Bass is too concentrated in the corners of my room.

Yoshinat0r

Distinguished
Nov 22, 2010
19
0
18,560
Hello, I'm having a very annoying problem where basically the waves outputted by my sub woofer are way too concentrated in the corners of my room and are putting a lot of pressure on my ears. The reason it is putting pressure on my ears is because my computer desk is right between two corners. I have drawn out some diagrams of how my room looks and where I have tried putting the subwoofer:

http://i495.photobucket.com/albums/rr317/Yoshinat0r/DIAGRAM1.jpg

http://i495.photobucket.com/albums/rr317/Yoshinat0r/DIAGRAM2.jpg

http://i495.photobucket.com/albums/rr317/Yoshinat0r/DIAGRAM3.jpg

In picture 3, it is more evenly distributed between my ears, but turning my head even slightly will cause pressure to build up in whichever ear is facing one of the corners. Even that is just really annoying.

Interestingly enough, only tones around 80hz are what cause this pressure in my ears. It is very very annoying, I don't even like listening to music with lots of mid-high bass anymore because my ears feel so uncomfortable. I barely have this sub turned up high at all, so that is not the issue.

Is there anything any of you guys recommend that I could try? Is there anything I could buy, maybe some kind of foam, that can stop bass from concentrating in the corners like that?

EDIT: I could try moving to the other section of the desk, but I really did not want to have to resort to that, since I like this section a lot better, and it works better for my surround speakers.
 

anwaypasible

Distinguished
Oct 15, 2007
718
0
19,010
your situation is very real and very common.
there are a few ways you could change it.
1. program some reverb for the subwoofer (but none of the pictures show the sub facing a good way to make the reverb work best, since the 2nd reflection never really gets aimed at anything to start the process of calibrating the soundwaves)
2. use the diagram #2 setup and put a large file cabinet or some tall and skinny piece of furniture in that corner to stop the soundwaves from bouncing around in the corner. (one of those glass display cases with shelves inside of it would work.. but you probably need to use glue to prevent the glass from vibrating and falling out)
3. you could buy bass traps that cover the entire corner.. but you could save some money and put some cardboard in the corner with some tape.
just put the tip of the corner into the middle of the piece of cardboard, and make sure the cardboard is thick enough to withstand some mild vibration.
this is supposed to be the cheap route, and it will help if you go from top to bottom.
but
cardboard will allow the soundwaves to bounce off of it .. and if the bass is now audible from the corner and annoying, then you need some acoustic panels.
you could put the acoustic panels on top of the cardboard.. or buy some corner acoustic foam.
if the corner foam is not the type of foam for the frequency you need.. then you are still going to have a problem, only the problem will be heavily reduced.
and it might be easier to simply try the cardboard first, and if you can 'hear' the bass in the corner too much, you are going to need some acoustic paneling.
but
maybe you could get some polyfil and wrap it up with a zip tie or a cord, then hot glue the polyfil onto the cardboard.
gotta do it from top to bottom to really get it to do its job (although the tip by the ceiling might prove to be not needed since the sub is on the floor).

anyways.. 'hearing' the bass isnt the same as the pressure tickling your ear.
the tickling is from soundpressure, and the 'hearing' the bass is dB level.
you could wire two subs up.. one backwards from the other, and still get a tickling sensation in your ear without hearing much of anything at all.
(not recommended.. only spoken about to provide a showcase of the difference between SPL and dB)


dont bother wasting your time with the reverb if you cant program the reverb for the subwoofer only.
and as i said, all of the photos show the subwoofer facing parallel to an opposite wall.
technically, the soundwave is going to try and bounce back the opposite direction it came from.. and when it bumps into another wave going from the speaker to the wall, then the wave is going to spread out.
you would be better off putting the subwoofer under the shelf or under the cabinet and listening to it like that.

if you do try to use some reverb.. you will need to measure the distance from the subwoofer to the wall, and then adjust the angle and distance for the 2nd reflection until the concentration in the corner goes away.
this might take too long.. and if you do find the sweet spot for the dials, it might not decrease the pressure enough.

