What the Best 7.1 Speaker system?

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torcator

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Hey guys, a couple of months ago I've bought a harman/kardon AVR 254.
I've been using my old speakers but right now I'd like to buy a new 7.1 speaker system.
What do you suggest me?

thanks in advance,
Ariel.
 

torcator

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Hey guys... 2 years ago I've post this thread requesting information about the speakers...
A couple of months later, after reading your suggestions I've bought the Svsounds system and it worked fantastic.

Then last year I had an international moving and I had to sell almost everything including the speakers.
so, right now... I was thinking on getting a new system...

so first let me tell you what I do already have:

2010 VIERA G25 Plasma
PS3 (of course)
HTPC (a power computer to download, storage and reproduce HD Movies)
DTV DVR

So, what I wanna buy is a good receiver to be able to manage all of this products. I want to buy one thinking on future so it will need at least 4 hdmi.
and for the home theater system, should I have to follow the advice of using a 5.1 or make sense a 7.1. To be honest mi living is not that big:
15 x 20 x 9 feet.

So may be I would concentrate the money on the 5.1
what I've learned from last time is that I really like a good sub-woofer.... so I'm not sure if it's better one big or two smalls..

about the budget... I really don't know...
so please suggest me.... I was thinking something like 800 for the receiver, 1200 - 1500 to the system and 200 to the subwoofer.


So.. what do you think?
thanks in advance for your time...
 

anwaypasible

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maybe its better to let the soundcard do the decoding.. it could save you some money on a receiver.

but i dont know if there are any soundcards that support the new dolby HD formats.

i'd say get some real 3-way speakers so you dont have to spend money on a subwoofer.

or get some 4-way speakers that have the subwoofer already installed.

you do know that a receiver sends subwoofer frequencies to the front left/right speakers dont you?
all you have to do is get (or build) a four-way crossover and chop up the frequency response into four categories.
subwoofer gets one chunk
woofer gets one chunk
midrange gets one chunk
tweeter gets one chunk

most people waste what they have because their front speakers dont play subwoofer frequencies.

i mean, if you spend $800 on an amplifier that can decode dolby surround.. why would you buy another amplifier for a subwoofer?

i understand that you might purchase a subwoofer with an amp that has 200-500 watts .. but its not necessary.

get two subwoofers that are rated for 100 watts and hook them up to the receiver with a 4-way crossover and the speaker cones will move in and out a whole bunch just like the 500 watt subwoofer.

the only difference is.. if you try to stop the 500 watt subwoofer with your hand, it probably isnt gonna work.
and if you try to stop a 100 watt subwoofer with your hand.. it probably will (with some extra pressure).

both speaker cones push on the air.
you would benefit from a long-throw woofer before you would benefit going from 100 watts to 500 watts.

two twelve inch subwoofers running on 100 watts each that move .75 inches
or
one twelve (or fifteen) inch subwoofer on 500 watts that moves 1.25 - 1.5 inches in/out

the two twelves are probably gonna win each and every time because there is twenty-four inches of surface area .. the 500 watt subwoofer only has twelve or fifteen inches of surface area.

DEDICATED subwoofers are more like fans than they are speakers designed to produce decibels.
if you want bass, you are asking for sound pressure levels.
the only way to pressure the air is to PRESS on it with a speaker cone.
the more cones .. or the bigger the cone .. the more air you are gonna press on.
 

MEgamer

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most people buy active subwoofers.

if u only take account of the volume, then it is power rating that shows loudness, moving of air and surface area gives u an idea of the extension of teh bass, not directly loudness. 500 watt 12 inch will be louder then2 twelve inch sub at 100watts in every way.
however there is a difference in diffraction but that is another thing...

by the way not exaclty 24inchs of surface area lol. it comes out slightly differnet.

about ur dedicated subwoofer bit. its also to depend on excursion. its a volume of air that ur moving not a plane of air. therfore u need to take into account of excursion,

multiply excursion with surface area, that is the theoretical amount of air u are moving.



you do know that a receiver sends subwoofer frequencies to the front left/right speakers dont you?
it doesnt if u set ti to small, which is what u should do.


i also dont think its nessecary to go to 4 way designs, since 3 ways even 2 ways are enough. plus when it comes to sound, active crossovers (ones in amps) are better then passives, you cannot completely crossover different frequency with a resistor... therefore some sound will leak.
 

anwaypasible

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'NECESSARY' ... hahaha
there are subwoofers flooding the market.

i really think there isnt enough importance placed on power vs cone surface area.
it takes a lot of work to make one speaker fill a room with sound.
that work is going to increase the cost of the subwoofer .. obviously because it increases the value of the product.

