65 replies to this topic

[Chicken Man]

Mark , I am not sure what point we are to debate here.

You will likely hear a difference ....but is it better ? I think not. .......This my own personal opinion.

You should know from experience that installing a stand-alone loudspeaker in a wall (an infinite baffle) will change its low frequency response, it will also change the dispersion characteristics of the loudspeaker too . Open baffle loudspeakers are even more sensitive to room placement than are sealed or reflex systems.
We are talking here about stand-alone loudspeakers being fitted with an external baffle for the sake of projecting 'its sound' into the listening space, not a completed system such as yours with an angled baffle where the front speakers are acoustically aligned.
A curved baffle will focus sound in the direction of the viewing area, which gives a desirable audible intimacy with the movie, it is much like cupping one's ears with one's hands when listening to music or whatever. So doing must change the audibility of sounds that would be normally camouflaged by room acoustics.
If you were to take away the surrounding baffle of your 3  front speakers you would notice a definite change in the intimacy of your movie experience. The baffle is acting as a reflecting plane for the front speakers which helps to integrate the sound with the image, but separately located loudspeakers on a different audible and visual plane don't integrate well at all.

C.M

Edited by Chicken Man, 09 June 2012 - 12:51 PM.

[MarkTecher]

Prior, on 09 June 2012 - 10:12 AM, said:

I'm sure your set up sounds great Mark, but you wouldn't be able to do an A/B test, as I would imagine the baffle can't be removed?

Cheers,

Chris

No it can not be easily removed.  The point being, for years I had speaker under the screen on stands and thought it sounded pretty good.  I then created the baffle wall system I have today and was WOW'd with the extra clarity it gave.  I liked it so much, I kept it.  In the past, if I didn't like what I was hearing, I had no reservations to pull it apart and start over.  I've had this now for the best part of 5 years and the ONLY thing I would change if I was to do another is make it larger for a larger screen which would also require a larger room, which I do not have at this time.

Chicken Man, on 09 June 2012 - 12:49 PM, said:

Mark , I am not sure what point we are to debate here.

You will likely hear a difference ....but is it better ? I think not. .......This my own personal opinion.

You should know from experience that installing a stand-alone loudspeaker in a wall (an infinite baffle) will change its low frequency response,

I bass manage so low was never a concern.  Yes it also boosted mid bass slightly, but the EQ is pretty flat in that area anyway, so the boost seems to be for the better in my case.

Chicken Man, on 09 June 2012 - 12:49 PM, said:

it will also change the dispersion characteristics of the loudspeaker too . Open baffle loudspeakers are even more sensitive to room placement than are sealed or reflex systems.
We are talking here about stand-alone loudspeakers being fitted with an external baffle for the sake of projecting 'its sound' into the listening space, not a completed system such as yours with an angled baffle where the front speakers are acoustically aligned.

Well that is one way to look at it.  When I build my current speakers in 2005, they were sealed and designed to be mounted on stands.  As I began integrating them into my CIH systems, I found they worked really well on a baffle and as it turned out, even better in a baffle.

Chicken Man, on 09 June 2012 - 12:49 PM, said:

A curved baffle will focus sound in the direction of the viewing area, which gives a desirable audible intimacy with the movie, it is much like cupping one's ears with one's hands when listening to music or whatever. So doing must change the audibility of sounds that would be normally camouflaged by room acoustics.
If you were to take away the surrounding baffle of your 3  front speakers you would notice a definite change in the intimacy of your movie experience. The baffle is acting as a reflecting plane for the front speakers which helps to integrate the sound with the image, but separately located loudspeakers on a different audible and visual plane don't integrate well at all.

I don't quite get your "cupping hands" remark as that (to me anyway) would make the sound boomy or echo.  Most people that listen to 2CH systems will toe their speakers in as aiming the speakers helps us to hear the steroe image better.   I simply took advantage of the fact that I had room due to building a curved screen that allowed me to do this, but it was done for imaging.  I could have made it flat behind the curved screen.  Certainly would have made the build easier.  

When I built my room, room acoustics was of a very high priority.  I wanted to address reflected and reverberent sound issues that plague pretty much evry HT I have heard (and I've heard allot or rooms).  In my case, one might think I over did it, but it works and there is no way I would use any less treatments now or in a future build.

If you clap your hand in front of the screen, all you hear is the clap.  It sounds odd because the usual reverb we normally hear is not there.  What this means is that the ONLY reflections or echos I hear are those recorded in the soundtrack itself.  A different story at the back of the room where I wanted some reverberation for the aid in spaciousness for the surrounds.  What I want to add is more diffusion here as I only have the one diffusion tile and would love to add another 20 or so to completey break up an reflections that occur here.  Diffusing tiles keep the room live without echo.  

I am currently working on a heated vacuum form to make these tiles, so the only expense will be the materials.

