Dedicated 7.1.4 Cinema Hi-Fi room (planning stages)

Bonesey

Standard Member
Hey folks, long time reader, but never contributed yet. Just purchased a new (to me) house and I've been given permission to create a dedicated cinema / hifi room. Room is 3.6m x 3.9m and I've got a good idea of what I'm aiming to create there.

I've done some rough Google Sketchup designs just using the online version to get a sense for what fits. I think I'm heading down the route of in-wall speakers, acoustically transparent screen to keep everything hidden. The only visible speakers will be the hifi floor standers.

The outstanding portions of the walls both sides and rear will be acoustic diffusers behind cloth and also allowing for the installation of the speakers. Small display shelf on right hand side of room for some subtle movie themed collectibles. The rear wall has the window but this will be fully hidden behind the acoustic panels. Top and bottom of the diffuser panels will be LED lit, and there will be a similar central panel running down the roof from front to back to hide speaker mounts / projector mount.

Screen in the design is 100" which I think is more than big enough for the room as is.

Comments welcome!







Update:

Here's all the links of useful sites that I've found whilst researching all this:

Triangle calculator for ceiling and surround speaker positioning.

Triangle Calculator

Calculating points of first reflection.

Locating areas of first reflections

Room Modes Calculator

http://www.bobgolds.com/Mode/RoomModes.htm

Acoustics Calculator

Calculate your acoustics | Troldtekt acoustics calculator
 
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00Paul00

Active Member
Now that's some proper planning! Looks great, enjoy making it a reality!
 

beechy06

Active Member
Looks good!

My only query/observation would be why are you having on wall speakers behind the screen then floorstanding stereo speakers? Or have I interpreted that wrong and just centre speaker behind the screen? You can get great stereo performance from a proper bass managed sub/sat set up, i’m sure a pair of subs would work better than having floorstanders plus would open up the room more.

Either way good luck with the build :thumbsup:
 

Bonesey

Standard Member
Entirely separate systems. Will be front channels for the cinema setup behind the screen, the hi-fi system is a work in progress and speakers might vary with time. Not always to match the cinema system.

I'm not sold on how I want to store all the AV / hi-fi gear either. No possibility for having it outside the room unfortunately.
 

dollag

Well-known Member
Looks great but cannot see any subs? whats the plan there?

regarding having different speakers for stereo, I am not too sure if that's necessary.

thinking of my own gear, they are sublime at both h/t and music and unless your spending serious money on either h/t or a hifi system, you wont really benefit from having separate dedicated systems.

getting an avr with h/t bypass and an separate integrated amplifier makes a lot more sense.

I personally feel spending £2000 on dedicated lcr would be better than spending £1000 on lcr just for h/t and another £1000 on stereo speakers.

might be a good idea to keep the LCR external if yuou want to change out speakers.

just my 2 pence
 

Bonesey

Standard Member
Well I have a loan of some ART Stilletto 6's for the hi-fi speakers and looking at a Luxman 505uX amp for the audio setup. AV equipment will be about 2k for receiver, 4k on speakers and about 4k for a 4k projector.

Yes, it might not be necessary,... but the stereo might not end up staying in there and I don't want to limit options.

I've contacted gikacoustics for some recommendations on room treatment and my local hi-fi AV place runs the CEDIA software for room acoustics and speaker placements. Sub(s) might go behind the seating. One in each corner. Or if that doesn't work then I will need to look at other options. Nothing is bought yet. I don't get the keys until end of October and I have a hell of a lot of other planning and spending to do before the plasterboard comes off in this room!
 

Cherrywood

Active Member
With that budget - have you considered Baffle wall with DIY speakers for HT?

Regarding hiding equipment - i would suggest at the rear of the room, although the running noise will be off putting, you wont need long HDMI cable for 4K which would have to be fiber & no need for door to hide all the LEDS.
 

Bonesey

Standard Member
Although it probably doesn't show particularly well in those pictures the screen area is proud of the front wall. So it is in essence a baffle wall, just not the full width of the wall itself. I havn't delved into the design of the speaker setup behind the screen just yet. However I was looking at the Monitor Audio Controlled Performance range to avoid the usual issues with in-wall installations.

I thought you were ok with HDMI for up to 10m for 4k transmission?
 

Bonesey

Standard Member
So, I've had a few emails with GIK Acoustic regarding treating the room. I've gone back to the design whiteboard and updated my drawings to include the treatments recommended.

I've not put anything back in the room yet as I need to mull over the design aspect of the treatment in regards to how I had it envisioned in my minds eye.

 

Bonesey

Standard Member
Yeah it is a lot, and believe me I've done plenty of reading. Of course this is from a company who wants to sell you acoustic treatment, so they're going to want to sell me as much as they think they can (within reason).

I think some of this advice will be incorporated, but not all of it.
 

mb3195

Well-known Member
All looks good, you're better off making your own acoustic panels though, will save you a small fortune. Looks like GIK are quoting for too many though. You would have no room left over to fit any equipment in, mainly due to the corner traps.

My initial thoughts on your layout is that the seats are too far the the back of the room. If you want a full 7.1.4 system, you will need to give your rear surrounds and rear atmos speakers room to breath.

Ideally you want to be positioning yourself around 60% away from the front wall. By doing this, you will create a full "bubble" effect quite easily. If this isn't possible, you may want to think about a 5.1.4 setup instead.

Another point, with the width of your room, you may be better having 3 seats rather than 4. I have the same width room and only 3 seater cinema seats (although mine are pretty big) and wouldn't be able to go any bigger. The benefit of an odd number of seats, is that the centre seat becomes the absolute sweet spot within the room. You will be bang in the middle for both sound and vision.