i would appeal that a 500 watts 12 is louder than two 12's when filling a room.
sure, it might be louder right next to the subwoofer box.. but even then, there are products that place a stubborn woofer with an amp powerful enough to make the stubborn move as normal.
its only when you are using the extra power to have an end-result that is a multitude higher.

its like needing that extra power because the impedance is really high.
but the reality is the suspension of the subwoofer is much stiffer.
thats why extra power can have a very comparative suspension on the air.

when you take a super stiff subwoofer and apply lots of power to it .. then place two very freely moving speakers and toe them in so you can bring the pressure to a concentrated point for measurement.. the two lower wattage subwoofers have the advantage of moving freely, which dimminishes the difference of wattage.

its done this way to make the hobby entertaining and informative.

i might have handicapped myself with using 500 watts compared to x2 100 watts.
because generally a doubling of wattage will double the output.
but that extra 100 watts isnt going to fill the room better than having two seperate speakers placed in opposite corners of the room.

THEN you have to factor in magnet strength.
a 100 watt subwoofer can compete only when the magnet is a multitude higher than normal.
or if the 500 watt subwoofer's magnet strength is a multitude less.

its not necessarily a common occurance to see a 100 watt subwoofer with a highly concentrated magnet.
but it is more common to see a subwoofer with a stubborn suspension mixed with a weak magnet.

you can verify this with the car audio industry.
back in the early 1990's .. subwoofers were running on 100 watts
early 2000 .. the subwoofers started running on much higher wattage.
but did the dB numbers change very much? no.. not unless the setup was accredited with speakers that show an improved industry.

it is possible to hear bass coming from a trunk and not know if the subwoofers are cheap speakers running on a 1,000 watt amplifier .. or if they are running some 150 watt speakers on a 500 watt amp.

i think lots of the new '1000 watt' systems are diluted.
and some of it is because the speakers are using a higher excursion motor design.

basically adding some extra 'driver' but not adding any extra 'speaker'
which is kinda like saying the sensitivity of the speakers have gone down and the general excursion has gone up.

its been a roller coaster of up's and down's with individual hardware being the cause.
and i wont be told i am wrong when there are many circumstances that are proof otherwise.

i'm not trying to say you are wrong and will always be wrong.
there are circumstances when the extra power provides extra results.
but usually this is what seperates a consumer level subwoofer from a premium product.

lots of manufacturers make inferior products that save money.
what it does is allow people to play in a group of higher wattage hardware.
its a celebration of the relatively easier to obtain high power audio gear.
and again, it requires audiophiles to be informative.. which is entertaining.

if the audio industry was making upgrades across the board, for all variables.. there would be stronger magnets, higher excursion, higher wattage, and lighter/stronger cones.

my two 12's pull out to full excursion with two simple fingertips (one on each side).
i guarantee you that a 500 watt subwoofer will require you to use two fingertips (or even three) on each side to pull the cone out.

its just like a car.
sure, the engine has more power.. but if the vehicle is heavier, you arent actually getting an acceleration increase.
i'm saying that the amplifier wattage has gone up.. but the output hasnt really increased.

i feel a little bit bad drilling this in.. because MEgamer sounds like he/she knows some characteristics of audio.
but if that it is true.. you should be able to clearly see what i am saying.
the 'driver' has increased a little bit thanks to the higher power.. but the 'speaker' hasnt been increased (or sometimes even decreased in some cases).

playing around with high and low sensitivity speakers should really help if you decide to experiment.
we know that a high sensitivity speaker will generally have lots of 'speaker' but usually with very little 'driver'
and it has been common that a lower sensitivity will have less 'speaker' but with more 'driver'
IF you start to mix 'driver' and 'speaker' together in either high sensitivities or low sensitivities.. you are dealing with a premium speaker.

i had two 12 inch infinity reference subwoofers in my trunk.
they had a high sensitivity.
and the result inside the car was lots of 'speaker' but not a lot of 'driver' (even though the speakers did move in and out.
it sounded like there was lots of decibels (audible sound) .. which is the 'speaker' aspect i am talking about.
but there wasnt a lot of pressure (the 'driver' i am talking about)
each subwoofer was getting 300 watts each.
they had a sensitivity of 92dB

some would say that a subwoofer doesnt need to 'speak' and only needs to 'drive'
but that isnt true.
once you take away the sub's ability to 'speak' .. the result is mud.
muddy speakers that have high amounts of detail will not play the upper range of frequncies because they are too busy blowing air (which is large excursion)
you cant have large excursion when trying to play upper frequencies.
the upper frequencies have a wavelength that is smaller than what the subwoofer is willing to dish out.
its basically stating that the subwoofer will move .25 inches freely and willingly.. but it wont move in and out 2mm

speaker sensitivity has been used to stamp on a label that states the ability of the speaker to move the cone in and out in small amounts.
although this doesnt always prove to be true.. and those such speakers are premium compared to the 'junk' it is being compared to.

