A Question Regarding Something I Was Once Told About Setting Trim Levels for Atmos Speakers...

[Kaskade89052]

Was wondering if this was true, or if anyone else had heard of it (if this isn't the right place in the forum to post this, please let me know; wasn't sure if it should be in the Receivers/Amps section or somewhere else perhaps).

I recall being told once that when setting channel trims for Atmos speakers -- whether they're modules or in/on-ceiling -- the levels should be a couple of dBs higher than, say, the left/right mains...so if, for example, the fronts are set at "+6dB" in the AVR or processor, the Atmos channels should be around "+9." Is this right?

We are contemplating upgrading our setup to accommodate Atmos (and DTS:X) down the road, but it will most likely be a 5.1.2 system, utilizing two modules atop our Polk RTi tower mains.

What's the truth concerning the Atmos channels in terms of trim levels? Should they be set up like any other speaker, or should extra trim be given to them as I was once told?

 

[ryanosaur]

Forgive, but why would you boost your system to +6dB Trim?
As I understand trim levels, you never want positive trim settings. "0" would represent full analog power. Additional boost requires digital boost which is generally considered bad due to the likelihood for additional distortions due to artificial augmentation of the signal via DSP.
Keep in mind, too, that every +3dB requires a doubling of power. If, for example, what may be a 50w dynamic peak at max analog amplification, you are now requiring 200w to make that happen at +6dB. +9dB would potentially see a 400w signal.
This is hypothetical.
But imagine a distorted 400w signal hitting those Atmos Modules you propose.



If I misunderstand how this works, I will gladly accept correction!

 

[ryanosaur]

OK... regarding your idea for using Atmos Modules...
Do you know if your room and setup will be appropriate for them? You will need to have the angles right for the signal to possibly hit your listening positions the way you want.
@William Lemmerhirt has a really cute drawing to illustrate this.

It may be that the modules will require a boost. How much actual boost would depend on your room set up and correction. But considering that the distance the wavefront will need to travel from the module to the ceiling then to your ears will be farther than the distance to your mains, yes I could well see that the atmos modules might require boosting.

 

[William Lemmerhirt]

OK... regarding your idea for using Atmos Modules...
Do you know if your room and setup will be appropriate for them? You will need to have the angles right for the signal to possibly hit your listening positions the way you want.
@William Lemmerhirt has a really cute drawing to illustrate this.

It may be that the modules will require a boost. How much actual boost would depend on your room set up and correction. But considering that the distance the wavefront will need to travel from the module to the ceiling then to your ears will be farther than the distance to your mains, yes I could well see that the atmos modules might require boosting.

I knew you always loved my artwork! Lol

This is just to give at least a little visual reference to account for placing Dolby Atmos enabled modules. all numbers are arbitrary, and does not account for simply tipping the DAE speakers forward are backward.
As far as setting the levels, that’s a matter of preference imo. If you want them to be level matched, then set them to 75db like all the others(subs notwithstanding of course lol). If you’d like to get more out of them, then also, just like any other speakers, set the trim accordingly. I don’t find any offense in setting them a couple db higher.

 

[AcuDefTechGuy]

What's the truth concerning the Atmos channels in terms of trim levels?

The ABSOLUTE TRUTH is that you need to be able to HEAR your Atmos channels when all your other speakers and subwoofers are blasting away.

The truth is, if you can’t hear your Atmos channels, then it’s like you don’t have Atmos at all.

Every room, every system is different. YMMV.

 

[lovinthehd]

Are you L/R speakers the same as your Atmos in any respect? Why would one's settings need to mirror another's by some pre-determined (and by who?) number of dB without regard to distance/sensitivity etc? Makes no sense.

ps lol thought about this a bit and thought of course once calibrated it'd just be 3dB louder....but it is in the end prefeerence....as long as it's a 3dB boost on Atmos Getting snow wacky here (been snowed in a coupla days now ).

 

[Kaskade89052]

I was merely saying that I had been told this once some time back (that the Atmos modules should be a certain number of dB's higher than the other channels, in general) and just wanted to know if there was any substantiated truth to that.