[Chicken Man]

MarkTecher, on 09 June 2012 - 01:58 PM, said:

No it can not be easily removed.  The point being, for years I had speaker under the screen on stands and thought it sounded pretty good.  I then created the baffle wall system I have today and was WOW'd with the extra clarity it gave.  I liked it so much, I kept it.  In the past, if I didn't like what I was hearing, I had no reservations to pull it apart and start over.  I've had this now for the best part of 5 years and the ONLY thing I would change if I was to do another is make it larger for a larger screen which would also require a larger room, which I do not have at this time.



I bass manage so low was never a concern.  Yes it also boosted mid bass slightly, but the EQ is pretty flat in that area anyway, so the boost seems to be for the better in my case.



Well that is one way to look at it.  When I build my current speakers in 2005, they were sealed and designed to be mounted on stands.  As I began integrating them into my CIH systems, I found they worked really well on a baffle and as it turned out, even better in a baffle.



I don't quite get your "cupping hands" remark as that (to me anyway) would make the sound boomy or echo.  Most people that listen to 2CH systems will toe their speakers in as aiming the speakers helps us to hear the steroe image better.   I simply took advantage of the fact that I had room due to building a curved screen that allowed me to do this, but it was done for imaging.  I could have made it flat behind the curved screen.  Certainly would have made the build easier.  

When I built my room, room acoustics was of a very high priority.  I wanted to address reflected and reverberent sound issues that plague pretty much evry HT I have heard (and I've heard allot or rooms).  In my case, one might think I over did it, but it works and there is no way I would use any less treatments now or in a future build.

If you clap your hand in front of the screen, all you hear is the clap.  It sounds odd because the usual reverb we normally hear is not there.  What this means is that the ONLY reflections or echos I hear are those recorded in the soundtrack itself.  A different story at the back of the room where I wanted some reverberation for the aid in spaciousness for the surrounds.  What I want to add is more diffusion here as I only have the one diffusion tile and would love to add another 20 or so to completey break up an reflections that occur here.  Diffusing tiles keep the room live without echo.  

I am currently working on a heated vacuum form to make these tiles, so the only expense will be the materials.

I 'project' the sound of my rear surrounds onto curved panels to assist with diffusion. I actually find this more of a problem to get right than the Front and Centre speakers as the rears are more widely spaced than the Fronts and are not idealy placed.

My batcave is 5 x 5 x 2.5 metres, almost perfectly half a cube, which is hardly optimal for good sound reproduction so it is selectively fitted with bass traps in troublesome spots along with carpeting and padded drapes . I think I will have another shot at it next year when my finances permit.

Building a flat-white, plastic membrane AT screen is set to be a near future project of mine as I find the present arrangement of my front and centre speakers could be better integrated with the screen.

C.M

Edited by Chicken Man, 10 June 2012 - 12:57 AM.

[SDL]

Mark you say you had the speakers on stands before and now are mounted in your baffle wall. My speakers are firmly mounted on solid shelves behind the screen and I have no issues, I have listened very carefully and there is no gap in the sound or noticeable movement from one speaker in the LCR series to the next. Not suggesting baffle walls don't work, but don't think they add a hell of a lot unless you have issues in the first place you are trying to fix,

[MarkTecher]

SDL, on 10 June 2012 - 09:47 AM, said:

Mark you say you had the speakers on stands before and now are mounted in your baffle wall. My speakers are firmly mounted on solid shelves behind the screen and I have no issues, I have listened very carefully and there is no gap in the sound or noticeable movement from one speaker in the LCR series to the next. Not suggesting baffle walls don't work, but don't think they add a hell of a lot unless you have issues in the first place you are trying to fix,

If they don't really add anything or there to "correct" issues, why do the best engineered rooms all have them?

[oztheatre]

MarkTecher, on 10 June 2012 - 07:08 PM, said:

If they don't really add anything or there to "correct" issues, why do the best engineered rooms all have them?

Maybe because if you're going all out, you might aswell put one in. Not like it's going to cost a fortune so why not do it?
And if done right I'm sure there's a benefit to be had, otherwise they wouldn't be used at all.

[SDL]

Exactly, there may be some small benefit, but it is a bit of a leap to suggest without one you have gaps on the sound. To me it is playing with the small percentages. Its a bit of a power cord debate really.

[MarkTecher]

oztheatre, on 11 June 2012 - 12:50 AM, said:

Maybe because if you're going all out, you might aswell put one in. Not like it's going to cost a fortune so why not do it?
And if done right I'm sure there's a benefit to be had, otherwise they wouldn't be used at all.

Umm, not really, no.  They put them in for the acoustic benfits, not because they can afford one.  Baffle walls work.  Treated baffle wall work better and why THX made them a ""standard" for their cinemas.

