Originally Posted by TL24
I know most of you are experts when it comes to this so I thought I'd ask so that I can get a better understanding on how to properly calibrate my home theater.
My current setup consists of a Pioneer Elite SC-71 hooked up to two Martin Logan Motion 40's (Bi-Amp). I've been tweaking the EQ on the SC-71 quite often but haven't hit the sweet spot yet. With that said, I was hoping some of you could shine some light on the frequencies available to me in the MCACC EQ setup:
Frequencies available to me from left to right:
I'd like a quick run down of what the frequencies control so that I can better understand my current setup to tweak it to my preference. I appreciate any help that can be given.
The purpose of an "equalizer" is to "equalize" all frequencies so they are all played back at "equal" volume. To properly use an equalizer, you need to know what frequencies in your system are being played back unequally to the other frequencies. Then you can target those frequencies with the equalizer.
For example, in the following graph:
... there is a large peak at 40 Hz, a deep depression at 90 Hz and then a wide peak from 100 to about 160 Hz. To "equalize" this graph to get all the frequencies at equal volume, you would need to cut the levels of the 40 Hz peak, boost the levels of the 90 Hz depression, and broadly cut from 100 to 160 Hz. If you did this, the resultant graph would look something like this:
This is still not a "flat curve, with all frequencies being played back "equally loud" but it is a big improvement over the original graph. In the original, the discrepancy between the loudest frequencies and the softest frequencies is over 25 dB. In the EQ'd graph, the discrepancy has been reduced to less than12 dB.
Note that the deepest depression at 90 Hz has been improved, but it still is the worst part of the graph. This is because deep depressions in the frequency response are caused by cancellations, where a reflected soundwave combines with another reflected soundwave, but the 2 waves are out of phase with each other. In that scenario, the negative side of one wave will cancel the positive side of the other wave, and the result is... no wave. This is what happening at 90 Hz in the original graph.
How does this impact your use of the "equalizer" in your Pioneer receiver? First, you need to realize you need knowledge of your system's frequency response before you can improve it. Unless you have perfect pitch, and you can perfectly identify the frequencies that are out of balance in your system, (which seems unlikely since you are here asking for specifically this kind of help), the only way to identify these problems is to *measure* them. There are lots of systems that can help you measure your system. Pick one and use it.
Second, you need to realize that your "equalizer" is a "graphic" equalizer. The frequency bands are "fixed" and you can't change them. Also, widths of the filters, (i.e., the range over which the filters affect the response), are fixed and you can't change them. So, using the example of the graphs above, you can't take the band at 63 Hz and move it to 40 Hz to cut the 40 Hz peak. Also, you can't take the filter at 125 Hz and make it broad enough to cover the whole range of the peak above and below 125 Hz. You don't even have a filter at 90 Hz, so you couldn't boost that range, even if it could have a beneficial effect.
Bottom line, an octave-based graphic EQ, such as the one in your Pioneer receiver, is essentially worthless as an "equalizer." At best, it's a glorified set of tone controls. Without a complete set of in-room measurements of your system, you're basically just taking a "shot in the dark" whether the application of the "EQ" filters are actually beneficial, or whether they even address the actual problems that exist in your system.
With your Pioneer receiver, you would be much better off using the on-board MCACC system with the Standing Wave Multipoint. That system actually measures the frequency response of your system in your room. The filters in that system are automatically adjustable for frequency and width, and they have a much better chance of correcting the actual problems that exist in your system in your room.
Only in-room system measurements will tell you exactly how well either system will work.