Frankly, I'd rather that content producers and their sound mixing and mastering engineers just improve the audio levels of their dialog tracks in relation to the rest of the mix. I already have my center audio channel goosed +3db beyond the professionally calibrated academy reference levels to help with legibility. The problem is that mixes are increasing in dynamic range, so if I elevate the center channel level (where most dialog is) even more to lift the occasionally inaudible utterance, some of the rest of the center channel content is too loud in relation to the other channels.
While my high-end home theater audio system has DSP functions like dynamic compression which I can apply to smooth out the center channel, that's relying on a blanket algorithm in an attempt to fix something that's much better fixed on the mixing stage in the first place. The mixing engineers have much better tools which they can selectively apply when needed and even have the option of problematic dialog being re-looped if necessary. It's their job to get this right and they certainly have the all the tools and training to do it properly and only when, and as much, as actually necessary. Having home viewers slap some auto-mode plug-in over the entire run time of a sound mix that was painstakingly hand-mastered scene-by-scene is objectively the worst way to solve the problem.
This simply makes no sense because the entire modern signal chain is digital. There's no technical reason the gain shouldn't be correct. The fact that dialog audio levels are still a recurring problem in my properly calibrated, 11.2.4 THX-rated dedicated home theater must be that the audio engineers aren't being given the time and resources to do their job properly or are being instructed to do this as some misguided aesthetic choice (looking at you Christopher Nolan).
I have no doubt that Dialog Enhancer features, which are available on many streaming devices and AVRs, can work well. They are basically variants of multi-band dynamic compressors tuned to target vocal frequencies on the center channel.
Both my streaming device and AVR each have their own flavor of dialog enhancer and they do help improve the problem substantially. But I don't feel 'good' about just leaving this kind of post-processing feature on long-term and certainly not as a widely recommended best practice (except for hearing impaired users). I guess the reason for my reluctance is more in principle than practical. It's just not the right technical approach to solving the root problem, and any automatic algorithm, no matter how adaptive, dynamic or clever, will sometimes fail to do the right thing. It also bothers me that every implementation of dialog enhancer I've seen is opaque and undocumented.
I've been in and around video and audio engineering for most of my career, especially on the broadcast tooling side creating new gear. I go way back to the analog days when we could only dream of having such a pristine digital signal throughout the entire signal chain. We were always battling generation loss and noise on the production side and on the home theater side, we spent time and money slathering various noise reduction and other 'enhancement' processing to fix the worst aspects of the degraded analog signals we received.
At long last, today we live in that sci-fi future nirvana where the same levels the director approved on the mixing stage can be exactly what you hear at home. So, yeah, I have some PTSD about still needing to slap some post-process on at home to fix issues that should not be there in the first place. We waited decades for this tech to arrive, so the engineer in me wants it to work - without fixes or user patches. And that means addressing the issue at the source.
While my high-end home theater audio system has DSP functions like dynamic compression which I can apply to smooth out the center channel, that's relying on a blanket algorithm in an attempt to fix something that's much better fixed on the mixing stage in the first place. The mixing engineers have much better tools which they can selectively apply when needed and even have the option of problematic dialog being re-looped if necessary. It's their job to get this right and they certainly have the all the tools and training to do it properly and only when, and as much, as actually necessary. Having home viewers slap some auto-mode plug-in over the entire run time of a sound mix that was painstakingly hand-mastered scene-by-scene is objectively the worst way to solve the problem.
This simply makes no sense because the entire modern signal chain is digital. There's no technical reason the gain shouldn't be correct. The fact that dialog audio levels are still a recurring problem in my properly calibrated, 11.2.4 THX-rated dedicated home theater must be that the audio engineers aren't being given the time and resources to do their job properly or are being instructed to do this as some misguided aesthetic choice (looking at you Christopher Nolan).