Is it okay sitting exactly at the rear wall ?

[dazkyl]

I can easily move my sofa forward for watching movies. My sub is the at left front corner near my left front speaker , and i noticed some rumbling coming out of the sub when i sit exactly at the rear wall. When i moved it a little bit forward,the bass was smooth and punchy. Can i stay at the rear wall and turn down the volume of the sub a little bit ?

Thanks. (Current sub gain knob volume is set at about 9'clock)

[Blu-Dog]

Originally Posted by dazkyl

I can easily move my sofa forward for watching movies. My sub is the at left front corner near my left front speaker , and i noticed some rumbling coming out of the sub when i sit exactly at the rear wall. When i moved it a little bit forward,the bass was smooth and punchy. Can i stay at the rear wall and turn down the volume of the sub a little bit ?

Thanks. (Current sub gain knob volume is set at about 9'clock)

You're probably getting the initial sound wave, and the one reflected from the wall, at about the same time. Moving away from the wall means you get a bit of delay from the direct and the reflected sound waves.

Turning it down will reduce the effect, but it will still be there - and perhaps be indetectable. If you can't get a foot or so away from the wall, it's going to be an ongoing issue.

[dazkyl]

Originally Posted by Blu-Dog

You're probably getting the initial sound wave, and the one reflected from the wall, at about the same time. Moving away from the wall means you get a bit of delay from the direct and the reflected sound waves.

Turning it down will reduce the effect, but it will still be there - and perhaps be indetectable. If you can't get a foot or so away from the wall, it's going to be an ongoing issue.

I move away about 45 cm away from the rear wall and the rumbling is all gone. Is that good ?

[richteer]

Originally Posted by dazkyl

I move away about 45 cm away from the rear wall and the rumbling is all gone. Is that good ?

Yep. Against the rear (or any other) wall is bad because of reflected sounds, and because that's where standing waves tend to appear. (It's also why putting speakers in the corner is a bad idea.)

[Big Daddy]

Sitting against the wall will make the bass too boomy and loud. Sitting exactly in the middle of a typical rectangular room will cancel all the low frequency waves and you will hear no bass.

[dazkyl]

Originally Posted by Big Daddy

Sitting against the wall will make the bass too boomy and loud. Sitting exactly in the middle of a typical rectangular room will cancel all the low frequency waves and you will hear no bass.

Yes, I noticed that,indeed. When I sat exactly at the rear wall, the bass was kinda higher and boomy. When i moved exactly to the middle of the room,there was no bass. When i just moved the couch forward from the rear wall a few cm's , the boomy bass was gone and it was smooth

[Big Daddy]

Originally Posted by dazkyl

Yes, I noticed that,indeed. When I sat exactly at the rear wall, the bass was kinda higher and boomy. When i moved exactly to the middle of the room,there was no bass. When i just moved the couch forward from the rear wall a few cm's , the boomy bass was gone and it was smooth

If you want to understand the reason for this, read the following thread and get really confused. Even I don't understand it.

A Guide to Subwoofers (Part II): Standing Waves & Room Modes

[slimdude]

The purpose of a LFE channel, is to produce low rumbling, and high bass from movie soundtracks. It's a subwoofer.

[Big Daddy]

Originally Posted by slimdude

The purpose of a LFE channel, is to produce low rumbling, and high bass from movie soundtracks. It's a subwoofer.

I was trying to help another member understand why subwoofers sound louder near the room boundaries and less pronounced in the middle of the room. I am not sure I understand the purpose of your post.

[slimdude]

Originally Posted by Big Daddy

I was trying to help another member understand why subwoofers sound louder near the room boundaries and less pronounced in the middle of the room. I am not sure I understand the purpose of your post.

I wasn't referring to your post. The original poster claimed that he was hearing rumbling from the subwoofer.

[dazkyl]

Originally Posted by slimdude

I wasn't referring to your post. The original poster claimed that he was hearing rumbling from the subwoofer.

Yes i was when sitting exactly with my back of my head against the rear wall. When i moved a few inches forward , the unwanted rumbling was gone. Whats the purpose of your post?