Refernce Level Question

[heeman]

This past weekend I was listening to some demo material in the HT and decided to take out the SPL Meter and take some peak measurements.

During the light cycle scene in Tron Legacy the system had a max SPL of 112 db...........is peaks of 105 db reference or 115 db?

 

[Zing]

If I'm not mistaken, it's peaks of 105dB from the speakers but peaks of 115dB from the sub (both of which are too loud in a home environment in my opinion).

If you've calibrated your system according to convention (which I'm sure you have) you should be achieving these levels anytime your master volume is at 0dB.

 

[heeman]

One of the bad features of the Outlaw 975 Pre/Pro is that during level setting, it does not have a set volume (like my Onkyo). The calibration Pink (or White) noise level is dependent on where the volume is set, it is not fixed. I have asked them about where Reference level is and I cannot get an answer.

I have calibrated levels at 80 db, that is when the volume is at about -25 db. We typically will have the volume at -13 db with most Blu Ray's.

All of this is somewhat subjective (what is comfortable during our session), however was just curious about reference peaks. 112 db was pretty crazy to say the least, the tactical LFE was moving pant legs and seats and we are on a concrete slab..............AWESOME...... :scared-yipes:

 

[Zing]

If you're pre/pro doesn't automatically adjust the volume to 0dB during the calibration process, then that's where YOU should set it. Calibrating to 80dB with your master volume at -25dB isn't really beneficial to you.

 

[heeman]

Think of what you are telling me.......

If I was to set the Outlaw to 0db, the SPL would be so unbearably loud with the test tone, that I would not be able to stay in the room. With the volume set at -20 it is over 95db, this happened by accident. 80db reading at -25db setting results in reference somewhere between -15 and -10 on the volume control of the Outlaw.

To state that calibrating this way is not really beneficial is not a correct statement. It is actually in line with the directions from Outlaw and other calibration processes that I have read.

I did not want this thread to turn into a debate..... :teasing-tease:

 

[Deleted member 133]

Pardonnez-moi for asking, but does it really matter?

Assuming that you've set proper relative levels between speakers, and that you have lots of "play" in your volume control on both the low (too quiet) and high (too loud) ends of things, and that you can therefore set a level that's just right for you for your typical program material / sources, isn't that enough?

Perhaps there's a point where the pre's output(s) become noisy at the top end of their limits, before you get it loud enough, but otherwise you'll probably have many dBs of noise-free range in your volume control to play with.

Or is reference level calibration more important than I think?

Jeff

 

[heeman]

^ I was going to edit my last post, but I see that The Infamous Man of Mackwood (Maxi-Me) is stating what I was going to say.

The purpose of using a test tone to calibrate/balance all of the speakers in the system at the MLP is different than determining reference and where reference may be.

So if there is enough headroom to make your ears bleed then I guess you are okay???

Where reference level is, is a different subject. It would be nice to know where the Reference Level is due to the fact this is the optimize setting for the Blu Ray format?????

Thanks Jeff!

 

[DIYer]

^ The former member whose p!ss is highly prized contact enhancer for electronics, wrote a primer on reference SPL for home theater (too bad the S&V forum is gone). In commercial theaters it's 85db. For home, it's 75db (because of smaller size room).

Here's a link on calibration --> http://forum.blu-ray.com/showthread.php?t=38765

 

[Randy]

^^^It is definitely a shame that all of that went bye bye. There was a lot of good stuff on there.

 

[Deleted member 133]

So if there is enough headroom to make your ears bleed then I guess you are okay???

I use a slightly less scientific standard than that: when Gen comes running down the basement steps screaming "TURN IT DOWN" and it's so loud that I can't hear her, I know it's dialed-in just right.

 

[heeman]

^ The former member whose p!ss is highly prized contact enhancer for electronics, wrote a primer on reference SPL for home theater (too bad the S&V forum is gone). In commercial theaters it's 85db. For home, it's 75db (because of smaller size room).

Here's a link on calibration --> http://forum.blu-ray.com/showthread.php?t=38765

Thanks!
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Measuring and Evaluating the Response
When you go into the receiver's manual setup mode and play test tones, the master volume on some receivers will be disabled and the test tones are played at 75dBC reference level for home theater. You can use the gain level for each speaker inside the menu and adjust their levels so that you get 75dB on the SPL meter. It is ok to adjust them a little higher in order to get 78dB or 80dB.

The master volume is not disabled on some receivers when you go to the manual setup menu. For these receivers, you can choose either the left front channel or the center channel and adjust the master volume until you read 75dB on the SPL meter (+5dB on the analog meter), or the level that the calibration disc specifies. Once you have completed this step, do not change the master volume.