its a little difficult to hold these characteristics as principles when dealing with subwoofers.
but there are more and more audiophile woofers that have a lower sensitivity and are capable of 'driving' and 'speaking' with a lower sensitivity.

you may come across a person posting something like 'dont judge a speaker's ability to play details on the 89dB sensitivity alone'

to finalize,
a speaker might have a NEED for the extra power.
but if there is no need, the output will be a magnitude higher which reflects the higher wattage.


but i guess i will go on about an experience i had the pleasure of going through with the subwoofers in my car.
those two 12 inch infinity references (model 1220w) were rated at 300 watts rms each.
and that is what they got.
they were in a sealed enclosure of 1.25? cu ft each. (maybe it was 1.5 cu ft)

i replaced those with a single 12 inch mb quart subwoofer (model rwe302)
this subwoofer was rated at 500 watts rms
but i could only feed it 300 watts rms
it was a display speaker that had never seen power before.. i picked it up for $50 shipped to the door.
i had an old bandpass box from a different subwoofer project.
after loading that sub in the bandpass box.. i was amazed by the fantastic details.
the mbquart sub also had a sensitivity of 92dB
but all of that 'speaking' was encapsulated because the front of the speaker was sealed (the plexiglass part).
the sound inside the car had much less 'speak'
i could now hear the 'drive'
dont rush to think that i couldnt hear any 'speaking' at all though.. because the 'speak' had much less amplitude, but it was about the same amount of energy as the 'drive'
this situation gave the subwoofer the ability to provide pressure, yet 'fill in the gaps' with 'speaking' details.
it sounded like pressurized 'with' and a bit of detail(s).

i dont really thing talking about it says a whole lot, other than the fact that i was able to go from a setup that 'speaks' more than 'drives'
which is the same as saying.. 'there was more decibels than sound pressure'
and transformed my listening experience to a situation that had the 'drive' and the 'speak' at about the same exact energy.
this goes to say that a high sensitivity subwoofer does have drive.. you just have to manage the extra 'speak' so that the 'drive' isnt drown out.


now to get elaborate..
i have a 50 watt 6.5 inch subwoofer from the klipsch promedia 2.1 set.
this one speaker alone 'speaks' a lot louder than my two 12's
but the klipsch subwoofer doesnt fill the room with bass like my two 12's do.
no.. no.. no..
its much different.
the klipsch subwoofer sounds like i am listening to air bounce around in cheap fiberboard before it is blasted out of the port.
and my two 12's sound like nothing at all.. the air inside the room simply gets excited with bass.
if i turn the two 12's up, the air surrounding me gets violent and the walls start to vibrate.
if i turn up the klipsch subwoofer.. the 'noise' from the box is really really loud before the walls start to vibrate.
there is no point of source when i listen to my two 12's
but i cant tell exactly where the klipsch subwoofer is.
all i can do about the klipsch subwoofer is place it in a corner and try to 'stretch' or 'smear' the noise by bouncing it off the wall so that it is a little bit harder to pinpoint its location.

i have learned the difference and i try to suggest that people dont add a subwoofer into their system that is gonna have the same 'pinpoint' noise affect.

once you start calibrating an equalizer.. you get the subwoofer at the same 'noise' level as the main speakers.
and i have done this by simply adjusting the volume of the subwoofer to match the volume of the main speakers.
but even then, you can totally tell that the bass is radiating from the corner and trying to 'smear' its way out of the corner.

i suppose this is a good time to talk about how subwoofer location is very important.
but you have to realize, putting a subwoofer in all sorts of locations isnt always possible.. and it certainly isnt going to mix well with the furniture layout.
you can use a pair of 3-way speakers and put them in normal locations to achieve a better blend of acoustic energy without having to worry if they are in the right place .. or try to move your furniture to accommodate.

you cant sit close to a subwoofer and expect it to fill the room with energy.
the sub will be way too loud.
usually you gotta keep the sub at the opposite end of the room.
and you dont want the subwoofer to be behind you when the rest of the energy is coming from the front.
it sounds awkward, which ruins the soundstage.

the original poster is asking about a 7.1 system.
that would include speakers that are capable of high detail.
and a subwoofer capable of details.

but it doesnt matter if the person purchases a set that can play details IF the speakers arent setup correctly.
time alignment really really helps.
although.. most of those tiny speakers will have a hard time filling the room with sound unless the reflections of the walls are utilized to create a field.

simply putting a subwoofer under the desk for 2.1 computer audio setups is easy.
but even then.. the bass seems to come from the floor while the mains are up on the desk.