to make it quick and simple without doing anything but moving the subwoofer..
you could put the sub under the shelf and try to let the computer desk catch the soundwaves before they travel up the wall and accumulate energy.
or
you could put the sub under the desk (in the corner) and point it at the doorway.
or
you could put the sub in the corner at the end of the computer desk and aim it at the corner by the shelf.. and hope the dresser allows the soundwaves to bounce around in such a way that the problem is canceled out from phase opposition.
or
put the sub in the corner at the end of the desk and point it at the top corner of the dresser and hope the pressure rolls off into the shelf corner without building up much pressure.
or
put it in the same corner at the edge of the desk and point the sub at the bottom corner of the dresser and hope the corner of the dresser sends half of the soundwaves into the doorway corner, and the other half of the soundwaves would spread out along the front of the dresser, and also spread all along the right wall.
but
maybe you need to put the sub in the corner at the end of the desk and point it at the bottom wall of the dresser (the middle of the side wall)
and see if that redistributes the soundwaves enough to lower the pressure.


this might work well for one corner, moving and aiming the sub, but you might find the other corner acting up.
and it is really a job for reverb or removing the corner by putting some cardboard up to change the shape of the corner to something like a stop sign shape.
 

Yoshinat0r

Distinguished
Nov 22, 2010
19
0
18,560
Thank you for the very long, informative reply :D

I have never programmed reverb for a subwoofer, I hope it's not too complicated.

use the diagram #2 setup and put a large file cabinet or some tall and skinny piece of furniture in that corner to stop the soundwaves from bouncing around in the corner.
I have a very tall ceiling, about 8' 6", so it is going to be difficult finding something that tall. Maybe I could find something though.

you could buy bass traps that cover the entire corner.. but you could save some money and put some cardboard in the corner with some tape.
just put the tip of the corner into the middle of the piece of cardboard, and make sure the cardboard is thick enough to withstand some mild vibration.
this is supposed to be the cheap route, and it will help if you go from top to bottom.
I am interested in this cardboard trick, though I failed to point out one detail about my room. There is a window on each side of my seating position that directly meets each corner. Not very convenient I suppose for trying to fix something like this.

cardboard will allow the soundwaves to bounce off of it .. and if the bass is now audible from the corner and annoying, then you need some acoustic panels. you could put the acoustic panels on top of the cardboard.. or buy some corner acoustic foam.
I wouldn't mind buying acoustic panels/foam, just hope they aren't too expensive. So for the foam, I would need to look for a foam that's designed for 80hz?

you would be better off putting the subwoofer under the shelf or under the cabinet and listening to it like that.
Well this shelf has no underneath where I could put the sub. The only place this sub could actually fit under would be the desk, since it's rather large.

you could put the sub in the corner at the end of the computer desk and aim it at the corner by the shelf.. and hope the dresser allows the soundwaves to bounce around in such a way that the problem is canceled out from phase opposition.
This sounds the most feasible to me, I will try pointing it at different angles towards the dresser.
 

Yoshinat0r

Distinguished
Nov 22, 2010
19
0
18,560
yea no repositioning of the subwoofer is helping. I'm going to have to either try reverb, or resort to bass traps. Though with the way my room is, I think it's going to be difficult to set up bass traps.

http://i495.photobucket.com/albums/rr317/Yoshinat0r/myroom.jpg

As you can see, I have no way of making corner bass traps, since there are windows on both sides that meet the corners. Very frustrating

EDIT: You'll have to excuse the ugliness of the desk, I'm still in the process of building it lol
 

MEgamer

Distinguished
Dec 19, 2009
810
0
18,960
position of the sub wont help. cos corners a corners, theres always gonna be huge bass there, you cuold try reposition yourslef, opposite of the dresser, that wil defintely help.

if thats a no no, then reduce the volume of the bass. using tone controls.
 

anwaypasible

Distinguished
Oct 15, 2007
718
0
19,010
i seen the picture of your room, and you are right.
the size of the room is too small for a reposition of the subwoofer to really help.
when you described that there was pressure build up in only one corner at a time, i thought there might be a chance to simply aim the pressure to a far away corner.
when the room is small like that, the pressure is going to build up faster than it can be released.

there really isnt a whole lot acoustic panels can do for pressure.
they are ment for decibel levels, not the air pressure in the room.
it isnt impossible to use acoustic panels for pressure, but they arent marketed with the specific description of being pressure absorbers.. at least not for audio.
the material is very different, as it feels totally different when you squeeze and compress the foam.
and some might say the foam is very delicate and shouldnt be squeeze and compressed because it wont work properly anymore.

