THX Reference Levels (Music VS Movies)

[Ghoostknight]

Hello,

i just bought some bluerays, to hopefully get rid of some streaming services and enjoy movies with lossless audio
i barely watched movies before on my speakers, just because it always left me unimpressed (keep in mind, i dont have a subwoofer, roomresponse is flat to around 35-40hz) specially compared to music

Now... i had a thought about all this THX stuff and the recommended levels are +10db for subwoofers that by THX guidlines get crossed over at 80Hz

i guess it really depends on the exact crossover but i tried yesterday a little around with the movie "D-Wars"
a "highshelf 0.7Q, -10db, 55hz, 12db/oct" filter (to kind of replicate THX reference levels) really gave the movie a nice oomph, for the first time it sounded kind of exciting to watch a movie, similar exciting to listen to music with a flat-ish response

now after 1-2 movies the thing is even with my thx compensation eq pretty clear, i have to get a subwoofer for movies, but honestly the EQ compensation + subsonic filter didnt sounded that bad either with moderate volume levels (but im pretty sure it can get better than this)

what i would like to ask now is this:
1. Do you utilize THX reference levels? (is it actually even a thing anymore?)
i feel like thx levels can only be really used for movies, for music it kinda sounds "club-like", do you switch back and forth here or try to get just a nice level with which music and movies sounds good? (i would guess something like +5-7db for subwoofers)
2. are thx reference levels still recommend for all movies? (apparently starting from the third star wars film, which was the first THX movie) i didnt quite get it, is it some kind of not much spoken about "standard" anymore to have subwoofers at +10db regarding movies or are newer "non-thx" movies actually different mixed?
3. whats your stand on movies vs music and specially subwoofer levels?

best regards

 

[gregorio]

what i would like to ask now is this:
1. Do you utilize THX reference levels? (is it actually even a thing anymore?)
i feel like thx levels can only be really used for movies, for music it kinda sounds "club-like", do you switch back and forth here or try to get just a nice level with which music and movies sounds good? (i would guess something like +5-7db for subwoofers)
2. are thx reference levels still recommend for all movies? (apparently starting from the third star wars film, which was the first THX movie) i didnt quite get it, is it some kind of not much spoken about "standard" anymore to have subwoofers at +10db regarding movies or are newer "non-thx" movies actually different mixed?
3. whats your stand on movies vs music and specially subwoofer levels?

1. What you’ve described is not a THX reference level, there’s no such thing as a THX reference level. What you’ve described is the standard Film/Movie/TV relative channel levels originally set by Dolby 5.1 surround and then continued in subsequent film/TV surround formats. Namely: Relative to the (3) front main channels, the LFE channel is set to +10dB in-band gain and the surround channels at -3dB. The surround channels at -3dB is typically only for theatrical film sound and is not applied to TV surround sound but the +10dB (in-band) for the LFE is. Also, there is not and should not be any gain added to the subwoofer, the +10dB gain is applied to the LFE channel only!

2. Again, it’s not a THX reference, it’s the relative channel levels of all TV and movie 5.1 (or greater) surround formats. So it should be applied to all TV and Movie sound when playback is with a 5.1 (or greater) surround sound system.

3. The subwoofer levels are the same for both music and movies, the subwoofer is balanced with the other speakers (IE. 0dB gain). With film and TV surround sound, the “.1” (LFE channel) has +10dB of in-band gain applied (not the subwoofer!). This +10dB of LFE channel gain should also be applied to music mixed in Dolby Atmos format.

G

 

[Ghoostknight]

Ohh.. thanks for claryfying

So i guess if we speak about the digital signal the LFE channel peaks to 0db and everything else up to -10db? so essentially the gain is already applied and i just have to calibrate subwoofer and main speakers for phase and matched volume... (and i guess maybe a touch of preference EQ)

ok then this thread was fairly pointless...

 

[gregorio]

So i guess if we speak about the digital signal the LFE channel peaks to 0db and everything else up to -10db? so essentially the gain is already applied and i just have to calibrate subwoofer and main speakers for phase and matched volume... (and i guess maybe a touch of preference EQ)

No. The LFE can peak at 0dBFS and so can any of the other channels, you have to add the gain to the LFE channel on playback! The mix is created with the output of the LFE channel set at plus 10dB in-band gain, so what’s in the LFE channel of the distributed mix is effectively at -10dB when delivered to the consumer, hence why it needs 10dB of gain added. However, that doesn’t mean that the LFE channel peaks at -10dB! Our hearing is much less sensitive in the range covered by the LFE channel (20Hz - 120Hz), therefore a movie mix will commonly employ some or all of that extra 10dB.

Modern AVRs always have this facility built-in to them, you just have to make sure that the +10dB LFE Channel option is selected when playing a 5.1 (or greater) surround mix. This assumes you actually have a subwoofer in your playback setup and the LFE channel is routed to it of course. If you only have a two speaker stereo setup, you should not select the +10dB LFE channel option, as doing so is very likely to overload your speakers.

G