• Welcome to The Audio Annex! If you have any trouble logging in or signing up, please contact 'admin - at - theaudioannex.com'. Enjoy!
  • HTTPS (secure web browser connection) has been enabled - just add "https://" to the start of the URL in your address bar, e.g. "https://theaudioannex.com/forum/"
  • Congratulations! If you're seeing this notice, it means you're connected to the new server. Go ahead and post as usual, enjoy!
  • I've just upgraded the forum software to Xenforo 2.0. Please let me know if you have any problems with it. I'm still working on installing styles... coming soon.

Heeman - WI Basement HT Build

heeman

PRETTY HAPPY.........
Famous
Okay, we are in contract on a home in Jackson, WI. A well built 1710 sq ft home on almost a half acre backing up to open space. The thing that we are thrilled about is the BASEMENT!!!

We have not owned a home with a basement since 1997.

This basement is dry and a clean slate. There is an area in the basement where they put an egress window and plenty of space with no support (lolli colums).

I am already planning the HT Build and have a very preliminary question as far as shape.

Are there any acoustical benefits to varying the shape from a normal rectange to a room the is slightly narrower in the front and wider in the back?

If so, how much?


I may also go for an IB Sub setup since I am working from a clean slate.

This build will be much more fun than the first................

Yea Baby!!

:music-rockout: :music-rockout: :music-rockout:
 
Keith,

I have always been under the impression that boxes and rectangles are not ideal and non parallel surfaces help. I think this applies in speaker design as well as room layout. Snell and some others use this a lot. A room that is wider in the front than the back may help tame some acoustical anomalies.

As has been discussed here before you can check some of the interwebz sources as well as the experts here.

http://www.cinemasource.com/articles/ro ... modes.html

http://thehometheaterbook.com/home-thea ... imensions/

http://www.diymovierooms.com/Home-Theat ... e-and-Size

http://www.hometheatershack.com/forums/ ... sions.html

Good luck and this should be fun watching your build progress.
 
heeman said:
Are there any acoustical benefits to varying the shape from a normal rectange to a room the is slightly narrower in the front and wider in the back?
Yes, absolutely. You'd be eliminating (or at least reducing) the problems associated with parallel walls. To what degree is the benefit? I don't know but have a feeling Flint and rammis will offer some helpful information.
 
That location is under 5 miles from the old farms I was at when growing up.

I hope you enjoy the brats, Beer, and wine.

Just North is West Bend and off 144 you will find a state park
Lizard Mound. Indian burial .
 
The non parallel walls will be a help on the first reflection points and help to move them further back into the room. They will not help in controlling the base with 80 hz being a sound wave of around 14 ft. So the big thing here is the first reflection points and the different size of the walls. If the walls have different length and width they will have a different room mode on each of the 6 surfaces.
This distributes the room modes and keeps any two or more from being on the same frequency.
Reducing the number of peaks or nulls in the room.
 
This will be a fun project to watch indeed!! Filint has posted a drawing of his "ideal" room which is pentagonal with a sloping ceiling. You are going down the right path for sure.

Enjoy!

John
 
Ideally you wouldn't have any two large parallel surfaces. Generally, having the front wall a smaller dimension than the rear wall and angling the rear wall somehow is a good approach. Then make the ceiling slightly slanted where it is shorter in front than in the back.
 
I like the looks of that room Flint. Now, if I only had a room where it were doable.
 
Using dimensions of nothing but prime numbers can't hurt either.

Something like 13"W at the front and 17'W at the rear with a length of 29' or 31'. As for height, maybe 7'H in the front and 11'H in the rear.
 
I like the way youre thinking Zing. 11" at the rear might be difficult and the 7' to 11' slope seems like it might get steep aesthetically and a little more difficult to build but those dimensions would certainly avoid dimensions that are multiples.
 
Flint said:
Something like this....

Just curious what the pro's and con's would be.............

Is it worth it, or just stick to a rectangle with typical absorption and dispersion treatments?

????????????
 
heeman said:
Flint said:
Something like this....

Just curious what the pro's and con's would be.............

Is it worth it, or just stick to a rectangle with typical absorption and dispersion treatments?

????????????


Something like i drew would make a massive difference, especially if the ceiling is also angled. Not only would there be much less need for reflections absorption, but the bass would not have the multiple node issues all falling on the same note in the scale. Because the room is not huge, there will still be a bass resonance based on the volume, and some smaller reflection nodes, but they would be dispersed across the bass range more randomly.

If you've ever had that one song where one bass note just blew out your ears, our a certain important pedal note in the music was completely inaudible, that would not happen in a room like I drew.
 
What would the acoustic results be if the front corners were identical angles but the rear wall had a slightly more dramatic angle so it were not parallel to the front/screen wall? And then the multiple planes along those two wall were eliminated to make the build a little bit easier?
 
In my drawing the front corners and rear corners with right angles, so make building easier.

Batman - I don't understand what you are describing. If the rear wall is not parallel to the front wall, it would help for that standing wave (front to back), but that's about it. And, if the room is a long rectangle, you would be addressing the smallest two walls. If one were to address only one set of parallel walls, the ceiling would be the best choice followed by to next two longest walls, which are the sides in most HTs.
 
I noticed in your drawing that the front wall has two angles at about the 1/3 mark and 2/3 mark. I'm suggesting make that wall straight and then have both the two front corners be maybe 92-93° And then maybe make the left rear corner be the same range (92-95°) without the one or two angles along the plane of the rear wall. So you basically have a trapezoid but the two rear corners are NOT the same angles. It would be a little easier to build also because 3 or 4 angles along the front and rear walls would be eliminated. And one could still angle the ceiling the way they want. The seating could be oriented parallel to the screen and the right rear surround would be just a little further away from the seating area than the left rear surround....which can be compensated for during calibration. This is of course if one course live with slightly less than perfect symmetry.
 
Ideally the room would be symmetrical from left to right. If the rear wall isn't symmetrical, reflections will be aimed to one side of the room and bass will build up in certain locations unevenly.

As for the front wall in my drawing, that was just to make it easy to draw, it could be a straight wall right up to the middle point where a column feature could be added to give you the ease of butting up an odd angle from each side.
 
Back
Top