As the test tones go through each speaker, use the adjustment level for that speaker (not the master volume) to cut or boost the output for that speaker to 75db. When you are finished, every speaker should output the same volume level to your listening position. Your subwoofer should also be adjusted to the same level, but if you like a little extra bass, calibrate it 5db more than the other speakers.

If you want to calibrate your system more fully, you may want to purchase the AVIA, DVE, or AIX discs. They are designed to work with an SPL meter and do a much better job of generating test tones. They also have specific instructions on how to calibrate your audio system. Most experts recommend that you use them instead of the calibration system built into your receiver.

 

[yromj]

Yeah, I was going to reference SH also. He stated that the benefit to calibrating at the reference position the volume scale, which should be 0 in our electronics, is that is where the system was designed to operate. However, I also remember part of the conversation turning towards the fact that given the quality of electronics today, the end result won't vary very much.

In Heeman's case where the volume is so high, that would mean turning the individual channels down enough to compensate for that difference. This would equate to lowering the gain of the amps to compensate for the gain of a pre/pro being so hot.

Personally, I would just pour a bourbon, grab my wife, sit down, and :happy-smileygiantred:

John

 

[Rope]

If ur ears start to bleed, it's too loud!

Rope

 

[heeman]

If ur ears start to bleed, it's too loud!

Rope

WHAT?

 

[Towen7]

Personally, I would just pour a bourbon, grab my wife, sit down, and :happy-smileygiantred:

:text-+1:

 

[Flint]

I have never given a rat's ass about reference level. I don't accept it as being necessary for calibration of a system. The only real benefit of tuning specifically to reference level is you will then have the ability to set the levels in your HT which perfectly match the levels in a certified THX, DTS, or Dolby theater. Theoretically that means you hear pretty much exactly the same thing the director and mastering engineers heard when they mixed the movie. If that mattered to me, I may be interested.

 

[Zing]

^ For a guy that's all about accuracy, I'd think you'd be all over this like white on rice!

 

[Flint]

Well.. for a movie I don't really care. For music, that's a different story.

On a couple of albums Frank Zappa listed the speakers used and the reference level when he mastered the music. He was attempting to give people an opportunity to hear pretty much what he heard. I dig that.

But, considering the massive impact acoustics and the speakers have on sound, and none of us have the same speakers or room as the movie engineer's, I doubt it is worth the effort just to get the levels matched.

 

[yromj]

Well.. for a movie I don't really care. For music, that's a different story.

On a couple of albums Frank Zappa listed the speakers used and the reference level when he mastered the music. He was attempting to give people an opportunity to hear pretty much what he heard. I dig that.

But, considering the massive impact acoustics and the speakers have on sound, and none of us have the same speakers or room as the movie engineer's, I doubt it is worth the effort just to get the levels matched.

Plus the effects in movies tend to be as artificial as many of the plots. Times like this remind me of what an A/V salesman told me once: After a demo scene which included a helicopter flying, he and the customer walked outside and a helicopter flew over. The customer pointed at it and said, "Wow! That doesn't sound real THAT [pointing inside to the HT demo room] sounded real!"

John

 

[Deleted member 133]

Well.. for a movie I don't really care. For music, that's a different story.

On a couple of albums Frank Zappa listed the speakers used and the reference level when he mastered the music. He was attempting to give people an opportunity to hear pretty much what he heard. I dig that.

But, considering the massive impact acoustics and the speakers have on sound, and none of us have the same speakers or room as the movie engineer's, I doubt it is worth the effort just to get the levels matched.

Plus the effects in movies tend to be as artificial as many of the plots. Times like this remind me of what an A/V salesman told me once: After a demo scene which included a helicopter flying, he and the customer walked outside and a helicopter flew over. The customer pointed at it and said, "Wow! That doesn't sound real THAT [pointing inside to the HT demo room] sounded real!"

John

Oh I don't know.

I don't think my HT could ever come close to replicating the sound and experience of being just feet in front of a Bell 412HP as it touches down on a city street in the wee hours of the morning, as my photos below illustrate.

Jeff

ps. I have just realized something as I look at the second photo that I posted. The pilot (white helmet) of that helicopter was an extremely accomplished test pilot, who while serving in the Forces, while putting a Sea King down on a destroyer's deck in storm conditions, had a complete engine failure while in the hover, and brought it down without injury to anyone on board. While landing on a city street between light standards etc. might be a little tricky for most pilots, it was nothing to him, and why I had no concern about being so close. Soon after those photos were taken in 2008, he was diagnosed with prostate cancer - which had spread to his bones and lymph system. He was given a 20% chance of living 5 years. He died in September of this year, and flew as much as he could throughout the long battle.