Axiom Home Page Forums General Discussion Advice from Axiom Owners HT Room - Advice on Speaker Selection and Layout?

I've sent this following to Axiom on a new HT install, but the more advice the better:

Plan : http://jmone.org/owncloud/index.php/s/x98p1DxM9z8xySY/download


"I'm also now looking at a new set of speakers as well that I will need a quote on. It is for a Home Theater Room and I'm tinking about the following 7.1.4 Atmos setup with some custom work for the front speakers due to depth issues:
- Pair of In-Cabinet M80 but they can only be 250mm deep
- In-Cabinet M180 but it can only be 120mm deep (eg like the depth of the custom on wall you sent me last time but with the In-Cabinet face)
- 4 x QS8 for Rear and Surrounds
- 4 x In Ceiling for Atmos
- All will need to be paintable
- 1 or 2 Subs (not sure what model for this size room, or maybe just a EP800 ???)"

Thanks
Nathan

...also should I look at direct firing speakers instead of the QS8 as 3 of the 4 can be located on Shelves (with the exception of the one over the Sliding Door).

Given the dimensions of your room, I would advise against QS8s. Bipolar speakers will serve you better.

1. What kind of distance will you have between surrounds/rears and listening positions ?

(a few feet suggests QS*, direct firing becomes more acceptable at greater distances based on the bit of experience I have)

2. My impression (not at all confirmed so I'm just saying this so you check) is that in an Atmos system people seem to be looking at direct firing for surround/rear as well.

(I stress I'm not at all sure of this, just that I have seen a couple of people talking about trading in QS for direct in the course of Atmos-fying their systems)

Thanks for the responses, and it seems most recommend Direct Fire, so I'm guessing M3???

I'd say the rear to wall to seating will be about 1.5m, but all surrounds are going to be positioned way above the "ear" height (in fact above the doorway height at say 3m on a shelf). The other option could be On Wall M3?? and angle them down to face the sitting position.

For an ATMOS system they do recommend direct firing. Specially with the QS8 firing up wards and the rear ATMOS firing downward on it.
NicBuol has done great research on this and very informative. He has a awesome setup you can probably see most on the posts on his HT here.

I would suggest going with atleast EP500 duals. I have EP350 and in a room 11.5 x .15.5 x 8 and one doesn't cut it. I am even considering three or four.

OK. I'm not even supposed to me online right now (doctor's orders as I am supposed to be prepping for a sleep study), so just a couple of quick thoughts that I am more than happen to expand on later.

Direct firing is ideal for all speakers in an Atmos setup. This does not mean that you can't have good success with some awesome QS speakers, but you need to be able to "plot points in space" which means having straight firing sound from every speaker in order to plot those different points. Diffused sound from quadpole speakers is not good for this. Even bi/di pole aren't great, but some have their uses with multiple rows of seats, but still direct firing is how the system was designed for home use.

Speaking of seats, where are they going in the room? Based off of your Atmos overhead speaker placement in the diagram that you linked, you are sitting smack dab in the middle of the room. Audio likes things in thirds. I would move your seating so that it is about 1/3 from the back wall, or obviously, 2/3 from the front. Adjust your overheads to form that Atmos "box" evenly around your seating area, and then push your side surrounds back a little as well.

When pushing those side surrounds back, don't be afraid to having them slightly in front of the seating area. For me, I have mine about lined up with the middle (from front to back) of my reclining seats. So about even with my head when sitting up. We ALWAYS recline, so when reclining, they are now just slightly in front of the listening area. Works a lot better than when they were in a traditional surround placement just behind the listening area.

Also, put your side and rear surrounds down to just barely above your ears, or as low as you can go without them being blocked by seat backs, or heads from people sitting next to you. This will give you more separation between the surround speakers on the walls and the elevated overheads.

Lastly, be cautious about corner loading your subwoofers. You will "excite" more of the modes of the room, but you will get more "boomy" bass. I know that you are limited by a fireplace, windows, doors, etc, but having one up front in the middle (right where the fireplace is at) and one in the middle of the rear wall is best, or one in the midddle of each side wall. Again, I know that this won't work, but I just want to mention it. For me, I ended up with my 2 large subs up front, originally about 1/3 from the left and the right walls, and then I did some room tuning and tweaked their actually locations literally by inches until I got the response I wanted. So maybe under the windows (as long as they don't rattle). If they have to be in 2 corners, maybe look at the front 2 corners, and try to sneak them away from the walls/corner as much as you can get away with.

