How loud do you go? Decibel Question (1 Viewer)

[Lee-c]

My system is calibrated to Dolby Digital Reference Level with Avia. My viewing distance (and Avia
calibration point) is 13 feet from the main speakers.

The volume I use for movies depends on the movie. Some movies have been transferred to DVD at
fairly restrained volume levels (and so you have to turn them up a good deal to get relatively realistic
volume levels), others are quite a bit louder. For intense action movies, I like to watch
at -10dB minimum or higher.

For example, The Lord of the Rings: The Fellowship of the Ring I always watch at -6dB,
which is thunderously loud. But it sounds very smooth on my system, so I can get away with it,
whereas most couldn't, especially at this distance from the main speakers.

 

[Kevin C Brown]

See, on the surface, I would agree with that statement. The problem is that when you go looking on the internet for "loudness" and "hearing (damage)" info, nowhere do they make a distinction of distortion vs not. Now, what I *would* say, is that a clean 120 dB signal is better for you than a distorted 120 dB signal, but distorted or not, a 107 dB signal is probably going to do your ears less harm than *any* signal at 120 dB.

Remember that the 120 dB signal is *still* over twice as loud as the 107 dB signal. (I think earlier in this thread: "twice as loud" can be taken as anywhere from 6 to 10 dB of difference.)

But now that I think about it, maybe it's sort of like integrating under the curve: i.e., the 107 dB signal could be worse for you if the components that are added by the distortion end up to be a lot more content at a lot more freqs than simply the "peaks" (read: dynamic range) at 120 dB. But I guess you'd have to do a spectral analysis of each signal to look to that level of detail.

 

[Vader]

OK, it's official: I'm comfused (more than usual). Last night I watched "Bring it On" in DTS at -9 dB. I checked from my "sweet spot" with a SPL meter, and it topped out at 86 dB. I calibrated using the auto-setup and then manually tweaked using the test tones. My equipment is as follows:

Denon AVR-2105 (configured to 5.1)
Infinity Alpha 50 (front main)
Infinity Alpha 37c (center)
Infinity Primus 150 (surround)
Denon DVD-1600
Boston Acoustics PV400

The room is mid-sized, roughly rectangular (I hope to have pics posted soon). My mains are 10 ft from my listening position, my surrounds are 7 ft, and my sub is 13 ft. Anybody have any insights?

 

[John S]

But what do you think is wrong??? Sounds like a comfortable level, allowing people to communicate easily during the program to me. I mean, nothing sounds like it's wrong to me.

 

[Vader]

John, its not that I find fault with it; I'm just confused as to why others find the same listening level (-9 dB in this case) unbearable, and it's comfortable for me (even a little low). I'm thinking that my system is not calibrated correctly.........

 

[John S]

Hmm, Calibration can be relative. I would not use the overall volume as an indictor or it being correct / incorrect.

If your systems blends well, and sounds good, you are close enough. I would say somehow your room is perhaps less reactive than others, and actually that is a good thing!!!

I mean, since it is a relative thing, you could just raise each speaker / channel a little, the same exact amount on each channel / speaker, and then it will be louder at a given position on the main volume knob, and still be a correct calibration. In my opinion anyways.

 

[Vader]

Well, since my ears tend to be very sensitive (and I go to great lengths to keep them that way), I guess how things are is perfect! I really don't need to have volume levels topping 100 dBs anyway, and am just a stickler for consistancy. Thanks for the thoughts!

 

[Phil Iturralde]

It's interesting that after 3 pages, very few expressed in real live SPL dB's (Decibel) how loud they go! All this Master Volume Control digital readout or assumed -5 or -10 dB REF Level, etc. doesn't translate real live SPL's in your room, which can vary depending on size, furnishing and AV equipment.

So, the standard should be the SPL's monitored @ your 'sweet spot' using your RS Meter!

Assuming that everyone REF Calibrated their setups correctly @ their 'sweet spot' ...

RS Meter: Dial = 70 or 80 dB respectively / Weight = C / Speed = SLOW
1) AVIA @ 85 dB
2) VE or DVE @ 75 dB
3) Internal AV/Amp test tones @ 75 dB

... then the relative observed SPL's @ their 'sweet spot' might mean something.

To save on your hearing, do what Dolby does @ the Cinema Theater's when they just monitor a movie playing, … @ your 'sweet spot', set your SPL's RS Speed = FAST! (Weight = C)

Equipment & Room size INFO should be included.

