Axiom Home Page Forums General Discussion Advice from Axiom Owners The HT Room Design

>>What is interesting is that the room dimensions coincidentally come close to fitting the golden ratio.

That was what got me thinking. Playing with Modecalc for a while seemed to indicate that the golden ratio was not actually best for distribution of room modes but it is pretty close. Playing with ceiling height is your only option to fine-tune the modes, I assume, but anywhere between 7' and 8' the results look pretty good.

Question for you -- on the drawing, it looks like the "D" area is the left hand side of the top part of the floor, with the right hand side being "something else". Is that correct, ie will the room's long axis run "up and down" ? Are you going to drywall all around the room or will there be openings ?

Question for all -- in this case (walling off a portion of a larger area) there are two approaches. Making big solid walls gives you better sound absorbtion, gives you even reflections on both sides (imaging) and lets you control the room modes by positioning the walls, but having very thin walls allows you to take advantage of the possibly superior room modes of the larger surrounding area AND benefit from the fact that the room modes extend to lower frequencies because of the larger distance between walls.

In Chess's case the smaller room looks quite good from a room response point of view (decently spaced modes down to 31 hz) but the 20-30hz area is going to be weak. How heavy do the walls have to be before they dominate over the outside basement walls from a room resonance standpoint ?

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20-30hz area is going to be weak.

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Nothing a 600 can't handle, though, right?

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Question for you -- on the drawing, it looks like the "D" area is the left hand side of the top part of the floor, with the right hand side being "something else". Is that correct, ie will the room's long axis run "up and down" ? Are you going to drywall all around the room or will there be openings ?

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That right hand wall will be drywalled indeed. The room itself will be a rectangle except for a small nook that starts underneath the lower venting on that right hand wall which the a/v equipment will be put into. The tv/screen will go against the very top wall while the couches will be more towards the bottom.
I'll add another scan later of a newly sketched design that incorporates some doors and walls although not quite to scale.

As for the second part, weakness in that low bass range can be compensated with several methods: second subwoofer, louder volume gain on present subwoofer or relocation of the sub closer to a corner.
Personally i like the second subwoofer idea.
This system will become primarily HT but any entertaining in the games and wine cellar will be fed by the equipment. I haven't decided yet if i'm going to use zone 2 or whether the distance from this system into the games room will suffice. With 2 french doors opening into the media room, the bottom wall will not be very closed off unless the doors are shut.

Chess:
Have you seen this?

The HT room I’ve been painfully….slowly building, was going to be a bedroom. I could use a HT more than another bedroom, but I don’t want a potential buyer of the home (when I sell), to be stuck with a HT if they want another bedroom.

So I’m running smurf tube from the closet to the speaker locations, and I’m running 2” conduit to the projector area from the closet. All the electronics are going in the closet. The closet is the typical 6’ X 2’ with sliding doors. All the gear will fit just fine, and the conduit and smurf tube will be terminated into a cable tray that no one will notice if this ‘gear rack’ area ever gets turned into a closet again. I’m also building a screen wall, but no stage. The wall will be “floated” over the hardwood going on the floors. The window will get some tight fitting light-block blinds (which are very common in Alaska, and work well).

For sound proofing, the walls and ceiling get sound bats (tight cell fiberglass), and a layer of insulating board – that black crap that itches like crazy and is a nightmare to install because little pieces fall down your shirt……uggg….. But, it’s cheap and works well. Sheet rock will go over the sound board, and some Knotty T&G Pine will be placed up the walls 24” as a wainscoting. Not decided, but I may put the pine on the ceiling as well, just to match the rest of the house.

Now for colors, I’m going with a dark walnut hard wood floor, and a latex satin, dark grey and red paint on the walls, and a satin clear coat on the pine. I hate flat paint because it’s just too friggin hard to keep little kids fingerprints off of it. And semi-gloss will be too reflective.

Will it all work??? Beats the hell out of me, but I’m giving it go anyway. And if a new owner wants to convert this room back to a bedroom, all they will have to do is remove the screen wall and throw some different paint on the walls.

No Mark, i have not yet seen that specific article.
I'll give it a read tomorrow.
thx

mdrew, i have some bad news about the sibilance issue.
I'll post it over in the appropriate thread tomorrow.

Congrats on the new home purchase. Does this mean a new sound system too? I won't attempt to provide any electronic setup advice as your knowledge in this area is way beyond mine, but I will add a couple of points for the gyproc walls and ceilings. I did not hear anything mentioned about "resilient channel". It helps to keep sound in. The rest of the household may like that idea at 2am. It also makes up for uneven floor joist and wall studding. It is normally 1/2" thick so does not take away from the room height or wall space. I would prefer to have a drop ceiling as it allows quick access for updates or problem solving the mechanicals. Maybe not for this house but on your next one is using longer span floor joists to eliminate the dreaded floor beam support posts. Warren truss floor joist are perfect for that or larger JSI's.

Good luck on the project,

Troy

Thanks Troy.
We will be putting in a drop ceiling in the rest of the basement. Only this room and the wine cellar will have a drywalled ceiling. I'm doing it for the acoustic reasons (drop ceilings rattle) but i should have access to one long wall from the utility room on the right side and along the rear wall which will meet up with a drop ceiling outside the wall partition.
In a sense i still have some good access to the ceiling.
We are planning on roughing in for a front projection unit so at least that will be done ahead of time. I can't really think of any other reason to need ceiling access right now, unless i need to fix something upstairs under the floor.