With all this talk about AVIA and DVE, I had a question about calibrating ones sub with the recievers internal pink noise. My question was in regards to the built in subwoofer test tone. I was told in the past that the tone is composed of many different low level frequencies. I was just wondering how would one go about calibrating their sub properly with a Ratshack SPL meter and this tone ? I know the Rat meter is not very sensitive and that is why there is a "compensation" chart out there. My question is, does the compensation chart apply to this tone ? And if so then what's the variable ? Also, is the THX Optomizer any good for rough calibration ? And if so then is there any "compensation" chart to follow with the LFE test tone ?
Test tones either from the reciever or a test disc don't take into account the error on the RS meter, so I would think it's probably a good idea to compensate regardless of the source for the test tone. I've found the AVIA test tones and those of my receiver to match up almost exactly when set at the same master volume level. I haven't tried the THX Optimizer but it's probably at least good enough for a rough calibration. Compensation chart would probably be the same as for any other test tone source. Hopefully Edward JM will chime in on this--he's the most reliable source I know of for sub calibration information.
My advice would be to get a test disc, because some receivers are right on, and others are way off for the sub tones (from your post, it appears you have seen the other threads, so you know not to get dve for your sub calibration) It is definitely worth the expense, and you will also use it for video calibration which is equally if not more important. If you are going to use the receiver tones you would treat them the same way you would the test disc. Most receivers are similar to ve and DVE in that they use 75 dB for ref calibration (72-73 in reality for the sub to compensate for the meter being off in the bass region). Since not all receiver test tones are equal, you want to double check your efforts. Once you set the sub you want to check it with bassy music that you are familiar with and is well recorded. I use Jazz that has a strong accoustic bass lines in it. In my opinion, for music, you want your sub to be authoritative, but not standing out. If you can notice the subwoofer, you are set too high. You want to increase the sub level just past the point where the sub and speakers are blended and the sub starts to stand out on its own, then back it up a little. You can then tweak it up for movies if that is what you like. Greg
