Axiom Home Page Forums General Discussion Advice from Axiom Owners My MCACC results Aperion/Axiom & Questions

In setting up the Aperions and Axioms, of course I ran the Full Band MCACC on my SC-55. The system came up with the following:

• Aperion*******Axiom
• L ** +2.0 ****** 0.0
• C ** -2.5 ****** -4.5
• R ** +3.0 ****** -0.5
• SR** +4.0 ****** -2.0
• SL** +6.5 ****** -2.0
• SW -12.0 ****** -11.0

(Sorry, can't get the UBB fixed spacing to work on here. If anyone knows how to keep the spacing, let me know).

When I first started listening to the Aperions, I was like, wow, these are really clean and sound great, then i realized that with these settings they should sound louder. Judge Dredd sounded awesome (I know, but its sound track is great for testing surround speakers. So now I put the Axioms back on and used the Aperion memory location. And they sound great too.

So my question is this: Is the MCACC settings a result of the efficiency/in-efficiency of the speakers? I mean, I' assuming the Aperions were set so much higher because they needed more "power" to achieve the same level at the MCACC microphone. Should I listen to the Axioms/Aperions at the same levels? Or just where I like the sound?
Thanks

I wouldn't worry too much about this. While the manufacturers efficiency may be coming into play, the goal of calibration was to even out each independent set of speakers so they are playing at the same levels in order to get the most accurate surround effects and soundstage.

So your Aperion's got correctly calibrated and then the Axioms got correctly calibrated. I see no need to compare the results of the individual settings used against each other unless you are concerned about pushing every ounce of power out of your receiver, also known as "going deaf".

For the second question, if you are trying to compare the two speakers, then you should be listening at the exactly same volume levels. Otherwise, as people have mentioned, people tend to naturally favor a louder sound.

This is where a db meter actually comes in handy. Both sets of speakers are calibrated to be equal among themselves, but as you have discovered, to listen to each set exactly at the same volume level for testing, requires an adjustment on the volume knob.

If you are just talking about what volume levels you should listen causally at, then listen at whatever sounds best to you.

Subwoofer at -12 and -11 seems way, way too much. This means that you should turn the level of the subwoofer down more before starting the test. The goal there is to get it as close to zero as possible.

Interesting, I thought the auto calibration would set the channel level so the speakers play the same loudness (at the main sitting position) relative to its reference. Therefore when the volume knob is set to 0dB, if calibrated properly I thought a SPL meter would show the same thing for both speakers. That was my understanding, maybe I'm wrong.

Those numbers look pretty good. Avoid that extreme measurement like -11 pr -12 by dialing back the volume/gain on the back of the sub. The +4 and +6.5 from MCACC on the Aperion surrounds might be giving you have high readings because the speaker is set to dipole. This speaker has a switch for multiple surround options. Dipoles by design are out of phase and might cause issues with the auto cal. If the switch is set to dipole try the bipole setting for the surround calibration and see if the readings change at all.
Make those two changes and re-run MCACC.

BTW what are the crossover settings on the speakers?

Too much? negative db lowers the power output. if I go closer to zero, the volume and power output is very loud. I have to turn the gain knob on the sub to nearly off.

But this doesn't make sense. I would think calibration would set the level relative to the listening position from the test tones, not the master volume. So speaker A is set to X, speaker B set to Y. They should "Meter" out to the same at any given master volume because the calibration "equalized" them. No? It's like setting pressure valves on pipes. A wider pipe (more flow) would need less a lower setting on the pressure valve than a narrower pipe because the pressure is spread out over a greater surface. But once you calibrate it, the valves on both pipes would "pop" at the same relative pressure. When I switch the speakers out, I do not change the master volume, just the MCACC memory position. And I have to say the Aperions sound much better. Crisper, cleaner, not tiring.

Did you do the equalizer on MCACC as well?

I did the calibration in Bi-Pole mode, even though surrounds don't come into play during stereo playback (unless you're DSPing the source) and Aperion states Bi-pole is music play back and Di-pole is best for movies. I'm listening to straight stereo now. The movie listening was very close. Each surround sounded equally good, with the edge going to Aperion. Again, more crisp and clean sounding. This is way I'm asking about the calibration settings. It's the only variable I can think of that is affecting the output.
I'll get the crossover freqs when I get home.

I'm not understanding what your saying... The way I understand this with MCACC (which I also use), is when MCACC sets the subwoofer at -11, it means the subwoofer is playing 11 decibels too high and MCACC is now going to send a signal to the amp in the SW that would cause an 11 decibel drop.