i just dont see the reason to purchase something that is supposed to provide enjoyment, but there is no care to setup the hardware properly.
its like buying a tent and choosing alternative methods to hold the roof up.
sure, you can stick a single post into the ground and point it straight up to hold the center of the roof up.. but all of the sides and roof are gonna sag, which makes it feel like there is very little room inside the tent.
if you just take the time to correctly hold the roof up.. you will have lots of elbow room and there wont be any tent material laying on your head or shoulders.

purchasing a subwoofer with a high wattage amp.. you might be purchasing a vehicle that ways extra, therefore you need a stronger engine to get back to normal.

i am laughing and giggling with my mental process because i have sat and typed a little bit at a time over the course of a few hours.
i know that the information included should help people who are thinking about buying a 'set'
its possible that the people looking to buy arent informed enough to know if a 'set' is actually the piece that fits into the puzzle.
or maybe.. they dont know that there are other puzzles that can provide the same entertainment.
which leads to the pro's and con's of the different puzzles.

**edit**

and another thing..
active crossovers are not always better than passive because the amplifier might have components that MUST play a wide frequency range for them to work to the best of their ability.
if you are driving only midrange frequencies, you would be putting a fraction of load onto a circuit that is designed for a wider frequency response.
using those components at a fraction of their capability can cause artifacts.
you might get a colored sound .. you might get less power to control the speaker cone.

and since using active crossovers is supposed to eliminate any in-line component artifacts/distortion .. and also to free up the amplifier's resources (hoping for more power to control the speaker = better details)
you would be making the problem worse .. or quite the same results if the passive crossovers are that bad.
i wouldnt say its a bad thing to try each method and listen for the best choice.
because if the amplifier doesnt suffer from such a problem, it would then be possible to eliminate any characteristics the passive crossover components inject into the signal.

i would hope for an amplifier that outputs the same quality regardless of frequency width.
and possibly one way to avoid such a situation is to use surround sound receivers.. each channel is dedicated to a chunk of frequency and as long as there arent seperate amplifiers for each channel.. you can get the components to work as normal because all of the frequencies are required.

and to add to that..
asking a power supply to provide power for only a specific chunk of frequencies can be bad.
the power supply itself and/or the power conditioning circuit might not like it if you arent playing the full frequency spectrum.
but if each amplifier circuit doesnt care about the narrow width of frequencies, you can combine amps to increase the frequency spectrum being presented to the power supply.
the train is only as slow as its weakest link.
so if the components for the amplification are okay with a narrow frequency width.. maybe the power filters arent getting sucked on appropriately and thus they dont release their power as originally intended.
goofy power makes for goofy results.
asking for a 'snippet' of power from 'goofy' power sources might make the components oscillate (to compensate for extra frequency of power not being used) or become restricted/confused because of the extra power.

you can draw power from a battery.
but you have to realize that you can change the method of sucking on the battery.
you can do it with a specific frequency or at specific interval patterns.
or mix those two together for frequency + duration + interval = casino dealer willing to dish out cards at full speed.

besides.. i dont like it when people disrespect electronics evolution.
they have been working at it for far too long for things not to be perfect.
and once you step into audiophile category, the differences that are noticeable need to be benchmarked and noted.
but that means taking the pro's and con's of the individual hardware.

i can only imagine the difference between passive crossovers.
one using junk components and the other one using premium components.. i would have to first start at the listening experience and take note of extra details.
then go on to look at things like impedance added because of the crossover circuit.

if the active crossover isnt digital.. then this whole mess is relying on the hope that the amplifier will focus its efforts to become a concentrated amount that increases details.
and that there is nothing in the way to ruin the focused effort of the amplifier except for speaker wire.
and the components inside the active crossover are going to govern what the amplifier has to amplify.
so if the components in the active crossover are junk.. you really bring yourself back to a lack of detail that could be improved.

although it is safe to say that all of this stuff isnt a science anymore.. its math.
learning the pieces available to create a puzzle is time-consuming.
some people stare at a television all day.. some people benchmark and take notes.
 

