The entire floor is dropped by 180mm. I intend to level it up with Plywood and carpet which will take up about 25mm. The rest of the 150mm, should I fill all up with 3 layers of 50mm rockwool?
Good resource on baffle walls.
A lot of the Avsforum home theatre of the month builds are also baffle walls.
For your main floor, I’ll avoid plywood since there may be spills and if it soaks through, you can’t get rid of the odor and the wood will rot…
Unless you have removable boxes + carpets that can be cleaned?
I will use marine plywood will reduce the amount of water that can be absorbed but not totally.
Will be using 500x500mm carpet tiles.
The plywood will be 500x1000mm. Screwed down. Can be removed if required.
What other option I have to raise the floor?
You could lay a layer of vinyl etc over the plywood, before the carpets. That should take care of any liquid spills.
Does it mean the GXC300 also required 90cm of space behind?
The AT screen will need to be about 1.3m from the wall.
There are two ways to this,
If you have a very large space, you can place the speakers away from the boundary, 2.2m, ie 1.3+0.9m location .
They will be ideal and free from boundary interference. Boundary interference is a result of the bass frequency energy reflecting off the back wall from your speaker, and causing a cancellation with the direct sound .
Another methodology is placing the speakers as close to the wall, or flush mount it to avoid the existence of a boundary. That way there is no energy reflecting off the back wall.
The rule of thumb is the closer your speakers are placed against the wall, the higher the null frequency/ cancellation frequency/ Null is. You then have less distortion and higher output from boundary gain, getting the phase & timing correct is a lot easier
Doesn’t mean the cancellation won’t happen , it’s just that we are now shifting the cancellation frequencies to a higher frequencies so we can use effective absorption panels to handle the bass
When you do that and you now have a crossover of 100hz, sending all those energy to the subwoofers, you now possess the capability to place the subwoofers in any part of the room to handle these cancellation frequencies
When you go full range, You cannot move your main speakers. Because u need to maintain the stereo imaging and balance. But you will suffer from these room modes. Hence I would advise you not to go full range.
Since you have the same speakers, it’s a lot lot more easier… when I get home, I’ll pull out the data I have on this…
I’ll explain here, exactly why one should not go full range , but instead use the subwoofers to handle Low frequencies where you have tons of options for subs placement and acoustic treatment to bring your system to nirvana
On how much toe in and how u intend to bring the best out of the MA, there is a strategy to doing this, using the Schroeder integral. It is pretty complex if you are not familiar with REW.
Everything will play a part, from your placement, to your room to acoustics to the degree of toe in and finally using sound test patterns to dial in the imaging
Then we have vibration control and how to prevent things from rattling in the room etc etc
It’s a lengthy process but u will need someone to help u if you are to bring the set up up to nirvana stage
There are just too many stuff on the internet, sometimes it can be time consuming , but it’s fun.
In short the fundamentals of this is , you gotta get these right.
- Room acoustics
- Noise , electrical , internal, external
3, vibration control - Placement
- Integration
Happy to host you one more time, to explain in detail the things you can try and should avoid.
If at the end of the day, you liked what u hear, you should follow that path to nirvana. If on the contrary, if you get the chance to listen to a set up that does full range and love it, take that path instead.
At the end of the day, there is no right or wrong, just preference.
But one thing I’m certain, the numbers don’t lie. I have accumulated enough experience to tell instantly how the room is gonna sound just by looking at the numbers.
We can’t defy physics
Ronildoq, Great Thanks for the detailed advice.
Most certainly delighted to go to your den again. That is a reference setup!
I have decided to switch the layout 180 deg.
- Now there are 0.6m to 1.8m behind the front speakers.
- The screen size is reduced from 4.6m wide (200") to 3.5m (160") at advice by wechnivag via a long and detailed whatapps. great thanks!
- The wider side will give 1.5m space between the wall and edge of sofa. Now I can use MA Gold 100 as he surround side speakers.
- The in wall 380 will be moved to use as surround back speakers
- Will put front sofa on slider or wheels. to move away when doing golf simulation.
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Bro, you’re the expert here, but maybe I can ask if it’s a better idea to do the room treatment after he moves in, since the room is a more peculiar shape?
Courtesy of Gavin:
Some diagram and response plots to illustrate the effect of baffle step and benefits of a baffle/screen wall design.