my first thought when looking at the photo was to use some acoustic blankets.. and fold them in half into the corner.

megamer is right, when the room is smaller than the pressure, a corner is a corner.. and because the soundwaves bounce around extra inside that area, the pressure builds up.
your cheapest and easiest option is to use polyfil in the corners.
it isnt the worst thing you could do, since using the cardboard would probably be more obnoxious.

if you are a bit questionable, go grab ONE bag of polyfil (the ones that are about the size of a pillow) and hold the bag up into the corner.
my instructions for you are:
pull the whole thing out of the bag as a solid piece.. then use whatever you want to wrap around and tie the polyfil to hold it together.
you are going to need probably at least six bags (three on each side).

the polyfil has the best chance of working because the material will absorb the air pressure and slow it down.
that is what the polyfil does inside speaker boxes.
so your ringing at 80hz might drop to 60hz or 50hz or 40hz
depending on the material, it will either drop the frequency or stop it completely.

the bass traps are going to do exactly what i said, create a cardboard (or wooden) panel with an acoustic material over the front.
maybe you choose these because they look more simple and 'professional'
but
pressure inside the room is caused by the number of soundwaves that do not cross paths with an opposite phased soundwave to cancel eachother out.
putting a bass trap in one corner isnt going to solve the bass in another corner.. that area will simply be adopting a new reflection that helps FORCE the soundwaves to bump into eachother in opposite phase.

your room isnt empty.. and that is why when you put the subwoofer some place, the one corner doesnt build up pressure.
there are physical objects preventing the soundwaves from 'floating' into that area.
so with that said,
an empty room would probably need a bass trap on one corner, and another bass trap on the opposing corner for the first bass trap to really reduce and do its job.

soundwaves work the same exact way a cue ball bounces around the rails on a pool table.
so if you feel a bit confused, check out some videos or tutorials about using the rail to bounce the cue ball.
and to finalize the small tutorial, imagine every time the ball hits the rail there is a light inside the lights up.
if you throw the ball into the corner and it bounces directly into the other corner.. that means there are TWO blinks in the one spot.. and that is how you know there is extra pressure built up.


something else that is sure to work..
if you hang the appropriate density material on half of the window, then put a rod up on the wall with some screws.. lay some more of that material on the rod...
depending on the thickness of the material will determine how much the sound pressure moves it.
those curtains look like the pressure will go right through it.
if you make the corner soft enough, the pressure will go down.
the only problem is finding the right material that does the job.
you would have to go to a fabric store to choose the right density.

something like wool will be enough to 'catch' the pressure without going through it.
but
it is too heavy when it hangs, and it will stop the process of absorbing the pressure.
sometimes wool is really heavy, and other times it is medium.. and it also comes in light.
the heaviest stuff isnt going to help you much.
the other two, well if you put rods up and leave slack in the fabric between rods.. you could build it so that there are extra rods for the window, connected to the main 'junction' on the wall.
it could actually look very fashionable.


sometimes the fabric vibrates itself loose and doesnt work as good, you would need to starch the fabric to get it stiffer again.
otherwise, you would have to use diffusion panels.. and if the blocks aren't setup well enough for the frequency you need.. it is going to look 'professional' but sound like a failure.
because the pressure can hit the diffusion panels and create a little cloud inches away from the panel.. those two panels would each have a cloud that meets, and you would have pressure again.

the audio pro's would probably tell you to point your direction towards diffusion panels.. but as you said, there are windows there and you dont really want to put up some stiff material that is going to make the windows being there seem totally stupid and pointless.
with the fabric.. you could stitch a loop in the fabric by simply grabbing the fabric in the middle.. pulling it backwards until there is some fabric overlaping, and sew it or staple it together to form a loop that the rod goes in.
this might allow you to push the fabric out of the way to view out the window.
or
put the rods on a wood strip, and connect the wood strip to some hinges.. and the hinges connect to another block of wood on the wall that is used for the other rods for the other wall.

