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Long story short, my lab is doing some experiments with sound. Infrasound specifically, meaning sounds under 20 Hz and preferably up to 100 decibels. The kicker is that the sound needs to be very stable and coherent, with no distortions, and none of us really know a whole lot about this kind of equipment. I've done a few google searches but most of the results give me specs that I really don't know how to interpret, so I'd like some recommendations if anybody knows about this kind of stuff. Cost is no factor right now.
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| # ? Mar 10, 2013 21:57 |
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| # ? May 18, 2013 16:47 |
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I don't know too much about speakers specifically but maybe some more information will help: What kind of distortion and stability are you looking at? If that's hard to put a number on maybe telling us what it's going to be used for will help? I assume by stable and coherent you mean the sound pressure will be even over a given area? Only other clue I have is the guys Mythbusters used for the Brown Note episode might be an option if you're in that part of the US.
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| # ? Mar 10, 2013 22:17 |
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We're observing physiological effects of being subjected to infrasound under various conditions. In order to control the effects as much as possible, we want to generate a standing wave that maintains a specific frequency and volume. We tried an old subwoofer that we borrowed from another lab, but even in the soundproof booth there was a lot of crap coming out of the speaker -- distortions that made it look messy and sometimes were even audible. I don't know if it was because the speaker was old or if it was just cheap to begin with. Another thought I just had, but might it have been crappy wiring as well? I know that's not as big a factor as some people like to say it is, but it is a thing, right? Also, I'll check out that brown note episode.
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| # ? Mar 10, 2013 22:32 |
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Have you thought about using a transmission line enclosure? You can tune them to the frequency that you want, the construction is dead simple and when you're done you'll have a righteous sub for your home theater.  http://www.passdiy.com/pdf/el-pipe-o.pdf e: This might be useful too: http://t-linespeakers.org/ Mandactyl fucked around with this message at Mar 10, 2013 around 23:30 |
| # ? Mar 10, 2013 23:27 |
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That is exactly what I need. Thank you. One of our guys actually thought of something like this but didn't know how to make it work and didn't know what to call it. I'll let him know he's a genius.
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| # ? Mar 11, 2013 00:06 |
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Awesome, glad that i could help. If you're worried about your cables I would swap them out with something in a heavier gauge. You should post pictures, I'd love to see the setup. all that science flying everywhere. 
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| # ? Mar 11, 2013 00:40 |
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In case you never saw the GBS thread about the subwoofer house, please be careful if you start to notice any weird, possible mental health issues cropping up. Some people think the constant exposure to low frequencies (including, but not limited to infrasound) might have worsened some latent condition and led to his suicide.  http://forums.somethingawful.com/sh...hreadid=3524992 SpelledBackwards fucked around with this message at Mar 11, 2013 around 04:47 |
| # ? Mar 11, 2013 04:40 |
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Nobody in the experiment will be exposed to the sound for more than 60 minutes, and we're getting some hell of soundproofing stuff coming in so the RAs will be fine too. I'll post pics if I can but there may be certain things that prevent me from doing so. I'll have to ask.
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| # ? Mar 12, 2013 03:10 |
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SpelledBackwards posted:In case you never saw the GBS thread about the subwoofer house, please be careful if you start to notice any weird, possible mental health issues cropping up. Some people think the constant exposure to low frequencies (including, but not limited to infrasound) might have worsened some latent condition and led to his suicide.
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| # ? Mar 12, 2013 03:31 |
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| # ? May 18, 2013 16:47 |
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Adire audio had created a motor with a panel that could do very low frequencies at 120 decibels. They went out of business, but designs might be out there. http://audiojunkies.com/forum/blog/...-subwoofer.html Motor video There is also something like the TRW-17. Phuzun fucked around with this message at Mar 15, 2013 around 00:23 |
| # ? Mar 14, 2013 05:29 |
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