 

[lovinthehd]

I think the proper by the book level matching would be the "reference" way to set it up....and if you like to change levels for various channels later, that just becomes "preference".

 

[Kaskade89052]

I think the proper by the book level matching would be the "reference" way to set it up....and if you like to change levels for various channels later, that just becomes "preference".

Thanks Lovin.

 

[Huey645]

Forgive, but why would you boost your system to +6dB Trim?
As I understand trim levels, you never want positive trim settings. "0" would represent full analog power. Additional boost requires digital boost which is generally considered bad due to the likelihood for additional distortions due to artificial augmentation of the signal via DSP.
Keep in mind, too, that every +3dB requires a doubling of power. If, for example, what may be a 50w dynamic peak at max analog amplification, you are now requiring 200w to make that happen at +6dB. +9dB would potentially see a 400w signal.
This is hypothetical.
But imagine a distorted 400w signal hitting those Atmos Modules you propose.



If I misunderstand how this works, I will gladly accept correction!

I'm no expert, and could very well be wrong, but I don't think that works the way you think it does, at least in my experience. The volume setting on the receiver is relative to what the trim levels are set at. Lets say your receiver has volume range of -60 to +20. You boost all of your trim levels by +3, and at least with every Yamaha receiver I've had, the new volume range would now be -60 to +17. But also, if before your normal listening level is at lets say zero before the adjustment, it would now only be -3 when used. So boosting the trim levels is still relative to what the volume setting is. Another way to think of it, it's also relative to the other speakers as well. So if you have speakers that need to be trimmed to -10, a -7 on another speakers is still the same exact scenario you described above. I'm the worlds worst explainer, so sorry if this is confusing, but try to think of those trim levels as relative to the volume setting more than anything, and the + or - is more for reference and set up than actually giving it more juice and the chance to fry speakers.

 

[Kaskade89052]

I'm no expert, and could very well be wrong, but I don't think that works the way you think it does, at least in my experience. The volume setting on the receiver is relative to what the trim levels are set at. Lets say your receiver has volume range of -60 to +20. You boost all of your trim levels by +3, and at least with every Yamaha receiver I've had, the new volume range would now be -60 to +17. But also, if before your normal listening level is at lets say zero before the adjustment, it would now only be -3 when used. So boosting the trim levels is still relative to what the volume setting is. Another way to think of it, it's also relative to the other speakers as well. So if you have speakers that need to be trimmed to -10, a -7 on another speakers is still the same exact scenario you described above. I'm the worlds worst explainer, so sorry if this is confusing, but try to think of those trim levels as relative to the volume setting more than anything, and the + or - is more for reference and set up than actually giving it more juice and the chance to fry speakers.

Thanks Huey....it's always the way I understood the speaker trims, as well. I've never had ANY issues running trims in the "+dB" range, for any speakers, as long as they're not at "+12dB" (or whatever the maximum trim is for a given processor/AVR).

 

[Kaskade89052]

The ABSOLUTE TRUTH is that you need to be able to HEAR your Atmos channels when all your other speakers and subwoofers are blasting away.

The truth is, if you can’t hear your Atmos channels, then it’s like you don’t have Atmos at all.

Every room, every system is different. YMMV.

Ummmmm....okay.....

But that's why I'm asking if they SHOULD be set higher than the others....

 

[Kaskade89052]

Forgive, but why would you boost your system to +6dB Trim?

I was merely using that reference as an example.

 

[Huey645]

Thanks Huey....it's always the way I understood the speaker trims, as well. I've never had ANY issues running trims in the "+dB" range, for any speakers, as long as they're not at "+12dB" (or whatever the maximum trim is for a given processor/AVR).

I've always been under the impression, that when setting up your gear, 0 on the volume setting should be what they consider reference listening level, and speakers should be adjusted accordingly, hence the + or - settings. This isn't like when you are adjusting for individual frequencies, and trying to boost a null, which from what I've been told is impossible.