maybe some 'dickies' brand fabric (not the denim.. but the docker type fabric that comes in solid color dress pants that people wear for work)
maybe that fabric is enough to catch the sound pressure.. or maybe you need two of them back to back.
(only supposed to give you a rough idea of what a light fabric can feel like while being dense enough to capture some air pressure)


how much pressure, and the character of the air in the room.. these can make a person like me have some difficulty selecting which fabric is going to be close for the requirement.
and if you dont watch what happens each time you try, you might prove to fail more times than succeed.

you know.. if you wanted to put the corners into a stop sign shape.. you could always put the things on hinges and swing them open to look out the window.
you would have to go above the receiver and above the computer tower.. but if the pressure was coming from the side of the computer tower and not the corner.. you should be able to get your face close to there (or use a paper towel roll) to determine that the pressure is really bouncing from the computer case and not the corner.

you could also try some cardboard across the top of the room where the wall touches the ceiling.
my living room has that, and it prevents the buildup of pressure, not so much the dB.
i mean, the dB do go down because the panel shoots soundwaves into the path of other soundwaves.. and the 'injection' is in a downward direction.
that forces the reflections to go downwards instead of lingering up by the ceiling.


to understand what the speaker is doing to the pressure in the room..
imagine the entire wall suddenly shoving itself 1ft inwards and scooting your desk backwards.
the air in the room will have no where to go, and it might make your ears pop like traveling up a large hill.
maybe close the door to help stabilize the pressure, or open it to let some of it out.
some might say the speaker cone is too big, and the cone moves in and out too much for the room it is in.
you dont need pressure to hear it.

**edit**

that is a gorgeous photo by the way.
 

Yoshinat0r

Distinguished
Nov 22, 2010
19
0
18,560
So i suppose the first thing I could try is buy this polyfil and put it in the corners? I'm not sure what you want me to do with it after tying it up, do I just stuff it in the corners all the way up to the ceiling?

something else that is sure to work..
if you hang the appropriate density material on half of the window, then put a rod up on the wall with some screws.. lay some more of that material on the rod...
depending on the thickness of the material will determine how much the sound pressure moves it.
those curtains look like the pressure will go right through it.
if you make the corner soft enough, the pressure will go down.
the only problem is finding the right material that does the job.
you would have to go to a fabric store to choose the right density.

something like wool will be enough to 'catch' the pressure without going through it.
but
it is too heavy when it hangs, and it will stop the process of absorbing the pressure.
sometimes wool is really heavy, and other times it is medium.. and it also comes in light.
the heaviest stuff isnt going to help you much.
the other two, well if you put rods up and leave slack in the fabric between rods.. you could build it so that there are extra rods for the window, connected to the main 'junction' on the wall.
it could actually look very fashionable.
Sorry, could you elaborate on this further? I don't understand what you're suggesting. Where do these rods go exactly on the wall? And what do you mean by the main junction of the wall?

the audio pro's would probably tell you to point your direction towards diffusion panels.. but as you said, there are windows there and you dont really want to put up some stiff material that is going to make the windows being there seem totally stupid and pointless.
I don't mind if I can get away with only covering the top-half of the windows with the panels. I'm not concerned with being able to see out the entire windows, I just want to be able to open them in the summer so some air can get into the room.

http://i495.photobucket.com/albums/rr317/Yoshinat0r/mywindow.jpg

The windows are very tall, so I can easily lose the top-half and not really care.

you know.. if you wanted to put the corners into a stop sign shape.. you could always put the things on hinges and swing them open to look out the window.
What do you mean put the corners into a stop sign shape? Sorry I know absolutely nothing about any of this :(

you could also try some cardboard across the top of the room where the wall touches the ceiling.
my living room has that, and it prevents the buildup of pressure, not so much the dB.
i mean, the dB do go down because the panel shoots soundwaves into the path of other soundwaves.. and the 'injection' is in a downward direction.
that forces the reflections to go downwards instead of lingering up by the ceiling.
So I would just tape cardboard all along the top of the walls and that might solve it? Does it matter how thick the cardboard is? I have a lot of spare cardboard, but it is rather thin, like 1/2 cm

that is a gorgeous photo by the way.
If you mean the one on my monitor, I just randomly found it on the internet, but yea, it really caught my eye and I just loved it :D
 