SDL, on 11 June 2012 - 12:29 PM, said:

Exactly, there may be some small benefit, but it is a bit of a leap to suggest without one you have gaps on the sound. To me it is playing with the small percentages. Its a bit of a power cord debate really.

So is everything we don't have in our own systems.  You mention power cables,  and I didn't fully understand diffusion until I got myself a molded tile and even though it is a single tile directly in line with the centre of the room, the difference, whilst small is noticeable to me.  From the seting position, it was a non issue to me.  I only realized that I needed to address this whilst standing to one side doing a demo. Then I heard it. It took me a few listens to work out what exactly I was hearing, then off to reserch my options to address this.  Now that I have it, I want more and so I am now in process of makinng myself a Vacuum Forming table for making these out of plastic.

[oztheatre]

MarkTecher, on 12 June 2012 - 10:51 AM, said:

Umm, not really, no.  They put them in for the acoustic benfits, not because they can afford one.  Baffle walls work.  Treated baffle wall work better and why THX made them a ""standard" for their cinemas.



So is everything we don't have in our own systems.  You mention power cables,  and I didn't fully understand diffusion until I got myself a molded tile and even though it is a single tile directly in line with the centre of the room, the difference, whilst small is noticeable to me.  From the seting position, it was a non issue to me.  I only realized that I needed to address this whilst standing to one side doing a demo. Then I heard it. It took me a few listens to work out what exactly I was hearing, then off to reserch my options to address this.  Now that I have it, I want more and so I am now in process of makinng myself a Vacuum Forming table for making these out of plastic.

Well put it this way then. If you can't afford one, you won't be putting one in.

[SDL]

Like anything though,maybe you can afford it but the thousand or more dollars for example might be better in a better transport or better speakers, hard to measure where the money is best spent.

[MarkTecher]

You can build a baffle wall from about $100.00.  I don't think it is a financial consideration, rather the physics (and maybe not fully understanding it) behind it that creates resistance to these things,

[oztheatre]

MarkTecher, on 12 June 2012 - 10:06 PM, said:

You can build a baffle wall from about $100.00.  I don't think it is a financial consideration, rather the physics (and maybe not fully understanding it) behind it that creates resistance to these things,

And the effort involved. It's something people overlook because they've either never heard of it and or only learn about it later.
I realise they're cheap to make so my logic is why not just put one in if you're going all out.

[MarkTecher]

oztheatre, on 12 June 2012 - 10:24 PM, said:

And the effort involved.

It is not like a load bearing wall.  The construction is actually quite simple, though the bigger the screen, the larger the wall and more bracing it will need.  Sheeting can be either double gyprock or MDF.  I've used MDF in all the ones ive done because I can get the speakers cutouts done when the sheets are cut to size. 1" foam is layered over the wall.

[oztheatre]

MarkTecher, on 12 June 2012 - 10:57 PM, said:

It is not like a load bearing wall.  The construction is actually quite simple, though the bigger the screen, the larger the wall and more bracing it will need.  Sheeting can be either double gyprock or MDF.  I've used MDF in all the ones ive done because I can get the speakers cutouts done when the sheets are cut to size. 1" foam is layered over the wall.

Yeah I agree. but when people hear about this stuff, often it's after the room is complete as it can be overlooked. They start watching movies, enjoying the room and never end up adding one in.

[SDL]

Neither a case of not knowing of them,or not being able to do them, just not really convinced about them. Have seen some people who are respected in the field suggest it isn't as easy as it is being suggested and that they can do harm,don't hear any of the problems they are supposed to fix in my own room,so as I say not convinced.

[MarkTecher]

oztheatre, on 12 June 2012 - 11:18 PM, said:

Yeah I agree. but when people hear about this stuff, often it's after the room is complete as it can be overlooked. They start watching movies, enjoying the room and never end up adding one in.

Hopefully towards the end of the year I will get to retro fit a room I did back in 2005.  This room was a great project because I was able to begin at the house planning stage.  The guy sold the house to the new owner and he wants to throw about $15K at it to get 3D Scope and stadium seating.  The room has a set of my speakers and he loves them and wants to continue using them in the upgrade.

SDL, on 13 June 2012 - 09:39 PM, said:

Neither a case of not knowing of them,or not being able to do them, just not really convinced about them. Have seen some people who are respected in the field suggest it isn't as easy as it is being suggested and that they can do harm,don't hear any of the problems they are supposed to fix in my own room,so as I say not convinced.

Well it depends on who you talk to.  There was a select few that will suggest what you have said simply to protect their own business.  They are specialists and want the public to belive that not just anyone can do this.  Other companies like Procella encourage all HT builders to install baffle walls and they ran the couse I did in 2010 where I learned what I did was pretty much correct.  The ONLY thing they recommend is a full height wall where mine is more of a "bafflet" being only the size of the screen.