====(let me start)

My Main HT:
JBL S26: (x6) Sensitivity (2.83V @ 1m): 87dB
JBL S-Center: Sensitivity (2.83V @ 1m): 91dB
SVS 25-31PCi (APR 2002) (x-over bypassed)

Yamaha RX-V1300:
- POWER RATING -20Hz-20kHz @ 8 OHMS: 6 X 100 W
- THD (%): 0.04%
- SPKR SIZE = Small
- X-Over = 90 Hz fixed

REF Calibration: 75 dB / SVS = 77 dB using Dolby Labs "Explore Our World" DVD DD-EX w/dedicated LFE Test Tones.
- RS Meter on a tripod, raised to my seated ear height @ my 'sweet spot', and angled approx. 50-degree toward the Center speaker.

HT/Family Room: 20' x 30' w/10' high vaulted ceiling (center beam runs 20' front to back)

SPL** readings from my 'sweet spot' approx. 9' from the Center (**RS Dial = 100 or 110 respectively / Weight = C / Speed = FAST)

The following SPL's*: No audible stress, distortion, clipping or compression:
*Fast LFE SPL Peaks (RS Meter Dial = 90 dB to 110 dB respectively / Weight = C / Speed = FAST)

1) CD Music: 95 dB to 100 dB (depending on CD digital mix)
- Jazz - by David Benoit, Bob James, Larry Carlton, Rippington's, etc.

2) HT blockbuster DVD's: 106 dB*** and a few times 110 dB****

---

***106 dB FAST LFE SPL (approx. -10 dB AVG below REF Level) has been my AVG setting for my usual once or twice a month Friday NITE presentation DVD's SPL's since 1998 and my usual family / friends crowd keeps coming back! No complaints that the SPL is too loud since as most know, many blockbuster DVD's with sub-sonic LFE occurs less than 5%-10% of the movie length (special effects duration, i.e., attack scenes, special effects, climatic end, etc.)

I found out early after REF Calibrating my setup in 1998 w/VE @ 75 dB, ... that 105/106 dB is loud enough to move the floor, couch, seats, walls, pant-leg's (when I got my SVS) @ ALL my seating locations in my 20' x 30' HT/family room, ... when the encoded LFE calls for the sub-sonic air moving effect(s), but still maintain an audible & understandable whispering dialog level (timbre-matched speakers is a must!) during the quieter moments during the movie!!! With my SVS, the sub-sonic movement sometimes starts in a lesser but noticeable degree around 93-95 dB (i.e. Pearl Harbor; Iron Giant SE; I Robot; etc.).

Let me clarify that my noted High SPL FAST LFE peaks above, ... is the approx. highest swing of my RS Analog Meter needle during the bombastic sub-sonic LFE explosions effects (RS Speed = FAST). I would say that the AVG. SPL's would be 10 to 15 dB (or more) below those high SPL's.

NOTE: My Master Volume Control (MVC) Digital Readout may not read -10 dB (-29.5 dB MVC digital readout) below my REF Level since some, if not most DVD's are mixed hotter! (FYI: REF SPL Level= -19.5 / Yamaha MVC Digital Readout)

But, over the years, I found that at my -10dB REF Level MVC Readout -29.5 location, ... the SPL's has been around 105/106 dB FAST LFE SPL Peaks for most of my blockbuster DD/DTS DVD's

In my HT/family room, I've documented and observed my FAST LFE SPL Peaks to be ...

REF Level = 115 dB (MVC = -19.5)
-5 dB below REF Level = 110 dB (MVC = -24.5)
-10 dB below REF Level = 105 dB (MVC = -29.5)
-15 dB below REF Level = 100 dB AVG (MVC = -34.5)

Also, what I noted above is what I consider to be clean, unstrained, comfortable, no fear of hearing damage playback and based on the dynamics of my JBL / SVS combination, those SPL's are still below the room vs. equipment threshold with some dynamic headroom to spare (***as noted by my 110 dB SPL peaks observant during "Atlantis - The Lost Empire" DVD movie - DTS w/forced-on Matrix 6.1; "Tomorrow Never Dies"; "Sky Captain and the World of Tomorrow"; "Pearl Harbor". etc.).

As stated above, room, speakers (smoothness, flat frequency traits w/no peaks or valleys in the critical hearing range [100 Hz to 15 kHz], wide transient dynamics - JBL trait) & equipment quality all figure into what SPL's you can achieve for music and HT.

Lastly, not all AV Receiver's are created equal, ... see my Is 100w x5/x6 really 100w x5/x6? webpage to see why.

NOTE: S&V Benchmark Results:

1) Output @ clipping - 5 Channels Driven (or more)
2) Distortion @ 1w - 8 ohms (THD+N %, 1 kHz)
3) Noise (16-bit signal, A-wtd)

Just my 2-cents,
Phil

 

[John S]

Hmm, I thought I had done that.....

