Originally Posted by iiK0NiiK
I'm currently using an Onkyo TX-NR676 with a BIC PL200ii subwoofer.
After following the guide as closely as I could, I've settled on a subwoofer level of around 3 o'clock (not quite 3/4 on the dial) and LFE level at -10 on the AVR. Since the Onkyo doesn't have Audyssey, I've had to manually adjust the level of my center channel and surround right to get a level SPL across all channels. Not a big deal, just me being OCD more than anything.
Question is, when I'm manually calibrating the subwoofer SPL in relation to the other speakers in my 5.1 arrangement, does the subwoofer need to match the SPL of the other speakers, or does it need to be a few decibels higher? (i.e. if all speakers are at 50dB when playing test tones, does the subwoofer also need to be 50dB?)
I'm not very familiar with Onkyo. When you say that the LFE level in the AVR is at -10, do you mean that the subwoofer trim level in the AVR is at -10? I think I recall that Onkyo subwoofer trims go lower than -10, and if so, then your trim level should be fine.
Most people will want to start with the subwoofer set to the same level as the regular channels. That way, if you add a subwoofer boost, you will know how much you are boosting your subwoofer in relation to the other channels. In theory, when your Onkyo does an automated calibration, it will be calibrating your audio system so that a master volume level of 0.0 will correspond to 'Reference' levels for 5.1 movies. That isn't strictly necessary, but it does give us a common basis for comparison if we want to talk about our master volume levels and our subwoofer boosts.
Onkyo should be using a 75db test tone to automatically calibrate your audio system to Reference. Saying that you may be manually using a hypothetical 50db test tone throws me a little. If I were you, I would let your Onkyo do the initial automated calibration. You can always make manual adjustments to it afterwards, but it should be fairly accurate for the regular channels, even if the subwoofer levels are off. I have heard several people say that the subwoofer levels typically are off with AccuEQ, but I can't confirm that personally.
Once you have calibrated your system, however, so that all of the channels are set to play at approximately the same level with a 75db test tone, you can make any user-preference changes you want to make. Most people probably add a couple of decibels to the center channel, for instance. And, nearly everyone increases the volume on the subwoofer in order to enjoy the amount of bass that they like. The initial calibration, based on 75db just gives us a common starting point. After that, by all means increase the volume on your BIC to any level that you prefer, and that your subwoofer can play without distortion.
I hope this explanation helps!