Alrighty, time to go to sleep before I get in trouble. LOL.

Thanks - Have a good sleep! FYI, this is a dual purpose room so I will have to make some compromises.

I've updated the Pic in the OP to show the seating position (from what has been described to me by the designer anyway) and changed the location of the speakers slightly, but:
- I have flexibility in moving the 4 x IC speakers anywhere
- I have flexibility in moving the 4 x Surrounds except for the height but they will NOT be at ear level (about 3m off the floor) but I can angle them down
- I can put a Sub in either or both of the positions marked

The physical build will not be till late Jan / Feb but I'm keen to get the equipment ordered so the builders know what to deal with. From the Feedback so far I'm now leaning towards:
- Pair of In-Cabinet M80 but they can only be 250mm deep
- In-Cabinet M180 but it can only be 120mm deep (eg like the depth of the custom on wall you sent me last time but with the In-Cabinet face)
- 4 x M3 On Wall Angled Down for Rear and Surrounds
- 4 x In Ceiling for Atmos
- All will need to be paintable
- 1 or 2 Subs (not sure what model for this size room, 2 x EP500 or maybe just a EP800 ???)

Thanks
Nathan

Yeah, I just wanted to tell you the target to shoot for. We all have to make compromises somewhere, but if you don't know what the ideal is, then you may be compromising something that is already a compromise.

Thanks for that (I get it), just trying to work out what models to use where.

Also forgot that while my current AVR (Yami RX-3060) is 11ch, it only has 9 amps... so I have to either get another 2ch amp or implement:
- 5.1(or2).4
- 7.1(or2).2

Any suggestions which would be the better config for this room?

Thanks
Nathan

That is a great question. Since the room isn't very deep (front to back), it doesn't allow for a lot of separation between surround speakers and the overheads.

One thing to consider is that you have 5 seating positions that are sideways. Those will be compromised in all sorts of ways if used for movie watching. I would cater the sound more to the main 6 person seating in the back. That is where a bulk of the movie watching will happen. In fact, I would be tempted not to worry about the sound for those seats at all. If you end up having a lot of people over to watch a movie, and you turn those other seats towards the screen, they will have to be far off to the sides so that they aren't in the way of the main 6 person seating, so no sound field is going to do well for those areas.

So if you go 5.1.4, then you should move your side surrounds further away from the screen, and bring your in-ceiling speakers closest to the screen back as well.

If you go 7.1.2, then the surround placement is OK. I would rather see the side surrounds closer to the main seating side of the room, especially since it would put the 2 in-ceiling speakers in front of the listening area anyway.

Here are some initial rough ideas about a 5.1.4 and 7.1.2 layout for your space with focus on always playing things back in either Atmos, DTS:X, or one of their upmixers. These layouts will provide room filling sound, good separation for Atmos/DTS:X overhead speakers, and still be closer to regular standards. I tried to keep your limitations/compromises in mind, but may have moved something to a location that would be a placement issue physically for you too. Only you will know that. I also did NOT touch the subwoofer placements.

I apologize for their crude look. I just did copy/paste/erase of things that you had vs. recreating the speakers that you have drawn up.

Thanks, that all makes a lot of sense! Couple more Q on what layout to choose?
- 5.1.4 vs 7.1.2 : Given my collection is almost all Blu-ray (without Atmos/DTS:X) would 5.1.4 make better sense for backward compatibilty.... or am I missing something?
- Also I'm thinking that for the incremental cost of 2 x IC to put in a 7.1.4 anyway as doing it later would be harder...... but would this layout even work given the lack of distance at the back (and if so what would it look like)? At the rear IC just above the Rear Surrounds?

Go 7.1.4 - more is better!
Seriously though, I am far from a tech expert on this, but as an analogy, I have a small HT room and had a few comments when building that 5.1 would be enough for my space. But similar to your thinking, it'd be harder to go back and add 2 channels than just put them in up front. So, since I had the walls open and money set aside anyway, I went ahead with 7.1. and I will say it has helped me with the upgradeitis itch. Never say never though!

Cheers,

Tossing my 2c in, I wonder if there would be enough separation between the ceiling and surround speakers, given the height the surrounds will be at? I use both Auro-3D and Atmos, and I think they would both be effected quite a bit.
Also, angling in (2) M3s from the rear corners for a 5.x.4 setup might work out better for the room shape and seating, and you wouldn't need the extra amp.
I've found I prefer QS8s over M3s for surround, even though counter to specs.

