Bass is too concentrated in the corners of my room.

[Yoshinat0r]

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.

 

[blackhawk1928]

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.

Yes, in my room I've two subs, a larger one and a smaller one, each from different manufacturers also, only one of them has phase control. IDK if this effects anything, but since the amp in my room has only one subwoofer pre out, I've got my bigger sub connected to the amp and then my second sub is connected to through my other sub. So when I make reverse phase it completely changes the areas of where the bass is located.

 

[anwaypasible]

Lows do not need to be in stereo to maintain a stereo image.

the reason why the above quote is true is because the soundwave is long enough to reject pinpoint obtainment.
the same will not be true when the subwoofer plays a subtle change.
could be a small pop or thud, could be transients from the subwoofer.
the frequency will get higher, and the above quote will become less of a fact.

major point to remember,
simply because the subwoofer is playing low notes.. that doesnt mean there are small pops and subtle changes that have the same wavelength.


some soundwaves are long enough that it is pointless to argue that the sound is somewhat stereo.
however, every space further away from the subwoofer has the potential to muddy things up and reduce the clarity.
the picture above from the original poster is a perfect example.
when the subwoofer is tucked away in a far away corner, there will be much chance for the soundwaves to bloom.
they are not the pretty blooming that happens with flowers and plants.
the swelling is obnoxious and false.
dont forget, some speakers have been known to make use of the swelling and only provide their most accurate sound representation if you are listening in that area.
but generally, the speaker sounds like crap anyways.. and you would know it because with the speaker pointed right at you from like 3-4ft .. you could come to the conclusion that the output isnt anything close to reality.
then get far back away from the sub in an opposite corner, there might be some added sound.
it means the speaker cant play that sound loud enough for you to hear it up close to the cone, and when the walls are used, they boost that small output because the ringing of the room helped.


using an equalizer to reduce the frequency is not always the best choice.
because if your ears are in an area that is constantly destroying the shape of the soundwaves, reducing the amplitude of that frequency means the clarity of that frequency is going to drown.. as it comes subjected to the stronger standing waves.
point here.. get a speaker that can play those smaller details more loudly.
and then, if you have a blooming problem at a certain frequency.. using the equalizer to reduce that frequency will be less harmful to the results.
obviously, if it happens once.. it can happen again, and probably will.
but
your chances of maintaining something that resembles clarity is higher because the tone is heard louder.



the putting the subwoofer up off the floor is cheap and easy advice.
but
with the cone up higher, it will be louder.
since the cone is up there, the muddy pressure will go up to the ceiling and down to the floor.
could provide less pressure at ear level.. and objects in the room could totally ruin the attempt.


when you break it down to the most simple factors..
it is like there is a complaint about wind blowing.. but the person complaining refuses to turn off the fan.
the wind is air simply moving.. not that the wind is blowing directly in your face.
like trying to light a candle but the flame keeps going out because there is a breeze.
not because there is a fan pointed directly at the candle.
the subwoofer is too much when combined with the resonant frequency of the room.
since the room is already ringing at 80hz .. you could lower the crossover to like 70hz or 60hz and lose some audio clarity at 80hz.

maybe you could get some drink carriers from a local fast food place.
put those along the wall with the speakers mounted.
with the edge of the carrier touching the window (slid far to the edge of the wall) .. it might reduce some of the pressure.
see, the pressure will reduce if you force the pressure waves to slam into eachother and cancel out.
but
it is a lot of work.
you can also scatter the soundwaves, and that is like taking a solid object and smashing it into lots of tiny pieces.
the drink carrier might be able to scatter the pressure waves enough to stop the ear problem.
the poly fill scatters the pressure waves too.. but it also holds onto the air longer.
the only chance the drink carrier has to hold onto the waves is in all of the spots that have holes (and the material that blocks your view of the wall)


i really wouldnt want to reduce everything with an equalizer unless the speakers are pointed directly at you.
when you are listening to the walls of the room, that is what you hear.
you can point the speakers directly at you and try to cut your way through some of the sounds bouncing off the walls.
but
without reverb, your results will be much lower.

as of now..
you have like all of the tricks in the book available to you.
it is up to you to start trying them out and come to the conclusion which one is the best for you.




