Subwoofer Calibration Levels?

On a subwoofer in a home theater setup, I have heard so many different theories regarding what calibration dB it should be at or near; I am told by Terrence that it should be 4 to 5 dB HIGHER than what all other speakers in the system are, while some tell me that a couple of decibels higher is all it needs to be....my main and surround speakers are on "+6 dB" on my receiver's calibration, and my center is on "+8" to compensate for dialogue, while the sub is also on "+6" because any higher and I am experiencing a loud "cracking" or "snapping" noise from the sub during extreme bass peaks on DTS and DD EX soundtracks; if all other speakers are on "+6" (the mains and surrounds, that is), should the sub be bumped to like "+10" if that is the theory?

I may be off track here but it sounds to me like you need an SPL meter and a test DVD like sound and vision. You then pump sound through each speaker (using the test DVD) and then turn up your receiver until the spl meter registers 75db or so. This is reference level. Once you set the sound level on the receiver dont move it during the rest of the test. Cycle through each speaker setting each to 75db. Once you get to the subwoofer you may find that 75db just doesn't give the impact your looking for so that is where u add +2 or whatever to get the SPL meter to read say 78db instead of 75. Hope this helps. If I am off track, I apoligize. If you have more questions, then I will be more detailed then.

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Originally Posted by poneal

I may be off track here but it sounds to me like you need an SPL meter and a test DVD like sound and vision. You then pump sound through each speaker (using the test DVD) and then turn up your receiver until the spl meter registers 75db or so. This is reference level. Once you set the sound level on the receiver dont move it during the rest of the test. Cycle through each speaker setting each to 75db. Once you get to the subwoofer you may find that 75db just doesn't give the impact your looking for so that is where u add +2 or whatever to get the SPL meter to read say 78db instead of 75. Hope this helps. If I am off track, I apoligize. If you have more questions, then I will be more detailed then.

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You are technically 100 percent correct, Poneal, if one were doing it the correct way through a meter; my settings were made through suggestions from a home theater expert who originally set my system up using "+6" as the all-around standard for the mains and surrounds, but that is another story for another day.....see the problem is that at "+6", the bass doesnt distort when playing extreme DTS and DD EX soundtracks, but pump that number up to "+7" or "+8", which would be equivalent to your suggestion of adding "+2" dBs, and I get a nasty "snap" when extreme low bass hits....so I need to keep the sub calibration level at "+6"...yet this doesnt allow alot of bass on soundtracks and such that AREN'T extreme in nature.

All subs will distort at some level. The only way to keep the sub from bottoming out too early is by buying the spl meter, there is no other way. They guy that set up your HT my be an expert, but his ear is no SPL meter, and never will be. The analog spl meter is only $40 from Radioshack, and it will tell you whether the sub is set up correctly or not. After using the meter, and setting everything up correctly, and you're sub still bottoms out at volume levels that are too low, it may be time for saving up for a better sub. Please take my advise and do yourself a huge favor and buy the spl meter, it will be the only way you know the settings are correct.

-Joey

Oh good lord! Don't get Lexmark/TLADINY going on an SPL meter. We have been telling him this for over a year. He refuses to get one. Even though it would solve many of the questions he continually asks over and over again. Will this time be different?

JSE

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Originally Posted by Lexmark3200

On a subwoofer in a home theater setup, I have heard so many different theories regarding what calibration dB it should be at or near; I am told by Terrence that it should be 4 to 5 dB HIGHER than what all other speakers in the system are, while some tell me that a couple of decibels higher is all it needs to be....my main and surround speakers are on "+6 dB" on my receiver's calibration, and my center is on "+8" to compensate for dialogue, while the sub is also on "+6" because any higher and I am experiencing a loud "cracking" or "snapping" noise from the sub during extreme bass peaks on DTS and DD EX soundtracks; if all other speakers are on "+6" (the mains and surrounds, that is), should the sub be bumped to like "+10" if that is the theory?

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And here's an easy way to get there from here. You play a movie with the loudest bang, boom, rumble and set the sub level as high as you can w/o cracking or popping the sub and then set all the other speakers according to what T say's and you'll be in business. BTW, this way you are trying to set up your speakers(with the db readout on the receiver instead of the SPL meter) will only work accurately IF all your speakers are close(real close) to the same relative SPL rating to each other.

The way I have my sub setup is as follows: I have the reciever sub level set to 0. I then used the DVD test disk with my receiver volume set at reference (75db). I then use the amp for the sub (i have a passive sub but will work with active also) volume knob to increase/decrease the volume of the sub until it reaches +3db above reference or 78db. This keeps the reciever sub level set to 0 and you control via the sub volume knob the amout of bass you want.