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Discussion Starter · #1 ·
so i upgraded to windows 7 and i had to re-download the driver to my MOTU firewire soundcard


the mixer now sports a spectrum analyzer that seems to go all the way down to 0 hz


the disturbing part is that on a lot of music the graph goes all the way to 0 hz with quite substantial amplitude i might say - about the same level as midrange signal


i used to think the peak energy in music is around 100hz with virtually nothing below 35hz but now it looks as if the peak is around 60 hz, and at around 35 hz there is a STEP to perhaps 10db lower but after going down by about 10db it just doesn't stop ...


ok so on most music it does stop at around 30 hz but on quite a sizeable portion of music it does not.


worst of all i was running sinewaves thourgh sennheiser HD555 headphones and i can clearly hear 18 hz. i am not talking about feel here i am talking about HEAR. also aside from the nausea i find the sound quite pleasing. purrrr.


and there i was thinking that i only need to get down to about 25 hz and i will be fine for music. crap.


so next time around my goal FOR MUSIC is probably going to be FLAT to 18hz and usable response down to DC.
 

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Who cares about sounds less than 25Hz for music. Its considered noise in the professional world. Noise less than 20Hz is used to warn elephants of incoming tsunami's lol. Name one musical instrument that can play less than about 40Hz or so other than a synthesizer. The DC components I think you are talking about is music recorded hot that was clipped which resulted in a flat line.
 

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Quote:
Originally Posted by NEO Dan /forum/post/17011774


Then I LOVE "noise"

Bring the noise...

Me to, love that 16 Hz pipe organ stuff!


mk
 

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lol pipe organs. Who honestly passionately listens to pipe organ music other than using it to test low frequency capabilities of their sub system. Give me the METAL.
 

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I love a good pipe organ track, but only on a capable system, Never in my car on the factory radio! but its not the only thing i listen to. I grew up on metal(currently enjoying the Iron Maiden Flight 666 Bluray, very good!)


Remember there is much more to the sound of an instrument than its fundamental notes, otherwise a piano would sound just like a violin. Many artists do thing such as pick slides and slapping the body. Add to that the complex chain of electronics that follow most instruments and you can easily see why music is much more than fundamental notes.
 

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Quote:
Originally Posted by Gizmologist /forum/post/17012055


So you want a frequency response from DC to daylight.

Depending on output levels, local radio stations may not approve.
 

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Discussion Starter · #11 ·
maybe my spectrum analyzer is wrong ?


Check the tracks:


Lady Gaga - Lovegame


or


Scooter - Nessaja


its a perfect example of what i am talking about. in both cases SPL drops like a cliff at 40hz but not to zero then stays at some level all the way down to DC


i wonder if my spectrum analyzer is lying to me. although i can hear the difference when i cut those frequencies off and this diffeerence sounds very similar to that 18 hz tone purr.


how can i check ?


considering that most dance club systems are ported at 40hz this would make sense. power has to drop dramatically around 40 hz but it doesnt have to drop all the way down because woofer has some compliance and will be able to handle SOME power even below the frequency where it unloads. there is no need to COMPLETELY filter information below 40hz. it just has to be padded down enough to protect the speaker and open up the dynamic range for other frequencies.


also the energy at 40 hz and at DC does not come at the same time. first the attack comes and the "rumble" comes sort of in between the kicks so its really not detracting from dynamic range at all and they can afford to have it there. it sort of goes POP-RRRRR ... POP-RRRR ... POP-RRRRR ...
 

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Quote:
Originally Posted by DL86 /forum/post/17011738


Who cares about sounds less than 25Hz for music. Its considered noise in the professional world. Noise less than 20Hz is used to warn elephants of incoming tsunami's lol. Name one musical instrument that can play less than about 40Hz or so other than a synthesizer. The DC components I think you are talking about is music recorded hot that was clipped which resulted in a flat line.

Are you serious...
The reason that most "professionals" consider it noise is because their system in most cases can't reproduce it. Many have never even heard a system that can, which is sad. Or they consider it not worth it in a live setting. I consider people like Tom Danley and Mark Seaton professionals and coincidentally they don't simply write off everything below 30hz. They might for high power live sound but that is because of the venue/application. I bet that they don't disregard it at home.


As far as musical instruments, how about: Pipe organ, kick drum, tympani, piano (28hz), bass guitar (Hello down tuned B string ), the human voice(that's right look up J.D. Sumner among others), etc...This is not to even mention the electronic instruments around these days and natural and unnatural effects like thunder, gun shots, trains, fireworks, etc. Most natural, complex sounds have a much broader frequency range than you would imagine. I've measured my kick drum with a calibrated mic to have content from 5hz where the graph cuts off up till 10khz. The fundamental energy is at 28-30hz BTW but there is significant energy well below that.



Here are a few examples...Oh I'm a metal guy myself so let's get some metal in there...


How about Obituary, Splattered.






Crowbar, And Suffer as One





Graveflower, Black Eyed Susan





NIN, The 4 of Us Are Dying





Here is some freakin Nickelback showing hefty sub 20hz bass...Follow You Home. I don't like the band but you can't say that they don't have some serious production clout behind them. Ick. I need to delete my GF's stuff on accident.

 

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Secret about consumer grade A to D. They are crap at low frequencies. If you really want to measure close to DC, then you need to look up a company in Canada called ICS. About $20K per card and you will have to write your own software. I would not believe anything below about 15 Hz and even at that, the analog section will have cheap caps in it.
 

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Discussion Starter · #17 ·

Quote:
Originally Posted by Ricci /forum/post/17015116


It's free. There's a link to the DL in the master list of movies with deep bass thread. http://www.avsforum.com/avs-vb/showthread.php?t=755493 Make sure you get the latest version if you happen to be running Vista.

thanks Josh. here is the spectrum for Lady Gaga - Lovegame. i get the same reading with the spectrum analyzer in my soundcard so it can't be a mistake.


you have peak energy around 55 hz. ( by the way my plastic JBL EON 1500 speakers were tuned to 55 hz ). rolloff from 50hz to 25hz and then from 30hz to DC the energy increases again ! ! !


 

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Quote:
Originally Posted by tvrgeek /forum/post/17015240


Secret about consumer grade A to D. They are crap at low frequencies. If you really want to measure close to DC, then you need to look up a company in Canada called ICS. About $20K per card and you will have to write your own software. I would not believe anything below about 15 Hz and even at that, the analog section will have cheap caps in it.

I disagree that you need a $20K SC for determining whether there is content below 20hz or not. Maybe if you need the last 0.3db of accuracy. It's easy to generate some sweeps or other signals below 20hz for a sanity check on your measurements these days. Not to mention that measuring the roll off of your system components is relatively easy as well. Additionally if anything the response below 15hz is going to be rolled off and under represented not over in my experience. My system that I took the waterfalls above with is about -1.8db at 7hz and -6db at 6hz. I don't know if I'd believe the relative levels to the nth degree but I'd believe whether there is signal there or not.
 

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Vas,


Try the "too many colors" palette it's the one everybody uses. There are a lot of good things that you can do with SL it's great freeware.
 
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