Originally we were looking to have a closed in dedicated HT but it would make the basement look too cramped. Instead, we have decided we will have it open as a media room. I'm starting to plan the layout and will have an approximate dimension of 21x15x7 (before walls are up). If needed, the dimensions will be adjusted so that no two will have a common denominator. The TV/future projector will likely go against either one of the 15 foot walls (leaning towards wall by stairs that has a small window - to the left of opening). I would have posted a picture/pdf, but I'm not sure how to here. I'm looking at getting the Epic 80-180.

What would be the best placement of a 5.1 sytem including height (surrounds on the wall)?

Would a 7.1 system work well in this room? If so, can you please also provide your recommendation on placement of the speakers for this?

Thanks for any help anyone can offer.

Welcome!

You'll need to figure out where the viewing area is. My sense - with a room that large - is that you will have adequate space behind the seating area to warrant 7.1.

One of the nice things about the QS speakers is that they are not fussy relative to placement. Generally, the surround speakers should be barely in front of or barely behind and to the sides of the main listening position. The Rear speakers typically go on the wall opposite the screen.

As to height, about 2-3 feet above the listeners' ears works well for both the Surround and Rear speakers. I put mine so that the bottom of the speaker is about 6'1" off the floor (that way, I don't ever bump my head; anybody taller than me can just be more careful).

Dolby has some excellent resources that show - with charts and everything - desirable angles and distances and stuff.

Wire or otherwise allow for multiple possible subwoofer placements. It's not practical for amateurs to model or project room nodes in open spaces ahead of time, so give yourself some flexibility, which can make a huge difference.

Have fun. Enjoy the journey.

If you have 2 rows of seats in that space, then I would highly recommend 7.1

If you have one row, and it is towards the back of the room (a LONG distance from the screen in my opinion), then go 5.1

My room is 14 feet wide, 24 feet long, and just less than 8 feet tall. I have two rows of seats and 7.1 sound.

It doesn't seem that much better or really even noticeable unless I do an A/B comparison between 5.1 and 7.1 while listening to the same material. However, it is critical when sitting in the back row as the "wide surrounds" are behind my front row (on the side walls) but in front of my back row. Without the 2 extra speakers/channels in the back, the sound would never envelop the rear seats.

Hi Ironman, and Welcome!
I believe 7.1 would work well in your room; if you have the funds I'd suggest to go for it. More and more material is coming in 7.1 these days, and when well engineered it does make a difference.
As for the height of the surround and backs, I heard both: ear level and about 2 feet above ear level. I like the ear level setup, but this is entirely up to you. You have to test it; as Tom pointed out, the beauty of the QS speakers is the they sound pretty good in almost any position.

Welcome to Axiom. Yes, slightly change the dimensions to avoid the 7:21 factor. Your seating position would establish the best speaker placement. The M80s should be separated about the same amount as your distance from them. The QS8 side surrounds should be mounted directly to the side of the listening position and about 2-3' above ear level. Back surrounds would be helpful if there's enough distance(say at least 4')behind the listening position for a rear sound field to form. If so, mount them on the back wall, also about 2-3' above ear level and separated by about the distance they're behind the seating.

Thanks for all the suggestions!

My ear level at seated position would be between 3' to 4'. When you guys say 2 feet above ear level does that mean the bottom of the surround? My ceiling once finished will be about 7 feet as I mentioned. Is there a minimum distance the QS8's should be from the ceiling? Would the top of the QS8 being 1 feet from the ceiling be enough?

The other thing is that I would love to have a 7.1 but with the way the room opening will be, I will be hard pressed to have the side surrounds directly to the sides. It's likely that they'll end up behind a little bit. If this is the case, would I be better off just going 5.1 and placing the surrounds behind the seating area? I just don't want to go 7.1 for the sake of it if my placement won't yield better sound.

You can get away with far less than 1 foot from the ceiling with the Qs. I believe mine are about 4 inches.

In my room, I didn't think going to 7.1 was a fantastic upgrade, mostly because the QS8's are so good.

I've been told by Brent 3" minimum.