Equalizer and purpose thereof
Hi everyone,
I would like to continue this important topic and respond to a couple of points made earlier.
The main problem, really, is that we can't run apps in the background on iPhone, so this precludes someone from writing a good equalizer/filter app that can adjust the sound coming out of the iPod/music app. I just want to check with the experts -- is what I'm saying, here, true? That is a big limitation, in my opinion.
Second, I want to respond to a few comments along the lines of "why should we need such a thing... isn't flat response best?"
I have been interested and involved in sound reproduction in practical ways (building subwoofers, cross-overs and doing sound measurements on an FFT analyzer back in college, for example) for my entire adult life, but I am not a snob in this area. I have run blinded tests where snobs say they can hear the difference between this and that, and most of them are blowing smoke (there is no repeatability to their claims, and no correlation between what they say they hear and the so-called quality of the musical source). Much of this is a psychological game that we are playing, I will argue. That is a topic for a blog, I guess.
I would say that music is one of the most important and most enjoyable things in my life, and I am an engineer who appreciates good science, but I refuse to get caught up in other people's technical hang-ups and pre-occupations with perfection.
I would say that the answer is a resounding "yes:" sound reproduction can benefit from good equalization in many, many situations. I have also seen people who have no appreciation for good equalization, so I am not talking about pushing all the low and high end sliders up on a 10-band equalizer when I say this, just so you are careful what you are imagining when I speak of equalization.
The most obvious place where equalization is needed, nay, required even, is in the car. If you look carefully at high end audio for cars, you will find products by Alpine and others to tailor the frequency response. See the Alpine Imprint KTX-100EQ, for example, which looks like a promising product. Also, the out-of-production (I think?), but superb Parametric Equalizers Alpine 3401 and 3402.
In the car, there are usually several extreme resonances that occur around narrow frequency bands. The most annoying ones seem to be in the 80-120 Hz range, but you might find several if you do a frequency sweep. (There is an app for that, by the way, called Generator.) A 1/3-octave band equalizer will help give us some relief, depending upon how creative you can get with cut-off frequencies on your subwoofer, and so forth, but these resonances really need to be addressed by "narrower" compensation. We need fine control of the band-width and set-point frequencies for several set-points, in order to tune out the most annoying (and tiring) resonances.
What I described above is called a "notch filter" by the audio geeks, and the method described above can be put into practice by use of a parametric equalizer (like 3401) with the Q set on the narrow side, and the frequency set points set to the annoying peaks. A decade ago, when I was really into car audio, I bought one of these equalizers (I think it was from Alpine) for around $700 and it was the best thing I ever did for my car audio experience. [This is a recent update: you can now get the Alpine 3401 for about $60 on Ebay or Craig's list if you are patient! -- maybe you will see one every couple of weeks across the nation.] No more strain on the ears.
We should be able to do the same things quite easily on the iPhone for the cost of about a $5 app. I noticed an app that has some of this capability. It is called LoopTastic. Alas, I presume something like this cannot run in the background to affect the sound that is coming out of other apps, and that is the main problem right now.
All that being said, I would love it if Apple would at least give us a decent user-configurable equalizer built into the iPod app (on iPhone).
The other thing I heard people questioning is whether the sound quality coming out of iPhone using AAC is good enough for a high end system. The answer is, it most certainly is, at least for a car. It is also plenty good enough for many home systems (95% of us would not reliably detect the subtle difference -- I suppose that is a more precise statement).
Yes, I know there is a difference for serious listening situations. I have been involved in serious listening situations, and my ears can pick up subtleties, so I am not some novice with an inferior ear, but I can say without hesitation most of us do not spend our time in serious listening situations. Nor do we need to do that in order to enjoy extreme pleasure from other kinds of listening experiences.
In closing, the most obvious place where a good equalizer, or better yet notch filter (or in more common practice, a parametric equalizer), is needed is in the car. That also happens to be where I do most of my listening. I know, I know... you audio geeks are cringing, like "what...huh...but...how can he say such a thing?" Sorry, but that is real life for most of us, so please just zip your traps for a minute so the rest of us can enjoy our music (or maybe we need a notch filter to remove the condescending noises that are too often directed our way).
