jst01 Posted April 10, 2007 Posted April 10, 2007 Mark, How do you find the OZTS Acuvision screen? I'm considering that screen or an SMX screen. How do you think they compare? I've no idea what the pricing is on OZTS screens.
CAVX Posted April 11, 2007 Posted April 11, 2007 Mark,How do you find the OZTS Acuvision screen? I'm considering that screen or an SMX screen. How do you think they compare? I've no idea what the pricing is on OZTS screens. Have not had a chance to test it yet... Mark
mgrobins Posted April 11, 2007 Posted April 11, 2007 By putting the centre channel right in the middle of the room you are equally 'exciting' the room acoustically. If you place the centre channel slightly off centre [just slightly] you will get a smoother response with a better more natural room decay. You want to aim for unequal relfection paths along the floor side walls, front wall etc. You can easily see this by a simple experiment with a spectrum analyser measuring both options. Its easy to demonstrate. The results are quite palpable and it is worthwhile doing with an acoustically transparent screen. The shape of your room will determine the requirement for this (and the HT screen placement). If your screen is already off-centre or the room is not an oblong then I'd suggest experimenting. As an example I had an L shaped room that acted to focus acoustic energy from one of my speakers such that it was louder around the corner in the L.... Not the prime viewing position I can tell you! Edit: Mark who let you back on here lol!!
CAVX Posted April 11, 2007 Posted April 11, 2007 The shape of your room will determine the requirement for this (and the HT screen placement). If your screen is already off-centre or the room is not an oblong then I'd suggest experimenting.As an example I had an L shaped room that acted to focus acoustic energy from one of my speakers such that it was louder around the corner in the L.... Not the prime viewing position I can tell you! Edit: Mark who let you back on here lol!! Apparently it was my email change that was the problem Anyway, I might try and assemble the screen this week end... Mark
JoshH Posted April 11, 2007 Author Posted April 11, 2007 The shape of your room will determine the requirement for this This is true - I should have added that I was talking about regular shaped rectangular theatres. Odd shaped rooms are much more unpredictable and as result often a lot more difficult to deal with.
Tweet Posted April 11, 2007 Posted April 11, 2007 This is true - I should have added that I was talking about regular shaped rectangular theatres. Odd shaped rooms are much more unpredictable and as result often a lot more difficult to deal with. Of course seating and other furniture in the room will help break up the symmetrical sound patterns anyway. With all that refraction and reflection its a wonder one can make any sense out of the sound we hear in a typical room. C.M
CAVX Posted April 11, 2007 Posted April 11, 2007 It is documented that human hearing is more sensitive horizontally than vertically which is why we can get away with breaking the horizontal plain with the LCR speakers. When it comes to the width of the sound stage, it is also documented that some people can hear within just 4 degrees of horizontal shift, but less than 4 was not audible. I read an article about shifting the centre speaker off the centre axis to help with room modes. It suggested that a shift no greater then 3 degrees would work... Mark
JoshH Posted April 12, 2007 Author Posted April 12, 2007 I read an article about shifting the centre speaker off the centre axis to help with room modes. It suggested that a shift no greater then 3 degrees would work... Yes - I agree with that thats why I said above it just has to be slightly off centre. And it definately does make a difference.
CAVX Posted April 12, 2007 Posted April 12, 2007 Yes - I agree with that thats why I said above it just has to be slightly off centre. And it definately does make a difference. In my case, I will be able to shift the whole LCR rig (screen and baffle) over a touch... Mark
mgrobins Posted April 12, 2007 Posted April 12, 2007 With all that refraction and reflection its a wonder one can make any sense out of the sound we hear in a typical room.C.M As long as it's not a nagging wife you're hearing you should be ok. I thnk that's the only sound every married HT enthusiest has tried to totally mask out .
CAVX Posted April 12, 2007 Posted April 12, 2007 As long as it's not a nagging wife you're hearing you should be ok. I thnk that's the only sound every married HT enthusiest has tried to totally mask out . whilst she is out of the room - Mark
JoshH Posted April 12, 2007 Author Posted April 12, 2007 every married HT enthusiest has tried to totally mask out You cant EQ it out either.... I tried
Tweet Posted April 12, 2007 Posted April 12, 2007 It's the ' fuzzy' logic they run on that gets me. ...... C.M
Gino Posted April 12, 2007 Posted April 12, 2007 By putting the centre channel right in the middle of the room you are equally 'exciting' the room acoustically. If you place the centre channel slightly off centre [just slightly] you will get a smoother response with a better more natural room decay. You want to aim for unequal relfection paths along the floor side walls, front wall etc. You can easily see this by a simple experiment with a spectrum analyser measuring both options. Its easy to demonstrate. The results are quite palpable and it is worthwhile doing with an acoustically transparent screen. Is this more applicable or significant to those with smaller rooms, and/or those with AT screens? What if I were to build a room with non-parallel walls?
