Question about "reference" calibration.

[rafaelsmith]

I have been messing around with REW the past few weeks.

Something is not clear to me is with regards to what I call my "reference" calibration point.

When I use a SPL meter and go thru my receivers test tones...I start with everything set to 0 then increase the AVR master volume until the SPL read ~75db for the front LET channel...then I adjust all the other channels to match. For me that comes out to a master volume of -20.0 (on the AVR display). So when watching movies I set the AVR master volume to -20.0..which I always assumed meant I was at "reference".

Yet when I do the check levels and such with REW...My master volume ends up around -34.0(on the AVR display) which shows 75db on the SPL meter.

Is this normal?

I ask because when I am finally done with all this and have done whatever EQing i end up doing...I would like to go back and make sure all 5 of my speakers and my SUB are matched...just not sure if I should not use the AVR's test tones anymore.

[JohnM]

The volume setting you need with REW will depend on the sensitivity of the analog input the soundcard is connected to and the sweep level you have set in the REW settings. For matching your speaker levels your receiver's test tones would usually be best.

[rafaelsmith]

JohnM wrote:

The volume setting you need with REW will depend on the sensitivity of the analog input the soundcard is connected to and the sweep level you have set in the REW settings. For matching your speaker levels your receiver's test tones would usually be best.

Thanks....thats what I thought.

Its just that a 12-15 difference on the master volume...at least with my AVR is rather significant. At -35.0 master volume...I can barely hear anything...while at -20.0 the windows are shaking. Yet REW seems happy....plots come out pretty much near the 75db target.

[tonyvdb]

On your receiver does the master volume go past 0db? This is generally what is called "reference level" pink noise should be 85db at 0db. Older receivers do not go by the same grid level and usually 0db is as loud as it goes. This is somewhat confusing for alot of people as receivers dont follow the general guidelines.
-35db as you said is usualy very soft but in your case -20 is very loud, this seems odd as there should not be such a dramatic difference between the two.

On my Onkyo I watch most movies with the master volume set at about -15db and that is comfortable.

[rafaelsmith]

tonyvdb wrote:

On your receiver does the master volume go past 0db? This is generally what is called "reference level" pink noise should be 85db at 0db. Older receivers do not go by the same grid level and usually 0db is as loud as it goes. This is somewhat confusing for alot of people as receivers dont follow the general guidelines.
-35db as you said is usualy very soft but in your case -20 is very loud, this seems odd as there should not be such a dramatic difference between the two.

On my Onkyo I watch most movies with the master volume set at about -15db and that is comfortable.

Honestly I have never bothered to go much past -15.

But this is what my manual says....so sounds like 0 is the max but it may allow to go past it..just wont display.

Volume Control
The volume may be adjusted either by turning the knob on the front
panel (clockwise to increase volume or counterclockwise to decrease
volume), or by pressing the Volume Control Buttons on the remote.
See Figure 62. The volume is displayed as a negative number of
decibels (dB) below the 0dB reference point, and may be changed
in 0.5dB increments.
Unlike the volume controls on some other products, 0dB is the maximum
volume for the AVR 247. Although it’s physically possible to turn the
volume to a higher level, doing so may damage your hearing and your
speakers. For certain more dynamic audio materials, even 0dB may be
too high, allowing for damage to equipment.

Gonna do some tests tonight...but i am pretty sure that at 0 my SPL would be much higher than 85.

Maybe I am not doign things right....but with my SPL set at 70....all channel gains on AVR set to 0...a master volume of -20db equal 75db from the left front speaker.

Will see where the master volume ends up for 85db....my guess is 15-17.

[Magialisk]

I'm not sure if this adds much to the discussion, but just as another data point I usually listen to movies between -15 and -20 on my Yamaha. It can go above 0 though I'm not sure exactly how far, maybe to +8? I don't know why you'd ever be going above 0 anyway unless you're either deaf or calibrated extremely improperly.

When first setting up REW I calibrated the SPL meter signal (with the REW test noise) and it was 75dB at -20 MV. What is funny is how when you're done EQing if you go back and recalibrate the SPL meter signal I had to turn it up to -11 MV to get the same 75dB. Obviously when you're doing 10 and 12 dB cuts over wide areas of the sub-100Hz spectrum that test signal SPL is getting cut right along with the rest...

[Bill 3]

Wouldn't your volume level/AVR output versus "reference" level depend on how effecient your speakers are?

[mojogoes]

I don't know if this may help too but on my old marantz depending on what level the intell volume is set say +5 / +10 then it would cut the master volume to say 0..........my onkyo 605 just goes from 0 /99.