MEgamer

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"the klipsch subwoofer sounds like i am listening to air bounce around in cheap fiberboard before it is blasted out of the port.
and my two 12's sound like nothing at all.. the air inside the room simply gets excited with bass.
if i turn the two 12's up, the air surrounding me gets violent and the walls start to vibrate.
if i turn up the klipsch subwoofer.. the 'noise' from the box is really really loud before the walls start to vibrate. "



try listening to the 2 12s outside, in open air, then u wont being saying this.

i dont get ur speaker and driver analogy. really if ur talking abuot thsi kind of topic then all u have to know is that surface area times excursion is proportional to the volume. know matter what size, assuming they weigh the same, its power thats dependent on volume.

if u have 4 inch sub and an 18inch sub, assume both weigh the same. (in ratio 18 would be lighter) give the same amoun of power, they wuold both be producing at the same decible (mic @ 1m). why???? becasue both would be moving the same amount of air. (4inch however will be more directional, at given frequency.)

there is no 'driver' and 'speaker' or its 'speaks'... wat kind of analogy is that???#

the kplisch dont fill the room, cos its got poor frequency response. it cant hit deeper and harder then the 2 12s therefore its gonna sound liek shizz and make a lot of port noise and distort b4 if even 'attempts' to vibrate the walls.

subwoofers produce frequencies that are omnidirectional, they are hard to pinpoint even in open space, its gonna be a lot ahrder in a room, where they reflect off walls.


"most of those tiny speakers will have a hard time filling the room with sound unless the reflections of the walls are utilized to create a field."

tiny speakers will have a hard time filling the room, because they have poor diffraction, although if they were pointing directly at u, it will sound just as if it was any other good speaker. positioning is crucial.

"simply putting a subwoofer under the desk for 2.1 computer audio setups is easy.
but even then.. the bass seems to come from the floor while the mains are up on the desk."

i have a cheap razer mako for computer, they dont sound as if my sub if under the floor... anyway....

most computer speakers are crossover at 150hz, so u are going to get some directionality. any if u are sitting at a desktop distance, ofcourse u can tell where its coming from... of course assuming there is a huge amount of space. (ive stood next to some 15s and i can tell its coming from there.) ...i bet even blind folded i would be able to tell.


active crossovers are better... theres no need to explain this... hi-fi speakers dont use ative crossovers cos they are passive. Damn expensive to make some good ones, cos its very difficult to design them, that will add nothing to teh original signal.... proffesional speakers would go for active xovers for a reason.
 

anwaypasible

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power is volume.. and that is power of the (coming from the) speaker.
doesnt matter how many watts you are feeding it.. it depends on how well the speaker performs when given the power it is designed for.

an abnormally strong magnet will boost a 100 watt speaker because the magnet is what drives the cone in and out when the voice coil is energized.
the spider can be stiff and resist the force of movement.
the magnet can be weak and provide little force of movement.

anyways..
when you tell me that there is no 'driver' or 'speaker' .. it makes me think you have simply read a book and dont have any hands on experience for yourself.
give me $25 and i will send you a speaker that has very little 'drive' and a whole lot of 'speak'

the speaker emits sound without moving very much.
generally based on the way the voice coil is wound.. but a magnet with a very thin focal point can also help provide the same end-result.

'drive' is the moving in and out without saying much.
'speak' is the exact opposite .. there is sound pouring out of the dustcap, but the speaker is barely moving.

if you have a speaker that can 'speak' a whole bunch.. then start adding 'drive' and the sound will start to move outwards from the dustcap.
a speaker cone has its own radiating pattern.
but the design of the motor also has its own radiating pattern.

zoom in on the speaker movement with me..
you can have a speaker that will play a single note and the cone will simply move in and out at the wavelength of the frequency.
OR
you can have a speaker that will play a single note and the cone will slowly move in and out (point to point xmax) while also moving in and out at the wavelength of the frequency being asked to play.

if you record the cone movement on a camera there will be a difference.
the first example, the cone moves in and out of the wavelength only.. and you will probably see the speaker cone ripple and bend.
but the second example, you will see the cone slowly moving in and out (within the linear xmax).
its like watching the cone move in and out of a total .75 inches .. but the wavelength only requires a few millimeters.

its safe to say that a speaker cone can move in and out more than what is required for the wavelength.
the results arent going to help you calculate your room very nicely.

a very very crude example:
i hand you a ball and i tell you to throw it.
it doesnt matter how far you draw your arm backwards (as long as it is drawn backwards more than 6 inches)
you draw your arm back and throw the ball.
if you draw your arm back 6 inches or less.. that is considered a toss, no matter how hard you move your hand forward.
and it really helps bring the situation to a close.
if i tell you to make the ball go through the air.. you have the choice of throwing it or tossing it.
how hard you throw or toss the ball is like changing the amplitude with the volume dial.

i know the throwing a ball example doesnt fit perfectly, perhaps because there is some confusion with 'drive' and 'speak' yet.
there are some speakers you can use for examples.
the kicker l5 or l7 both have lots of 'drive' with very little 'speak'
the cone moves in and out a great deal.. producing pressure inside the car.
an infinity subwoofer has lots of 'speak' with very little 'drive'
inside the car you hear the subwoofer, but you dont feel the bass as much as the kicker sub.

