has any one heard a L5 kicker 12 or 10? how do the compare to 2-10s or 2-12s?
as far as loudness and sound qulity

 

no ones heard or used one

 

ive heard the L5 compared to one kicker comp 12. the L5 was bout 3 times louder lol.

 

l5's are great... i've installed may of them. depends on your goals tho.. i'd rather get two kicker comp vr 12''s then one l5.

 

I've installed several in cars in the past. they are good. Remember the bigger the speaker generally the box gets larger exponentially, and the amp power requirement increase. Also the type of base you get is slightly different with the larger speakers, it tends to get what i call sloppy base (but you can get great SPL). the reason for this is the surface area of the cone that has to move and the momentum necessay to change cone direction is greater and hence dosen't happen as quickly. if you compare some long throw 8" or 10" with the 15" with a frequeny generator feeding the amp with a square wave of 80HZ(mid base region) you can hear the difference. the smaller speaker the baase has a real kick or snap to it. so if you want clean reproduction use the 10". If you are concerned with SPL then use 4 X 10" driven by multiple amps. you can parallel the inputs to the amps instead (especially now with the 4Volt hi Level preAmp outputs from the decks) Its impressive, just be sure to get speaker Phasing Correct


Modified by Jollybandit at 7:52 AM 12/28/2006

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote">the type of base you get is slightly different with the larger speakers, it tends to get what i call sloppy base (but you can get great SPL).</TD></TR></TABLE>

Actually the bass from the larger speaker tends to be cleaner. The cone moves very little (compared to a smaller speaker) for the same output, and the VC stays within the linear region of the magnet. For smaller speakers, the VC moves a lot more, and the unlinearities of the driver are output as distortion.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">the reason for this is the surface area of the cone that has to move and the momentum necessay to change cone direction is greater and hence dosen't happen as quickly.</TD></TR></TABLE>

If that were the case, big subs would only be rated up to 50 hz. How come PA 18 inch woofers can play up to ~300 hz?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">if you compare some long throw 8" or 10" with the 15" with a frequeny generator feeding the amp with a square wave of 80HZ(mid base region) you can hear the difference. the smaller speaker the baase has a real kick or snap to it.</TD></TR></TABLE>

All that depends on the speaker and the box. Even 18 inch subs can be made to "kick" like smaller subs.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">so if you want clean reproduction use the 10".</TD></TR></TABLE>

If you want clean reproduction, get the biggest sub you can fit/afford. If you want the sub to "kick" like a smaller sub would, put it in an undersized box.

 

I have worked in sound and Audio engineering for 20 years, and cars are always the worst environment for sound reproduction. for reflection and refraction angles and the inherent flexibility of the body of the car Unless you have a tight specification made box enclosure it alters the performance. Some of the above made statements don't sit correct with common sense, basic engineering or Physics

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Actually the bass from the larger speaker tends to be cleaner. The cone moves very little (compared to a smaller speaker) for the same output, and the VC stays within the linear region of the magnet. For smaller speakers, the VC moves a lot more, and the unlinearities of the driver are output as distortion.</TD></TR></TABLE>

This depends if you are using a ported or non ported enclosure. you can still restrict he the cone to the same linear VC region with 10" subs. Larger subs cones can move just as far but mostly further than smaller counter parts (look at the play at the connecting rim and remember its a pie squared relationship). larger subs also suffer from mass distension. that is if they are stood vertical the mass of the suspended coil actually flex's the cone and rests on the magnetic core in the sleeve which induce can frictional distortion - you cannot guarantee the equal stress across the surface of the cone - in fact worst on larger speakers that's why they try yo resolve it by putting concretric reinforcement ringds in the surface of the larger cones.Very visible on some speakers.
Yes larger speaker don't need to move the cone as much to get the same spl as there smaller counterparts, plus larger speaker have larger cone distortion generally across the entire moving surface. to be perfect they would be made of fine solid brass/copper, have no outer rim coupling and have directional orientation arrows for mounting and cone suspended from the centre core, or electrostatic speakers -as the really good theater speakers do.....but then this is a car.
You still require to move the entire cone of any speaker against a construction & air resistance the bigger the surface the less perfect the response mimicked. These are only a few of the issues of speaker construction, let alone if you place the speaker in a box that has fundamental ratios between the sides and introduces standing wave or sound cancellation - and more likely in larger situations


