So I Have Found A Bass Cancellation At My Listening Spot

[Mister Pig]

I had just gotten my DAC back from service. Installed it into my rack, and while cleaning up my tools I noticed I had nice bass response, and things were sounding mighty fine.

Sit down on my listening futon, and I find that my bass response seems diminished. Thought it could be break in, so give it some time. I then fired the system up this morning, and same series of events. Less bass response at the listening spot.

Now I move forward on my couch about a foot, bass comes back in nicely. Problem is that the soundstage is so panoramic at the first listening spot, its just killer!! So I need to stay at that spot, but deal with this bass cancellation issue.

I am a bit close to my rear wall, and it does have a set of french doors behind it so I cannot block them off. The wall on one side is irregular. I need to find a bass trap solution, and where to locate them.

Anyone got any info to reference?

Regards
Mister Pig

 

[manu et deo]

Do you have the space to add a sub? For ht, I have added and adjusted subs just for this purpose. if that's not what you mean or are looking for please ignore my comment.

 

[Chip Chester]

Do you think it's where you're sitting, or what you're sitting on?

 

[djnagle]

In my old room i had great bass in my listening chair. On the couch to the left .... no bass. At the chair to the right.....way too much bass. If you cant move your chair or your speakers get the Dayton 12" sub and put it on your chair and crewl around the perimeter of your room and at the spot where your head the best bass, that is where you put the sub.

 

[Mister Pig]

Do you think it's where you're sitting, or what you're sitting on?

Imagine its where i am sitying as if i move a foot forward on the couch the bass strengthens, but the downside is i lose a great amount of layering i have in terms of soundstage presenation. Which i want to keep, so I have to fix this null point.

Regards
Mister Pig

 

[djnagle]

Are you up against the back wall? If so you will always get better bass leaning forward.

 

[HTHMAN]

You are experiencing bass nulls and adding a sub will probably solve your problem. I had nulls in my home theater setup until I added and properly placed a second sub. Read up on "distributed bass" if you are not familiar. Probably add it to the B speaker terminals and adjust volume and positioning until right.

 

[ConradH]

It's a law of nature, the listening spot will have either a bass suck-out, or an 18 dB peak. I gave up years ago.

 

[djnagle]

No reason to give up. Use multiple subs and all the nulls and peaks will flaten out.

 

[JLange2010]

I’m a bit of a fan of your posts, so I have a vague knowledge of your speakers. It is hard for me to imagine what sort of sub quality would be needed to keep up with the rest of your system.

Your dilemma seems agonizing, with an ostensible choice between great soundstage or bass, but not both. While I do not have knowledge dealing with the problem, I’m eager to hear of what sort of solutions you discover.

One thought comes to my feeble mind - is it conceivable that the two issues are somehow related? That is, would the increased bass when you move forward possibly create a sense that the soundstage is decreased as a result of more bass, which might create a slight diminishment of relative volume in the mid/treble range? It is my understanding that the upper frequency range is more directional. It thus seems like, hypothetically, cutting back on relatively non directional frequencies could potentially create what might seem like a better soundstage because it would allow for greater emphasis and focus on the portion of the music that is easier to discern where it is coming from.

I have no background in any technical understanding of how audio works, so my apologies if I am asking a really stupid question. But your problem got me to thinking about sound directionality and how it may or may not contribute to soundstage. I know there are a lot of experts here and I hope to learn a little should they choose to respond.

 

[enginedr]

 

[Mister Pig]

Well one of the considerations when purchasing the JBL 4365 is that they would be stand alone speakers. This room is also my living room, and while it does contain stereo equipment, one consideration is to not have it look like an audio surplus warehouse, because my dining room opens into the living room. We have friend over from time to time, and the living room has to have some aesthetic appeal.

So the point being, I am not loading the room up with subwoofers to supplant a pair of 200 pound speakers with 15" woofers. The JBL produce bass deep enough to feel when fed a decent amount of power. I am not dragging RCA cables all the way around the room and over door ways to do distributed bass, nor am I punching holes in the floor and running them under the house.

