infrasound, need speaker and amp recommendation

[chundle]

hi all
i'm doing some experiments with infrasound, nothing particularly musical, but i need to play with frequencies in the region of 10Hz - 25Hz. Can anyone recommend a good speaker/amplifier combination that would be good for this? I don't need a lot of power, and I'm going to be varying the frequencies, so I'm not doing the usual thing of using pipes (which are generally used for particular frequencies). Any pointers would be gratefully received...
Are there any subwoofer's out of the box that will go down to this low? looking at most specs for subwoofers say usuable frequency range of 40Hz and up, etc.
CH

[bob1]

Whats the experiment some kind of infrasonic weapon?
You can pick up a subwoofer that will go down to 20hz ,but going down to 10hz might be a bit harder and will cost a lot more.

[chundle]

no not a weapon,he he! just some experiments with sensation (i.e. what people feel...).
i know it's going to cost me a fair bit to get down to 10Hz... any suggestions how?

[Nimby]

Originally Posted by chundle

no not a weapon,he he! just some experiments with sensation (i.e. what people feel...).
i know it's going to cost me a fair bit to get down to 10Hz... any suggestions how?

What's your budget?

My cylindrical SVS 16-46PCi goes down to 15Hz with a gently rising tendency to +10dB at 15Hz in my 30 foot room. (large room effect LF gain can be used to increase gain at even lower frequencies)

Easy 100dB capability at low frequencies if needed. I can rattle all the windows below that frequency (15Hz). But I am not allowed to.

BTW: It has a built in 350 watt amplifier and is mains powered.

My home-built, sixth-order series bandpass subs go down to below 10Hz in a 20" cube. They can make you puke on only 30 watts on a signal generator.

You could have borrowed one (or even two) of these as they are not in use. But I doubt you are in my part of the world. (Denmark) and the postage to send them to you would be quite phenomenal.

Regards
Nimby

[Mark Grant]

Not sure how you willl get 10hz, but have a look at these to give you some ideas:

http://www.servodrive.com/contrabass.html

Read how they work, the speaker cones are moved by a servo motor rather than magnetism, so might be interesting

probably far too expensive, although I would like one to try sometime.

Mark.

[Sunil Banga]

http://www.ultimateavmag.com/feature...ay/index3.html

$5000 is the price!!

[Mark Grant]

Expensive but look at the performance

Compares well in that test to the Genelec HTS6

Mark.

[JBL 4645]

This sounds like the gadget he is building an experiment to curse structural damage?

Or like he said "what people feel"…no kidding.

InfersSonics if played at the correct frequency at around 7Hz and if played at very
High sound pressure levels will mach the body’s resident frequency and this can result in….

Feeling dizzy…chest pains…internal damage…and fatal death….

Mate I do hope you are not putting someone into harms way…because I have tried it at 8Hz and it’s not pleasant at all…

So don’t fool around with infersSonics…too much unless you are so incline too do so…

And knowing the consequences and the repercussions…

You are entering a field of science that needs to be read and understood first before undertaking something that could result in injury…to the loudspeakers and amplifiers…

Good luck

Ashley…

What you need is a ButtKicker - no seriously that's what it's called.

They are used extensively in simulators etc to replace those sensations not produced by sims motion alone, used in some of those fairground 'virtual' rides too.

Some high class cinemas have them under the seats too.

Frequencies from 5 to 200Hz !!

check 'em out ... ButtKicker

[bob1]

Originally Posted by JBL 4645

and fatal death….




Ashley…

Classic as far as i can remember most death is fatal.

[JBL 4645]

That wasn’t meant to a joke playing around with infersSonics can be used for good intensions or for evil…and we have head of acoustic weapons…

Anyway how many films have recorded soundtrack information below 20Hz if there is something that as gone past me without knowing then I want to know the details and technical specifications…

Tactile is another form of low frequency unit like the butt-kickers and size and weight and cost issues as well…there a lots of ways too doing this add lots of 18in sub bass units and this will further increase the frequency range down lower into the infrasonic range and EQing and active electronic crossovers high powered amplifiers and some electronic triggering to produce a lower octave just under the low frequency playing…

Sounds like universals patented SENSUUROUND for Earthquake 1974 Oscar winner best sound….

I might play earthquake chapter 8 in a moment via the THX at 0dB that shaking feeling…

Ashley…

[bob1]

Originally Posted by JBL 4645

Anyway how many films have recorded soundtrack information below 20Hz if there is something that as gone past me without knowing then I want to know the details and technical specifications…



Ashley…

Take a look at these waterfall charts on Home Theater forum CLICK ME

[alexs2]

Chundle was originally looking for means of conducting some experiments with infrasound,and also specified that it does not have to be at a high power level.

Thus any worries about damage to internal organs or "fatal death",and acoustic weapons are irrelevant,and have already been covered in any case....no more on that thank you.

[JBL 4645]

Yes that was fascinating, though, I do like other graphs, unlike predator vision!

But those infrasonic notes down at 10Hz easy to reproduce acoustical, and if there was enough room for me to place 7 more JBL 4645 THX subs along with the amplifiers, taking up room in another part of the of the studio flat then, I would do this…

But I’d only have to calculate the room and number of JBL 4645 that would be needed…

One more JBL 4645 will suffice…as I can play an infrasonic spot frequency below 20Hz that shakes the back windows and about 20 feet away…due to the wave lengths distance…

Adding more to this does extended and once I have calculated and plotted its levels, I’d turn the level down for the LFE and other sub bass and anything in the infersSonics range…

Ashley…

[alexs2]

JBL...you've already been asked above,and in other posts,to keep your own efforts on topic,and refrain from advice which has little or no relevance to the original post.

Chundle is NOT looking for 8 or more subs.....just one,to conduct a few experiments with,as stated in the original post.