Sonos Arc Ultra era 300s and 2 Subs 4s not loud enough

The Sonos go into low power mode after a few minutes, mine seem to wake fairly quickly. It might be that the Sonos and your TV are taking a bit of time to handshake adding to that necessary delay.

As to volume make sure you have no Sonos volume limit set, other than that the volume setting on the Sonos should be able to enable full volume. Keep in mind the numbers shown are only to make it easier for you to set them to a desired volume and are otherwise meaningless. 

 My TVs have no internal volume control when set to pass the audio to my Sonos, you might confirm that applies to your TV too.

Room physics has a significant impact on subwoofer effectiveness. Moving one or both SUB’s will have an impact that will be positive or negative.

Thank you.
Volume limit is off. For the song I sent an example I use it at 100% volume and you can talk normally.
And yes, my tv settings have the Pass Through ON.
I'm coming to the conclusion that the system doesn't actually offer enough power. Having practically the same volume as a Bose 600 with a 5" sub is almost disappointing. I just want to be 100% sure to deal with this.

Im happy with the subs. I use both bass settings at 0. I could add bass if I have more overall volume. For what I have now they are more than enough.

Mine also takes a few seconds to turn on, when I turn on the TV it takes 3-5 seconds before the sound is activated on my Ultra and thus the entire system.

As for the volume, there are many factors that come into play, when streaming movies from Apple TV 4K, I experience really good sound on Apple TV+, Disney+ and HBO, but on Viaplay the sound is terrible and here I have to turn it up quite a bit. In other words, the quality/volume depends on where you stream from. (Maybe SONOS is more sensitive than others)

With music there is also a big difference, the same applies here, but there are also other things that come into play. Where do you stream from, your phone, Apple TV or the TV itself and how. Airplay is undoubtedly best over your phone as the sound is degraded by Bluetooth. Personally, I thought the sound was best when I stream directly from Apple TV.

There are also settings in your SONOS App that can improve the audio experience, especially by choosing Full or Background when playing music, and adjusting how loud your Era300s play. I have mine as Background with +2.

A funny thing I found out a few days ago is that if you turn off speech enhancement, music plays much louder from your Arc Ultra.

I only use HDMI.
I also use my Era 300s at -2 and full.
Speech enhancement always off.
The system unfortunately is weak in power for most sources (this is my conclusion). When paying Atmos content listening to Apple Music is “enough”.

Didnt know this could be done.

Do you think Sonos could release an audio volume control based on the source volume?
My connection is only via HDMI, but the drastic differences in system volume with different audio sources are unacceptable.
Yesterday I watched Superman 2025 and used the volume at 90% to get a sound that wasn't even that loud.
If I wanted to experience the sound better, I wouldn't be satisfied even at 100%.
And I'm not a 16-year-old boy. I'm 54, and I've never really looked for much volume. It's actually off-putting when used with some music and movie sources.

There is no “standard” volume level for audio broadcasts. Advertising volume is often louder than that for programs/films. Different stations on the same streaming service may be different. Sonos devices just play what they’re sent. 

To have a common level to compare; have you tried to play music directly from the Sonos app? In this case you will have the source directly from internet to the speakers. 

With a lighter set-up (Arc+Sub3+2Era300) I never go over 50% of the volume. I suppose that during a party with the room full of people could reach 100% before the police arrive 😅 but strong enough antway.

I would check deeply the Apple TV or the display settings. Or perhaps you have a living-room like a church, with ceilimgs over 10 m and 200 m2 😉

Yes, I've used the Sounds app's streaming service, and the volume results are the same.
I want to clarify that for some videos, the sound is acceptably loud. When used with some videos or music at volume 70, I already get good results (which, in my opinion, should have the same result at 50%).
The problem is that with certain sources, as I mentioned earlier (Superman 2025), I have to raise the volume to 90% to get results that are far from what I expected for that volume level.
My living room is approximately 40m2.
Having used a BOSE 600 with a 5" BOSE subwoofer in the same room and getting practically the same volume results, I'm actually considering replacing the entire system. It's a real shame because the sound quality, especially Atmos, is sensational. Sonos did an excellent job delivering sound quality.
I might try the Sony Bravia Quad Theater. I'll test it before I buy.

You might want to consider a component setup with a high-power multi-channel AVR powering individual speakers. Not as convenient as an integrated system but far more volume potential.

You`re right. Since I love convenience, I'm going to try to “test drive” some soundbar systems.
It would be amazing if Sonos released more power for this system in an update. I don't know if that would be possible. If amps are already almost at the limit.

Since my Arc Ultra, Sub 4 and Era-100 surrounds will play far to loud for comfort in my very large room I don't think it is a Sonos amplifier issue, unless yours is broken.

Stanley, you make me jealous LOL.
Now my system is drastically lowering the sound alone at times. I really must have a problem with the system.