I do watch fairly often at true reference levels by the way....

100db + on continuous, over 120db on the heavy peaks.

That first T-Rex roar on Jurassic Park, will visably frighten people at those levels, just as it did in the pay theaters.

 

[Kevin C Brown]

Good point. Next flic I watch, I'll try to get some real SPL readings.

 

[Nathan Stohler]

Keep in mind that even though there is a reference level defined, some movies are just "hotter" than others, so don't get too hung up on reference level. It's nice to have a level to refer to, but just calibrate your system and set it at the desired level, and try not to damage your hearing.

 

[Lee-c]

As Nathan said, some movies are done with "hotter" audio than others. It's not that calibrating your system
doesn't mean anything, it does. It's just that not all movies actually hit the kind of peak
volume levels that are allowed within the DD Ref. level specs for the volume you are listening at,
whereas some action movies actually are louder than one would expect at the master volume level
you are listening at with your calibrated system. For example, you might be watching
a comedy and the sound levels are rather tame, and you can turn it quite a bit, since there
are no harsh sudden high SPL peaks in the movie. On the other hand, when you watch an
intense action movie with explosions and gunfire and things like that, there may be many
powerful sudden leaps in SPL that push to and even beyond what the official DD Ref. level standard
calls for at the master volume setting you are using at the moment. This is especially
true with deep bass, which can sometimes be way over spec.

So when we say we are watching a movie at -10dB on a calibrated system at the listening
position where we did the calibration, then others can know what volume you are listening at
by going to their own listening position in their own calibrated stereo system and listening
at the same master volume level, but that only applies when watching the *same movie*,
because the volume levels can vary from movie to movie. AND this is assuming that your system
is capable of playing at the specified number of dB's below, at or above DD Ref. level,
so you can replicate the SPL levels in your own home at the listening position you used
for calibration.

That's what's great about Ref. level, everyone knows what you mean when you say, "I was watching
The Matrix at -8 dB last night.". If you want to know what that sounds like, then go your
DD Ref. level calibrated system and watch the movie at the same level from the viewing position
where you did the DD calibration from and you will be hitting the same SPL peaks. Again,
assuming your system can actually play that loud, which might be limited by your
speakers and/or your amp.

The differences between rooms and distances from the main speakers, etc. has already been taken
into account when you did the DD Ref. level calibration in the first place.

 

[Andy_Steb]

Derek, I'll try to help you in your confusion.



Your system is probably calibrated just fine. The problem is your assuming 0dB on your Denon is ref level. I would have to guess reference level on your system is +10.

So watching your dvd at -9dB(on your system) = 86dB(peaks) = -19dB Ref level.

 

[Vader]

Andy, that makes perfect sense....

 

[Phil Iturralde]

My SPL @ -8 REF Level** playing my son's Matrix DVD (**per my Yamaha Master Volume Control Digital Readout -27.5) = 109+ dBc FAST LFE SPL 'real live" Peaks monitored @ my 'sweet spot', 9' from my Center; approx. 25' from my SVS, in my 20'x 30' HT/family room! (Sounded glorious by the way )

Was your 'real live' 109 dBc FAST LFE SPL Peaks @ the -8 dBc below REF Level @ your 'sweet spot'?

Normally, with the majority of my DD/DTS-5.1/6.1 blockbuster DVD's in my library of 480 DVD's, ... my MVC -10 dBc Digital Readout @ -29.5, the FAST LFE SPL Peaks = 105/106 dBc!

Like I wrote above, my 'real live SPL AVG' for most of my DD/DTS-5.1/6.1 blockbuster DVD's is ...

REF Level = 115 dB (MVC = -19.5)
-5 dB below REF Level = 110 dB (MVC = -24.5)
-10 dB below REF Level = 105 dB (MVC = -29.5)
-15 dB below REF Level = 100 dB AVG (MVC = -34.5)

What's your 'real live' SPL monitored @ your 'sweet spot' playing Matrix -8 dB below your MVC REF Level (next time pick a time code, chapter or scene!)

Phil

 

[Lee-c]

Phil Iturralde: Well, first off, I didn't make any volume claims in my post when I mentioned the watching
The Matrix at -8RL. I was merely using that as an example of how useful DD calibration is. Since you
can then talk with other stereo enthusiasts who also have DD calibrated systems about volume levels
relative to reference level when watching a particular movie, and they know what you mean by that.
It gives a common reference point.

But since you asked... I get 110dB (c weighting, fast) at -8RL in The Matrix during the helicopter crash.