Question about ATMOS 7.2.4 processing

[Flint]

Since I've abandoned surround sound in my own home, I am no longer paying close attention to the technology being released for surround sound. I am lucky to know enough people in my area to get to demo the tech, but I avoid long technical discussions with them since most have no idea what they installed in their homes.

So, here's my question....

I see that all the new ATMOS surround configs list two LFE channels, as in 7.2.4 surround. So, if the first number represents the horizontal plane surround channels, the second number represents LFE channels, and the third number represents height channels, does that mean there are literally two different signals being produced for the LFE channels? In other words, is the "2" in the channel scheme a mono signal split to two outputs on the processor, or are the two outputs on the processor separate signals which could be completely different from one another?

Any surround nerds here to answer that for me?

 

[CMonster]

As far as I know it's just one signal. I've never seen a movie list more than an X.1.Y soundtrack. Some processors have the ability to set different distance/delay and level settings on the their two LFE outputs but it's a mono signal. I think they're just taking advantage of the nomenclature used by many enthusiasts (at least on AVS Forum) to denote the number of subwoofers one has in their system.

 

[CMonster]

I did some digging on Wikipedia and Dolby's website and didn't see any mention of multiple LFE channels.

 

[Flint]

So, why not just make any number up? It could be 7.4.4 or 7.8.4. What's the point?

 

[CMonster]

So, why not just make any number up? It could be 7.4.4 or 7.8.4. What's the point?

This is in the signature line from a friend of mine who posts quite a bit on AVS:
Archaea's 9.12.4 Home Theater Room

He has 12 sealed subs in his HT. I think it's just becoming acceptable for enthusiasts to use that short-hand form instead of saying 'I have a 9.1.4 system with 12 subwoofers.'

I noticed Onkyo was advertising their units with two sub outputs as X.2.Y and I'm guessing other manufacturers probably do the same. I think that's a bit shady.

 

[Flint]

Could I get the respect of my enthusiast friends if I build thirty-two 4-inch subs and wire them in parallel to get a 7.32.4 system?

Is eight "okay" subwoofers better than 2 state of the art subwoofers?

 

[jomari]

i was more curious to find out if the height channels have discrete signals sent to them, or is it the7.2.4 just an emulation of 7.2.2 signals spliced into 4.

 

[Flint]

i was more curious to find out if the height channels have discrete signals sent to them, or is it the7.2.4 just an emulation of 7.2.2 signals spliced into 4.

When Dolby first introduced this format on the world, it supported discreet height channels - as many add the industry would accept. As such, I imagine it is discreet channels in the home ATMOS format.

 

[CMonster]

Could I get the respect of my enthusiast friends if I build thirty-two 4-inch subs and wire them in parallel to get a 7.32.4 system?

Is eight "okay" subwoofers better than 2 state of the art subwoofers?

We have some real bass heads here in KC and I think many of them are over-the-top. But they are not posers. They are not just trying to one-up others by having more, or bigger, or whatever. I believe they are misguided, I've told them my opinion, but they have experimented, and traveled to other HTs, and gone to trade shows, and befriended multiple ID founders, and strive to achieve the sound that makes them happy. They are passionate...

 

[heeman]

We have some real bass heads here in KC and I think many of them are over-the-top. But they are not posers. They are not just trying to one-up others by having more, or bigger, or whatever. I believe they are misguided, I've told them my opinion, but they have experimented, and traveled to other HTs, and gone to trade shows, and befriended multiple ID founders, and strive to achieve the sound that makes them happy. They are passionate...

We have the same here in WI and there is no way to reason with them. Oh well....

 

[Razz]

I think it's just the ability to set a delay to each channel.

 

[Flint]

People can do whatever they want, and they should. I just dislike the bragging about number of subs, as if the only way to prove one is really into this hobby is to have 10x the sub output potential than remotely necessary. I think it leads to confused newbies wasting money and becoming dissatisfied.

 

[Flint]

I think it's just the ability to set a delay to each channel.

Can you adjust the delays of each LFE output independently? If so, could you also apply separate EQ settings? If so, then this could be meaningful.

 

[Flint]

This morning I visited a home theater here in my area as the owner was considering hiring me to consult with him on acoustic treatments.

Well, I walked into one of the typical "man-cave" style theaters with huge, plush theater seating backed up against the rear wall, mismatched surround speakers from different manufacturers placed against the walls or in corners, 4 mismatched subwoofers crammed into whatever open spaces against the walls were left over, and less than ideally placed in-ceiling height speakers made by yet another manufacturer. Additionally, the owner had one of the largest Hi-Sense TVs I've ever seen mounted slightly off center on the wall opposite the seating.

I asked to audition his system to get a feel for the sound at present. I quickly discovered that despite what many would tell you, you can have TOO MUCH bass. No joke, I could not even hear the dialog or sound effects if there was any bass in the soundtrack. Even mere dialog would cause my chest to get slammed with bass impact if the speaker used a P, T, or other pop-inducing consonant. Ugh...

I asked him what he was looking to accomplish and he pointed out that he and his wife struggled to hear the dialog and the ATMOS speakers, no matter how loud he turned them up, seemed to never be on.

Really?

I suggested that the bass was a bit strong, and he asked if installing bass traps would solve the problem. Without laughing, I suggested he turn the subwoofers down a bit to which he said that wasn't an option because he was disappointed there wasn't more bass already and if he didn't hire me he was going to spend that money on another new subwoofer he had just auditioned at some local store.

I made polite conversation with him until he decided buying a subwoofer would be the best use of his money and left.

I am not joking, the LFE channels had to be no less than 40dB louder than the rest of the speakers.