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">If that were the case, big subs would only be rated up to 50 hz. How come PA 18 inch woofers can play up to ~300 hz?</TD></TR></TABLE>

that doesn't make sense??? larger speakers do actually have a lower FO and a smaller BW. take a look what they use in "shaker" speakers (these are rated DC to 80hz) used in engineering for vibration testing & powered by valve amps- or the real enthustiest to get the real base you feel not hear.
You can hit any speaker with any generated frequency (even if it is outside the specified -3DB points) and the speaker will reproduce a proportional response. That's why they developed graphic equalizer to accommodate for the non linearity and mismatch of the Freq. crossover points on speakers. to give a more flat response to us humans bad hearing (every person has a different hearing response curve too)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">If you want clean reproduction, get the biggest sub you can fit/afford. If you want the sub to "kick" like a smaller sub would, put it in an undersized box.All that depends on the speaker and the box. Even 18 inch subs can be made to "kick" like smaller subs.</TD></TR></TABLE>

with the larger speaker in a car you cannot resolve the acoustic sound because of the length of the generated pressure wave, you rely on reflections to try to difuse and get some sound replication, but the entire car resonates.( i think this is what we call Duff Duff or Techno)Most people who put large speaker in there cars, get the best base 100mtrs behind the car, and all they hear inside is distortion and feel the pressure-wave on the eardrums, Unless you have been in a proper sound room or music room-only then one gets an appreciation of true sound reproduction.

I can recommend some reading if you want to know more!

Multiple smaller controllable better than larger uncontrollable !!

Power Is Nothing without control

Check out WRX -STI Eaters setup another trainned enthustiasts audio setup whos on this site and knows there stuff - note 4 X 10" subs??? i wonder why???
gOt SoUnD ?
http://s11.photobucket.com/alb...%2069/
http://s11.photobucket.com/alb...nster/
http://www.precisionmobilesoundwerks.com


Modified by Jollybandit at 7:00 AM 1/4/2007

 

How did I miss this thread?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote">if you compare some long throw 8" or 10" with the 15" with a frequeny generator feeding the amp with a square wave of 80HZ(mid base region) you can hear the difference. </TD></TR></TABLE>
Why on earth would you use a square wave?

80Hz is not what I would call "mid bass"

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote"> the reason for this is the surface area of the cone that has to move and the momentum necessay to change cone direction is greater and hence dosen't happen as quickly.</TD></TR></TABLE>
Mass is a constant the only thing needed to change "as quickly" is more current.
Which what we are talking about is reponse time. Mass is not the deciding fator in deciding how fast a speaker can change direction.
hence your thought is a common misconception.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote">with the larger speaker in a car you cannot resolve the acoustic sound because of the length of the generated pressure wave</TD></TR></TABLE> I'm not sure what you read or the math you used to figure this out.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote">I can recommend some reading if you want to know more! </TD></TR></TABLE>Yes please point out this bad information.

I have some recommended reading material for you.
http://www.klippel.de/download/group.asp?group=35


Modified by nsxxtreme at 9:13 PM 1/4/2007

 

I do see we read and reference similar sites. -define base -generally in the region of 40hz to 250hz (some say 140hz) mid sub band is 80hz an thats what the engineeering firm i work for utilizes.

Utilising the components of the square wave you can calculate the Q factor of a speaker you know LCR type resonant stuf - engineering evaluation. also 0.35 X 1/freq (rise time stuff)gives you the effective response and you can also apply spectral analysis to the inherent speaker with over or under dampening effect due to the colapsing magnetic field cutting the inductive magnetic core generating back emf. and s domain calculations. these are easier to do with a square wave. As the referenced article simplifies suggesting & refering to as a DC offset. also a square wave is made up of many sine waves thats why iits used(Fourier Analysis). yes it is not practicle in real life and in some circumstances damage the speaker core . Pulsse wave analysis same technology as used in some radar system, but this is done for audio.

