Mark McConnell

calibrating at 55dB- is that okay?

I calibrated my 6.1 home theater system at 55dB using my SPL meter and the test tones from my receiver. Does this matter? I'm afraid to turn the volume up so that it reads 75dB on my SPL meter from where I sit because that would be very loud and I don't want to blow my speakers. This is just temporary until I get the Sound & Vision calibration DVD in the mail, but won't those testones be pretty loud too? Can I calibrate lower than 75dB for that disc? I wouldn't ever be listening at Ref level anyway.

ScottCHI

what speakers and pre/pro/amp/receiver?

how far away are the speakers from your sweet spot?

"All men are frauds. The only difference between them is that some admit it. I myself deny it."

Bill Kane

Mark,

Don't worry, hardly any "average" home systems are played at Reference Level, but you may be cheating your audio enjoyment by selecting such an artificially low level as 55dB. Let's take a quick tour of where Reference Level derives...

Based on Dolby Lab standards from the early/mid 1990s developed for in-theater sound systems, the technical standard for auditorium reproduction has become 105dB PEAKS from the main speakers and 115dB PEAKs for Low Frequency Effect (LFE) channel, measured at the theater listener's seat.

Technically, many home users can hit these levels with regular 100 wpc receivers, capable 12-inch subwoofers and floorstander Mains. People with smaller HTIB speakers probably find they'e not capable of handling these peaks as safely. But you're right, a home living room isnt a theater auditorium and it's TOO LOUD.

Now the AVIA calibration disc will have us calibrate at a TEST level of 85dB to save our eardrums while setting up; however, the real world DVD audio playback will be the 105/115dB standards.

So no one says we have to listen at this level. Just set the volume too where you want it. For ex. my Yamaha volume reads -16.5dB at Reference Level, but I listen about 10dB quieter near -26dB.

Reference in this application is a "scientific" absolute. It's not necessary, but if we all set our rigs to Reference Level, it means we're talking the same language as we chat with others or ask questions to compare our system calibration.

Once you have your disc, if you feel your speakers need tender care, you can shave say 10dB off the ref. std. by calibrating the spkrs to 75dB (set-up level only). Then you look at the receiver volume level and remember this mark as your maximum or top level.

G'luck

bill

Mark McConnell

Thanks, Bill. That helped alot. I have a much better understanding now.

Chu Gai

To add a little to Bill's wonderfully concise summary, consider that the level you were thinking about is getting close (it varies) to the ambient noise levels in your home. Setting it higher allows for more accurate balancing if you will. Then when you listen, just tone it down as Bill and many others do.

Yee-Ming

Just to chime in, I personally also find Avia's 85dB to be annoyingly loud at times, so what I did was since 0dB on my Marantz was meant to be reference (works out nicely, at 0dB little or no adjustment to any speaker gets an 85dB tone), I turned down to -10dB and calibrated at 75dB. You could do the same at -20dB and calibrate at 65dB. Once everything is set, crank up to reference level (in my case 0dB), check everything is in fact 85dB, and you're done.

In practice I never watch a movie at reference, -20dB is about usual and when I "crank it up" at the very most I'm somewhere around -6 to -10dB.

Chu Gai's point on ambient noise is well taken, hence my suggestion to double-check at whatever your reference level is, for 85dB test tones (on Avia), when you're done.

ScottCHI

the volume levels on receivers aren't "meant" to be representative of anything. it's just a relative scale.

the SPL you acheive in your room from each speaker when you set your receiver at 0dB is entirely dependent upon the efficiency of the speakers in question, the effects of the room, and most importantly, the speakers' distance from your listening spot.

0dB on your receiver's scale, just by chance, happens to be reference level in your particular set up.

"All men are frauds. The only difference between them is that some admit it. I myself deny it."

Yee-Ming

Well, to be clear, I'd decided that 0dB would be a "good" or "convenient" mark to set as reference, and as it turned out by default the 0dB setting was pretty close (+1 or +2 adjustment needed on the front three, IIRC).

But you're absolutely right, "reference" is arbitrarily set, just happens that for me 0dB worked fine.

It's also dependent on how the receiver's manufacturer sets the scale. As I understand it, for instance, Yammies' scales are quite different from Marantz's, so most people find that with minimal boosting, you'd wind up with a so-called reference level at about -20dB, on the Yammie's scale. In contrast, HTiB might literally set 0dB as pretty close to mute, and you'd typically listen at about 25dB, with maybe 30+ as being pretty darn loud.

William*E

Another Question then.....
I have a Pioneer 814K......

I've always set

Left-Right at 5db
center at 10db
surround at 10db
sub at 10db

and the main level is usuall at 41db (lower the number the higher the volume)

Now is this okay? Ideal? Now to me it sounds good, but the last thing I want is to damage my equipment because of improper levels.

Thank you in advance.

T-REKZ INC.®

ScottCHI

http://www.hometheaterforum.com/htfo...hreadid=204362





why would you repeat that same question in this thread?

"All men are frauds. The only difference between them is that some admit it. I myself deny it."

William*E