one more thing you could try..
get a beach towel and tape it to the ceiling so it is parallel with the wall that has the speakers mounted to it.
leave about 2 inches between the towel and the wall.
that should help too.
lot easier than mounting the fabric rods.. but it doesnt look as nice or 'professional'
and sometimes getting a towel to hang from a ceiling is a real pain.
tape probably wont work for long.. and if it does, it is going to pull off the paint when you are done with it.
you could get some hooks that screw into the ceiling.. and these would probably last for a long time if the threads are big enough and the drywall/plaster isnt crumbling.



i cant hang anything on my walls in the apartment i am in.. so i had to take the impulse response of the room in combination with an equalizer.
you do something like that and you will see that you will once again have pressure.. but at a lot more frequencies, and obviously the volume would have to be louder.

 

[Yoshinat0r]

Thanks so much for the replies guys. To me, this is a crazy amount of information to try and process :lol: But I was wondering if something like this has a chance of solving my problem:

http/www.diy-home-theater-design.com/bass-trap-build.html

It looks simple enough to build and it seems like I have just enough room to put it in the corner to my left where the bass is being concentrated.

Do you guys think this would be a good thing to try, or should I stick with trying the polyfil with the rods and stuff?

 

[blackhawk1928]

Well I really don't specialize in bass traps, but I do know that room acoustics make a huge difference in sound quality, if your room has poor acoustics, there will be spots with extreme amounts of bass and other spots, perhaps a few feet away with virtually no bass. Perhaps bass traps can help, i'm not sure about that at all.

 

[Yoshinat0r]

That's exactly what happens. When I walk around my room while playing a bass tone, some spots are super concentrated while other spots it disappears entirely.

I mean, when I bought my sound system, I never even thought to consider stuff like this, because I didn't know about any of it. I didn't know about my room being too small for the sub, or having to acoustically treat the walls

 

[blackhawk1928]

its not really about room size its about acoustics, different types of materials and surfaces absorb or reflect sound waves causing uneven and weird sound effects in a room. If you have lots of furniture in random places in the room, lots of stuff on the walls like paintings, pictures, and other stuff, they can either reflect or absorb the sound which can potentially ruin directional projections.

For example, if you want surround sound in a room with poor acoustic handling, a sound that should originate from for example, the Front Left speaker, will reflect off the other side of the room and reach you from what seem to be the Rear Right speaker, which messes up the surround effect. Thats why you generally want sound to be absorbed throughout the room, so its not reflected. Acoustic treatments make worlds of a difference.

 

[anwaypasible]

you are steering the situation towards a room that has no ability to use the dolby surround format, much like i was.. but worse.

yes, acoustic panels all over the walls and the ceiling and floor will reduce the impulse reponse, as well as the soundwave bouncing from wall to wall.
but as i said,
you cannot get 'virtual speakers' without using the reflections.

corners will always accumulate soundwaves without any digital sound processing.. unless you put something in the corner to block the tight pinch.
round tubes are a pain in the butt to try and calibrate reverb with, since the soundwave can go in many directions because of the round surface.
that is why the bass traps use a simple flat edge, because the reflection is easy to predict.. and if you have calibrated some reverb, you wont lose all of the calibration because you created wind when you reached into the bag of popcorn and brought the popcorn to your mouth.
or because you were laying on a couch and decided to move to get more comfortable.

put two 15 inch woofers in there with 1 inch excursion each.. 500 watts each, and if those speaker cones are moving 1 inch each.. you will see that there is too much pressure without any steering.
if you keep it up, you could break a window.
might start with a crack.. or the window flex is high enough to eventually cause the window to shatter.
no amount of absorbing soundwaves is going to fix that, unless you are trying to absorb the soundwave from the subwoofer before it has any chance to send the soundwave to the wall.
and even then.. if the output is high enough from the subwoofer, you will start to see problems again with the further away the absorbing attempt is made.

you cant soak up everything, because then you wouldnt hear anything.
it is like trying to ride a bicycle without holding onto the handle bars.. you dont wanna fall, you need to grab hold of the controls.


