What is "reference" levels?

[HTADDICT]

I am not new to home theater, but I hear this all the time ... listening , setting up etc. etc. at "reference levels" I wish I could say that I know what this level is but I ashamedly admit that I do not, could those of you who post using this reference fill me in. What is a reference level? I just bought a new yamaha receiver and a pair of rf-7's a rc-7 a pair of rb 10's for front effects, rs -3's for surrounds and my old rf'3-s for surround backs. And would like to play with setting other than the ypao. So maybe you guys could help me out. Just a webster dictionary description of reference level would be fine.

[JewishAMerPrince]

Reference level is an spl level established by Dolby Labs (and I also believe there is a THX reference level), in order for designers to "tune" a theater. If I remember ccorrectly "reference level" is something like 115 db ...hopefully somebody here can help on that one.

[toddvj]

What ARE reference levels.

Reference Level means loud.

[TheEAR]

People,dear people. Google is your best friend here folks!

Dolby reference level...

Volume level of an audio system with the volume at the 0 decibel setting resulting in 85 decibel volume with a test tone and 105 decibel peaks. Dolby reference level is the volume level used in movie theaters for movie presentations.

THX reference level...

Volume level designated to be used as the standard in THX certified theaters and home THX installations setting volume at 75 decibels when fed a continuous test tone and achieving 105 decibel peaks when the volume control is at the reference 0 decibel setting.

Look on audiovideo101.com and you will get plenty of answer for these more...dark and mystic brain stormers. []

A reference level of 115dB is probably a reference at the national high SPL

torture labs. []

[sfogg]

Reference Level is every speaker being balanced such that on playback

the maximum peak level per speaker is 105dB at the listening position

with an average level 20 to 30dB lower. For the LFE channel the maximum

peak at the listening position is 115dB.

Depending upon the equipment where this occurs will vary on the volume

control in your receiver/pre-pro. THX Certified equipment will be at

'Ref Level' when the volume is at 0dB on the control assuming the

system was setup properly in the first place.

To find 'Ref Level' in your own system if you already have your

speakers balanced between each other get a test CD/DVD. It will likely

have have some type of test tones on it. Pink noise can work for this.

If you are using Pink Noise set your meter to SLOW and 'A' weighting

(removes the influence of room modes on the levels). The test disc will

say at what level the pink noise is recorded at. It will likely be at

-20dB or -30dB.

Apply that level against 105dB. IOW 105 - 20 or 105 - 30.... so either 75dB or 85dB. That is your target level.

Now while sitting at the listening position play the pink noise. Adjust

your MAIN volume control so that you read either 75 or 85 dB (as

required above) on the meter. The volume setting on your

receiver/pre-pro is where it should be set if you want Ref Level

playback.

Alternately you can pick an easy setting on the volume control and

while playing the test tones use the individual speaker balancing

controls to set each speaker to 75dB or 85dB. When you take this

approach be sure to set the meter to 'C' weighting while doing the sub.

Where you set the main volume control while doing this is where it

should be set later on if you want to listen at Ref. Level.

Be warned that if your sub(s) don't have limiters/protection in them

more and more movies coming out now are sub busters for those that

attempt to play back at reference level with subs not capable of those

levels.

Shawn

[sfogg]

"A reference level of 115dB is probably a reference at the natiolan torture labs."

Nope, that is the peak level of the LFE channel during Ref. Level

playback. Assuming the subs are up to the challenge of course....

Shawn

[TheEAR]

"A reference level of 115dB is probably a reference at the national torture labs."

Nope, that is the peak level of the LFE channel during Ref. Level playback. Assuming the subs are up to the challenge of course....

Shawn

Yes peaks only,as subwoofers can hit high peaks but sustained high SPL would be ill advised for your hearing.

[sfogg]

"Yes peaks only,as subwoofers can hit high peaks but sustained high SPL would be ill advised."

Yes, many subs could run into serious heat problems trying to do those levels for terribly long.

As far as hearing goes levels like that at low frequencies are

dramatically much less dangerous then those levels higher up in

frequency.

Hearing damage is based on both frequency and level... not just level.

Shawn

[TheEAR]

"Yes peaks only,as subwoofers can hit high peaks but sustained high SPL would be ill advised."

Yes, many subs could run into serious heat problems trying to do those levels for terribly long.

As far as hearing goes levels like that at low frequencies are dramatically much less dangerous then those levels higher up in frequency.

Hearing damage is based on both frequency and level... not just level.

Shawn

True,a 120dB at 20hz will n be as irritating as say 1KHz at 120dB.

[HTADDICT]

Toddvj, by far my favorite answer, thank you!

I stand corrected - What are reference levels? (that would have made my english teacher cringe).

[HTADDICT]

also- hey jerry, from rushisrighton-should have expected to see you over here.