for a subwoofer, yeah.. you might want the cone to move in and out without 'speaking' so that you have nothing but loads of air to get the sound from.
this is the essence of muddy sound.. pure mud if you will.
but the only way to get subtle details from the load of air is if the air is sealed up and the air pressure has the ability to flow freely (unobstructed) to allow the subtle changes in wind move throughout the cabin space.
and it isnt necessarily possible until the air chamber is already pressurized.
that means.. to accomplish a quick change of the speaker cone.. a piece of string hanging from the rear view mirror MUST move at the exact same time the cone moves.
if the cone moves outwards (and stays there).. the string needs to be pushed forwards and stay there (gravity will draw the string through the air until it is settled and sucked on)
if the cone moves inwards (and stays there).. the string needs to move backwards towards the seats and stay there.

this is optimal.. but takes designing to accomplish.

if you just throw an amp and subwoofer into the trunk and the cone moves outwards and stays there.. its gonna take some time before the string moves.
since the cabin isnt already pressurized.. the string will only vibrate.
that means subtle details wont be as solid and pronounced.. which means you wont hear them at all.

i have seen a video before of the pattern emitted by speakers.. if the sound pressure is high enough, you can see it and record it with a camera.

obviously i am about at the end of what i know.. because i dont know how those patterns contribute to 'drive' and 'speak'
but i can make a logical guess.
if you have nothing but 'drive' .. the pattern seen will simply be LFO's and you will see exactly how the chamber is bouncing pressure and creating a pattern.
its a choice to use only specific polar patterns or the entire polar response.
specific polar patterns will show lines throughout the room as they combine to create the most pressure.
obviously you have to have enough pressure to break visual standstill.
but the chamber has lines going through it like spider waves when specific polar patterns are used.

when all of the polar patterns are used.. the entire chamber will stay completely solid and there wont be any 'liquid movements' unless they are purposefully induced.
however, if you are using inferior math to try and create a perfectly solid chamber.. you will see the artifacts because there will be liquid movements.

and let me just stop right here and tell people who dont know what i am talking about.
if you have ever been to the drag strip and watched funny cars race down the track.. you know that you can look across the track at the other bleechers and see them liquify as the car goes by.
its because the sound is loud enough to move the air with such strong pressure that the air distortion can be seen visually.

there are sound chambers with speakers that are powerful enough to make the same visual distortions.
sometimes you can actually pay to demo one of these.. i dont know if there are any available to the public or not.

what they do is take room LFO's and shrink them and shrink them until there is hardly anything left.
the reason why they are called LFO's is because 'usually' it takes low frequencies to produce enough pressure to consider a visual distortion.
there may be better words used to describe some things now that they have been teaching acoustics in college.
but the room fills up with soundwaves.
if you make the room easier to throw soundwaves first, you can manage experiments easier because the soundwaves have the air needed.

it IS physics.
there are physics in a speaker.. yes, a person of physics can create a speaker to fulfill their needs. (although not necessarily welcomed)
but its really about the physics of air.
completely about the physics of air as long as you have a speaker.
the speaker emits a pattern.. and that pattern is what is important if you want to take any speaker and make it sound the best it can in an environment.

i realize how far off i am about 'driver' and 'speaker'
what brought me to the conclusion was a 12 inch woofer i bought off of ebay.
the woofer was very stubborn and refused to play lower frequencies without a lot of amplifier power.
say from 30hz to 50hz .. the speaker didnt want to move in and out.
and that means there was sound pouring from the dustcap .. radiating to the outer edge of the cone because the cone was very stiff .. and the results are nothing short of what the cone could do to the air.
i did manage to get 30hz out of the woofers after using an equalizer.. but one of the voice coils became unwound.

what appears to be logical..
the actual voice coil and magnet where sensitive, which produced the sound.
but the suspension of the woofer was very stiff, which means the speaker cone didnt want to move in and out for any reasonable length of excursion that a woofer should be capable of.
it boils down to the fact of the voice coil 'willing' to move in and out.. but the speaker cone didnt want to.
its possible for the inside of a speaker.. where the voice coil is glued.. to move in and out a bit more than the outer edge of the cone.

this is one way a speaker can 'speak' without moving very much.
because you arent going to see the dustcap area move in and out more than the edge of the speaker cone.
also, this changes the pattern that is emitted from the cone significantly compared to a speaker cone that has a soft suspension (the stiffness of the spider and the stiffness of the surround).

to playback a frequency.. the speaker has to move in and out at the right interval, which is time dependant.
but the speaker can move in or out extra as long as the phase is flipped at the right interval.
flipping the phase is the amplifiers job.
moving in and out is the speakers job.