my thoughts on the sand filled tube is this..
the only reason the sand is there is to deaden the thud from cardboard flexing.
if the thing is in the corner and the cardboard is allowed to vibrate, then it is going to sound like you can hear it.
that isnt why you put it in.
you add the sand until one of two things happen:
1. the sound from that space of the room is dead
2. you cant get the thing to sound dead, so instead.. you add/remove sand until the timbre of the sound matches the timbre coming from the speakers.
the whole concept is ment to do one of two things:
1. provide some sound deadening for the corner of the room, usually because the corner is blocked and the soundwave reflection pattern hits the round tube and scatters everywhere.
2. provide a cheap way to put a 'virtual speaker' into the room.


i think this is hilarious..
because what turns out to be an inexpensive corner bass traps was also a very expensive trick to widen the soundstage.

say for example you have two speakers in the front and want the sound to appear 'wider'
usually these tubes would be recommended as a cheap alternative to redesigning the entire room.
you could twist the front speakers in such a way that the reflection from the rear wall would bounce forward and hit the tube, and then bounce towards the listening position again.
sometimes you needed to have a board on the back wall to help point the soundwave to the tube.
and you would have to move the tube until the soundwave hitting it would bounce at the right angle so the listener could hear it.



apparently the original poster doesnt seem to think the sound pressure is enough to make any difference.
tickled ears from sound pressure isnt going to go away without pointing it at a place in the air where it can be extinguished.

that is like saying you have a room full of newspapers stacked up along the walls.. and there is a plastic swimming pool holding water somewhere in the room.
a person hands you a flamethrower and says 'dont catch any of the paper on fire'
meaning.. you have to aim at the water ONLY.

there comes a time when you put that round thing into the corner after you were complaining about hearing bass from the corner.. and it only makes it worse.
depends on how the soundwaves hit the left side and the right side of the tube.

when you are complaining about a corner.. it is like there is a lightbulb in the corner shining.
you say 'i am trying to look at the screen and dont need the light in the corner of my eye'
so naturally, you want the light bulb to get much dimmer.. to the point of going out completely if needed.
and without any care, you put the tube into the corner and see that the light from the bulb actually gets brighter (or stays roughly the same).

when you start dealing with digital sound processing.. it works like this at the beginning..
you have a dim light in each of the four corners.
you mess around with the settings until the light is moved from the corners and is put into the space of the middle of the walls.
that means there will be light at the middle of the wall and it will slowly fade out as the light gets closer to the corner.
if your digital sound processing was more advanced.. you would take the light and force it to move to the center of the room where all four come into contact with eachother.
then you have the option to try and force the light to die, or you could seperate them a little bit until it looks like a number four on a piece of dice.. and then adjust the position until your head is in the middle of those four dots.

pre-programmed digital sound processing, or because there is furniture in the way, can cause lights to form again.
they will be less bright, but inevitably there.
some sound absorption can keep those lights from re-appearing, but the absorption will also make those lights in the middle of the room less bright.

it means you need more power from the amplifier, more power handling from the speakers, and lots of detail pumping out of the speakers... because speakers that sound really good in a room with no carpet are going to sound like complete trash with all of their flaws revealed when you put them into a room with lots of sound absorption.

meaning the price of the whole setup is going to go through the roof.
it is bad enough as it is nowadays, you get a speaker and you dont know if it is going to sound better in a carpeted room or a bare room.
once you take it away, you shouldnt expect to get it back.
bare room reverb can be custom programmed to form the timbre in the air space.
all peaks and dips can be eliminated, depending on programming intelligence and processor power.


it helps to know if the phase of the sound from the corner is 0 degrees.. 380 degrees.. or 180 degrees.
BECAUSE the phase that leaves the corner is going to be coming into contact with the soundwaves between your ear and the corner.
you design some reverb that puts 180 degrees of phase spewing out of the corner, and then run a line of soundwaves between your ear and the corner with 0 degrees of phase.. when the two come into contact with eachother, they will cancel out and you wont hear much of anything from that space in the air.
it gets pretty simple tricky...
if 0 degrees bumps into 180 degrees in a head on collision.. there will be no sound at the spot they collide.
if 0 degrees t-bones into a 180 degree soundwave (hits it directly in the side) ... then the sound will be cut in half.
just think of it like ripples in the water.
what happens when you push down on the water in a tempo'd pattern while you are in the tub?
the water will run to the edges and violently splash.. and in the corners, the water will probably go out of the tub.
if you get your timing right.. you can get the water in the corner to fly straight up and even fall back into the tub more than it splashes out of the tub... meaning it goes up and falls inwards.
lots of tubs have the rear corners angled so you can lay back.. and those arent the corners i am talking about.
you would be lucky to see the water in that corner go straight up into the air and fall back down straight.


