How to Setup Your Room for Atmos and Immersive Audio

@donavabdear

This is one of the reasons I like Tom Holman’s work. BTW, if you haven’t checked out @mikelavigne virtual system yet I think you’ll find it a great (perfect?) example of room setup:

Tomlinson Holman research on wide’s states:

1) The front half of the room is more important than the back half!
What is perhaps the most repeated mantra I heard during my visit was how the decision to add 2 rear channels when 7 channel sound offered itself as an improvement over 5 channels is according to Audyssey, a serious error. IF these extra channels are available, they should be added to the front, NOT the rear. Why? Human hearing has far better spatial acuity in the front of us than we do behind us. According to Tom Holman, we can resolve auditory spatial information to about 1 degree in angle in front of us from right to left, (Horizontal plane) and about 3 degrees in height (Vertical plane). Both of these sensitivities are far greater than what we have for sounds coming from behind us. Hence Audyssey’s preference of multiple channels in front and sides, and one required for rear channel sound.

2) Width is more important than height!
Width is crucially important in placing instruments and recreating acoustical space. Concert halls with side walls perpendicular to the stage are considered by experts on the subject to be acoustically superior spaces to fan shaped halls. One of the reasons here is the importance of the early reflections from the right and left side walls perpendicular to the stage. In the "fan shaped" concert halls, the splayed side walls did not support the same kind of early reflections and are one of the main reasons these halls are not judged as good by the experts. To quote Mr Holman, "it is known in concert hall acoustics that the first side wall reflection is the single most important reflection direction, it sets the auditory source width... Channels constrained to plus/minus 30 degrees are too narrow for that". For this reason, the DSX standards (7.1, 9.1 and 10.2) support a left wide and right wide channel at plus/minus 60 degrees to reproduce the kind of side wall reflection you would hear if you were seated in a great concert hall."

@kota1

as far as number of speakers, past a certain number it’s more a room size and immersion by degrees issue. and then there is the reality that to get the best processor and the best feature set, that’s Trinnov, and their entry level is 16 channels (which can be expanded to 20 if need be).

i went from my Anthem AV60 with 7.1.4 to the Trinnov with 9.3.6 the quality difference of what i heard profound. same speakers, just a couple more of them. but night and day. the processor quality difference was game changing. and also the ability of the processor to ’re-map’ the locations of your speakers can make all the difference depending on your room challenges. i have a side window and side patio doors which effect where my 2 side speakers can be. no problem with the Trinnov, it will ’steer’ the perceived location with it’s set-up wizard.

pure magic.

so more speakers only help if the processor is up to the task of optimization.

and the Trinnov is really just a very large powerful computer, not any off the shelf chip set. and completely software based. so upgrades are downloaded and easy. little worry about the normal obsolescence as movie sound evolves.

@mikelavigne

That is very helpful, thank you. I have been in the Marantz ecosystem and felt that everything at the $3K to $7K price point was more of a lateral move regarding features than a step up in SQ, regardless of the brand. There was a night and day difference when I stepped up to the paid Audyssey license and a calibrated mic so the DSP is very important. @brianlucey is a mastering engineer who is mastering in Atmos and gave the Trinnov very high marks. He felt it was essential and to your point, it wasn’t about the channel count but their proprietary DSP. Thanks for the heads up. BTW, I had an issue with a picture window on my right wall. I didn’t want to block the light with a heavy acoustic or blackout curtain. I hung an acoustic lens 3D diffusor (auralex) that let’s the light pass through. It may not be very attractive but completely resolved the acoustic problem that was plaguing my MLP from the window without blocking it.

@donavabdear

You have the "magic" ingredient to knock your sox off immersive audio, POWER. Your Genelec speakers are already TRI-AMPED! Why not make THAT system the ONE and make your HT about your chill space?

With your background there isn’t any reason you couldn’t have a killer studio at home. You got the ears from your years in the studios, now get your home studio acoustically the way you want. You know some engineers actually prefer the ASC Attack Wall over a traditional space. You can set them up on a dime.
You got the speakers, you got the IP, now what about the space?

Measurements??

@kota1 The more I think about it and the more I play with my panning joysticks on my ProTools S4 control mixer I'm thinking symmetrical is not the proper layout for surround channels. In my Home Theater everything is symmetrical and fairly large, I set it up with and without the Lyngdorf Room Perfect DSP it doesn't really make a difference except it seems to turn up all my surround sound speakers. My professional system is not symmetrical other than the front L, C, R speakers and it images perfectly with or without the DSP. I think our brains are fooled by symmetrical surround sounds, symmetrical is not natural nothing really happens like that and our brains can't process rear surrounds coming from equal and opposite angles. Therefore I'm keeping everything a little off of symmetrical and leaning on the object orientation of the phantom channels. I've never heard of someone going about it this way before, the speakers are close to symmetric but not exactly and I'm not using any DSP at all so the imaging is only ½ the distance of the difference of the out of symmetry factor. I think that is the key to very nice ambiences and shockingly tight imaging in the surrounds. I'll let you know where this path takes me. I'l be working on it all night I think.

Also if you know of some good Atmos test downloads that would be helpful, Thanks.

Also I saw Shen Sun today at an amazing performing arts theater here in Boise the music was beautiful and the mics they used were cheap u57s mostly (very low end work hors mics) and the orchestra soundsd wonderful because the room was so good, moral of the story if you have a good room many sins are forgiven.