anwaypasible

Distinguished
Oct 15, 2007
718
0
19,010


to the ceiling probably isnt needed.. only the space where your ears are, but also a little bit higher to keep the pressure from finding its way building up in that area again.
(give a little bit extra on the upwards and downwards area of all your listening position, including when you lean back in the chair and the chair tips back)

this is a typical square room shape:
http://www.teach-nology.com/worksheets/early_childhood/shapes/square.gif

this is a typical square room with bass traps:
http://upload.wikimedia.org/wikipedia/commons/b/b8/Vertex-transitive-octagon.png

reverb is a crazy thing.. you could use one speaker on ANY of those walls and the sound would appear to be coming from any of the walls.
if the speaker is on the left, sounds on the right could be much weaker.. and that means the 3d effect is broken.
a speaker on any two of the colors facing opposite of eachother and the sound can appear to be coming from any wall.
if i put an empty grill on the wall and another grill on a different wall with a speaker behind it.. you wouldnt know which grill has the speaker behind it unless you were close enough to hear the actual speaker.
that is the power of reverb, and if you used it with your sub you could get some of the pressure to cancel out in the corners.
but
your subwoofer might not be able to handle all of the reverb.
making those 3d sounds in the stop sign shape is a lot more easier than forcing the pressure to do something.

anyways..
if this picture was like the photo you took of the room .. the window rods would look kinda like this:
http://i54.photobucket.com/albums/g95/anwaypasible/rods.png
the black is the rod
the red is the 'junction' that i was talking about (on the same wall as the front speakers)
the yellow is those curtain rod pieces of metal that are usually metal or plastic and shiny.
with a hinge on the red part, you could swing the far left and far right rods (not the straight rods) .. those could swing back and forth to give you access to the windows.
and again, you dont have to go all the way to the ceiling.

with the fabric on those rods .. it would look something like this:
http://i54.photobucket.com/albums/g95/anwaypasible/curtain.png



..and..
i wasnt talking about the picture on the monitor, i was talking about the picture of the entire room.

**also**
the rods with the yellow 'globes' on it.. those would attach to the wall like a towel rack (or towel rod if that is what you call it).
it is a bar with a connector on each side.
the bent rods would only have one connector, and that would be near the red line.
 

anwaypasible

Distinguished
Oct 15, 2007
718
0
19,010
forgot to mention..
you would have to cover the bottom half of the windows to help your ears receiving pressure.
doing the top half is only going to adjust the problem a very small amount (if any at all)

if i was you, i would consider putting the desk on the wall with the door.
then put the sub under the desk and open the windows to allow the room to bleed out the pressure from the windows and doorway.
but
there are alternatives, and those are all spoken about above.

**edit**
and geez, if you are really desperate, put some air in some balloons and dont fill them all the way.
put some of those in the corners.
i dont know if it will work as good with only one balloon going down the corner.
you would probably put one balloon on one wall, the other balloon on the other wall and make the balloons touch to fill the corner.
they are giant diffusion panels kinda.
but
the property they have over junk diffusion panels is that the balloon can actually get pushed in by the pressure, AND push back with the wave as it goes up and down (pressure goes up and down).
technically, it is supposed to lean in and shove the pressure towards the middle of the room.
but
with two balloons in the corner..
some of that pressure will get shoved back, and some of the pressure will go into the gaps of the balloon to really help.
see
only one balloon will get pushed in by the pressure and stay there on the 'push' wave.
on the 'pull' wave, the balloon will push back and could cause the problem to grow worse :lol:

you could actually fill them up with enough air precisely until the 80hz is gone.. but you might have a new frequency, and the balloons will lose air.
i really dont recommend using only one balloon.. because the problem has a lot of potential to grow.
the simple shape of the balloon can cause dispersion of the pressure and might alleviate enough of the pressure to make your ears stop getting tickled.
but
the two balloons are better.
you have to try both ways:
1. the balloons are supposed to not be full of air, so you should be able to smash them together to hide the corner visibly.
2. the balloons still are not full of air, but you can see the corner with gaps from the balloons not making full contact.

one of them two will provide the superior result over the other one.
and maybe a bag of balloons is cheaper to test my truth.

unfortunately, i have no idea how much pressure is in your room.
so if the pressure is really high.. the balloons are not going to show a huge improvement, and that is because your subwoofer output is way too much for the room size.
it will work for decibel accumulation, and that means it CAN work for pressure too.. but pressure is a beast compared to decibels.