Where are you based? I'm always happy to demo my room for people wanting to do something similar.
 

Harkon321

Well-known Member
That's a lot of treatment!

You might want to read through the last 20 or so posts in this thread - MK sound speakers (part 2)

Interesting debate about the amount of treatment used, and if indeed treatment should be used at all (!).

I feel that treatment should be used, but I'm not sure about filling the room with it.
I've been following that thread with interest over the last few days. I found the idea that no treatment should be used quite shocking but haven't voiced my opinion as it's based on reading rather than experience.

Alot of the builds on the AVS forums do absorption up to ear height all the way around the room, with full absorption on the front wall and often on the back. Top half of wall left open for reflections.

The picture he's been sent looks alot but it's possibly just first reflection points. Might be worth playing with REW or similar in a room of those dimensions. It's almost a perfect square which isn't great at all for standing waves etc
 

Bonesey

Standard Member
We'll see how much motivation I have for DIY once I've finished remodeling the rest of the house!

Ok, so the dotted line that you can see in front of the seating is the 60% mark away from the screen. If I place the headrest of the seating at that point the edge of the seating is almost in the doorway. Setting it further back is going to make it more usable as a room that I can actually use. So, 7.1.4 might be out, can revert to 5.1.4 then.

Seating is a tough one, you're right. It's an awkward width room. I've tried a lot of combinations of seating to find something that even manages to fit 4 comfortably and I think it's just going to have to be a sacrifice. It's only ever going to get used by myself and partner, most of our friends are couples. So really need to seat 4.

The panels on the left and right walls should cover the first and second reflections. Obviously I'm just eyeballing the location at the moment.

The only ones I have issue with as regards space would be the rear panels as I no longer have wall space for in-wall speakers. Have reverted back to them for some advice.

MB3195, I've just moved back to Aberdeen.

As a bizarre side note. Has anyone every installed AV equipment vertically? I could in theory place the equipment in the hallway but it would need to be as discreet as possible. I can't theoretically think of any reason why you couldn't have an AV receiver mounted on the wall as opposed to against it. How about DVD/Bluray players?

 

Bonesey

Standard Member
I'm going to do my impression of a 3 year old.... 'why?'. :)

What difference would it make to a solid state AV receiver to have it vertical and not horizontal? (disc players aside for the time being).
 

mb3195

Well-known Member
I'm going to do my impression of a 3 year old.... 'why?'. :)

What difference would it make to a solid state AV receiver to have it vertical and not horizontal? (disc players aside for the time being).
The vents for a start are at the top to allow heat out of them. They also work quite hard to minimise jitter and interference by having feet on the units, I don’t think sticking it on it’s side would do much good.
 

Bonesey

Standard Member
Hmm, will do some more digging on that.

So, further on my journey of discovery and audio treatment research. Found a little calculater that should show first reflection points. Which is handy for a rough placement of treatment panels.

Locating areas of first reflections

 

Bonesey

Standard Member
Ok, so taking into account the points of first reflection and the GIK advice. I've also calculated out the optimal positions for the surround and ceiling speakers.

So the Dolby positioning angles for the surround speakers projects them beyond the walls. So i've adjusted the position forward to sit at the correct angle on the side walls rather than on the rear. Which is fine because at the moment the acoustic treatment remains on the rear wall as per GIK advice.



If we add back in the acoustic treatments I can see two conflicts. First is with the ceiling clouds and the forward ceiling speakers clashing. The second is with the rear bass traps and the surround speakers on the wall. But it should only be a minor adjustment.

 

mb3195

Well-known Member
It's very rare to have a perfect room, you will generally need to make some compromises.

It's great you're already planning where your acoustic treatment will be placed as people normally think about this after the event.

I would suggest though, get your seat position nailed first, then speakers and screen, then work around these. As you've already realised, you cant place speakers behind the ideal location of your panels, so they will just have to go as close as possible.

Another easy route for reflection points, is to use the mirror reflection technique as this will be based on your actual seating/head position, this is probably a more accurate measurement as it will be based on how you actually sit, not a theoretical seating position (people generally slouch).

There is a different school of thought on what the most important aspects of the room are to treat, but one area that I wish I did (I didn't have room) was the corner bass traps. This is where the bass can get trapped in the corners and cant escape, causing the bass to be muddy.
 

Bonesey

Standard Member
Thanks, yes, I've mapped out the seating position correctly. Headrest for the seats is about mid-point between the door position and the rear wall. So between 1.0m reclined and 1.2m sitting up. It's enough to allow some room behind to achieve as much of the bubble effect as possible.

 

Bonesey

Standard Member
So a bit more consultation with GIK and tweaking of the planning in Sketchup.

7.1.4 is achievable and hopefully realistic. First image shows view from above and to the front of the room. Acoustic treatment has been adjusted slightly and I had mistakenly placed an extra Absorber in the middle at the rear of the room that wasn't needed. I've also reduced the height in order to place an AV tower there but really struggling to find a decent priced one that suits.

Second image shows corrected 92" screen size (instead of 100"). Not pictured is the three acoustic clouds on the roof that sit in between the two forward Atmos speakers.





Current choice of equipment: (±£15,000)

Remote control - Harmony Elite
Bluray player - Panasonic DMP-UB900
AV Receiver - Denon AVR-X6400H
Projector - OPTOMA UHD65 DLP
Projector mount - Optoma OCM818
Screen - Acoustic transparent 92"
Speakers - Monitor Audio CP-WT240-LCR for front, left and center, CP-WT150 for surrounds, CP-CT150 for ceiling speakers and CW10 for subwoofer.
Seating from HomeCinemaSeating
Acoustic Treatment from GIK (or similar)
Media tower - BDI Mirage 8222
 

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