Car audio sq setup

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Turtle-Dude
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Postby Turtle-Dude » Fri Mar 31, 2006 10:38 pm

Thanks for taking my suggestion to heart. Now I'll point you to Low freq. reproduction in a sealed environment and especially here Bass Principles for the answers.

Some have learned what they know from experience, some from a book, no matter. There is ALWAYS more to learn.
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quality_sound
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Postby quality_sound » Fri Mar 31, 2006 10:49 pm

ssssy wrote:you can't hear a 5hz tone so playing a 5hz tone as loud as you can will do nothing to test this theory. It will damage your ears though and can cause other internal ailments.


Funny, the tests I've seen done with 5Hz tones loud enough to stop a dog's heart didn't affect it's hearing. Maybe I imagined it. Or maybe the dog's naturally better hearing kept it from hearing damage??

you need to go study your physics again, you only need to be a quarter wave length away to hear a given tone at near full gain.


You aren't hearing that tone. You're hearing the quarted tone and your brain is extrapolating the full tone based on the other tones it IS hearing.

Not to mention that sound waves reflect of of things until they dissipate.


If the wave is longer than the car it's not bouncing off of anything.

All speaker measurements are taken at 1 foot, by your definition of physics you would only be able to measure a speakers response higher than 1100hz and you would be unable to hear anything under 500hz in a car. Since my voice is in the 500hz range and people don't seem to have a problem hearing me when they are closer to me than 5 feet I don't think your theory is sound.


None of this applies because it's not the same environment. We're talking CLOSED SYSTEMS, not free space. Pay attention.

This is one of the most ridiculous internet propagated rumors i have ever heard and is based on nothing but horrible misunderstandings of fluid dynamics and how they relate to the audio environment.


Really? I bet the 2 guys that are "propogating this rumor" have a pretty good understanding of fluid dynamics as well as open and closed field audio dynamics.

Speaker size and throw are directly responsible for the perception of speed, accuracy and attack in bass notes. The further the speaker has to travel to achieve the desired volume the longer it takes for that speaker to get back to the same point in its throw to reproduce sound. The human ear can detect nanosecond differences in phase, which is what slow, sloppy speakers lack, phase continuity. The slow and or sloppy travel of a woofer causes phase distortion in accompanying notes making them sound off and unrealistic.


Nope. Motor strength, cone weight and diaphragm compliance dictate cone speed. And again, how "fast" a woofer sounds is dictated by the MIDBASS frequencies. Unless you're running your sub in the 100-200Hz range the MIDBASS DRIVERS are going to be doing this work and dictating how "fast" your woofer sounds.

Once again, you have no idea what you are talking about, do not give other people advice, everything you have said is wrong.


Hmm..I think you may be on to something here. I'll have to give back my trophies and the trophies my customers won since I opbviously have no clue about good sound and howe to achieve it in a car. Thank you for showing me the light. :bowdown:
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ssssy
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Postby ssssy » Fri Apr 07, 2006 9:38 am

ok Einstein try using your model of physics to explain headphones then. let me guess your brain extrapolates everything under 10,000hz.

You have no idea what you are talking about. Take a physics class pick up a book on fluid dynamics whatever but buy a clue.

I am getting really tired of internet jockeys and backyard installer trying to pass them selves off as physicists.

I AM A PHYSICIST.

and PS you didn't stop a dogs heart with a 5hz wave nice try though and save your lies for someone who will buy them

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Postby quality_sound » Fri Apr 07, 2006 11:04 am

ssssy wrote:ok Einstein try using your model of physics to explain headphones then. let me guess your brain extrapolates everything under 10,000hz.


Again, different environment. The sme thing woudl apply though as far as the cutoff freq. and pressurization. With headphones they're playing into a MUCH smaller volume so a small driver with little throw can still produce bass.

You have no idea what you are talking about. Take a physics class pick up a book on fluid dynamics whatever but buy a clue.


Although very similar there are some DISTINCT differences in fluid dynamics and basic audio theory and I think that's where you're getting hung up. We're not filling the car with water and the waves do behave differently. Read eith of the books in the link posted.

