Hi Avfan, I have both those dvd-a's and I have noticed they are mixed kind of strange. for instance you have guitars or vocals louder than the original cd, the foreigner dvd-a is like that,vocals jump out at you.

In the original post I noted that I used the 990's internal test tones to set the speaker calibration. From what I can tell from this forum the the 990's test tones are white noise. I have a copy Digital Video Essentials and it has pink noise test tones. When I ran the DVE test tones the speaker settings changed rather dramatically. Now the L is -3 (-7), C is -4 (-3), R is -5 (-7), RS is -2 (0), LS is -5 (0). Original settings using the 990's test tones are in parenthesis. I do notice the stereo image is slightly to the left when listening to CDs in stereo and I may make some minor adjustments to those settings. DVE does a pink noise pan across the speakers and the SPL meter waivers very little. During my limited listening sessions I like the sound better now.

From a 2006 post, Gonk summarized:

"Basically, white noise is a "flat" line all the way across the frequency spectrum, while pink noise is filtered to account for the behavior of human hearing."

So the question is: Is it better to use white or pink noise to set speaker calibration?

If this was a poll, at this point I'd say use pink noise.

That is wrong, and the differences have nothing to do with human hearing. White noise is flat per frequency - i.e. all frequencies have equal amplitude, but pink noise has equal energy per octave, which will yield a perfectly flat trace if a system is dead flat in response. If you look at white noise on a spectrum analyzer, you will see a 3dB per octave rise with frequency - not something you want to use to measure for flat response.

Because there is increasing energy within each octave as frequency increases (there are more frequencies represented), the energy within each of those octaves is more; 3dB, or twice as much more per octave.

That said, the signal used in home theater equipment and on most test disks is filtered pink noise. It is filtered to have energy in the approximately one octave region straddling 1kHz, and nothing anywhere else in the audio spectrum (except for the different signal used to test the subwoofer levels).

The full bandwidth pink noise on some disks is actually more accurate in determining the real SPL over the entire audio band, but it is also more work to interpret, since it gives really more information than most people need to do something as simple as calibrating a system.

If you use bandwidth filtered pink noise from your preamp to set levels, chances are very good that if you check the levels using full bandwidth pink noise, the results will be different.

In any event, you should never use white noise for testing any audio system unless you know how to interpret the resulting data.

Thanks for the insights Altec and the recommendation to stay away from white noise to set speakers, at least for us more casual users. In all fairness to Gonk his quote was his summary of a link regarding white and pink noise.

The DVE disc does use filtered pink noise to set individual speakers; it is referenced as "Band Limited Pink Noise". DVE's pan is full bandwidth and at least across my front three speakers the SPL meter held constant. I got a 2 to 3dB fluctuation across the rear speakers however.

Does anyone know with certainty the 990 uses white noise for its internal test tones?

I think I can bet the farm that it uses bandwidth limited pink noise.

White noise is, as I mentioned before, not flat within it's bandwidth.

I guess we could get into a semantic debate because all pink noise starts out as white noise, and is then shaped, but that is more information than you probably want.

Not sure if the 990 uses "white noise" for speaker calibration but I had the same experience using the 990 test tones vs. using my DTS or AIX test tone calibration discs. Using the RS meter and the 990 test tones gave numbers that were completely different than the DTS or AIX discs I used. For some reason, when I used the built-in mic of the 990, then the speaker levels were the same as the DTS or AIX discs. Only the subwoofer level was too low. Had to boost it 4dBs so it could better match the mids and highs. Wish Outlaw would hurry up with the firmware fix of having the 2 channel sub go into the positive range.

I never really questioned the settings using the 990's test tone until I tried DSOTM SACD and Hotel California DVD-A, but now that I look back they were odd. M&K speakers went through a pretty rigorous testing protocol and it seemed weird the center was so much different. I know the room and speaker placement can have a huge impact, but my L,C, and R are placed in a similar fashion. The L and R are about 3 feet away from the side wall thereby minimizing the side wall effect.

If Altec's farm is safe, I'd suggest the limited band pink noise from the various calibration discs (DTS, AIX, or DVE) may be a good source of sound to set up HT speakers.

I would agree with Altec in that it is probably a filtered pink noise being used for calibration. Reason for this is that you want to get as close to a flat response as possible from your sweep. In so doing the deviations from the measured response in flatness are readily apparent. The easiest way to to obtain a near flat result is to utilize a signal with a downward slope of 3db/octave. That of course means a filtered pink noise.

This is what gets me...
We try to get the best possible calibration on our system and the damn movie studios change up the outputs on our channels...
Am I right!

97db wrote

We try to get the best possible calibration on our system and the damn movie studios change up the outputs on our channels...

I think the movie studios actuall y try to get the relative levels they think should be. Though I will change the levels as I see fit I have no quarrel with them since I believe they (probably-?) are trying to get it the way it's meant to be.

My disagreement is with the SACD production. Not all are good. So you don't know which to buy.....so I don't. Furthermore, because of the live recording I did, and with the maasters I listen to (i.e. copied from multi in dts) I don't need SACD.

If the members of these forums happen to be in Northern Maine, sometime, PM me in advance.