Edit: Final thought, if you used on-wall M3s you might be able to mount them flush in the rear corners, closer to head level. Since they have downward facing ports, that wouldn't interfere. Not only would you be following the Atmos angles for surrounds, you would also have good separation between your surround and height layers. 5.x.2 with zone 2 maybe?

Looking forward to seeing how you work it out.

Yeah, I agree with Steve and as I stated before, that separation is important, which is why I placed the speakers in his layout where I did.

That said, putting the surrounds in the rear corners puts them in the same plane as the rear overheads. That just won't work well. Nice idea though from a "where can I stash these speakers" perspective.

Keep in mind that any immersive setup still relies heavily on a solid base 5.1 or 7.1 setup. In a 5.1 setup, the surrounds are on the sides, not the rear, and while the seating area is pretty far to the back, you really don't want the surrounds in a 5.1 setup (which should be the base that you build off of, or a 7.1 if going that route) behind the listening area. Most 5.1 soundtracks are created to just go to the side of the listener, and not behind them. That is where 7.1 comes in. Sound mixers wanted to take the surround experience even further by giving sound behind the listener, without losing the long standing side surround sound.

In my diagram above, the side surrounds are actually in front of the standard Dolby spec as well, but this has been experimented with countless times over at AVS for years now - having side surrounds in front of the listening area when there are either rear surrounds (like in a 7.1 setup) or other speakers further back, like the overhead Atmos speakers, and people have raved about it. It also allows for greater separation between all of those speakers, filling in the audio "gaps" in the room more, and letting the receiver/processor handle the sound placement.

Again, my diagram edits were based off of using only native Atmos/DTS:X content or one of their upmixers.

None of it is ideal, but that is the space that we are working with, and it will still be a great experience.

I still stand by my "monopole only" stance (I went from four QS8s for surround duty to four on-wall M3s when moving to Atmos and love it), but like Steve indicated, he loves it with his QS8s and "to spec or not" you really will have a great sounding room with speakers filling those gaps, and I am certainly not going to fault someone for liking quadpole speakers (about as far away from spec as you can get, LOL) in an Atmos setup if they like it.

Your room isn't as great as a purpose built space for audio, but your room also serves multiple purposes, and will have a cozy feel to it even when not watching movies.

So now you have even more to think about. Steve brings some new thoughts for you to the table.

Lots to think of.

I'll mull all of this over as I wait to get the plans back from the builder/designer as the front three speakers will need to be customized to fit the space.....

I'm leaning towards putting in a 7.1.4 physical layout and then hearing what is "best" in this space with either a 7.1.2 or a 5.1.4 driven (or adding a 2ch amp for full 7.1.4). Also due to the sloping roof, the rear IC will be 2m higher than the Rear Speakers (that will also be angled down to the seated posn) - so I should get some separation???).

Thanks for all the feedback!

My vote 7.1.2

The sloped ceiling with a sharp apex at the rear of your room is going to cause problems if you place ceiling speakers nearby. You are going to get a pronounced "cupped hands" effect on your response in those channels with an after ring. The energy arriving at the listening positions will be almost all reflected energy off the rear wall. Not ideal for a discrete object mix.

Nick's 7.1.2 diagram layout is near ideal. The location of wall mounted M3s for rear surrounds will cause hot spotting near listeners. I recommend widening their positions slightly and aiming them at the main listening position.

Sounds like you are accounting for your ceiling slope when positioning your ceiling height channels.

The 2nd order bass width null will be shifted towards your sliding door wall by a couple of feet. You will have a hole at 39hz in the mlp if you put your subs on the left wall with wildly varying response over the listening area. They should go under each window on the front wall with the left sub output lowered to compensate for boundary gain.

So, predictions for rear height channels: I stole this image from online (sound and vision) and edited it to illustrate what I think the trend on the response will be. This is the best case scenario for ceiling mounted rear height speakers. Likely you can add pitched ring too.



This is all based off some quick napkin math and acoustical theory. In the spaces I have been involved with the math usually follows trends in real (rectangular) rooms though.

What do the "openings" in your room open to? This will affect your room decay times and low frequency behavior to a huge degree. I hope you have a good designer. The rear ceiling corner is an issue. (The issues I brought up are obvious and an HT designer should spot these right off.)

** Note that I too was somewhat reluctant to put the rear surrounds so close to the seating area in his diagram, but that is where they should be for separation (plus horizontal location in an ideal world) and he said that they would be mounted high on the wall, pointing down, adding to the distance and dispersion of sound which *should* mean less hot spotting.

