I am looking for ideas. I have a home theater setup now and am getting ready to upgrade my speakers (I posted some question earlier). I love the QS8's but my home theater will be moving to a much bigger room (the 7000 cubic ft room I posted about in another thread). So here my dilemma:
The rear wall is quite far from where people will sit and watch tv. People will sit say 15-18 ft from the tv (LCD tv), the wall is around 15ft behind them.

I am planning a 7.1 surround.
Can the QS8's be effectively mounted on the back wall (seems kind of far)? If not any ideas on how a person would resolve such an issue. I am about to start remodeling, so I am looking for ideas that could possibly meet the WAF. I don't think the wife would accept the qs8's hanging from a hook.

You could use the QS8 stands.

Or mount them on the ceiling just above the back of the seating area.

To be a pain, I'll point out that you should avoid having your listeners at 15ft from the front and back walls. Land of the Null! But I would not worry about the Qs without a close reflective wall. Put them as directed on the sides of the listeners and the will perform as advertised. The question of rear-surround is more difficult.

Some in your situation have gone with direct radiating speakers on the back wall, others use Qs back there, but some say the benefit of the Q that far away is lost and the cheaper direct equivalent is enough. Others have done mid-room setups for the rear speaker where the rear wall is actually in another room and suspect their spouse and guests don't want to hear the helicopter at 105db as they cook!

I'd hang the rears from the ceiling using the Axiom full metal ceiling bracket. Unless that solution gives you wiring, aesthetic or cost problems. If that's the case, I'd do as Charles suggested and get some M2 or M3's for the wayback rear wall position instead. That might even make more sense depending upon how you're using the rest of the room - if you've got people spending time in that half of the room, you might like to have "all channel stereo" there rather than the diffuse sound of the QS series.

Agreed

Ditto agreed.

Tritto.

No; all channel stereo isn't an adequate substitute(for standard usage)for surround sound which sends different content to the surround speakers than is sent to the mains.

As to positioning the QSs or other back surrounds on the back wall(spread widely apart, a distance similar to the distance from the seats)that far back there shouldn't be a significant problem. Delay and level to compensate for the distance will be adjusted during calibration.

I think we were all in favor of using a direct firing speaker for the 6th and 7th channels, not to necessarily twin them for channels 1 and 2

Zimm is right, the center of the room is the worse place to sit, right in the null of a room. 38% from the front wall or back wall is ideal. My room is bigger than yours and I have my Q's hanging 7ft off the ground (bottom driver). The left surround is the only one with a wall behind it.

You could put the Q's on the back wall and adjust the distance, dB levels to compensate when calibrating.

sirquack,

I was looking at your setup. My setup will be somewhat similar to yours but for now it is not a dedicated HT. For now i am still in the designing stages of this room. So everyone knows I am in the process of an upgrade to a better HT. I would love suggestions for seating distance, speaker placement etc etc. My future plans most likely include a PJ but for now it is an old Hitachi 53 inch RP HDTV (1080i only):( My next upgrade will probably be a 55 inch samsung led.

My thoughts about the room have gone from placing speakers throughout the room for HT/multichannel audio to basically splitting it in half. It is going to be a multipurpose/HT room. My speaker choice is leaning towards M60/M80 vp150 and 4 qs8's (eventually). Currently I am building a Rythmik ds1500 (vented model with the new 500 watt Rythmik amp).

This process is going to include rewiring the room (low voltage and some high voltage) tearing into sheet rock. Building a media rack etc etc. This a total remodel. The room was a garage and is becoming the HT/MP room.

Thanks for all the help
Bill

Hey, I want to hear more about your Rythmik build!

I wanted to build a sub, a friend of mine has more knowledge than I do and the necessary woodworking tools, so we are building it together. I took some pics of the process. Here is how it came about>

I did a bunch of research @AVS. I decided on a Rythmik build. I downloaded the plans from Rythmik and purchased the Driver and AMP. I decided on a vented model (which by the way I have not read about anyone building).

So I bought a sheet of 3/4 inch MDF and we started the process. I will tell you that the instructions are ok from Rythmik but the measurements seem a little confusing for a first time sub build such as myself.
As we approached the time to deal with the ports I found it necessary to contact Brian @Rythmik. He was very responsive and pointed mr to ports sold at parts express. He told me I should go ahead with a dual ported model (so I did). We installed the ports. The ports are 3 inch ports by 18 inches long.

Next I saw that Rythmik was coming out with 500 watt servo amps. So I contacted Brian and he advised me that I could upgrade to the 500 but not the 600 for the DS1500 driver that I purchased, so I paid him the $$ (only $70 xtra).

We are currently in the final stages of making the box look nice. I had to decide on a finish. I really wanted a piano black finish but decided against it due to the likely hood of error. I decided on a Real wood laminate (Red Oak). I purchased a jet black dye and a gloss lacquer. So we are currently applying the laminate.

We cannot wait to test the sub. If you guys want I will post some pics later tonight.

