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.

Yeah. My understanding is that MCACC is calibrating at the listening position. The only important thing is changing the memory calibration for each set of speakers.

Try experimenting with the X-Curve on the Pioneer Receivers. I'm assuming Pioneer since your using MCACC. This could help cut some of the high end from the speakers, making them both sound more similar.

I don't necessarily want them to sound the same. I want each set to sound the best they can. If that means they sound differently, that's fine. That is what I am evaluating. I just don't want to cut one system short by not having it calibrated or set up properly and chose one over the other using poor data. Right now, the Aperions are sounding clear, more detailed, less fatigueing to my ear (this is how I can describe it, don't know if they are the proper terms). This is for music, mainly. Movies sound about the same for both set ups.

How are the speakers set up for testing? Are you substituting them in/out of the exact same spot or do you have both sets on the floor at the same time? If both are set up at the same time then one set will invariably have placement advantage over the other. I would also try disabling the MCACC and just keep the channel level settings, unless you've already determined that you prefer MCACC on for both sets of speakers.

Your room / listening evironment can have an impact on how speakers sound, as can your ears (ie. personal taste). It's natural to like one over another, but if you really want to make sure you gave them both a fair shake then you need to try and make the playing field as even as possible.

First, before discussing the merits, a point of terminology and technology: the level control on the back of the sub which changes the volume isn't a "gain" control. Audio amplifiers and pre-amplifiers have fixed gain; what those controls do is to change the amount of incoming voltage which is let in and subjected to that gain from nearly all of it to nearly none of it, thus changing the amplified output and resulting sound level. When, as in this case, the MCACC calibration has reduced the sub the maximum amount, the sub level control should be set a little lower and the calibration re-done so that the sub result is closer to 0(doesn't have to be 0, just closer than the minimum).

Yes, the difference in the MCACC results for the two speakers is due to the difference in sensitivity(or efficiency)of the speakers. NRC test results(more on these later)show that the Axiom is about 3dB more sensitive than the Aperion, i.e., the Aperion requires about double the amount of power for the same sound level. The calibration results shown approximate this 3dB difference, allowing for some error in the measurement, and the volume level of the two speakers would be reasonably close(although the volume difference alone possibly might be audible in careful blind comparisons)when the receiver volume control is at the same setting for both.

The judgment in the first post was that both sounded "great", although this was changed in the post two hours later. The NRC test results on the Aperion , shown here indicate that the Aperion has a less smooth frequency response and a higher distortion level than the Axiom, shown here . Although both certainly qualify as high fidelity components, the Axiom would appear to have the edge in smooth, clean reproduction.

JohnK, so you're telling me I like the speakers that should sound more distorted and less smooth? Could that be because of the calibration of the MCACC? I understand the knob on the back of the sub is not a gain in the pure sense. Hsu refers to it that way. When I calibrated it, I had the volume fairly low, what's interesting is the sub calibrate out within one dB each time. And the distance measured out nearly the same.

My original intent of the thread was to determine if I was testin each speaker system fairly and equally. I don't care if the calibration for each one is completely different as long as it's correct and they sound good.

The main goal of calibration is to set the speaker levels relative to each other. I would suspect that an auto calibration routine would also adjust to a set loudness (in db) level, so, in theory, both sets of speakers should be at the same loudness level. Too keep things fair, you should verify this with an spl meter at a fixed position (tripod, not hand held) where you will be listening. The reason for a tripod is that slight variations in the position of the spl meter will give different loudness readings.

As I understand it, equal volume/loudness between the speakers being evaluated is critical to the fairness of the test.

Speaker positioning is also critical as it effects how the speakers interact with the room and thus what you hear at the listening position. Harmon went so far as to design a fast rotating platform so that the speakers being evaluated were at exactly the same position.

The only way around the latter issue is to do a comparison, swap the speaker sets around in position, and repeat the comparison.

Taking notes would be important as well.

If I were doing this comparison, I think I would set all the channels using an spl meter and leave the MCACC out of the equation since it changes the signal to the speakers. That way the speakers would be judged on their own merit at the same volume in the same room. Then I would probably send the Aperions back . Just my 2 cents.

You wouldn't need to spend money on a SPL meter to do this. All you would need to do is spend a few minutes reading the manual to make an adjustment in the receiver settings to disable any of the MCACC equalization (the calibration/level matching would be still present).

I'm just not familiar with Pioneer. I'm a Denon and Onkyo guy.

True. If the MCACC equalizer/room correction can be disabled but the speaker distance and channel levels determined during the calibration are retained, that would be perfect. Apples to apples.

(The MCACC can be disabled using the remote-similar to turning off the Audyssey equalizer on the Denon.)

Yes, and I have done this. with the Pio SC-55, I can set Pure Direct mode, which takes out all processing and only puts out what is put in from the source.

Only one thing wrong with disabling MCACC. If you are going to be using it, wouldn't you want to know which speaker sounds best with it on?

I would make 2 judgements, then. One with MCACC on, and on for the correct speaker set, (I'm a good one for forgetting to switch stuff like that during a test). One with MCACC off.

Fortunately with Pioneer Elites, you can save multiple MCACC settings.

When you say Aperion's sound less fatiguing to the ear, to me, that means they probably are missing high end detail. When I say to use Pioneer's X-CURVE, I meant that as an experiment, to see if attenuating the highs would make them sound more like the Aperions. I was curious to know if it made that much of a difference. (You may have to run several tests, because X-CURVE works in 1/2 decimal increments.)

I was incorrect about the pure direct mode. It does not cancel out the MCACC settings. I just picked an empty MCACC memory location. This has 0.0 db in all channels, no EQ, no x-curve deviations. totally flat.

CatBrat, what I meant by less fatiguing is that I don't seem to strain to hear the details. Like high-hat cymbals bein ticked very lightly. Sort of like discerning the details easier. What's interesting is when I play the Axiom with the Aperion MCACC settings, of course they are louder, but the Axioms sound distorted. Too much power, I guess? I don't do this long, only a minute or two, because i don't want to damage the speakers, if that is possible.

Yup, the Axioms are very revealing speakers, buy what you enjoy...I'm happy!

Well, you definetly want to play the Axiom's with the Axiom MCACC settings. Wouldn't make sense to play them with the Aperion settings, and vica versa.

I haven't compared the Axioms with any other speaker. But not sure why you would hear more detail with the Aperions.