Originally Posted by Soulburner
Thanks. That is HDMI 4.
You're right that reference is 115dB for peaks, yes, but not for sustained output. And that's at the theatre. In-home reference level is 10dB less, so 75dB from mains with 95dB peaks, and 85db from subs with 105dB peaks.
Originally Posted by jamiebosco
I'm pretty sure that speakers calibrated to Reference Level will be 85dB(105dB peaks) for main channels and 95dB (115dB peaks) for LFE - whether it's at home or the cinema.I think most agree that this will "feel" much louder at home due to small room acoustics and choose to listen at a lower volume. Maybe @mthomas47
Alexander can correct me if I'm wrong?
When I use REW output HDMI4 with the MV at 0dB I get a 115dB(ish) sweep
This issue can be a little complicated sometimes, but Jamie is correct. Reference is, by definition, peaks of up to 105db for the regular channels and 115db for the LFE channel. That is true for both commercial cinemas and home theaters.
Several things make HT a little more confusing. First, our AVR's and test discs use a 75db test tone to calibrate our systems to Reference. At one time, 85db test tones were used, but they were too loud for most people. Even the 75db test tones can seem very loud to some people, and 85db is exactly twice that loud.
After the calibration is complete, our AVR's do an internal recalculation to add 10db to the regular channels. It was already compensating for the LFE channel, since that channel is also calibrated with a 75db test tone. After calibration, when the master volume is 0.0 and depending on specific content, the regular channels will be hitting peaks of 105db (if they are capable of doing so) and the LFE channel will be hitting peaks of 115db.
The second thing that sometimes makes HT Reference a little more complicated is that in an HT of about 20,000^3 or less (which is virtually all HT's) Reference sounds louder than it does in a commercial cinema. Smaller rooms seem to amplify the apparent loudness. Commercial theaters are much
larger than 20,000^3. Various audio experts estimate that home theaters can sound anywhere from 5 to 8db louder than commercial cinemas at "Reference". Small HT's of about 1500^3 or less would sound the loudest and very large HT's might sound only about 5db louder--perhaps even less so if they were heavily treated.
It can be a little confusing in actual application to individual home theaters, but the basic principles don't change: Reference is peaks of up to 105db for the regular channels and 115db for the LFE channel.