i am drawn back to sensitivity of the speaker again and again.
see.. if the spider, the surround, and the voice coil all have a desire to play a specific frequency.. playing a frequency far from the speakers desire can make the speaker become angry.
when this happens.. the speaker will move at the frequency it wants to move, with the frequency its being asked to play being mumbled.
OR
the exact opposite can happen.
the speaker will play the frequency it is being asked to play, but will mumble on about the frequency desired.

mumbling the frequency asked to play isnt going to provide lots of energy emitted for that frequency. (no 'speak')
instead.. the speaker says 'i am gonna play 30hz whether you like it or not'
and the 30hz added to the requested frequency makes the cone move in and out more. (the 'drive')
it can and should be seen as an artifact when all you want is the frequency you requested and nothing more.
BUT
you can use the 'desire' to your advantage.
if you ask a subwoofer to play 40hz and the subwoofer wants to play something else (usually a lower frequency) then you can get the benefit of emitting 40hz into the air.. and then use the lower 'desire' frequency to push outwards on the ripple, which is like the speaker playing a frequency and then shoving that frequency away saying 'get away from me'

its a bit easier if you think about it in steps.
to start..
you play four quick pulses (thats moving in and out eight times)
then you throw out a large (single) pulse.

it doesnt make sense because it looks like the speaker is playing 4hz at small amplitude, then 1hz at high amplitude.
but if you take those two seperate events and place them directly on top of eachother.. they will happen at the same time.
how and why does this make sense you ask?
because you get free amplitude without using the amplifier..!

now if the speaker plays 1hz and mumbles or struggles to play 4hz.. obviously you are asking for 4hz and you are getting it, but it isnt very loud = no (or little) 'speak' and all 'drive'

in practice, these setups dont always play each note with the same amplitude.
if there are severe timing problems.. usually the 'desire' frequency will win the battle and the 'requested' frequency will be forced to play 'affected'
that can cause a warm sound if the 'requested' frequency has timing problems that are found to be 'slow'
and it can cause a cool (or bright) sound if the 'requested' frequency has timing problems that are found to be 'too soon'

once you stop playing around with single frequencies and start playing some music.. you will see the cone moving in and out a whole bunch, but there isnt lots of volume coming from the speaker.
you think to yourself 'normally when the speaker is moving in and out like that its really loud and i have the amplifier turned up to 75%'
but you actually have the volume turned up only 50%

and maybe you dont realize this at all.. because lots and lots of the speakers that have flooded the market do the extra cone movement.
speakers from the 70's .. if you turned them up and the cone was moving in and out a whole bunch, you could point that speaker to your chest and feel all of the sounds being played.
and you could feel those sounds with very high detail.. what was requested to play is only what the speaker is playing.

nowadays.. if you want the same experience, you have to find some concert speakers.
not to be confused with DJ or band speakers.
actual concert speakers.
if you have the volume on those up.. you can stand by them and feel every little detail of the guitar string.
you can even feel the tip of the guitar pick.
those speakers are playing what is requested and nothing else.
DJ speakers have a hard time playing what is requested.. and they are also playing something extra that isnt requested.
that is why you can stand by a DJ speaker and feel vibrations.. but they dont match exactly with the audio you are hearing.
the feelings arent late or delayed.. what you feel is seriously loose and confusing with a bit of what you are hearing being felt.

speakers arent tight and precise when the cones are moving extra.. however, they are getting better and better.
the extra movement from the cone causes bloated air pressure and speakers sound like they are trying to fill a balloon.
some speakers dont have it as bad.. but they are dull with the details.
they dont sound plain dull anymore.. they sound dull and bloated.
bloated sounds like you have a fan blowing air between you and the speaker.
putting a fan in the room so that the air blows sideways directly in the line of sight between you and the speaker is not always the easiest thing to do because the fan might make too much noise and ruin your ability to listen to the speaker for a difference.

i have had the pleasure of listening to speakers that dont have excess cone movement.
it sounded like i was listening to paper speakers.
they didnt have lots of dynamics.. but all the main sounds were there and vibrated my body without any extra nonsense.
you might be able to find some old woofers that do the same thing.. but they are part of the same group of speakers that lack the extra details.
they sound dull and lifeless.. but they sound like they are running on enough watts to zap you.

if you start to use digital room correction to flatten your frequency response.. the programs you use should be able to listen for the extra cone movement while recording the sine sweep.
it would come across as the sine wave and something extra.
the digital room correction might think that there is a room resonance problem there and adjust for the room resonance.
it should make for an interesting end-result.

however, the digital room correction software might see the extra cone movement as extra amplitude for that frequency.
and that would simply raise the frequency response measurement for that frequency and be adjusted.