Bill

Of course we want pics, even if there's no Teri in them.

My room is 26' deep and after reading this, I measured and my seating area is right at 13' doh

My front speakers are 3' off the front wall though, so I was wondering if that made a difference, or are the walls the critical thing?

Walls. You will be missing bass at that spot (or getting ridiculous booming).

Thanks for the reply! *starts pushing his couch*

BillH,

As some will recall, I went through ad nauseum testing of back wall vs mid ceiling mounted 7.1 rears. I had ordered QS8s for the backs. My room is 31' deep by 23'wide (seating 12' from screen, back wall 16' behind seating). Originally I had direct firing spkrs on the back wall. Yes, Audyssey (or other) does adjust for the distance, BUT if anyone is occupying that rear half of the room (my wife did), they get blasted by the elevated dB level req'd to reach the seating position! After much OCD testing/thinking, my wife actually preferred the idea of mid ceiling mounted 7.1's so she would not get blasted! I caught much grief with back wall 7.1's! Do not do this, trust me.

The bottom line from my lengthy testing:
1) Back wall- no way, unless no one is ever back there, but if you must, use direct firing speakers.
2) Mid ceiling, 7' or so back from listening position worked best in my large great room. AND both my wife and my concerns that they would look like eyesores mid ceiling was not the case (for us).
3) In mid air, in my large room, the QS8s did not project well. They lost too much low end! The theoretical 'rule' is that the sub picks up the missed low end. In my case, when turned up to loud movie levels, the radiant firing Q's sounded way too bright. The M2 sized direct firing speakers had much better sound (bass, etc), which makes sense due to the much larger interior space of the bookshelf style spkr.
4) Looks of mid ceiling: I actually covered the black DF speakers with white paper to see how they blend in better. Now we don't notice them much at all. I will eventually get some white speaker cloth too.
5) I made my own custom brackets thinking I needed to be able to rotate them towards the back half of the room for 7 ch stereo for parties or just full room listening. The 7 ch stereo sounds great with them facing to wards the HT. The M80s seem to fill the room just fine so it sounds good everywhere.
6) I used my DIY 8' speaker stands to test speakers (QS8 vs. direct firing) and best location for over two weeks. Did I mention OCD.


.
.

.
.
Photo bucket- many photos


If you want to read my saga in it's entirety, you can find it here.. (Warning: enter at own peril... 11 pages )

Ok here are some photos of the build. Sorry for the poor quality (camera phone):










I am currently applying lacquer to the laminate and hopefully can provide a nice picture of the finished product. The crappy pictures don't do it justice. It is turning out nicely.

What a great and informative post. Thank you I certainly appreciate your help. One thing, it sounds as though if you were to order the M2 again, you would order them in white. Am I correct in my understanding.

Bill

I would definitely want an M2 in white. Not the High Gloss White because I want speaker to blend in as much as possible with the ceiling (for me) rather than stand out. Oh, the $250 price bump would also deter that choice.

My choice would be between 'paintable' at a $35 price bump or maybe the white maple w/ white grill because it is pretty white.

Has anyone sanded the standard vinyl and spray or brush painted it? If so, how did it turn out. I would consider painting it flat white as the ceiling is painted. If anyone has done this, please post some pics.

PS. Holy Cow. That looks like quite a sub you are building. Excellent craftsmanship!

As I mentioned, due to excessive loudness in the back half of the room (if anyone is there during movies), I went with mid ceiling backs. I was surprised that with the M80 fronts, the room was filled very pleasantly when I used 7 ch stereo for music! I thought I'd want to rotate the backs toward back wall, now I don't bother. For me, with the kitchen and dining room in the back half of the great room, this set up was a good choice.

As you notice in my photobucket gallery, I ordered both M60s and M80s. The 60's were very nice, but the 80s just sounded even better in my 31'x23' room. I figured the extra drivers would help fill the space just a bit better. For me it was WELL worth the $300 extra price! Plus, no upgrade-itis, unless an M100 shows up. Room acoustics and personal preferences make surround speaker choice variable. I am very glad I ordered 4 QS8s to test out for my room acoustics and taste. For only $30 return cost per pair, that is a cheap cost to be able to try them out for sides and backs against direct firing (at least in back 7.1 locations). The consensus seems to be that for side surrounds QS8s are a great choice. In my case, the side QS8s needed to beat out my already installed 8" Kevlar woofer in walls, which have a Much larger interior sound space with very good acoustic deadening material. If I had had direct firing bookshelfs protruding from the wall for sides, I bet the Qs would be my sides today. If you do not have a small pair of direct firing speakers to test against the qs as 7.1 backs, I'd strongly consider ordering a pair of M2s as well. I wish I had actually done that. Now, spending constraints make me need to wait before thinking of upgrading my backs. If they had been on my first order, I'd have kept 'em!



Good luck with the myriad of decisions you need to make.

Nice pics of the sub build, Bill! Thanks for posting them. I will be very interested to hear your assessment of the sub.