Problem with MCACC & 45tx?

Discussion in 'AV Receivers' started by Ken_Chengr, Apr 22, 2004.

  1. Ken_Chengr

    Ken_Chengr Extra

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    I ran the auto setup on my 45tx and I have some strange results. My question concerns the fact that it set all of my speakers to -10.0db. Can that be correct? Won't that result in a serious loss of volume?

    Two runs arrived at the same setting. It also set my speakers to LARGE, but I was expecting that.

    Hobby or torture, the jury is still out!
     
  2. Steve Schaffer

    Steve Schaffer Producer

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    Ken,

    Did you get the correct microphone--should be a small black round flat one with a domed grille, about the size of a half dollar with a rectangular projection on the bottom to fit into a slot in a foam disc about 2 or 3 inches in diameter. Has about an 18 foot long cord to plug into the miniplug under the drop down door on the front of the receiver. The microphone should be placed as closely as possible to where your ears are when seated in your usual viewing position, not placed in front of any of the speakers. If your mike is not as described that may be the problem.

    -10 db is the lowest available setting so it should not have set that on auto-setup.

    Before running MCACC, turn volume down to about -40db, then go into the onscreen menu and select "surround setup" then "auto setup". The volume readout should rise to 0db before the test tones start.

    edit: just read in your other thread about the volume knob problem--that's not normal and may be why your MCACC isn't working properly.

    Maybe also double check all your speaker connections at both ends.
     
  3. Ken_Chengr

    Ken_Chengr Extra

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    Steve,
    Thanks. I have the mic from Pioneer, but I don't have the foam disc. I clipped the mic to a cloth, so it would stay put, and placed it very close to ear height on the sofa.

    I just ran it again and I got very different results, a mixture of + and -. I also noticed the test tones were much louder. I didn't really want to get a SPL meter, but I may have to. Would you leave the EQ settings even if you found the SPL way off? I don't have a golden ear, so I may not be able to improve the EQ.

    Ken
     
  4. Steve Schaffer

    Steve Schaffer Producer

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    Ken,

    What you've done with the mic is just fine.

    If you're getting a mixture of + and - speaker level settings, and all are within a range of -10 to +10, you're good to go. The MCACC can't set anything out of the manual adjustment range which is -10 to +10db for each speaker. As long as your MCACC-derived settings are between the -10 to +10 limits I wouldn't worry.

    I had an spl meter for years before getting the Pioneer, used it for my previous 2 Yamahas and 1 Sony ES. After letting the Pioneer do it's MCACC I dragged out the meter to check it's accuracy--it was dead on, within 1 db for every channel. If it sounds good to you now, I don't see any need to rush out and get a meter, but put it on the list for future aquisition as it is a fun thing to play with.

    BTW, if MCACC set your sub level much below 0db, you may want to turn down the volume knob on the sub itself and rerun MCACC until you get closer to a 0db sub level setting. This is just to insure that the receiver puts out a high enough sub level to trigger the sub's auto-on circuit.

    You might also find that the distance setting for the sub is off by a few feet, leave it alone if it did this. Mine always sets the sub distance about 3 or 4 feet farther away than it really is, and resetting this manually to the true distance hurt bass response, maybe has something to do with the "standing wave" phenomenon of low bass frequencies.
     
  5. Drew_W

    Drew_W Screenwriter

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    MCACC comes close, but I'd get an SPL meter just to double check everything. It's a great ~$35 investment.

    I ran MCACC on my 53TX, and then tweaked with an SPL meter. Some minor adjustments were made (+/- 1dB or so as required), but on average, the MCACC does its job quite accurately. And the speaker distances weren't off by all that much either.



    MCACC automatically changes the volume to 0dB to run, then returns it to whatever it was after it's done.

    You could also try mounting the mic on a camera tripod with a small piece of tape since you don't have the little foam base.
     
  6. Steve Schaffer

    Steve Schaffer Producer

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    Drew,

    I was referring to the volume knob on the subwoofer, not the one on the receiver.

    If the sub volume knob is turned up too high, the MCACC will come up with a subwoofer setting of -10db which is the minimum available from the receiver and thus not necessarily accurate.

    Turning volume knob on sub down and rerunning MCACC until the reciever selects about a 0db sub level insures accuracy and also makes the auto-on feature on the sub work more reliably.

    I am aware that the receiver sets it's own volume to 0db when you perform MCACC, and drops it to whatever it was previously set at after MCACC is completed. It also does this whenever you perform a manual level adjustment.

    For whatever reason, the manual on my 45tx recommends turning the volume way down before starting MCACC, even though the reciever turns itself up to 0db prior to running it's test tones.
     

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