sound absorption panels are not supposed to stop reflections, but they probably do a mighty fine job of slurring the reflection angle.
just about anything that sits on the wall and continues to allow the corner to keep its shape is not going to help eliminate the sound coming from the corner.
cheap materials will help a little bit.. the more expensive stuff will bright the audible level down lower, but wont stop it.
must re-shape the corner or use digital signal processing.
the fabric on a rod idea is supposed to work like a spider web.. the web is invisible and lets the insect clumbsily find their way into the web, and once it makes contact.. it is probably stuck there for good.
same with the fabric on the rods.. it lets the soundwaves linger into the corner, and instead of allowing those reflections to happen.. they hit a really soft spot and die.
doesnt always work 100% .. but as long as the pressure and soundwaves isnt blasting right through the fabric, the success rate is guaranteed.
that is why i said it is important to get the fabric right.


i mean,
you could try the tube, it will do one of three things:
1. completely work
2. sound exactly the same
3. make the sound from the corner worse

the professionals would want to know exactly what the shape of the soundwaves are in the corner before they start to sell you something.
that is how they go to their shelf and pick the least expensive product that is going to work.
it saves them money from not wasting anything.. and it makes them look good because it works.

i am no professional.. but i am consciously aware, just not as consciously aware as the pro's.
any professional that recommends a bass trap is being a punk.
they dont know what angle the soundwave is hitting the corner, and that means they dont know what angle the soundwave is going to be hitting the bass trap.
and to try and save their butts from being wrong and looking stupid.. they put some sound absorbing material on the face of the bass trap.. making the cost of the product go up like 3 or 4 times (maybe more).
you would hate to put a mirror in the corner and turn your head to the corner and see the subwoofer staring you in the face. (of course you would need a mirror on the other wall too but, that is how soundwaves work.. although sometimes the angle is a bit off).

i would tell you to try the tube if you want to.
but if you dont fill it with sand, the cardboard can vibrate.. and the sound wont be as dead as it could be.
and with that said.. the reflections that do bounce off of the tube without any sand, they will be increasingly sharp with more sand added (because the cardboard is more resistance to vibration.. as if to say, the cardboard is harder)

i dont know where you are going to put the tube.
if you cut it so that it fits on the shelf your receiver is on.. that is gonna be like 20 - 30 lbs of sand probably.
hoping the shelving unit can hold all of the weight.

things get a bit simple again too..
because if you put sand in the bottom and pack it tight.. you can get a gradual rise in the cardboard vibration.
that means the very tops of the tube can be allowed to vibrate up by the ceiling and make the sound appear as if the entire wall is talking to you.
and back in the day.. that is what people paid for when they hired somebody to calibrate their system.
the installers would be construction workers who constructed the room until the desired effect was made.

common requests would be:
make it sound like the whole wall is talking
make it sound like this mantel in the middle of the wall is talking
make the back wall stop talking
make it sound like the dome in the ceiling is talking

these requests are all forms of pleasure that dates back to the roman times with their cathedrals.
each request is like asking them to build a miniature cathedral.

any of the professionals should agree, if you have a problem with a corner.. change the shape of the corner.
and your room has those windows there, so it makes every 'corner change' a pain.

people with a clear knowledge of today's technology would tell you to change the signal timing with a digital signal processor.

see.. the cone moves in and out at a set speed for each frequency, but the reality is.. the cone could be moving slower or faster than the frequency and suffering from overtones (usually because the room is supposed to help).
people can get in there and tell the speaker to move faster if the speaker can handle it.. or slower.. to try and change the soundfield in the room.
chorus does something like this with their oscillation and echo.
except.. the echo works by slowing down the signal, and using pitch-correction to keep the audio the same pitch as it is slowed down.
this continues to happen for a short time, and then the chorus plugin starts to double the output and you hear the echo.
but in reality, you could keep slowing the sound down and using pitch-correction.
eventually your speakers wont handle it, or your amp wont handle it.
it is kinda like introducing a square wave into the signal.. but instead of the top of the square being flat, there is audio information there.
to try and help the speaker or the amp.. you start to introduce oscillation, and that is supposed to flip the phase from positive to negative.
it can keep the voice coils cooler (or safe from short circuiting), and it can keep the amp from being destroyed (again, running cooler or short circuiting - falling/blooming short).