Have you ever picked up a 15" and a 10 " you can feel the effective mass difference!! where do you think that is due to???

i suggess that you look up the defination of momentum. or the defination a physics moment. i think your way off base with that statement. really mass has nothing to do with it. you try stopping a tennis ball a 10km/h compared to a car at 10km/h. hmmmmm. i know which will take less counter energy.

final point has nothing to do with the maths it has to do with the human ear ability to funnal audio waves via the ear cannal and disseminate audio tones. the ear is an amplifier and a audio channel - where the sensory pick ups are the ear drums and fine hairs. some sounds actually penertrate via the skull and other sensors. large signals dont make the distance as they supress all these mechanisms untill a reduction of pressure amplitude.

in engineering terms wave length in inverse of frequency. pressure wave length is a different kettle of fish(made up of many facets).

what you are premoting is with response time is only a gramatic explanation of the same concepts. even amps have a response time. they express this as a phase shift of the output signal from the input signal which is also frequeny dependant. as well as a physical depreciation of of output level with frequency refered to as frequency response.

what i deal with on ocassions is this evaluation. how else do you think you get those nice graphs that show you the response of a speaker. i also get involved with phase noise cancelation senaeriio's

there is a lot of pedaled nonsense and general rules of thumb which are premoted by audio companies & installers. there is nothing wrong or bad, it is simplified, and there is even conjecture on some topics between disciplines of study & models used. some good PHD stuff

there is lots in the areas to look- Sound and Audio Engineeering, Physics books, human Anotomy books etc.

will provide some general 2 year uni reading references from my library.some gets quite mathematically heavy and involves some "quantium" physics. -hehehe
(pls note that i have simplifed some of the concepts for ease of understanding)

 

Quoted from Dan Wiggins
"One thing I think that's being overlooked in the concern over transient response and mass is the fact that drivers are a constant acceleration device. If the acceleration is constant, then the rate of change of the acceleration (transient response) must also be constant (derivative of a constant is a constant). As such, for a given driver motor, adding or removing mass will not affect the transient response. It will only affect the SPL (actual displacement).

Another thing to keep in mind is that, because of the constant acceleration nature of drivers, displacement AND velocity increase as you go down in frequency. Dropping down an octave will double the peak velocity of the cone, and quadruple the peak displacement (if the SPL is kept constant).

Lastly, keep in mind that the same motor that accelerates the cone is also the same motor that deaccelerates the cone. The cone is always driven by the motor - it never is allowed to 'spring free'. A quality amp will provide as much current as needed to make the driver operate properly, and can in fact "drive" the speaker to rest. If the amp does become current starved, then all bets are off, but then you're in the realm of clipping as well...

Now, what resists current flow in a speaker? Impedance. What part of impedance varies with position and with frequency? Inductance. This is where you get the limit on current flow in the motor, which limits the force exerted against the driver. Mass doesn't change with position or frequency - it's a constant. It does scale the force (F=ma), but it does so independent of frequency. This means it reduces to overall acceleration of the driver, but at all frequencies, and hence does not affect transient response (which is - by definition - a frequency-dependent quantity). Mass will scale your SPL; it will change the efficiency of the driver. But it will not affect the transient response."

I'm an engineer but I dont design speakers, and I believe in giving credit where credit is due.


Modified by nsxxtreme at 9:13 PM 1/4/2007

 

1) a car battery can only deliver so much current, and a amp can only tolerate so much current. as i agree with the last statement in the starvation senario.
2) velocity, acceleration, and displacement are all related in physics. the maximun acceleration of a speaker is a fixed constant. but across the range of driven frequencies and power it is non linear in charastics.also speakers have different cone stiftness

If all parameters are held in perspective then the statement would be true with the assumptions made. BUT
keep in mind there is a big difference between theory and the models we use and what happens in practicality.

yes SPL is affected by displacement. BUt acceleration is not a constant . other wise you wouldn't get proportional physical movement response of the cone to the applied level of the signal (volts and current), let alone the rate of change of the applied signal.

(Read further). IF a speaker cannnot respond to a transient then it is also outside the natural response of the device?
and
there is no "spring effect" so some time & energy is lost in the deacceleration process before the cone changes direction to a radical signal change

- wow distortion through physical overshoot and lag and hence a physical limitation, which means a depreciation in its SPL which means mass has a effect in reality to a rate of change - becareful about what you are quoting and talking about here!


makes the two of us engineers and we are on the same wicket - i think just ive got some physical implementation practice. so what you've stated actually goes some way to supports my original claims on speaker size.

thanks

Oh and what about air resistance or friction. let alone gravity! put it in a vaccume and the laws of physics change again.



Modified by Jollybandit at 1:31 PM 1/5/2007

 

*rolls eyes*
I understand physics just fine.
Your use of them is twisted.

