Avia sub calibration can barely hear sub

Discussion in 'Speakers' started by Mike_J_Potter, Jul 1, 2004.

  1. Mike_J_Potter

    Mike_J_Potter Second Unit

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    I just got my avia dvd today, I decided to check out the audio calibration after doing the video related stuff. I was checking out the sub calibration, and I notice that the sub tone is not as loud as the center or main, is this because of the lower test tone? I also notice that around 60-70hz the bass seems to drop off but comes back up just below 60 hz when doing a 100hz-20hz sweep on the LFE channel. I don't have a SPl meter yet to verify this but will next week I can post spl levels at various levels if needed. The dip in response is definitly there though I readjusted the levels (neighbor apparantly changed it to - 4db instead of +4db) and it seems to be better now. Is this normal or should it be fairly flat, I know it will dropping off at low frequecies , but don't understand a dip around the 70-60hz range. The sub is a Infinity Entra powered (125w) 10 inch sub, running off a HK AVR125 with all speakers set to small in a medium-large room. Various sub locations have been tried and phase and gain settings have been tried also.
     
  2. Robb Roy

    Robb Roy Supporting Actor

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    Mike,

    Yes, the lower frequencies will sound quieter on Avia (the human ear is less sensitive in that range). This is why when people calibrate by ear they almost always run their subs quite hot. That doesn't mean, though, that your sub wasn't already set too low. That dip you are hearing is likely a null at your listening position. Playing with placement is your best bet for dealing with that. Once you get the SPL meter, tweak placement until you get the flattest response you can, and then recalibrate with Avia and the meter. Experimenting with the audio calibration portion of Avia without a meter is extremely difficult, and will likely lead to more questions than answers.

    -Robb
     
  3. ChrisWiggles

    ChrisWiggles Producer

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    room acoustics. Untreated rooms will have huge swings in response in the bass especially. Try playing with placement as mentioned, or using some treatments and some EQ maybe if you can't solve it with better placement, etc.
     
  4. Edward J M

    Edward J M Cinematographer

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    The way I read Mike's post, the readings he got with Avia were before he adjusted any individual speaker levels?

    The goal is to adjust the individual speaker levels so that they are all at the same volume on the Avia test tones. Most people use 85 dB at the listening position at Master Volume 0.0. If the speaker in question doesn't register 85 dB, adjust its individual level until it does. This can be accomplished with the AVR set-up menu(s). The subwoofer is a little harder to get right since there will be some variation between channels, so it's best to run the sub tone in each of the five channels to evaluate them before settling on a final subwoofer level setting.

    A word of warning, don't play the Avia intro section at Master Volume 0.0; it will be too loud. The test tones are mastered about 20 dB quieter than a normal DVD, so they are designed to be played at Master Volume 0.0.
     
  5. Mike_J_Potter

    Mike_J_Potter Second Unit

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    Thanks for the advice I got a handle on what I need to do now. I did tweak the levels when I bought the receiver but not too much. I'll set them back to 0 for the calibration. Meter won't be here until wed Looks like it should be a interesting project. I'll let you know how it turns out.
     
  6. Mike_J_Potter

    Mike_J_Potter Second Unit

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    Got the meter and it worked great. The sub was way hot (+10B), and after turning the level down on the sub and adjusting it on the receiver it sounds allot better (I may have had some clipping on the sub) The frequency dip is there but not as bad. The other levels were way off also, turns out the center was hot and the rears were low. Now it sounds allot better and my other problem with watching movies in 5.1 went away (rear sounds never were pronounced enough)
     

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