I am getting really tired of internet jockeys and backyard installer trying to pass them selves off as physicists.


I never said I was a physicist did I? For a supposed scientist you sure don't read well.

I AM A PHYSICIST.[/quote]

Good for you. You're still wrong.

and PS you didn't stop a dogs heart with a 5hz wave nice try though and save your lies for someone who will buy them


I never said I did that. It was a controlled lab experiment. The military was trying to see if VLF at sufficient volume would be an effective weapon. No I didn't take part in this first-hand, but being in the military I get to read all kidns of interesting things.
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quality_sound
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Postby quality_sound » Sat Apr 08, 2006 5:34 am

Good point, Edison. I'm done with this.
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ssssy
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Postby ssssy » Sun Apr 09, 2006 4:34 pm

The only thing that is different between a set of headphones and a car is the distance of the speaker from your ear allowing for much lower gain and the fact that the speakers don't interact with one another.

And by your theory that you can't hear a sound wave at a distance less than it's wave length you would not be able to hear anything lower than approximately 10,000hz (1.35").

I would love to hear your explanation of how headphones allow you to hear wavelengths that car audio speakers will not.

I'm not hung up anywhere. Air is a fluid and everything that has to do with reproducing sound is regulated by fluid dynamics. Free waves traveling through water do not act differently in any appreciable way that is relevant to this discussion.

There are only two relevant effects varying distance from a sound source has. It modulates gain and phase for all frequencies. That is it. It does not change your ability to hear it. Just how loud it is and whether or not it is in phase with other sound sources playing the same frequency. Whoever told you different was mistaken as are you.

This is why moving around inside a car makes things sound different. Because as you change your distance from the individual speakers you change the gain and phase characteristics causing partial frequency cancellation.

It only takes two minutes to prove your theory wrong for anyone who cares to try it. Sit in your car and play a 20hz tone. If your speakers are capable of reproducing this frequency you will hear it just fine. And since there is no other audio there will be none of this so called brain interpolation.

You must have horribly misread whatever you are claiming to have access to. First off VLF is a term used to describe radio waves emanating from 3-30kHz it has nothing to do with sound waves. However, high powered VLF radio waves can cause all sorts of problems with living things.

Secondly while I appreciate your service stating that you are a member of the military does not lend a bit a truth to your story. I have spent the majority of my adult life in the military working in wave form physics and linguistics and while I have certainly not read every report I have yet to read one with successful results from out of range of hearing sound weapons. They simply take far to long to have any real affect.

Please educate yourself and stop propagating misinformation.

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Postby quality_sound » Mon Apr 10, 2006 3:49 am

Why is it so hard for you to wrap your head aound the fact that you're listening inside a box?

When you move a sub in a car it's not getting louder because it's closer to you, it's getting louder because of the way it's coupling, or not, with the car.

I never said you can't hear 20Hz. I said you can't hear it in a car. In a car you FEEL 20Hz.
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lunisport
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Postby lunisport » Mon Apr 10, 2006 10:41 am

DJ Magic Mike

FEEL THE BASS

IB4TL :rofl:

Can't we all just get along?

Better yet, let's test your theories and build a system in a car. You guys provide the components, and I'll provide my GTI. :eyes:

ssssy
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Postby ssssy » Mon Apr 10, 2006 6:45 pm

Why can't you wrap your head around the fact that it doesn't matter if you are in a car, a fish bowl, an airplane, wherever. There is air between you and the speaker. The speaker vibrates the air. As long as the speaker is playing a frequency that you are capable of hearing you will hear it. The only thing you can change with distance is the perceived loudness.

The only issue playing music inside a fixed area causes is phase cancellation zones due to reflected waves. Cars are not sealed well enough to cause significant standing wave issues. Nor are they sealed well enough to stifle the vibration of the air inside and it's ability to transfer sound. If they were every time the car hit a bump and the chassis flexed it would force air in and out of your lungs. Not to mention that you would expend all the usable oxygen inside the car within a hour or so, pass out and die.

