Originally Posted by holyindian
My apologies, its 75dB not minus.
Yea i read on the manual that after setting up the auto-cal not to touch the settings on the sub.
I have a THT subwoofer, its a huge 36x36x24 subwoofer. They are like the Danley DTS-10 subs, the THT is considered a monster in the world of Folded horned loaded Subwoofers. The sub does not have an inbuilt amp, but is powered by an external amp the Dayton SA1000.
Now when i turn on the Audyssey auto-calibration, during the very first step at Subwoofer Level Matching, I start the SW Test after which the subwoofer roars for few seconds and then i get a message saying
"Please adjust the level of your active subwoofer unit so that the level indicates approx. 75dB
In this case do i have to turn down the gain knob on my external amp? And when i do turn it down to bring down the value to 75dB (which is initially 98d marked in a red box), when i bring down the gain knob on the amp the numbers slowly start falling, and by the time it shows 75dB, the gain knob on the amp is almost 1 on a scale of 10. Thus making the sound from speakers and subwoofer like a hand held radio after tha auto-calibration.
I used to have an Onkyo SR-TX604 amp earlier, which also used audyssey calibration, but with that.. the speakers/subs sounded better than the imax theater.
Again, as i said, i cannot set the gain on the sub, as there is no knob or control of the amp on the sub. My subwoofer has an external Rack mountable amp the Dayton SA1000.
And here's the picture of the subwoofer.
I am not sure, is it cos the sound coming from the subwoofer is so massive the audyssey reads it as above reference level??
I do get a feeling I am doing something wrong, audyssey has tuned many a THT subs, i am not sure where i am messing up.
You've gotten good advice above, I'll just add a couple of things.
The main thing that the autocalibration of speaker levels is doing is to get every speaker to put out equal epl with equal input, so they acurately reflect what goes on. Your old recever had Audyssey 2EQ, and did not have DynamicEQ or Dynamic Volume. It is these newer technologies that make Audyssey want to not JUST equalize the speakers, but set them to a known otput level for a known input level. That lets Audyssey know where the movie mixing and movie playback "reference level" is (every movie mixing stage uses the same reference level) so that the newer techs wil work right.
that's why it's trying to get your sub into the 75 dB range.
You'll just have to make yourself not worry about where the volume control is. Our hearing and the dB scale are logarythmic (10 times power equals 2 times loudness). Some amps have linear volume controls, so thatthe first 20 or 30 dB of adjustment are all in the first 1/8 to 1/4 of the adjustment range. My guitar amp suffers from this, making it hard to set the level when I need to be quieter.
In the end, though, your sub will be able to fully provide every single decibel called for by the movie or music even with its low volume control setting. Don't worry.
Now, I have to say it is possible yo've gotten used to non-calibrated sound. If your sub was 20 dB above reference at it's old amp setting, it is very likely that your old Onkyo could not bring it any closer than 5 or 10 dB above the level it should be. All AVRs have limits on how far they can trim the speakers and they do not issue warnings when they lack enough plus or minus to get things right. The only way to tell is to look at the trim settings and see if they are maxed out.
Two things. First, I recommend that you calibrate and live with the correct levels for a while and see if, while there's less impact, it's kind of nice not to have midrange sounds swamped out by the loud bass. Note that using Dynamic EQ, if you listen below reference, will make up for a lot of your missing bass, by boosting bass and treble to account for the fact that as things get quieter, humans hear those frequencies lwss well. So with DYnEQ it's possible you'll have all the impact you think you are missing! And it'll be the rignt amount of boost at different frequencies in the bass and adjust itself if you listen at different levels at different times. It's a good thing IMO.
Now, if you find after say 2 weeks that you just plain prefer the bass more boosted, nothing bad will happen if you turn the sub back up. THe usual recommendation is to do it with the sub level trim in the receiver rather than on the amp volume knob so you know how much change you made and can get back to or change your deviation from reference easily.
Finally, as I understand it, some AVRs default to have Audyssey Dynamic volume on at full strength. This will give you wimpy sound at high levles (makes everything audible quite nicely when you listen very quietly, but it's not good for normal listening). Make sure it is OFF when making critical judgments about your system.