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Low Frequency Subwoofers

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=55374
Printed Date: March 29, 2024 at 2:33 AM


Topic: Low Frequency Subwoofers

Posted By: zuhare
Subject: Low Frequency Subwoofers
Date Posted: May 08, 2005 at 8:39 PM

i need to know what kind of subs and box do i need to get the lowest frequencys out of them. i already blew 2 cerwin-vega Vmax 800 watt DVC, in a vented box, put new kicker comp vr in same vented box but did not get the response i wanted i am thinking of Infinity perfects or kenwood excelon.

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zuhare



Replies:

Posted By: Alpine Guy
Date Posted: May 08, 2005 at 9:10 PM
1 Single Adire Tumult 18" on paper it looks like it should make you crap your pants at 20hz

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2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.




Posted By: ss-installer
Date Posted: May 08, 2005 at 9:15 PM
the box didnt sound good cuz it wasnt built for the subs. you need to find the specs on your subs and have a ported box made and tuned to 40-50 htz, for low frequencies. its all about the box.

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Posted By: AJRXtreme
Date Posted: May 08, 2005 at 9:31 PM
are you able to hear the subs at 20hz? Has anyone ever heard of anything crazy happening to someone from the high bass levels inside a car? Like deaths, fecal spills, heart attacks, ear drums being blown, etc.?

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03 F150 on 24's
HU:Pioneer DVD5700
Frt:MC57
Subs:(12)S12L7
Amps:(3)KX2500.1's, MC-2004




Posted By: Poormanq45
Date Posted: May 08, 2005 at 9:51 PM
Heard of all of the above.

But it all still occurs at extreme levels, 120dB and above.

Yes you can hear a 20Hz note, but it requires a tramendous amount of power to get an audible/useable sound from the sub.

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Posted By: Alpine Guy
Date Posted: May 08, 2005 at 9:56 PM
i have had girls puke, never a guy,,,,my buddy had diareah one day, , i cranked the system and made him poop his pants just as i dropped him off in his driveway haha ( i was nice and didn't do it before going out)

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2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.




Posted By: SAMT18
Date Posted: May 08, 2005 at 10:03 PM
you made someone crap their pants?  GOOD LORD!  you must have one hell of a system in there forreal




Posted By: Ravendarat
Date Posted: May 08, 2005 at 10:17 PM
I agree with what ss-installer said about the box being key, but I dont agree with the frequency. I would be tunning the box down far further, some where around the 28hz range. But thats a personal preferance. Also you should be using a subsonic filter when using a ported or vented enclosure, it helps protect the subs and helps prevent wasting power on frequencies that you cant use anyways.

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double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer




Posted By: haemphyst
Date Posted: May 08, 2005 at 10:21 PM
AJRXtreme wrote:

are you able to hear the subs at 20hz? Has anyone ever heard of anything crazy happening to someone from the high bass levels inside a car? Like deaths, fecal spills, heart attacks, ear drums being blown, etc.?

Poormanq45 wrote:

Heard of all of the above.

But it all still occurs at extreme levels, 120dB and above.

Yes you can hear a 20Hz note, but it requires a tramendous amount of power to get an audible/useable sound from the sub.


Alpine Guy wrote:

i have had girls puke, never a guy,,,,my buddy had diareah one day, , i cranked the system and made him poop his pants just as i dropped him off in his driveway haha ( i was nice and didn't do it before going out)


Urban legend, man... Episode 25 (Feb 16, 2005) of Mythbusters tried it... Proved scientifically it does not happen. Something like 153dB at frequencies between, like, 5Hz and 20Hz. I cannot remember the numbers exactly, but it has been debunked. Meyersound provided all of the gear, and it was televised, on a respectable network, called The Discovery Channel.

Hate to do that to ya, but there ya are...

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: Poormanq45
Date Posted: May 08, 2005 at 11:53 PM
Good read. Note that I just said that it requires an extreme amount of power to get a useable tone at sub-sonic frequencies

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Posted By: haemphyst
Date Posted: May 09, 2005 at 6:42 AM
Poormanq45 wrote:

Good read. Note that I just said that it requires an extreme amount of power to get a useable tone at sub-sonic frequencies


No, It's cool... Also note, I said nothing about that NOT being true in my previous post...

However, I am now going to say that is not NECESSARILY true. I have mentioned before the 18 inch transmission line subwoofers I helped build for/with my buddy Dave.   Here is the link to see the smaller of them... the other is approximately 4 inches larger in cross-section, and 6 inches longer. In room, these monsters will reach 112dB at 18Hz, with only 20 watts per channel! (I will admit, 18Hz IS an even order harmonic of the room's resonant frequency - a ghastly 72Hz, floor to ceiling, and 36Hz, wall to wall, TWICE... for a 12dB peak at 36Hz - Blech! - square rooms SUCK for bass...) At 13Hz and 12Hz, (their resonant frequencies, respectively) we honestly don't KNOW how loud they get, as we never had a mic that was effective at those frequencies. I will tell you, though, when we decided to go for an Fs of 15, and the tuning ended up that much lower, we never MEANT to land RIGHT on the resonant frequency of the house in which they are installed! With less than 25 watts @ 13Hz we have LITERALLY vibrated the garage door - and I ain't talking just a little vibe, either - it was more like a SHAKING of the garage door!

So you see, your statement is a little misleading... Not wrong, however... It is possible to achieve EXTREME output in the subsonic regions, with a very SMALL amount of power, you just need to be certain your system is designed properly to PRODUCE such a frequency, and the room helps. posted_image

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: soundmasta
Date Posted: May 09, 2005 at 7:55 AM
get on ebay and pick up a phoenix gold cyclone. thats what they're made for

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Posted By: DYohn
Date Posted: May 09, 2005 at 12:07 PM

Extremely low frequencies at sufficient SPL have been shown to cause loss of voluntary muscle control.  I was involved in a project with the Navy back in the 70's looking at this very phenomenon.  However, it is extremely unlikely and probably impossible for any commercially available audio system to generate sufficient pressure waves to cause this.  And if it had been accomplished. it would not affect selective human bodies but rather everyone within the pressure wave boundary.  Low frequency sounds cannot be "aimed."  So if one person had "crapped themselves," so would have everyone who happened to be the same distance or closer to the source.  (This, by the way, was predicted using mathematical models and proven in a warehouse on Mare Island, California in May 1979 when a test system was energized and six people within a 20 foot radius fell to the floor.  The system generated 4.3Hz at approximately 210dbC.)

Back to the original question, any good subwoofer can generate all the lower audible frequencies, but it is the system design that determines actual response below 100Hz (as haemphyst has described.)  Most people cannot hear anything lower than about 25Hz, by the way, although sounds below 50Hz are easily felt in your body's sympathetic vibrations.  Prolonged exposure to 85db is sufficient to cause hearing loss below 100Hz.



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Posted By: 5150azn
Date Posted: May 09, 2005 at 12:11 PM
Imagine the chicks I could pick up if I had subs that made people pass out.

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Tell the Snap-On guy I'm not here!





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