Normally moving a subwoofer closer to you will make it sound worse because of phase and time of arrival issues.

None of your several attempts at an explanation as to why you would not be able to hear a particular frequency have any merit. First it was because you are too close to hear it, this is obviously not true and disprovable by anyone through several different means. Now it is because you are listening in a sealed environment, which isn't true to begin with and even if it were would not preclude you from hearing a given frequency.

You are just wrong. The statement that you can not hear a 20hz wave inside a car will never be true unless inside the given car there happens to be a vacuum. If you have based other beliefs on information from the source that you got this information from I would reevaluate that information as well.

quality_sound
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Postby quality_sound » Mon Apr 10, 2006 8:44 pm

ssssy wrote:Why can't you wrap your head around the fact that it doesn't matter if you are in a car, a fish bowl, an airplane, wherever. There is air between you and the speaker. The speaker vibrates the air. As long as the speaker is playing a frequency that you are capable of hearing you will hear it. The only thing you can change with distance is the perceived loudness.



Because you're not in FREE SPACE. You're INSIDE A BOX. Look at it like this. You can get standing waves in sub enclosure yes? Then why not in free space? Because the sound is trapped in a box. Same thing applies in a car.

The only issue playing music inside a fixed area causes is phase cancellation zones due to reflected waves. Cars are not sealed well enough to cause significant standing wave issues. Nor are they sealed well enough to stifle the vibration of the air inside and it's ability to transfer sound. If they were every time the car hit a bump and the chassis flexed it would force air in and out of your lungs. Not to mention that you would expend all the usable oxygen inside the car within a hour or so, pass out and die.


You, of all people, should know you don't need a perfectly sealed car to get standging waves. You can get standing waves in a ported box as well as a sealed box.


Normally moving a subwoofer closer to you will make it sound worse because of phase and time of arrival issues.


Phase issues are cause by being out of alignment. And moving a sub closer may actually improve the phasing, especially if the original positioning had it out of phase before. This is all HT stuff though because like I said before, in a car, this would only apply to midbass freq. anyway.

None of your several attempts at an explanation as to why you would not be able to hear a particular frequency have any merit. First it was because you are too close to hear it,


I NEVER said you it was becasue were too close to hear it. I said it was because you're in a car and under the freq. that correllates with the longest dimension in the car you're just pressurizing and depressurizing the car.

Now it is because you are listening in a sealed environment, which isn't true to begin with and even if it were would not preclude you from hearing a given frequency.


I tell you what. You order those 2 books that Turtle liked you to and argue with the writer. Maybe you'll like the same things I'm telling you better coming from a guy with more degrees than I can count.

You are just wrong. The statement that you can not hear a 20hz wave inside a car will never be true unless inside the given car there happens to be a vacuum. If you have based other beliefs on information from the source that you got this information from I would reevaluate that information as well.


See above. And when you build a car that wins finals and actually APPLY some of your "knowledge" come talk to me.

For now, I'm done with this thread.
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Postby lunisport » Mon Apr 10, 2006 9:53 pm

Dj Lunisport on the 12's, and I got a request from the phone lines...

"Shut Up" by the Black Eyed Peas

"shut up, just shut up shut up, shut up just shut up shut up"

:box:

This pissing contest is really gotten out of hand. I would have locked this topic a long time ago if I could. Being humans, yes, we all want to explain how this works and how that works, but sometimes you gotta just chalk it up to experience. Science has its place, and so does experience. I'm not taking sides on this issue, but sometimes science can't explain everything.

Riddle me this, y'all.

If an airplane was going through some sort of malfunction or crisis, would you rather have at the helm a seasoned pro who's seen danger before or a booksmart greenhorn who says 'I read about this before, where is my SOP?'

I'm not calling anyone a pro or a greenhorn, I'm just kinda upset that this has dragged on so long.

Let it go already, one-up-manship has no place in our world of Dub Love. This is just about as insane as 'you stepped on my shoe, I'mma kill you mofo'.

