Bass is clearer and more impactful when I stand vs. when I sit

Wow, deja vu all over again! Another guy had almost the exact same question recently. There's nothing wrong with your speakers or your room. What you are hearing is perfectly normal. In order to fix it you first need to understand why it is there in the first place.  

All you are hearing is bass modes. All frequencies reflect off walls and when the reflections come back and hit the wave coming from the speaker they either cancel or reinforce. When they cancel you hear less or nothing. When they reinforce you hear it louder than it should be.  

All that is happening is that when you are sitting you are in a cancellation area, and standing up gets you out of that area. This has nothing to do with the direction the speakers are pointed. High frequencies are short waves and highly directional. Low bass is very long waves and the direction the speaker is pointed is so meaningless many speakers are designed with inward or back firing woofers, and subs can be pointed directly at the wall.  

This happens in all three dimensions, by the way. You notice it standing, but listen, you will also notice it moving to the left or right, closer or further away.

This is why normally the first step in speaker placement is to move around both the speakers and the listening chair listening to bass looking for the smoothest bass response. Don't forget - move both the speakers and the listening chair.  

This also illustrates why placing speakers in a room often requires some degree of compromise  If full range speakers with no sub are used, the spot that generates the best bass response may not work well for imaging and vice versa.  And while a separate sub(s) may free up the placement of the main speakers, there is always that difficult issue of transitioning at the crossover point -- again placement that generates the best low bass may not be the optimum spot for the best transition at the crossover frequency.  

It takes lots of experimentation to find the best compromise for you in your room.

I improved the sound of my listening position by getting a different chair and changing the rake of the speakers.

If you are using as subwoofer? Like millercarbon and mlsstl said, experimenting with the position of both your listening spot and the speakers is the key. If you are using a subwoofer you can also experiment with positioning it's height by putting something under it. 

Nodes.

Yup, nodes.  I had a nasty one around 300hz.  Same thing, could hear it standing up but not seated.

Move your speakers around.  Experiment.  Move them closer to the walls, then further.  Move thrm up and down if possible.  Different stands for temporary testing might be good.  Use chairs or whatever else that you can use as trmporary stands.


Move your listening position around if possible.

I went from being -6db from 30hz all the way to 200hz to 0db to +3db from 28hz to 200hz just by different height stands and speaker placement.

Thank you everyone for your input!

I will try positioning both speakers and chair. May be I will try with chairs first because the speakers are 60k/each, which is too heavy for me. 

@asctim: I'm not using a subwoofer. 

If you need to move your speakers use furniture moving pads appropriate for your floor that allows you to slide them more easily.  After you find the best spot then you can obsess about spikes and such.

+1jc

big changes happen to your frequency response just by moving your speakers.

changes imaging, soundstage and frequency response big time

I'm surprised no one mentioned room treatments specifically? It sounds like a null like others have said and I completely agree with experimenting with seat and speaker position. Just adding that room treatment for bass control might be helpful as well. Depending on how far the front baffle of your speaker is from the front wall certain frequencies will be reflected back to you when the frequency range goes into modal territory. This is SBIR. If your speaker is further from the wall this will become more difficult to treat as the reflected waves are lower frequency. Maybe you could try moving the speaker closer to the wall. Otherwise you may want to get bass traps for the front wall or 3 to 4 inch thick panels. You could also treat corners with bass traps but those are large and get ugly if your space is small. 

I will give you an animation to try to simplify what these gentlemen are trying to explain to you. Room treatment is a bit expensive. But if money is no problem then go for it. It does work.
https://www.acs.psu.edu/drussell/Demos/superposition/superposition.html Two sine waves travelling in opposite directions create a standing wave This is a good example that isn't too hard to understand.
These are the finest. Read thoroughly and check the animations.https://www.acousticsciences.com/high-end-audio/bass-traps
And a mechanical solution that is not as expensive, but is a good bang for the buck is to minimize the resonance by decoupling. Again not perfect but good for less money.
https://isoacoustics.com/Good luck and don't get too aggravated, rooms are the biggest challenge to tame. The information is available on line, and there is many DIY projects that can be found on YouTube that work, and are cheaper.

@quanghuy147 , Do you have carpet on the floor? Wall to wall with a pad underneath?  You have a vertical node problem not a horizontal one.
I have noticed that media rooms with wall to wall carpeting have less of a problem with this. The other solution is to get speakers that do not radiate up and down, vertical line source speakers.

Sounds like you have a bass null at the listening position.  I have the same situation, i.e., there is more bass in my room pretty much everywhere except in the listening position.  The bass is great at the sides and far back of the room.  The problem is that this is a family room(don't have a dedicated listening room) and I can't really arrange the furniture much differently. 

Null, node; these phenomena are caused by standing waves in the room. A standing wave in this case is where a bass note is so long that it is able to reflect off of the wall behind you and cancel itself.

No matter what anyone says this cannot be cured by room treatment using bass traps or room correction using Digital Signal Processing (DSP). In the case of the latter, the cancellation means that you can put nearly infinite power with the same result until the wall behind you collapses. With the former, to be effective the bass traps need to dynamically move about the room as the bass notes change.


The more elegant solution is to use multiple subwoofers arranged asymmetrically in the room. This breaks up the standing waves and you get evenly distributed bass. The trick is to make sure the subs don't go above about 80Hz so as to not attract attention to themselves. Then the main speakers will convince you that the bass notes are coming from them. Audiokinesis.com makes a sub called the Swarm that is meant specifically for this use; its one of the very few I've seen that is designed to be as close to the wall as you can get it and still be flat (to 20Hz), and they are not crazy money.

@atmasphere Thank you for your advice. I just look at the website about Swarm, they are very interesting! I would try it if I had a bigger listening room and get approval from wife :)

This is normal. Over time I’ve realized that a great way to mitigate this is to have speakers that begin to drop off slowly at a relatively high frequency. You don’t want speakers that are flat to 30hz. You want speakers that begin to drop off at 80 hz or so and output slowly decreases from there. You still want your mains to have good sized woofers for the punch they provide. And you want them to have useful output in the deep bass, but it should be at a significantly lower level. The reason is that if you’re down significantly at 50hz the room problems will be greatly diminished. You won’t have a massive peak that overwhelms the room. Get a sub, or subs, to bring the deep bass levels up to where they should be. If you put your full range mains where they’re best for everything but the deep bass and it turns out the deep bass is terrible, then what?

Hi, the other guy here.

I took the advice I received to move the speakers - PMC MB2SE - closer together about a foot each closer to the center, as close as practical to the media unit, and also further forward about 6”. Towed in towards the seating position.

Problem solved.

Positioning was the key.