Effect of the baffle step
Mounting the speaker in a cavity causes some pretty nasty problems
It can be done after he moves in, no problem.
There is no other way if the shape is odd, we need to measure since the room simulation will no longer work
It’s gonna be challenging and we will need to find the spot where the multiple subs are helping each other
Try and cater for a spot for subwoofers at diagonal front back positions . Take advantage of the boundaries, where the subs can be placed at trihedral sections of the room.
Over the years, I’ve tried many different approaches, from “Geddes technique “, to ‘welti” approach , “parham” approach and when I finally got the lyngdorf, I see clearly why methodology from lyngdorf works best. In their videos and interviews, they advocate having subs at corners and boundaries, with 1 main advantage in mind, Timing. That’s what they strive and advocate . Because in their approach, the explanation is very simple . I explain in layman terms
The claim is, like it or not, the room is always a part of the equation for us. We have to work with the room, there is no two ways about it . We cannot escape the room. Then peter lyngdorf explains it further, he said, when you place the subwoofers at the corner of the room, the SPLs go up as a result from boundary gains. When u place it in the middle of the room, you may get a smoother response at the listening position, but notice that your SPLs are lower, compared to the subwoofers placed corners of a solid wall.
We were puzzled, so we thought, hey, we want a smooth frequency response ! Don’t we all strive for that ?
He says, when the subwoofer energy radiates in omnidirectional frequencies, when it sums in phase, do you get a gain in SPLs ? The answer is yes, you have a gain when the frequencies sum in phase. When there is a cancellation, the SPLs reduces, that means there is a lot of frequencies having cancellations and the results are you have phase issues at other frequencies.
This makes perfect sense to me, because what we are after, is not the subwoofer decay time, but the decay time in the room itself. When most of the energy in the room is combining and in phase, they rise fast, they also stop fast
This is why I can tell u, a solid boundary is where you should place the subs, ideally 1 front 1 back.
This is just one small part of the story…
Hey bro, I think we have the same taste. Personally I love the ribbons from the GX300.
I don’t play those Metallica or concert stuff etc. So the speakers really suit my taste and there is no sense of fatigue from long hours listening to them
It’s a lot easier to explain when u pop by because i have the same set of speakers and all the measurements data on the laptop
Nice u get to use the same speakers for surrounds. I can’t find any GX300 for surrounds, they are no longer available . Coherence is important and having all 5 same will help for sure
Yes let’s catch up offline. Once u have decided with the layout, I can help you out with the measurements and acoustics
It will be easier when u pop by, listen to the variances, then make a calculated decision on your next step. Then if it works and u like what u r hearing, u just follow up and execute
I believe u will be one happy man at the end of the day.
Partly teasing him but I don’t think those MA will be there when the dust settles 
I’ll say when all the equipment comes in and it’s the final setup then he measures
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I watched the Anthony Grimani video with Gene. The idea of hiding acoustic panels behind pulled fabric wall is fabulous. If aesthetic is a concern, doing the room treatment before setting up the equipment may be a good idea.
Just like Ron, hiding all the acoustic panels and speaker behind the AT screen
Great advice by Gavin, I think the reverse is good, with a 160 inch screen. u need the width for the surrounds, they can be very very immersive when dialed in with subwoofers to have that physchoacoustic bass steering effect when used with a lyngdorf processor
If you can have the subs at the areas marked in green or red, they should be good. (Green preferred) Or if possible on all 4 locations. Or stacked at green locations
Having the odd shape room is not really bad, there is very less chance of bass cancellation. Do note that the pressure zones behind MLP is the focus, but at this room length, it will be manageable. 2x 15” subs looks insufficient though, but it’s a good start , depending on how bass crazy u r.
I have 2 units of Rythmik E15hp. Can add 2 more if required.
After the room acoustic is done, next will be the projector as the current JVC X7900 will be move to MBR.
Was thinking of JVC N7 and Gavin educated me on nits and fL. For good HDR, ideally will be 40fL. N7 is only 24 fL at 160". So need to allocate money for a higher end projector. Wrote to SIM2 and they are hooking me up with a local dealer.
After the projector, then I look at the pre-pro and then the amp. now I am using X6300, parasound for left and right, rotel for center and 4 surrond and emotiva for ATMOS.