You want something to do besides argue on a chat board, take that energy and read "How to Win Friends and Influence People" then apply that to your everyday life. I've read it, and applied it, and my life has gotten so much richer.

Instead of knocking heads, why not synergize and add to the richness of NorCalVW. Petty arguments like this are probably what caused the splintering of the VW community on the Internet (although in person, I'm glad to say we're all pretty much One Love).

If this post causes you to have beef with me, come tell me in person at the NorCalVW BBq at Vasona PArk on Saturday. Don't hide behind a bulletin board.

:lovesign: guys!

(/soapbox)

(watch, I bet this thread will still go back and forth like a tennis match... :eyes: )

ssssy
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Postby ssssy » Mon Apr 10, 2006 10:47 pm

When you are in a car you are in free space. Your car is not sealed, nor is it pressurized. Air is freely exchanged from the interior to the exterior to maintain common atmospheric pressure just like your house or if you were standing outside in a cool breeze. Making any calculations based on the fact that your car is a sealed environment and capable of being pressurized is faulty.

Except in the most extreme conditions and high spl applications, besides the area between the dash and windshield and footwells there are generally very few cars that have standing wave issues.

I have worked on many cars that have won many awards, the first in 1987 it is what got me interested in wave form physics, and including cars for Boston Acoustic, MIT, PPI, MB Quart etc.

Phasing is an issue of at what point the sound wave reaches your ears or another sound wave in relation to any given point in the cycle of the wave. It is not only an alignment or speaker polarity issue although these are common causes of speakers being out of phase. The phase becomes particularly relevant when dealing with low frequencies that have considerably long cycles. The predominant reason that subs sound better or worse placed in different areas of a car is phase reactions with other speakers.

You said that you are too close to hear it using different words and you just said it again. Subwoofers shift pressure regions in the interior of a car as a byproduct of their excursion. They do not pressurize or depressurize a car except in the most extreme of applications. If your sub pressurized and depressurized your car it would force air into and out of your lungs and would interfere with you body's ability to process oxygen giving you hypoxia. There are systems out there that can do this but represent the exception not the rule. Your subs simply move air around inside your car the don't pressurize anything. Pressurizing something requires a sealed environment and forcing more of liquid into it than is normally possible at a given altitude. Scuba tanks are pressurized, air planes are pressurized, your car is not and never will be.

If someone has written a book stating that you can't hear a certain frequency just because you are in a car; I would not waste my time or money reading it as they obviously don't know what they are talking about. However my guess is that you misunderstood what you were reading or the book was oversimplified because it was intended for people to apply things not understand them.

If you would like to go on living your life believing that you can't hear a 20hz wave in a car be my guest just don't tell anyone else because you are wrong.

I have no beef or bad blood with anyone. I just take issue to people misinforming other people. If someone is mistaken for whatever reason and I can help them or others correct that I will. And I will not agree with someone who is wrong simply because they like to argue or remain ignorant.

Where is Vasona park, I'll buy you all a :drink: and demonstrate exactly how well you can hear 20hz in a car. Not trying to hide at all.

:lovesign: 2

quality_sound
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Postby quality_sound » Fri Feb 02, 2007 5:34 pm

Damn Charlie, I totally forgot about this thread.


ssssy- Since you won't believe me, argue with David or Richard about sub bass in a car. I used to think like you did, then I actually listened to them with an open mind and guess what, I LEARNED something and my cars, and my customers' cars, got better sounding for it. Yes I know a car isn't atmospherically sealed, but it IS acoustically sealed. Think of it like a ported box with a port that's too small; it will act like a sealed box won't it? Cars are the same.
http://www.autosound2000.com/

I'm through arguing about this.
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Postby Turtle-Dude » Fri Feb 02, 2007 8:18 pm

:baller:
Turtle



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Postby ohsnap » Sun Feb 04, 2007 7:06 pm

AHHAHAHAHAHAHAH. idk. im delirious again. I PWN J00 ALL!!!!
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