those old paper woofers had a job to do.. and that was to produce black sound, which is sound that is so detailed and not colored that you started to forget that there was a speaker in the room as your brain's imagination led you to believe the person is actually talking with his/her mouth and not through a speaker.

they have added fans to the sound regardless of the clarity.
and they have also made the timing too early which makes the speaker sound 'bright'
cant complain too much when the extra details are there.. because its a huge improvement of the speakers from the 60's and 70's

an important detail is how that extra sound pressure is affecting the room.
old speakers, you would actually hear some echo.
new speakers, you hear 'air' when you turn the speakers up and look for the echo.

i think the extra cone movement plays hell on trying to determine frequency phase.
i'm thinking the old voice coils had smooth and gradual phase changes.
the new ones have phase differences that are all over the place.
meaning.. the old ones had maybe two per octave.
the new ones have eight or twelve differences per octave.
OR
maybe the old ones didnt really have any phase differences at all.. and all you had to do was correct 30 degrees gradually across the frequency response.
i wouldnt know these specifics because i havent messed around with the old speakers.
but looking at frequency response measurements, the phase flips 180 degrees dozens of times.
my dynamic microphone didnt have phase problems since it was calibrated at an audio lab.
the amplitude correction eliminates varying phase of the microphone.. because any that did exist are now compensated for.
but since my microphone fell off my lap and broke.. i will be trying a phantom powered condensor design.
and since dynamic microphones are not as instantaneous as condensor microphones (unless the mic has small voltage applied)
the difference will be the speed of electricity compared to the speed of magnetic inductance.

anyways.. i am now depressed after having gone through the problem of extra cone movement.
i used to think one speaker was better than the other simply because of the way the voice coil was wrapped.
but i have grown to learn that there are other things like design effort put into the magnet and the movement characteristics of the spider.

my two twelves have a soft spider.. and the surround is almost soft enough that you can blow on it and watch it indent.
i know that the soft surround really helps the edge of the cone rather than being stiff and dissipating the vibration.

i am really bummed that i cant find any pictures or videos of high sound pressure that causes visual distortion.
although i did find this:
http://www.zainea.com/visual.htm
it shows the LFO's i was talking about.. but they call it 'sound propagation and scattering'
looks like the speaker is installed flush on the floor and they are having a look at all of the reflections, and not the initial energy emitted from the speaker.

this website shows a drawing.. its nothing photogenic though:
http://artsites.ucsc.edu/EMS/music/tech_background/te-01/teces_01.html

i am off to hunt down some real photos of sound being visual.
 

MEgamer

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Dec 19, 2009
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'drive' is the moving in and out without saying much.
'speak' is the exact opposite .. there is sound pouring out of the dustcap, but the speaker is barely moving.

u worded it in that people dont really understand... its prety simple actually...,
theres no neeed to put it in that analogy.

ill put it in another word for, something that OTHER people WILL understand.

play a 20hz signal... for an 18 inch, the speaker doesnt neeed to excurse as much to play as loud...say 90db.

now get a 4inch sub and tell it to play 20hz driven till its loud as 90db, that speakers will then have a huge amounts of excursion... now that is your 'drive' and the 18inch one is'speaking'... but then thing is theres no need to put it like that.. cos they are both the same thing.... what are they both doing??? moving air... how much air in comparison??? (leaving all the factors the same), they are moving exactly the same amount of air...

sound will not be poring out of the dustcap... since the dustcap is fully glued to the driver which is glued to teh voicecoil and the spider. if the driver is not moving, then nothing is....

u are splitting the idea of how sound moves and interacts with a medium... into 2... that is pretty much the same thing... erm.. what?
 

anwaypasible

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Oct 15, 2007
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it was a really long post.. and if i had to say it again, i just came up with a simple way to word it.

the speaker is 'congested' with other frequencies of longer wavelength.
those longer wavelengths arent necessarily the same amplitude as the requested frequency.

as far as i'm concerned.. if the amplifier was oscillating and sending that oscillation out to the speaker.. the situation would have the same principle.
moving in and out while playing other frequencys.

and we all know its possible because speakers play more than one frequency whenever music is played through the speaker.

but anyways.. i would laugh at anybody losing a bet to a 4 inch speaker moving the same amount of air as an 18 inch.
the excursion on the 4 inch would be massive.
simply pulling the basket out of the bag would make those involved in the bet think twice.

a bar gag.. and a chance to show off a monster 4 inch speaker LOL
 

MEgamer

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so i did say keeping all factors the same.... a 4inch would have a massive excursion only if ud wanted it to... no one here was assuming the 18inch was playing at extreme levels that the 4inch can not compete... only u...

u don't sound like the person that even goes to a bar..., not the last word on ur pic either.