Your saying "type of base you get is slightly different with the larger speakers, it tends to get what i call sloppy base"

Your reasoning for this action just isn't so.
Your trying to correlate transient response (response time) with woofer mass and it just aint so.

Try saying a complete sentence without going off on a tangent with irrelevant information.

http://www.adireaudio.com/File...d.pdf



Modified by nsxxtreme at 10:30 AM 1/5/2007

 

Very interesting reading - and produce by a audio manufacturer and seller. Its all great stuff on impulse testing. however it too is based around some broad assumptions. Also the rule of thumb we use is that the sampling frequency of acquisition system need to be a minimum of 10 X the driver signal and the accuracy of the measurement system must be a factor of at least 10 time better than that to get true reproduction mechanisms. Second a audio signal is a complex wave not a impulse. Third it is not considering the human anatomy aspects of the human ear

under measurement conditions we have utilized systems with 0.001% THD on driver signals and and a whole bank of National Instruments and HP gear to give us almost pure clean signals and measurements. We are also using laser technologies to measure to the micro millimeters the physical cone movements ( and x-cone flexing)

Some of the thinking behind this article has been challenged in subsequent publications, and what is referenced and referred here

Do you know what effects an inductor - let alone any wire-it has a inherent dc resistance. the impurities and the diameter and length of the conductor determine it residual DC resistance. The number of turns of a coil, the diameter of the and the former that it is wound on determines its inductance . (please note that most speakers have a fixed magnet and the coils when driven they are shifting on the former- out of the primary lines of the permanent magnetic lines of flux. This is also altering its inductance and also changing the response to a given frequency. like i said a moving coil over a fixed magnet also generates an opposing EMF)

note the more powerful the driving amplifier the lower Gage (thickness) of wire need to handle the current....which has a knock on effect of the mass.

there is also two lines of impulse testing with the system set up and they exert some other interesting models not covered here. This is why I've gravitated to this field because it always raises challenges & changes in the models developed (the interpretation of the results and how they may fit the Mathematical Models)

We are drafting some further publications material In which we will be challenging some of the concepts of speaker manufacturing and models and presented as papers to the IEEE and the IE Australia. As i stated before i am simplifying allot for those involved earlier. We have some prominent people involved and a number of PHD students. We hope that our finding will achieve better efficiency s in audio reproduction. We evaluated over 200 makes and models of speakers (car and other)and then trialed some innovative stuff of our own(trade Secret)

A speaker is a Electromechanical device (takes electrical energy to a mechanical movement) with a range on inherent losses and induced distortion.

It is not only uniformity of the coil and the mass of the air it drives, which is proportional to surface area of the cone, and note a cone is V shaped so the air resistance is different depending on the direction you drive it. but also the mass of the cone, the mass of the coil, gravitational mass, reverse inductive induced masses form imposed emf and so on. The Mass i refer is generalization of all this and others which have varying degrees of influence.


We could go on and on.........but for every published paper you provide i bet i can find another that presents another opinion...... The question that you've got to ask is how dose this relate to the whole audio reproduction picture. and better still how to use this knowledge for the pleasure of your ears.

speakers are a really inefficient devices. and there are many facets that alters speakers performance we are arguing over one facet of the picture. and even you agree, and in the quoted reference and other material on the site- the size of speaker alters reproduction to an applied given signal .

SO OK may be i over generalized some difficult concepts -so not to overwhelm, but i glad to find another person with a deeper interest - not a superficial one. You are someone i would and have enjoyed an intellectual and challenging conversation.

A finishing Quote - The more you know -The more you realize how little you really know !



Modified by Jollybandit at 11:27 AM 1/6/2007

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote">and produce by a audio manufacturer and seller. Its all great stuff on impulse testing.</TD></TR></TABLE>
Its a published paper with an author.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote">We could go on and on.........but for every published paper you provide i bet i can find another that presents another opinion......</TD></TR></TABLE>
Would gladly look at a published with author paper stateing a different opinion on the matter.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote">Third it is not considering the human anatomy aspects of the human ear</TD></TR></TABLE>
This is what I mean by irrelavant data this has nothing to do with proving or disproving changes in trasient response based on mass.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote">Second a audio signal is a complex wave not a impulse. </TD></TR></TABLE>
It's only complex if you send a complex signal. A 50 hz sinewave is not complex you dont need a complex wave to show the transient response due to a 50hz source. I also think your missing the frequency response data shown at the end.