the fabric should be an equal beast for the pressure.
the polyfil will probably come in second.
and the balloons come in at a far last.


the cardboard has to withstand lots of flex.
i have some twelve inch woofers that can provide enough air to blow out a cake full of candles.
i used cardboard to cover the midrange holes when i took the midranges out.
i used three layers of pizza box with screws going into the screw holes of the speaker cabinet.
it works just fine.

for the top ceiling cardboard.. you could use whatever to get the thickness of a single piece of pizza box cardboard.
but
two would be better.
three is probably overkill.

you will need to glue them together.
and if you do, dont use a scribble like you would do for ketchup or mustard.
you want to smear the glue across the whole thing like you are painting some nails or a wall.
it will keep the cardboard stiffer, most importantly, and it will also keep it from rattling in the future.


just be warned..
dolby and dts dont work for corners like that.
and if they do, stop! (wait until we have rooms built in the octagon shape before you start to entertain us in such a way.. and tell us the shape so we can select it like a DVD menu option)
 

Yoshinat0r

Distinguished
Nov 22, 2010
19
0
18,560
So basically, gathering from what you've said, this is what it all comes down to:

- Bass traps aren't the best idea because they aren't specifically designed for pressure, but rather for the decibels of the bass?
- The fabric/polyfil will probably work well but I have to cover both top and bottom of the two windows.
- Balloons could work but it isn't guaranteed and frankly I'm not sure I would want balloons just randomly sitting in my corners lol
- Programming reverb is hard and might not give me the results I'm looking for

And I couldn't really "move" this desk anywhere, it is huge, and it's all connected and extends all the way down the side wall

I guess I'm screwed unless I want to put a lot of work into making these fabric rod inventions with hinges. Also one thing I have not tried is pointing the sub at the ceiling, but you said my room is simply too small for the output of the bass, so it probably wouldn't matter :sarcastic:
 

anwaypasible

Distinguished
Oct 15, 2007
718
0
19,010
your ears have a height level.
and when you move your head, those height levels should be calculated too.
using anything long enough, you can touch your ear and the wall to get an idea.
then 3 - 5ft extra from that point in both directions.
you said your room is 8ft tall.. so i am thinking you will want from the receiver up, and from the desk up.
maybe you leave 2ft of space between the ceiling and the polyfil.

and yes,
bass traps will block the corner to prevent the tight squeeze that allows the pressure buildup.
that pressure will go someplace else.
bass traps should come in different widths.. so if the width isnt wide enough, then the corner technically still exists.

not everybody is going to say your room is a nightmare, they will look at the cause of the pressure.. and that is the subwoofer.

with the sub facing the ceiling.. the wall to ceiling corners would be the primary source of pressure.
then the wall to wall connections would be the secondary source of pressure.
usually the floor to the wall would be secondary, but you have lots of things in the way to prevent the pressure from 'floating' or 'bouncing' back to the floor.

maybe that is enough to get the pressure out of the corners though.
hard to know if it is absolute pressure or accumulated pressure.
you say both corners can be excited at once.. but didnt say anything about the other corners being excited at the same time.
and you also didnt say anything about the port of the subwoofer allowing you to turn it on its back.


i would simply say..
if the pressure is bothering you, the subwoofer might have too much power going to it.
and less watts with a bigger box ported to 20 - 25hz would mean you still hear the bass, but without all of the pressure.
this may not be the answer for you if the problem frequency is 80hz
and
you shouldnt have your subwoofer crossover that high to begin with.
but
with those tiny speakers, i can totally see why you would want to leave it at 80hz since the bass from those speakers isnt going to be much.


programming reverb for a subwoofer IS really hard.
because there isnt any reverbs out there that are ment for the LFE channel.
if my memory serves me correctly.. the creative x-fi reverb is for front/back/center+sub (or only the center?)
i dont have a picture of it and i dont have the software installed (my card broke).

why not use an equalizer to lower 80hz ?
or
since most crossovers are 12dB slope per octave.. why not lower the crossover a little bit and let 80hz play with a rolloff?
 

blackhawk1928

Distinguished
Jul 15, 2008
236
2
18,860
Seems like you have the situation handled, but your problem is very likely due to poor room acoustics. Also, if your subwoofer has the option of phase (either normal or reverse), try both and see if it makes a difference. May I also ask what kind of subwoofer you have?

