What Do You Think Of This?

[cmyden]

Hello folks, long time lurker, first time poster. I love the info I've found in these forums.

I'm designing my first home theatre in my basement. I'm looking for opinions on whether or not 1 foot is enough distance from the sidewalls for the mains I'm planning on buying.

The speakers in question are the Avant 906 series (the ones recommended in the Audioholics $12K home theatre guide).

I'm planning on building the screen for my LCD projector first, and mounting it permanently the wall, which is why I need to decide on whether or not 1 foot will be enough.

I know this is subjective to a variety of factors, but I'd definitely appreciate anyone's gut reaction opinion. It's a concrete basement, drywalled, carpeted, and no rear wall (well, it's far behind the theatre seating). The roof is those removable foam tiles.

1 foot from the wall is where the edge of the speakers would sit, so an estimated 15" to the tweeter.

I've attached a quick drawing of the layout.

Thanks for any advice, help, or feedback you can give!

 

[jaxvon]

I assume that you'll be mounting the projector from the ceiling. In this case, you're going to need to raise the level of the screen. Projectors throw in a "right triangle" pattern. This means that when you have the projector sitting normally on a tabletop, the image comes out in a straight line from the bottom of the lens (toward the screen) and upward at an angle toward the top of the screen. When you invert it, the projector will output an image straight out from toward the top of the screen and at an angle toward the bottom. The result is that you need to mount your projector lens about equal with the top of the screen. Now, you CAN angle the projector and use keystoning to adjust the image, but that isn't recommended.

 

[cmyden]

Thanks for the advice Jaxvon. The projector I'll be using is the Sanyo PLV-Z4 which has lens shift (100% up/down offset, 50% left/right). As I understand it, this is a preferable solution to keystone correction.

The drawing I attached was more to show my concern about the speaker placement, if I'm able to keep them 12" from the wall, I should have complete flexibility over the height of the screen.

That's actually one of the reasons I'd like to find out! (It would also give me flexibility with the height of the speakers).

 

[W_Harding]

Early reflections

Having speakers that close to the side walls do present some problems. At your listening position you receive the reflected signal from the wall as well as the direct signal from the speaker. If I was to try to work with such a set up, I would buy or build sound absorbing panels that I could attach to each adjacent sidewall to mitigate the early wall reflections. Although my set up does not place the speakers quite so close to the walls as yours does, I still use sound absorbing materials to attenuate the early sidewall reflections. The sound is clearer and the image better defined. Good luck. It looks as though you are setting up a great home theater.

 

[cmyden]

Good idea W_Harding. Do your sound absorbing materials look pretty decent on the wall? I'm sure there are some attractive solutions out there.

The other layout I could conceivably go with has the speakers below the screen. I've attached a drawing to show how it would look.

I wouldn't have as much flexibility with the speakers in reference to up and down, but I could put them wherever I wanted to left and right.

If you had to pick one, would you rather have the flexibility to move from the wall, or up and down (to be in line with the listener's ear) ?

 

[W_Harding]

Looks OK to me.

I have used two commercial sound absorbing products, Sonex and ASC Tube Traps. Currently I am using the Tube Traps which are freestanding columns 11" in diameter and 3' tall. I have them placed strategically between the speakers and the wall. When I used the Sonex, I attached it directly to the wall.

I have also noticed that there seem to be about half a dozen other products available from other companies. Some products are more attractive than others. With a little web searching, you should be able to find something you like.