Home Theater Forum and Systems banner
1 - 1 of 10 Posts

· Registered
1,405 Posts
Those test disc are for a quick and easy setup. For best results you would use 1/12 octave RTA in REW and playback some Pink PN in the singal generator. I'm thinking this will be like the Full Bandwidth but it will take out some of the averaging. You would calibrate so that the speakers are around 70dB on the Spectrum window and if your using an RS meter, the sub is going to measure around 4dB higher on the RMS input. You set this 10dB higher than the center channel using a 1/3 octave scale. After all this you might find that your THX optimizer would read about 75dB for the speakers, then the sub could measure around 74dB - 75dB. Keep in mind that the sub operates on a different voltage singal than the other speakers, but it should still measure 85dB at -20dB FS or 75dB with the optimizer. There is no need to do SPL calc for measuring pink noise.

The reason you may be getting different results could be because of the decoder in your system doing the signals. In this case you would want to verify that this is the problem by burning a CD using REW of the Pink PN at -33dB FS for 75dB at -10 on your receiver or other decoding/pre/amp device. Remember that reference level is 0dBv and you should never listen higher than this.

If it sounds like there are dips measure, or try to keep this in mind when setting the level.
1 - 1 of 10 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.