Was reading a few articles comparing Lyndorf and Trinnov. read until headache hahaaa.
If you haven’t yet gotten the subs, I would suggest you go for the JTR RS2, 18” subs, to provide the extension down Low frequencies.
These subs should fill in the room with adequate energy and still have ample headroom
Again if you run the speakers in full range, you will not be able to enjoy details down the lower octave…
Say for example if the subs that you use is a 12” subs and they are only good down to 30hz, adding a sub here doesn’t really give u the full benefits. Because the speakers are already able to run down to 30-40hz range. However, when you go 18”, they can provide the extension down to single digits, at least if it was the JTR subs. So you will want to use a subwoofer, that will provide something that the speakers will find hand to reproduce. This is where again, running the speakers full range is never a benefit.
Even if u run it large, they now handle the same range of frequencies, and instead of complementing each other, they are now fighting to re-produce the same frequencies. When that happens, again you have to start dealing with frequencies cancellation problems that could have been avoided in the first place
What we are trying to improve in the set up, is resolution and details. Details that the speakers are not able to reproduce without any form of distortion . This is where a subwoofer with good extension down lower frequencies, comes into play to supplement the entire set up
The moment you push the speakers, playing uncompressed audio etc, the speakers start to stress, what follows is loss of headroom, what follows after that is distortion
A lot more to follow, stay tuned… I’ll advise along the Way, including your room layout, and what all these means… as easy as possible to understand
As for processor, both the lyngdorf and trinnov are very good processor. If you need my honest opinion, my personal take is this
The DAC and the Object placement (processing of Atmos Signal) is superior to many processors out there . However, you will a professional calibrator and they are not cheap
The Lyngdorf is superior when it comes to bass management. The room perfect is simple to use as the system time aligns every single speaker to every single subs. Auro Calibration times can run for more than 2hours . Object placement and DAC is not as good compared to the trinnov. I can guide you woth lyngdorf as I own one, without having to pay a hefty calibrator fee
Continuing with placement of the subwoofers. When you place it at the corners, the subs placement should go like this pic below , leaving an air gap behind
Not this way like the one below
Very important is to isolate the subs from the ground, lifting it, so it doesn’t introduce any unwanted distortion by transmitting energy through the floor.
One of the best methods I have found , and that I’m using now , is to use a 6mm cork and sorbothane in combination under a 4cm granite base that will provide the mass. And then when you can, get your carpenter to build something like this with an air gap, sturdy.
This will work as a pressure plate absorbing Low frequencies pressure moving downwards
Then place your subwoofers on top of this removing the original footers
Following up with that, get steel shots of 25kg each, and place it at the top cabinet of the subwoofer
You will then have a good head start now, the energy moving through air is so much more controlled in the lateral direction and what follows is extremely fast transient attack and decay times with very Low distortion .
You now have a decent isolation that when played loud, will not disturb your neighbours downstairs. A lot of benefits if u ask me.
- No disturbances downstairs even at loud volume -5mv
- Fast attack and decay times
- Good timing response
- Controlled cabinet resonances
- Articulated bass
With this approach, you are heading in the correct direction. Whilst I agree there are many ways, by SLE or TPE or BKE… this methodology is proven and at least verified.
What I find important is that you need to follow the right source/ people/ studios/ room when building your theatre room . When I visited the dolby studio back then, my intention wasnt really to go and enjoy and listen to how good the room sounded. They had tons of speakers like 15 to 20 speakers playing. That won’t apply in our homes. More speakers just means more problems to deal with. My main purpose was to observe “ why they do it that way”
As mentioned, there are so many ways, but why didn’t he take SLE? He took BKE instead.
I shared that in XP forum some years ago, the reason it sounded so good was because the studio had very good room criterion. The noise was extremely Low and the dynamic range was good. Somehow I got into some argument with another member called badenglish, who just doesn’t understand or agree to the benefits of why we need to have a room with Low noise
So that was one part of the journey that I followed. And this is also what I think you can try and follow. That is why I need to host u, after u listen to the set up and u like every bit of it, u just need to follow closely what I have done. You will get there …
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Low floor noise is indeed important to me. Can hear more details even at a lower volume. (Bro, no 5mv for me at home)