 

[anwaypasible]

i just watched a most beautiful video on youtube that compares sound with and without room treatments (absorbers and diffusors).
you can see and listen to it yourself here:
http/youtu.be/dB8H0HFMylo?hd=1

but as i have already said.. the room full of treatment does not work with dolby digital or dts sound effects. (much of the reason why they have stopped trying to create 'virtual speakers' and simply put a physical speaker there.. and the results come up extremely short)
see.. you could put a 'virtual speaker' in one single spot.. and a physical speaker could recreate that single spot.
but
when the 'virtual speaker' is casting a sound across the length of the room.. there is no comparison, as the sound is fluid.. meaning there are no gaps whatsoever.

a room with no absorbers or diffusion can use spatial technology to make it sound like a lawnmower is running up from behind you.
literally... from the back wall and it sounds like someone is pushing the mower closer and closer to you.

with the absorbers or diffusors, you wont get the same effect.
you would be LUCKY if the lawnmower gets louder and louder to 'tease' the thought of the mower getting closer to you.
but all of the timing necessary to trick the brain into thinking there is a real presence creeping up closer to you.. all of that is gone.

it is an effect.. used to fill in the gaps between speakers and make the surround sound possible.
most times you arent in an atmosphere, and that means you arent in surround sound.

a big difference between having rear speakers and having surround sound.
the word itself 'surround' should be enough to explain itself.
but if it isnt enough.. try the word 'blanket' or 'drown'

it is a bit annoying to see the audio industry trying to push out the tool to every home.. only to have things like room treatments come along and destroy any chance of something special.

i see clearly that the stereo music doesnt have a whole lot of spatial effects.. and that leads to the complaints about the room sounding like crap.
get an equalizer to flatten out the frequency response and you wont be complaining anymore.
the equalizer calibration can translate to the dolby digital and dts audio.
for the dolby digital and the dts audio to work perfectly.. your rt60 times need to be as flat as possible.
but thanks to squared digital sound processing.. those high rt60 times can actually help make the audio echo go away faster.. since it can be designed to use the echo to an advantage.

as always..
a flat frequency response and a flat rt60 is going to keep the timing and the frequency amplitude 'referenced'

you need it to be taking audio seriously.
and it can help with problems in the corners.
since you will either raise or lower the amplitude until all of them are the same.
and then your only complaint would be where the sound is actually coming from.
that is something reverb can conquer.

 

[americanaudiophile]

Just saw this thread so if I repeat something I am sorry.
1. EQ as was suggested. You never mention what the sub is connected to, PC or surround system. If it is a PC then you can use the eq that may be available in the driver for your sound card or playback software.
2. You never mention brand and model of sub. Many if not most subs have a built in peak at 80hz (the port is tuned here) which gives that greatest subjective amount of bass at the expense of quality. The sub may be making the room acoustic problem worse.
3. Try aiming the woofer up to the ceiling. Try blocking the port of the sub. If your sub is bandpass and you cannot see the speaker itself you cannot do this so aim the port to the ceiling. This type of sub where the speaker is not firing directly into the room but ONLY through the port has the worst performance and is to be avoided.
4. Corner traps will have to be pretty big to work and you may not have room. You could try to build a flat panel resonator which can be made from 2x6 lumber and plywood. Make a frame out the 2x6 with the 6" dimension as the depth and cover the front of the frame with the plywood. This will hang on a wall so size to fit. If this works you can cover the plywood with a rug, foam or posters to make it look better.

 

[jacobboe89]

equalizer , cut some bass or play with speaker placement there are some other things you could probably try but it looks to me as if you have plenty of suggestions if your sub is ported and nothing else produces results you might try plugging the port and de-tuning your sub. some people prefer a sealed enclosure for their to sub for sound quality purposes , porting is usualy done increase sound output, sometimes porting increases noise.