CurtPalme.com Home Theater Forum

stefuel · Posted: Fri Apr 10, 2009 2:14 am Post subject: Theater reference sound level

What level do you have your theater calibrated to? I was in the understanding that 70 db is the standard theater reference level. I calibrated my setup to that level so I could test my subwoofer placement. Then.........I popped in Quantum of Solace Shocked

That opening scene (the car chase) just about blew out my eardrums Thumbs Up

Question: If it is calibrated at 70 db and you turn down the master volume to about 60 db, is it still calibrated.
Question 2: Do wild bears $hit in the woods and if so, would you hear it at 70 db's Laughing

akajester · Joined: 09 Jul 2008 Posts: 934 Location: Wisconsin

It's still calibrated, but you're not listening to the movie at the "reference" level they created it in. At least that's my understanding. I don't think this goes in the crt forum either. Smile

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

Does anybody know how many theaters actually run at the reference level? I've heard that a lot of multiplexes will keep stuff low - especially bass - to avoid bleed between the packed-in theaters. And a local place that only has one theater really CRANKS it. So is the local place going crazy and calibrating to 110db Wink

or is everybody else playing it at quiet-mouse level?

**AnalogRocks** · Posted: Fri Apr 10, 2009 4:30 am Post subject:

I saw the 1997 Re-release of Start Wars in a signal movie theater. No multiplex. The sound was so loud it had everyone covering their ears. It was ridiculous.

Tom.W · Joined: 09 Mar 2006 Posts: 6635

A good read on THX...

http://www.hometheaterhifi.com/volume_13_1/feature-article-thx-1-2006-part-1.html

ecrabb · Posted: Fri Apr 10, 2009 5:26 am Post subject:

THX reference is 105dB, so if your system is calibrated to that reference, your loudest peaks should be at 105dB in the room. You may or may not have the amplifier power and/or speaker efficiency to be able to play that loud - especially cleanly (without clipping). A newer Audyssey AVR or prepro will calibrate 0dB to 105dB at the listening position.

I typically watch movies at around -20dB (85dB) at my listening position, maybe -15 or -10 if I'm really into it.

I can run my system in "demo mode" Wink

right at or just below THX reference, but it takes about all 300 watts my Crown's have on tap have to play at that level cleanly. If you have more efficient speakers, you could do it with much less power.

SC

Tom.W · Joined: 09 Mar 2006 Posts: 6635

Now if we just had perfect hearing..... Rolling Eyes

schmoe · Joined: 30 Mar 2008 Posts: 374 Location: Seattle, WA

Tom.W · Joined: 09 Mar 2006 Posts: 6635

Something else to think about.

http://www.timesonline.co.uk/tol/news/uk/health/article689894.ece

http://www.earhelp.co.uk/dangers-workplace-noise.html

David_Web · Joined: 02 May 2007 Posts: 418 Location: Sweden

Don't forget sub should be +10dB so 115dB reference. That is LOUD!
Oh and structural damage can occur at sub 40Hz so be careful. That is why most PA don't go much below that, at least not at 0db.

"No - the farther from reference you go the more uncalibrated the sound becomes. Ever noticed how you lose most of the bass when you lower the volume? "

That is due to perception and hearing sensitivity. That is why you have to turn up the volume above a certain level to hear bass at LF.
I would never let anything screw up the response by altering the curve (boosting bass an HF) when lowering volume. That is just sick.
Everything will just have unnatural bass and sound unbalanced.
I take HI-Fi any day.

"I popped in Quantum of Solace That opening scene (the car chase) just about blew out my eardrums"

Saw it yesterday. Not impressed. Sure the rumble shook things around but...
Sound design was just as anything else. Mediocre. I wonder when they will start making proper movies with proper sound again.
It's just loudness war with subs.

greg_mitch · Joined: 03 May 2006 Posts: 5320

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

Jesse S · Joined: 12 May 2007 Posts: 209 Location: Etobicoke

That's 105db peaks in *each* of the 5 or 7 channels and 115db from the LFE. That's potentially 121db+ if the mains and LFE are sent full signal.

It's not that loud if the room is treated properly and the system is up to the task. My IB can easily hit 125db+ but it's more felt than heard.

If your system is calibrated to -20, you can still have peaks over 101db. Also, DTS doesn't adhere to dialnorm so it can be 6db hotter. Dolby is more consistent with dialnorm.

Tom.W · Joined: 09 Mar 2006 Posts: 6635

http://www.abelard.org/hear/hear.php#noise

Just a heads up. Protect your kids from hearing loss...

**AnalogRocks** · Posted: Sat Apr 11, 2009 6:43 pm Post subject:

I wear ear plugs anytime there's loud noise. I even wear them in the summer when I'm cruising with the windows down.

You only get one set of ears.

stefuel · Posted: Sat Apr 11, 2009 6:51 pm Post subject:

Tom.W · Joined: 09 Mar 2006 Posts: 6635

Chip are you saying your wife is a loud mouth ?

Hope she doesn't read this forum...... Wink

**AnalogRocks** · Posted: Sat Apr 11, 2009 8:37 pm Post subject:

I have a low WAF factor because I have a G/F. She ocasionaly tells me to stop spending money on tech/car stuff. Then I give her the 'look' you know the one. Where you look at her like she has 3 heads with serpant hair. LMASO

Then she gives up. Or at least represses it for 6 months Laughing