakeOutfitters Quote Link to comment Share on other sites More sharing options...
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