 

[Kaskade89052]

Are you L/R speakers the same as your Atmos in any respect? Why would one's settings need to mirror another's by some pre-determined (and by who?) number of dB without regard to distance/sensitivity etc? Makes no sense.

ps lol thought about this a bit and thought of course once calibrated it'd just be 3dB louder....but it is in the end prefeerence....as long as it's a 3dB boost on Atmos Getting snow wacky here (been snowed in a coupla days now ).

I have not purchased any Atmos speakers yet (please see where I indicate "down the road" in my original post) so there's no way to even answer your first question; of course, they will most likely not be a match to my left/right speakers because those are Polk RTi towers and we'd most likely be picking up Atmos modules from a different brand.

As for the mirroring aspect of your post, I was merely saying that I had been told, some time ago, that in general (regardless of particular systems, setups or speakers) Atmos modules should be a couple of dBs hotter than others; of course it would be impossible to technically assume what's right for one system and room would be right for another.

At the end of the day, I don't have speakers for this yet, so this is all speculation and discussion; I suppose I'll wait till we actually set up some Atmos add-ons (with a new AVR) to revisit the topic.

 

[Kaskade89052]

I've always been under the impression, that when setting up your gear, 0 on the volume setting should be what they consider reference listening level, and speakers should be adjusted accordingly, hence the + or - settings. This isn't like when you are adjusting for individual frequencies, and trying to boost a null, which from what I've been told is impossible.

That is accurate -- ideally and technically, you want to adjust the trims for each channel -dB/+dB (whatever they need) so that when you hit 0dB on the volume scale, you're at "reference." However, my AVR doesn't even have a "relative" volume scale readout, just an "absolute" scale (which runs from like 0 to 99), though Onkyo claims "82" or so on this scale is about reference when calibrated properly...all this being said, though, I have always set up my speakers to PREFERNCE, not REFERENCE, making sure the channels are as balanced as possible by ear and tweaking a bit here and there (raising the center a couple of dBs higher than the mains for dialogue compensation, etc.).

I think you're okay so long as you stay away from extremes on the trim level scales (i.e. "-12" or "+12" dB).

 

[Kaskade89052]

OK... regarding your idea for using Atmos Modules...
Do you know if your room and setup will be appropriate for them? You will need to have the angles right for the signal to possibly hit your listening positions the way you want.

Well, my ceiling is (pretty much) perfectly flat and isn't the "popcorn" type, and it's pretty low...plus, we have two big tower speakers as main left/right channels, equidistant from the sweet spot, so I assumed modules could sit atop them...

It may be that the modules will require a boost. How much actual boost would depend on your room set up and correction. But considering that the distance the wavefront will need to travel from the module to the ceiling then to your ears will be farther than the distance to your mains, yes I could well see that the atmos modules might require boosting.

Thanks.

 

[William Lemmerhirt]

Ummmmm....okay.....

But that's why I'm asking if they SHOULD be set higher than the others....

No. If you have them positioned correctly so that you can hear them and they are integrated properly, they should be level matched. IF you’re concerned with being technically accurate anyways.
Otherwise set them to taste.
Curious about the original question though. Do you remember why exactly it was said to raise the trim?

 

[Kaskade89052]

No. If you have them positioned correctly so that you can hear them and they are integrated properly, they should be level matched. IF you’re concerned with being technically accurate anyways.
Otherwise set them to taste.
Curious about the original question though. Do you remember why exactly it was said to raise the trim?

Thanks Willy.

As for why it was originally said to me....I THINK it was something along the lines of "if you don't raise them a bit higher, the cues in those channels are going to get 'lost in the mix' a bit."

 

[William Lemmerhirt]

Thanks Willy.

As for why it was originally said to me....I THINK it was something along the lines of "if you don't raise them a bit higher, the cues in those channels are going to get 'lost in the mix' a bit."

Roger that!
I think what was said could be true for any surround speaker. Lol

Every room and combo will have different sets of tweaks that will make you happy.