Originally Posted by craig john
The main limitation of those bands is the complete lack of adjustability of the center frequency and Q.
Agreed. In professional audio most experienced production people would take a 4-6 band full parametric eq over a 31 band graphic eq any day of the week. Even though the graphic has a lot more knobs it is just not as effective in the real world.
If you have peak at 42 Hz, it's completely worthless to have an EQ band at 63 Hz.
I'm not quite there with a judgement of "completely worthless" as adjustment of the too-wide band can still help with tone quality. This despite the obvious cost in hurting a big crowd of sounds to deal with one bad actor. Its a lot less than I would prefer but I'm not sure I'd throw out the baby with the bath water given no other choices.
All graphic equalizer suffer this limitation, making them virtually useless. A parametric EQ, with adjustable bands and Q's is a much more useful tool.
I'm beginning to suspect that many of the self-eq schemes in modern receivers are based on this same 7 band graphic equalization with all of the obvious limitations. This partially explains why they are generally better than nothing, but nearly as good as what many more experienced people even amateurs, do manually with more sophisticated equalizers and analysis.
While 30+ band graphic eqs are less desirable than far more modest-seeming full parametrics, they do deal with sound in roughly critical band intervals that have psychoacoustic signfiicance.
The current usage of generic 7 band graphic eqs yields far, far less capability than true 1/3 or 1/6 octave eq, which are the current professional standard. For example the current Crown/Harman IQnet power amp and speaker management DSPs cascade both graphic and full parametric eqs.Edited by arnyk - 7/20/12 at 5:30am