Also, unless your sub is very weak, I recommend keeping it away from the very corners, yes bass will sound louder and deeper due, but will also sound more distorted and muddy which my ears hate, while putting it away will give you cleaner, more undistorted bass that (for me at least) feels easier on my ears.

I don't know if anywaypasible has covered what I said above, just mentioning it. The distortion from bass is what kills me, it sounds like really loud farts which gives me a headache after a while. To prevent distortion, make sure you have a good source...which means good cables, good source (either lightly compressed mp3's or .wav CD files) and and no analog connections. Oh yeah...and if the sub is passive, a good amp obviously.

Not sure if it will fix or if this is cause of your problem but its what did it for me.
 

MEgamer

Distinguished
Dec 19, 2009
810
0
18,960
phase only makes a differnece, if it is being crossed over to a mains speakers, or is palying together with another subwoofer....

on its own the phase doesnt amtter, cos when sound waves reflect, its waves becomes out of phase by 180 degrees, this is the same with all waves, NO MATTER what phase you project the sound waves in. (this is only on hard surface though)
 

MEgamer

Distinguished
Dec 19, 2009
810
0
18,960
really??? i get know difference unless i have the rull range playing with it, like at 80hz frequency which is the centre of teh cross over frquency.

by the laws of physics, phase should make no difference to the perceived sound, when its the only source available.in other words wave pattern of superimposed waves, should be exactly the same.
 

blackhawk1928

Distinguished
Jul 15, 2008
236
2
18,860
Well...on the system I'm talking about, the sub has a cut-off at 200hz (yes I know its high). and I've got another sub also. When I make the phase to reverse, the bass is extremely concentrated in the front corners and the middle gets almost no bass, while when phase is set to normal, the bass is much more equally distributed around the entire room.
 

anwaypasible

Distinguished
Oct 15, 2007
718
0
19,010


that is exactly how it is supposed to work.
if you have lots of acoustics on the outside perimeter, then flipping the phase will make the inside of the room more acoustical.
it is simply a matter of in and out, and where the in's are as well as where the out's are.

yes, the pressure is going to be in the corners again..
but
when two soundwaves come into contact with eachother, they can cancel eachother out..
or
they can increase in amplitude.
it should make obvious sense that the waves making contact in the middle of the room are touching eachother in a way that is canceling out the sound.
thereby flipping the phase, those soundwaves would then do the opposite.

accumulated pressure is and remains accumulated pressure within the room.. that fact can keep the corners 'air-y'
and the only way to move the pressure someplace else is reverb.
sometimes the reverb isnt powerful enough to stretch out long enough that is needed to pass the corner and continue into the middle of the room.

it is a jigsaw puzzle without visual indentification.
but
you can kinda get a glimpse yourself if you realize that the cone pushes outwards and the air is like a gelatin.
the wave will go out in all directions, and the center of the wave depends on the dustcap.
the outside of the wave depends on the shape of the cone indent.
some speakers have a completely flat cone (some old precision power subwoofers)
and even still, some subs have a much less curve.. like the jl audio w7


megamer would be right to argue when the problem is tickled ears from too much pressure.
decibels are not the same as wind that can blow out a candle.
the difference in size is humongous for sound pressure.
some speakers can spit out decibels without moving much at all.
and those speakers rely completely on the tune of the box to play lower notes.
sometimes these subwoofers dont have the box tuned right, and the subwoofer cone belches in and out (and is often pushed extra until the speaker bottoms out - or the voice coil frys)
this leads to the pressure problems.. and a whole lot of bass you can feel, as it rattles the windows.

some people consider an elegant system to be one that plays all the notes, but doesnt do it with a lot of window shaking power.
this means much much bigger boxes, and can have the benefit of less amplifier power.
pretty much how they did it in the 60's and 70's
but
i think the 70's introduced more speaker cone excursion, with enough that could rattle a window.
probably those giant paper 15 inch woofers with the 'newer' foam surround instead of the paper accordian type.
and then there was still people who had 15 inch woofers with the accordian surround, but there was more ability to move in and out.
some people went to theater type speakers (or concert speakers) because they were larger and could play the bass to keep up with the competition.