My mind works on a data driven interrupt please provide data

 

1) yes but all published papers generally have authors and the excellent ones include refrenced material and sources to back up theory, or practice. i have had a few publications in my time too.
You cant believe all that you read on the internet. especially when there is no methods, assumptions, controls , cross references ...etc.
The problem is manufactures focus only on the positives.
True R&D iss generally more dynamic and has a balance view of the problem - not on just one article but draws on a range of tried and tested methodologies.
2) look harder then! when our paper is published i provide you with the refernce of the document to get another view. and you can read what we have referenceed untill then its under copyright & non disclosure clause of the specifics of our practices
3)the initial topic was never aimed at transient response. it was a BIG genaralisation on the speaker performance with size and the subtile differences- sloppy is just a descriptive term i used .
4) ok, ok your getting a little anoying and podantic, i was refering to inteligable audio like music, voice, opera. Not a fundamental sole frequency.

i do note there is parts of my statements that you dont pick on. SO i guess you think there is some truth in the information reported & studied. -

I Note that you havent really contributed any intelliagble research of your own so to get a balance view or interpretation.

Or You are trying to justify yourself with only one others work - what crentials do you hold to discredit nearly 4 years of research and study and considerable expendature of research grant moneys.

Please Theory and practice and interpretations are wide and varied. I think you have chosen one that suit your Arguement.... spend some time and do some broader reading.

why Do you think most professional systems generally choose to use multiple Amplifiers feeding multiple 10" or 12" sppeaker in stead of a single 15" ofr 18".

Why do you see most stage speakers with multiple 10"or 12" speaker in them instead of a 15" or 18"

because people hear the difference .

Remember english and Mathematics are poor ways of describing what accutually occurs in nature or reality. you try to model the findings that generally suits or has a high correlation with the circumstances.

you know what they say with data driven systems, **** in -leads to crap out

OH the article dosen't even adress the inertia aspects of overcomming the movement frictional aspects, or the cone stifness or retardation due to edge binding of the cone to the frame.

the only way to affect a un hindered cone coil in motion to change direction is to reverse the applied EMF. the cone coil has a mass and a changineing acceleration. this then causes rapid - not instanteonous de acceleration. the article dosent even look at Phase shift or other aspects. it simpily focuses on SPL transient response with no regards to other informative engineering measures

we will have to agree to disagree!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote">You cant believe all that you read on the internet. especially when there is no methods, assumptions, controls , cross references ...etc.
The problem is manufactures focus only on the positives.</TD></TR></TABLE>
Well there is at least one thing we can agree on

You present a statement but offer no data. Vs a published paper that is well written and easy to understand and presents data to back the claims. I can read it and at face value it makes sense to me.

Present me with something to dispute the claims. If your an engineer you know claims get know where without data to back the claims.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote">what crentials do you hold to discredit nearly 4 years of research and study and considerable expendature of research grant moneys.</TD></TR></TABLE> I know this work was done how? Because you say so?
I'm picking more on how your trying to present your claims then I am your claims, I think your taking this the wrong way.
I'll give anyone the benifit of the doubt but I expect a little more then its this way because I say so.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote">and you can read what we have referenceed untill then its under copyright & non disclosure clause of the specifics of our practices</TD></TR></TABLE>
I would gladly read it and please post a link when its published.

I'll try to send an email to Dan Wiggins and see if he would like to contribute since its his article in question. He has posted on this forum before.

 

I also suggest you do some reading on magnetics fields and motors in general. i found some more nonsense of yours - a fan or motor brushless or not generate pulsed magnetic fields and when near the low level lines feeding an amplifier can induce eddy currents in the RCA lead which are amplified and can create unwanted hum or noice. Even at the higer input line levels it can be sometimes heard although you've improved the signal to noise ratio.

That is also why they dont suggest running yous RCA lead feeding the amplifier too closse to the power rails of the car electrical system or Amplifier.