As I think about this, I did have a single listening chair that I used, but it was an older one where the frame for elevating foot rest broke. I ended up moving a futon couch we had upstairs in the guest room down here for an interim solution. The listening area is about the same, but it might be slightly different. Also probably a different height. I wonder if this is enough of a difference to create some issues. I would think it would be more to the relationship of where I sit versus the rear wall behind me. The problem I got is this arrangement worked before the loss of the previous listening seat, did not have this problem at all.

Now about this rear wall. It has a pair of french doors that I cannot block off. It also has a stepped wall on one side, as this is the boundary to the downstairs 1/4 bath, and it notches into this living room. On the other side of the french doors is where my record rack is, and its an IKEA 4 by 2 standing on end. Getting a bass trap on the stepped wall is easy, but getting one in the other corner where the records are is an issue. And nothing can be done in front of the french doors. Perhaps I can put an acoustic panel on a set of legs and have one I can move into place for an evening of listening.

I suppose the other open is to move the speakers back about a foot towards the front wall, and leave the couch where its at, and see if this changes the bass null. I need at least this distance I got now between me and the horns to keep this beautiful sound stage I have. Of course the front wall reflections might become an issue then. and with a fire place between the speakers, I would have trouble mounting an acoustic panel there. I do remember a friend of mine having a bit of trouble in the bass due to his fireplace, and as I recall he blocked it off and got an improvement. We do not use this one, so this might be an option also.

But the sound stage is fantastic the way things are now. I got this huge spread in terms of depth, height, and width. Some albums that are studio creations the back up singers are three feet in front of the speakers and outside the right wall in terms of aural location. This is not something I want to lose. I just have to find a solution to this bass suck out.

Regards
Mister Pig

 

[fredgarvin]

Sometimes tipping the speakers back, even as little as 1/4" can improve bass nulls.

 

[HTHMAN]

Have you tried moving a little closer and moving your speakers a little closer together or moving back and spreading the speakers a little furtherbapart so you maintain the same listening angle. After all, they are only 200 pounds, Easy enough to move around to experiment.

 

[noise gate]

If I understand correctly, when you leaned ahead, the bass came back.
Did you skid your Futon ahead and try listening in that spot to see what happened?

I've experimented with all kinds of speaker placement & listening positions. One thing I really noticed was finding a good position in a room can be totally messed up depending on how high the back of your chair/ couch is.

The difference between a low, mid height, and high backed chair can work just like a wall behind your head. It's covering, fabric, or leather/vinyl can affect sound.
Just something I thought I'd throw in for consideration. A really comfortable chair can alter or even ruin the sound in a room set up. Something to consider when shopping for the perfect listening chair.

 

[Mister Pig]

Well this futon is only a temporary solution, its going to be changed out for a leather love seat in short order. Once I find the right one. Although the wife is lobbying for a leather sleeper sofa. We got one spare bedroom, but when all the kiddos congregate here we don't have enough sleeping accouterments. The back of my speakers are just slightly more than 3 feet off the front wall, so I don't want to push them back if I can help it. And the futon frame is just on the edge of an alcove, so it cannot go back further. I am considering corner bass traps to see if I can minimize these nodes. But as you know bass traps are not cheap, especially with sipping, so it would be nice to know they will do the job before I shell out the cash for them.

Regards
Mister Pig

 

[enginedr]

I would try one of these
http://www.hsuresearch.com/products/uls-15.html

 

[4-2-7]

Perhaps I can put an acoustic panel on a set of legs and have one I can move into place for an evening of listening.

Try removing the ones you already have hanging, maybe reflection will help.

 

[Bob in WI]

"I am considering corner bass traps to see if I can minimize these nodes."
I finished a pair of bass traps made from 2" Owens Corning 703. Even with my skills, its not hard to get a living room presentable product.
The cost is reasonable.
Whether that would solve your problem, thats another issue. I was working a different problem.

 

[E-Stat]

Would you care to share the room dimensions and relative positions of both speakers and your listening positions - both nulled and not?

It's quite common for rooms to have bass nulls in the center. I find that using roughly thirds lengthwise for both speaker and listener optimizes response.