CAVX Posted April 12, 2007 Posted April 12, 2007 Back on track All rooms have room modes. Moving the centre speaker slightly off the centre axis will work in all size rooms. Rooms with non - parallel walls (side walls) will still suffer the some of the effects but calculting them is much more difficult. You still have the front/rear wall and ceiling floor room interactions to take into account. You could make all 6 surfaces non parallel, but that might require some expert advise. I'm sure Worx is up for the challenge... Mark
The_Preacher1973 Posted April 12, 2007 Posted April 12, 2007 What if I were to build a room with non-parallel walls? Well if you do that you may just tip the scale from people thinking you're eccentric to just plain crazy. I like it.
Gino Posted April 12, 2007 Posted April 12, 2007 then my work here will be done I do like the idea of not just the side walls, but the roof and floor being non-parallel
CAVX Posted April 12, 2007 Posted April 12, 2007 then my work here will be done I do like the idea of not just the side walls, but the roof and floor being non-parallel Visit any "well designed" cinema and you have exactly that... Mark
Taki Posted April 12, 2007 Posted April 12, 2007 The off center logic also applies to all positioning in the room. Don't want to put speakers center with any dimension. So this includes not only left to right, but also up and down and front to back. Same goes for the seating area. Worse place for sound is dead middle of the room. Also try to avoid sitting in the middle of the width dimension (eg. 2m in a 4m wide room) The best seating area for sound is 38% from either the front or back wall. This is the space where least acoustical problems exist. It's funny how much these free adjustments can make to the sound. Unfortunately, most people prefer to buy bigger amps and speakers, instead of simply moving the speakers and seating in the optimal locations and putting up some basic acoustic treatments.
JoshH Posted April 12, 2007 Author Posted April 12, 2007 It's funny how much these free adjustments can make to the sound. Unfortunately, most people prefer to buy bigger amps and speakers, instead of simply moving the speakers and seating in the optimal locations and putting up some basic acoustic treatments. AMEN. Usually the best improvement made to most ppl's home theatres is correcting their seating and speaker postions. Is this more applicable or significant to those with smaller rooms, and/or those with AT screens? Both. All rooms have room modes. Moving the centre speaker slightly off the centre axis will work in all size rooms. Rooms with non - parallel walls (side walls) will still suffer the some of the effects but calculting them is much more difficult. You still have the front/rear wall and ceiling floor room interactions to take into account. You could make all 6 surfaces non parallel, but that might require some expert advise. AMEN again! I'm sure Worx is up for the challenge... Bring Money
CAVX Posted April 12, 2007 Posted April 12, 2007 Even though I have referred Worx, it doesn't mean I won't have a crack at it for you either Gino. I'm just not THX certified is all... Mark
Curious Posted April 12, 2007 Posted April 12, 2007 Even though I have referred Worx, it doesn't mean I won't have a crack at it for you either Gino. I'm just not THX certified is all...Mark Reminds me of an old saying: "I'm not a gynaecologist, but I'll have a look at it for you..."
mgrobins Posted April 12, 2007 Posted April 12, 2007 Find a really well built theatre and work out the raitios they use Gino... might get you in the ballpark for your room dimensions. I'd love to do some acoustic treatment in my HT to improve the audio but I don't think I have the wall space... One side wall is basically a bookshelf, window with wooden blind (blocked out behind so maybe I could drop the blind and do something here). Front wall is my non AT screen which almost takes the entire width. I guess smaller rooms can be a problem in this regard. (Mark if you have any suggestions feel free to PM me or post here.... you've seen my HT room a few times).
Gino Posted April 13, 2007 Posted April 13, 2007 Reminds me of an old saying: "I'm not a gynaecologist, but I'll have a look at it for you..." classic When the time comes I'll be sure to ask the experts, for the ht room design that is
Recommended Posts