then in the 1990's..
speakers like cerwin vega really pumped up the box to speaker cone excursion ratio.
they would belch out bass.

then in the mid to late 1990's the dedicated subwoofer came out for dolby digital.
the industry has been pushed forwards towards the dedicated subwoofer ever since, and it seems like only a rare few ever look back.

i tell people pretty quick and simple.. no matter if your room has 15 inch woofers for the front/center/rear speakers.. the dumbed down audio mastering is still going to put some bass on the LFE channel.
it could be a copy of what goes onto the front or center channel.
and
it could also be something specific to make your room shake.

it should be expected that one day we will have the proper 12 or 15 inch woofers in every single speaker, and there will be tremendous bass that is positionally accurate.. and there will still be 1hz - 20hz (or is it 1hz - 10hz ?) from a very large speaker, or an array of speakers, to specifically build pressure in the room.
it isnt necessary at all when the main speakers are given all of the audio.
and any LFE effects would then be completely digital FX designed to add thrill to the experience.

weaker systems can appear to raise the floor of a room.. kinda like a 3d effect, but done with pressure.
stronger systems can make the floor appear to fall.
if there is a system put in place, the floor could be tilted front to back .. side to side .. back to front.
this could be really cute when watching some jet pilot do manuevers.
or
imagine the floor dropping every moment when the 'bullet time' was activated in the movie 'the matrix'

this is kinda far away.. because people need better dedicated listening rooms.
drywall just isnt going to cut it, as it will crack and bust to be remaining as an embarassment.
concrete works.. and maybe some blocks that have had their inside wall drinking glue.
maybe some type of fiberglass between them.. but i would think the fiberglass would crack too (just not as quick as drywall)

dedicated listening rooms of such magnitude require either going into the basement.. or choosing somewhere in the middle of the house, and put some jacks under the area to support the concrete walls.
but
concrete cracks too.. eventually.
plastic would be awesome if it didnt vibrate.
carbon fiber would vibrate too.. unless you did lots of layers, and that is too expensive.



acoustic paneling isnt going to help in this situation.
the acoustic paneling will not drop the pressure in the room without adhering to the soundwaves and their phase.
you have to realize that there is wind (like from a fan) that needs to be pointed somewhat precisely to get the wave in opposite phase to come into contact with the wave by the acoustic panel.
flat panels wont do it unless they are aimed in all sorts of crazy patterns.. and expect to lose as much as 3ft - 4ft per wall.
diffusion panels can be designed for a specific frequency.. but there is no way of them knowing how big your room is and where the panel is going to go so that they can design the shapes perfectly.
a single soundwave of 80hz is false.
there will be other soundwaves bouncing into the diffusion panel.. and if those soundwaves are 80hz too, then your chances are higher.
but
rooms dont all work like that.


since acoustic panel sellers dont openly advertise their willingness to help people with their room size and frequency.. one could assume that those details are private.
either private for 'industrial' use.
maybe private for 'commercial use'
or
downright private to force custom installers to make their own.


there are waves bouncing from one wall to the opposite wall.
waves bouncing from one wall to another connected wall.
waves bouncing from the floor to the ceiling.
waves bouncing from the wall to the ceiling.

if you wanted 'custom' help..
they would need to know where exactly the panel is going to go, and what soundwave pattern is touching that area of the wall.
that is the only way to do it correctly with perfect results (especially without any reverb).
 

MEgamer

Distinguished
Dec 19, 2009
810
0
18,960


an yes it works like that cos u have another sub. if you have mutiple subs, and switch different pahses for different subs, you will cancel out teh peaks and nulls, you can even control directivity.

but i was tlkaing abouit a single sub. im geussing you only change the phase on one of them.
 
This is standing waves.
An EQ should be used to dump one frequency, the resonant frequency of the room. When the EQ is used to dump that one frequency, the booming will stop.

Also lifting the sub off the floor, and away from the walls, will kill the efficiency.

Standing waves will form in corners, and any room has a resonant frequency. That's why there's EQs, digital or analog, software or hardware. You just subtract the one frequency and the problem is solved.

And yes, low frequency is omnidirectional...which means you can use a single mono sub on any system and it works just fine no matter where it's hidden, located, etc. Lows do not need to be in stereo to maintain a stereo image.