Oh unlaess you are using balanced coax feeds and a LNA.to get the best signals as we do.

im sure dan wiggens wont have anything to say - nearly as much as you have

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote">i found some more nonsense of yours - a fan or motor brushless or not generate pulsed magnetic fields and when near the low level lines feeding an amplifier can induce eddy currents in the RCA lead which are amplified and can create unwanted hum or noice.</TD></TR></TABLE>
Dude you got issues honestly.
Can yes, but the induced signal is minimal compared to the source. I have put brushless fans on amplifiers for years never once induced hum or any audible noise. Noise produce from a fan with brushes happens for a different reason then noise produced from a brushless fan. A statement like this shows how much "practical" experience you actually have.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote">That is also why they dont suggest running yous RCA lead feeding the amplifier too closse to the power rails of the car electrical system or Amplifier. </TD></TR></TABLE>
I also have done this for years, RCA right on top of the power wire running a 100A system with no noise.
Why?
For one you need an AC current to induce noise. The majority of the current in the power wire is DC. Yes you get some AC currents.

You need a loop to induce current. Since there is no "loop" you would have to use the cross sectional area of the rca wire. This is a fairly small value.

The magnetice field cannot be parallel to the loop if you expect any induced current. Obviously nothing is perfect and you will get an angular difference.

Again the amount induce is so small compared to the source never once has this been an issue for me. Can you get induced noise this way sure. But I have never gotten it.

99.9% of audible induce noise I have found turns out to be a ground loop and not actual "induced" noise.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jollybandit &raquo;</TD></TR><TR><TD CLASS="quote">im sure dan wiggens wont have anything to say - nearly as much as you have</TD></TR></TABLE>If you have issues with his articles take it up with him dont bash someone that has no idea your bashing them.

You say you have data to back your claims but then present none. I'm done here because this will get no where.


Modified by nsxxtreme at 2:37 PM 1/6/2007

 

I dont discredit any thing, i take it all on board, but i also access it credibality on the merits it contains on the basis of its background sources. as any qualified person does.

I suggest you by an oscilliscope and do some testing. A straight wire is still a loop and it also depends on the length the wires run in parallel. Just because you havent experienced it dosent mean it dosen't occur. Constant voltage with high transiational currents do induce cross talk. would you place your leads feeding an amplifier arround your ignition coil leads? no!

What about switching voltage of indicators?

what you are refereing and as i mentioned is the Signal to noise ratio (i.e a 1V pre out compared to a 4V pre out) but then if the tune is generating only a 30mv input signal to the amp and you are getting a 1mv noise( through what ever means) through an amp you will have a audiable hum, (and by hum this impliciply means a ac voltage or current or magnetic source) stick your mobile phone near your pc speakers or you amp leads and listen for the T30 before you phne rings.

unless mate you have hearing damage or tone deaf

the only way to reduce magnetic interference is to have spacial separation, shielding, or conductors crossing at 90 degrees. here are some contray publications to yours earlier. with references.
look up what engineers refer to as left hand rule and right hand rule with current flow and inductors......dude how do you think air transformers work??? or even speakers work? magntics

here is some further reading but Technical Publication from Accredited sources Mate - you are inexperienced and certainly not well briefed

1) http://www.acmebass.com/scienc....html

2) The Journal of the Acoustical Society of America -- August 1999 -- Volume 106, Issue 2, pp. 539-540 ( and whole jouranls registered to the evaluation of speakers like the link below)
http://scitation.aip.org/dbt/d...00001

3)Journal of Applied Physics -- 15 May 2005, Development of Hi-Fi microspeakers with a woofer and a tweeter used for mobile phones - this in particular looks at the effect of mass on generated audio

An if you visit a library
US Patent 3838216 -DEVICE TO EFFECTIVELY ELIMINATE THE MOTION INDUCED BACK EMF IN A LOUDSPEAKER SYSTEM IN THE REGION... William B. Watkins which also looks at what i was talking about with effects of eleminating and minimising reverse emf and the loading effect ( or a mass effect)

Monopole low frequency test woofer -David Alan Dage

and there is a tone of stuuf pertaining to audio evaluation and accessment on the IEEE web do some searching on this and you may broaden you learning
http://ieeexplore.ieee.org/Xplore/guesthome.jsp

Happy reading our paper which is under review contains over 300 references - and im just selecting a few which discuss this minor area.

yes Earth loop are the most comman experienced for of noise, besides broken leads (which on one occasion ive also seen act as antenna's picking up an AM channel)


Modified by Jollybandit at 7:26 AM 1/7/2007


Modified by Jollybandit at 7:55 AM 1/7/2007

 

i wasnt lookin for math lol but thanks

 

sounds like my college physics professor!