That was my thoughts on it anyway. But yes, generally having a speaker right next to, or behind your head will not be so good.

Why so high back there? Didn't catch that. Ah I see, to match the sliding door speaker height all around. Makes sense now.

Sorry my brain always turns into an audio lawyer now. If\then risk\reward kinda mentality. lol. I admit I got caught up in the nice diagrams and went from there.

No harm, no foul.

Getting closer. After speaking with the designer we have moved the Subs to the front and a Vertical M80 Custom for the Center. Going to also try to wire up in 7.4.2 (might as well get the extra two speakers now). Here is the new pic: http://jmone.org/owncloud/index.php/s/2nt23tLFQvvHZPP/download


This is what I've asked Axiom a quote for:
- Pair of M80 Floorstanding with Custom Paint and Cloth in DULUX Natural White – PN1E1 – Low Sheen
- 1 x Custom M80 (to be a Vertical Centre Speaker) – Like my previous Custom M80 On walls but this time with an “In Cabinet Face”, with Custom Paint and Cloth in DULUX Natural White – PN1E1 – Low Sheen
- Pair of EP500 Subs with Custom Paint and Cloth in DULUX Natural White – PN1E1 – Low Sheen
- 3 x M3 Bookshelf with Custom Paint and Cloth in DULUX Natural White – PN1E1 – Low Sheen
- 1 x M3 On Wall with Custom Paint and Cloth in DULUX Natural White – PN1E1 – Low Sheen
- 4 x M3 In-Ceiling Speakers (Stock White)

I think that you mean 7.2.4

That subwoofer placement is a lot better.

I am still concerned that your rear overheads and rear surrounds are pretty much stacked on top of each other, but with the in-ceiling speakers being very tall in the rear, hopefully you can get some good separation between those and the rear surrounds. I would think so as long as you aren't mounting the rear surrounds 10 feet off of the ground or higher, you will be ok. Ideally still down to just above the listener seating ear height.

If you can swing that, then you will have a really sweet setup.

Thanks! and yes 7.2.4 ....fix my pic .

Given the lead time, I figured best to get the ordered now and sort the exact layout detail in Jan/Feb as stuff starts to go up as who knows what I'll find in the way. I should have a least 2.5m separation between the rear IC and surrounds. Also, worst case is I end up driving 7.2.2 or 5.2.4 and just have a couple of spare speakers I can re-purpose.

Now to find something to power the extra two speakers. My Yami is an 11ch receiver but only has 9ch amps so I need an outboard 2ch amp. I did think about an Axiom 2ch Amp as it has a trigger but the price is made me pause... Still I think I'll ask them for a quote on this as well...

Hows this for an Idea, for the rear surround use the "M3 Computer Speakers" instead of an external AMP and normal M3s?

They will only be A$250 more and come with the power amp built in. Nice and clean, but would it work taking a signal from the Yami's Pre-Out? Any other Downsides?
Thanks
Nathan

You will need to land a receptacle up there and a jumper speaker cable between speakers if I remember right along with input feeds. The built in amp in the computer speakers is great for closeup listening but I'm not sure how it would hold up with a dynamic Atmos mix at further distances. Its 75w if I remember correctly.

I would recommend doing it right and buying another power amp for your fronts and assigning the free AVR channels to surround duty. Buy used to save $ and get something substantial. The gear in the rack can be sourced locally to save dough.

Thanks - Tried to call Axiom to discuss a few time but it goes through to Voice Mail for Debbie .... but her VM is "Full" and you can't leave a msg.

I just did the measurement conversions, and realized we have about the same size rooms. Mine is 24'x15' but with an 8' ceiling all the way across. I went long instead of wide, because of window locations. Look forward to seeing yours.

Thanks to Ian (who is working over the Christmas Holidays!!!), I have the speakers ordered.....

Now debating how to power them. I can get the Yami - MX-A5000 for A$3K to team with my existing A3060, Ian is working out a match using the ADA.

Ian's not really working. This is audio we're talking about. He's having fun.

Exciting Times. All the gear has arrived and Ian sold me an ADA1250-3 to power the L/C/R! The builders are starting next week and I've a Question on the cable runs (approx 10m) to the front Subs from the Yami AVR. Should I just use RG6 Coax or ???

Thanks
Nathan

Jmone, are you going to have terminals at each, like a wall plate where you can jump from the wall to the sub with RCA cables. Also how long is the run.

The will be 10m runs and I can terminated them anyway I need (plates, direct wire etc)

Mmmm the seems the runs will be about 20m due to the way they have to pull the cables.