HELP: Calibrating...Is This Correct?? (1 Viewer)

[Mike Strassburg]

As you can tell by the title I'm not having a good HT day. VERY confused and hoping someone can shed some light on this for me. I've done a bunch of searches but am still in the dark.

Here goes. I have a 3802 with a 6.1 Klipsch Legend set-up & dual Tempest sonosub. I'm using the Sound & Vision disc which appears to cablibrate to 75db. Can anyone verify this?

RS analog meter. C weighted/slow, in listening position angled towards front wall about 50 degrees.

So I back off all the speaker levels to -12 and set the volume at 00. First test tone pegs the meter big time. I end up calibrating with volume at -10. Mains are still at -12 which is 75db on the meter. CC and back center are @ like -10 to get the 75db reading. Does this sound correct? Seems like most guys calibrate at 00 volume and end up around 0 on the speaker level. Could the 100watt/db efficiency of the Klipschs have anything to do with that??

Now for the sub. Volume still at -10 & sub level at -12 I get 100db on the meter. I guess I need to back off the sub amp level, but I've always been told to run the amp wide open to avoid clipping when really cranking up the volume. Is the sub really running this hot/loud, or am I doing something wrong??

Funny thing is that before calibrating I was running all speakers at 0 & sub @ -8. I'm guessing that the -8 volume level I normally listen at is probably way above Ref, correct??

Help Mr. Wizaaaaaard......

 

[Michael R Price]

Wow, I'm not surprised you were calibrated so hot judging by your setup. You're going to think reference level is quiet.
Yes, I think you calibrated correctly. The insane sensitivity of the KLF-30s (98+ dB) is the reason you had to lower the level so much.
I'm not sure about the HS500, but the PE plate amps have so much gain you can't crank it more than 1/3 to 1/2 without getting absurdly high output. So yes, that makes sense.

 

[Brian Fellmeth]

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Seems like most guys calibrate at 00 volume and end up around 0 on the speaker level. Could the 100watt/db efficiency of the Klipschs have anything to do with that??

I suggest a different approach. Reset all speaker levels to zero, then dial down the main volume way lower than 00 until the left main is at 75. The number displayed by the reciever is arbitrary. It should not be at zero. It should be at whatever produces 75 dB with the trim centered. Then, trim the other speakers to match the 75 on the front left. By starting with you amp volume so loud (because of the high efficiency of your mains) and trimming down so low, you are painting yourself into a corner. In addition, you are robbing your amp of headroom.

 

[Michael R Price]

Actually no, since at any given volume level the amp is putting out the same amount of power. I don't get how any particular calibration method hurts headroom.

 

[Mike Strassburg]

I'm going to calibrate again tonight to get all the levels even without worrying about "Ref level" as I listen WAY louder anyway.

Once done I'm going to boost all the speakers the same amount (around +6) so the sub doesn't over-power them, and I can leave it set at -8 without having to turn the amp down. I was actually MUCH happier with the speakers/sub balance before I calibrated, but I do want to make sure the levels are even all the way around.

Thanks for the feedback...Mike

 

[Brian Fellmeth]

Actually no, since at any given volume level the amp is putting out the same amount of power. I don't get how any particular calibration method hurts headroom.

So your saying that an amp can produce the same SPL of clean output with a line level of 100mV peak ot peak as an input of 1V ? I don't think so. Trimming everything down to -12 has the effect of decreasing the input viltage to the amp channels at the line level. This will raise the noise floor and force the amps to run closer to full throttle to produce a given SPL.