Dolby Pro Logic IIz questions

[Big Daddy]

Originally Posted by AmberMosquito

hey big daddy, you seem to be very knowlidgeable in this area.. so i was wondering what you think about audyessy(im sure i spelled it wrong) dynamic eq. Should I use it when playing bluray movies at a loud level? 73 being usually the loudest i ever need it. Does it add anything at loud levels? Or is it only for use at lower levels? When I do use it at lower levels I usually have to turn it wat down cause it makes the surrounds + front very loud. and it adds a ton of base. I have an onkyo txnr708 with 5.1+front height. do you know the difference between the NR model and the SR model? any insight on these matters would be greatly appreciated.

First of all, make sure all your speakers and the subwoofer are calibrated properly. Double check with an SPL meter.

Audyssey Dynamic Equalization is meant to be used at low volumes. Technically, as long as you are below reference level, using Audyssey Dynamic Equaliztion is a good idea. Reference level is extremely loud. I would leave dynamic eq on all the time. However, if it bothers you so much, turn it off. It is a matter of personal preference.

Brief Explanation of Audyssey Dynamic Eq:
Multi-channel audio is mixed at high volume and is meant to be played back at very high reference level. However, in home theaters, people turn the volume down and as a result the sound quality suffers. Normally, when you turn the volume down for surround sound movies, the bass and surround effects suffer. With the Audyssey Dynamic EQualization, you can regain this information even at low volumes.

For more detailed information, check the following links:

http://www.audyssey.com/technology/dynamiceq.html
http://www.electronichouse.com/artic...ynamic_volume/


Reference Level:
Reference level is defined for film mixing and movie theaters. Every studio and movie theater is calibrated according to this level. It represents an average of 85dB for the regular speakers on the SPL meter (set on C weighting and Slow) using a band limited (500Hz to 2,000Hz) pink noise at the listening position. The peak level is set 20dB higher at 105db and the LFE peak level is set +10dB higher to a maximum of 115dB. The purpose of the +10 dB gain for the LFE channel is to increase the dynamic range of bass sound such as explosions and crashes. This means when the receiver master volume is set to 0dB, the regular speakers are expected to play a peak level of 105dB and the subwoofer is expected to produce a peak output level of 115dB. This is louder than most people can tolerate, so people normally set the master volume much lower than 0 when watching movies or listening to music. Furthermore, such loud bass level places a heavy burden on the subwoofer and requires multiple high-end subwoofers to produce it accurately.

Because 85dBC test tones can be very loud in a small home theater room and can damage hearing, receiver manufacturers through the encouragement by Dolby and THX decided that a reasonable test-tone level is 75dB and that is the level that most receivers use.