Volume and calibration - Does this sound like a correct approach ?

[timetohunt]

OK. Working on calibrating the room and receiver. I'll play with EQ settings later, not too much worried about that now. My concern, is volume and level setting.

While its not the absolute reason for this, I often caught my wife sneaking up the volume to deadly levels when I was not looking (god love her, she even likes it louder than I do, one reason we will stay married through death and defness). And she will do this on the subwoofers as well.

Lucky for the distortion lights on the amp that drives my fronts. When they start intermittently showing red I know we could be on iffy ground in terms of how much is being put out. If they are solid red, in my mind something will break before long and the volume is turned down immediately.

So with a Receiver, a separate mains amp with gains, and 2 powered subs would this be a correct approach?
1. I used a few CDs and DVDs that I sort of consider reference in terms of volume levels. An average output for me. I know some recordings are going to be much lower and a few might be louder. The ones I chose were on the louder end.

2. My receiver gos from -80dB to +12dB on the volume scale. Using my so called reference discs I set the front amp gains at a level where if I approach 0.0 dB on my main volume on the receiver its loud. About as loud as you might want it without distortion. You have a couple twists of the knob available and it will still sound good, but for the most part you know you are in some very loud territory after 0.0dB. I don't know anything about this, I just thought that might seem like a logical place for reference. One, I can tell her, never touch the front gains, and watch it once you approach 0.0dB on the receiver.

So here are the questions:
1. Given what I stated above, am I ready to calibrate?

2. What effect will the volume settings on my powered subs have during an automatic calibration with the receiver? I just set them at 3 quarters up before calibrating, cuz I don't know. What's the advice there?

3. Once calibrated, can I adjust/tweak this whole thing up or down the scale of volume by using a manual ch level adjustment. In other words if I add plus or minus say 1dB on all my channels, is it relavtive? Or does 1dB setting on a front left speaker not equal same on a surround speaker and are things thrown off?

Thanks.

 

[MDS]

0 is the convention for reference level so that negative numbers are -x dB below that reference level and postive numbers are +x dB above that reference level.

What you did though is calibrate to a level you think is 'loud enough' based on a sampling of different discs. As you said each of those discs will have a different average level. If you happened to use a modern CD with an average level of around -12 dB then your calibration will be WAY off for movies which have an average level of around -30 dB (which not coincidentally is the level of the test tones on the receiver).

You should do the same procedure using the receiver test tones and adjusting the receiver channel levels and the amp gains until you can get each channel to read 75 dB on the SPL meter. If you do that, you will have Dolby Reference Level when playing movies at 0 on the volume scale. CDs that have a higher average level than the test tones will of course be much louder at 0 on the volume scale.

Yes you can tweak the levels on the fly while listening. Most receivers will reset to the calibrated level once they are turned off.

 

[Thaedium]

Too tired to think right now, but the db setting is not a volume setting perse. Its the amount of power being given to the speakers to use. The dynamic range in the content will affect this as well. So say you have it set to +1db on the reciever, a loud explosion might spike in range and cause clipping. And whispering might still sound ridiculously quiet.

Setting the individual speakers to run hot or cold ie +db for hot, and -db for cold is something I've always felt was a bit unnecessary unless trying to compensate for room acoustics etc. And I doubt it will be of much use for what you are intending. If Wifey has a thing for loud music, if you set the fronts for -db's she will just tune it up more until she gets the noise she has been seting it too all along. Better just to tell her the moment she hears any sort of distortion to turn it down some, and then some more just to be safe.


er... nevermind. I just realized how tired I am, I didn't even read what you wrote correctly.


1. Pretty much, MDS has some good ideas on this.

2. There is in fact an affect that your powered subs will have during an automatic calibration. Depending on the calibration tool being used, it may detect and determine that the subs are too loud for that level. So as MDS mentioned the recievers calibration tones will be played at -30db, and you have your subs at a level that go well with reference level music. The tool may determine that the sub needs to be turned down, and prompt you to do so.

3. What I wrote above the nevermind portion more or less applies to this. If say you set the front left to +1db, and the right left to =1db it will not throw off things. But there is no need for it unless you are compensating for problems with room acoustics, position, etc.

 

[jcPanny]

Max volume levels

You might measure the peaks with an SPL meter when you have the volume cranked up and make sure you are not doing perminant hearing damage.