It's been my experience that Polk Audio tweeters are some of the best at ANY price. Compare the highs of the Polks to even the super-pricey Martin-Logan planar magnetics or other $20K price class speakers. You'll see that they compare QUITE favorably with much more expensive speakers.
It's VERY difficult for me to recommend speakers because NOTHING is more subjective than sound. Each of us hears sound differently. What may sound like harsh highs to me might be "clarity" to someone else. What sounds like out-of-control, poorly-eq'd bass to me might be "good bottom response" to someone else. You get the idea.
Take Bose for example. I grew up listening to 808s and 804s (as PA units w/active EQ). They are the PA version of the famed 901. The vast majority of people listen to a Bose speaker and think-- "Wow, that sounds great".
See, Amar Bose realized that while human hearing technically extends up to 20Khz, VERY few people can actually hear that high. Most people can barely detect even 16Khz. So he didn't see a need to reproduce the very highest octaves. Thus, many Bose designs had NO TWEETER at all, just 4. 5" drivers that produced what he deemed sufficient high frequencies.
If you play a "high" note on a piano, it only registers up to about 5Khz. If I crank up my electric guitar and my Mesa Boogie amp, I can scream a high note that sounds ear piercing, but my guitar speakers only respond to about 5Khz.
The reason that highs are important then, is only because of HARMONICS. These are the infinite combinations of frequency multiples that determine the Tone of an instrument. Harmonics are why a C2 note sounds different on a flute than on a trumpet than on a guitar, etc. A pure tone with no harmonics sounds like a tuning fork-- a hum.
So, to clearly reproduce the uniqueness of Celine Dion's voice, you need to have clear high frequencies that can reproduce the 2nd, 3rd, and maybe even 4th order harmonics that her vocal tonality contains.
Also, research suggests that even if a person can't hear a pure tone generated at 16Khz, they CAN hear a difference in tonality when all frequencies above that point are muted. It's because the highs contribute a lot to the sound- they are more important when in the context of harmonics than when simply a pure tone.
As an example, you can listen to Mariah Carey on her older recordings and hear that when she sings, it sounds like there is a perfect unison exactly one octave higher. This is because her voice contains VERY strong second order (fundamental frequency X 2), so you hear the next octave up.
Finally, high frequencies are responsible for signalling to our brains information on location and time relative to other sounds. Ever pull up at a light next to a bass-booming junker? Notice how it's often difficult to locate which junker is actually the one with the overdone bass. This is because bass is omnidirectional-- it radiates out equally in all directions. This is why you can put a subwoofer almost anywhere, even firing into the floor, and it still sounds great.
Not so with higher frequencies. The higher they are, the more directional they become.
Imagine that you are standing in front of a single driver (transducer) playing a midrange frequency. The sounds radiates out in a cone-shaped pattern from the point source of the driver. You can move from side to side and the relative volume of that pitch will seem fairly constant.
As the frequency gets higher, this cone because narrower and narrower, reaching the point where you can't move much to the left or right without a significant drop in perceived volume level.
This is why with direct-radiating speakers you have the "sweet spot" where each tweeter is firing right at you. If you can make it so left and right tweeters are equidistant from your left and right ears, then you will experience a startling "image" where it seems you can actually POINT to where the different instruments were located when the recording was made (assuming simple stereo recording, nothing panned hard).
In order for this "image" to have the utmost clarity, it's important that ALL the frequencies that are even remotely directional seem to come from the same place. In other words, you tweeter and midrange drive should be located in the same place or as close together as you can get.
There is a way around this limitation, though. It's called a "D'Appolito Array". All this means is that instead of having one mid and one tweeter, you arrange the drivers with TWO midrange speakers and one tweeter EXACTLY HALFWAY between them.
This configuration tricks your ear into thinking that the midrange is coming from the tweeter, because when you hear the same thing from two equidistant sources, you brain averages them and thinks the sound is coming from the point halfway between them. VOILA-- a "virtually colocated" midrange pair and tweeter, when they are physically three separate drivers.
Anyway, back to brand recommendations. The top of my list for bang/buck is Definitive Technology. I own a pair of BP2000's with the built in powered (300w)15" subs IN EACH ONE. I have all the bass I could ever want, and it's adjustable on the back to I can tune the crossover point and level to match the bass response to the room they're in. My speakers were floor models, so I got them for $2K instead of $3K. I've had them 6 years now and they still amaze me with every listen.
Also, the DefTech speakers are Bi-polar, which gives you the lush "sound everywhere" of a Bose-type speaker while STILL giving you the clarity and imaging of a direct-radiating speaker.
I've heard a million speakers, and you can definitely find more EXPENSIVE than the DefTechs, but you won't find anything that sounds better by any significant amount.
They are now up to the 7000 series (7000, 7001,7002, 7004, 7006). The differences as you go down are subwoofer size (from 14" down to 8") and subwoofer amp power. They have really crnaked up the sub power since I bought mine. Now they're up to 1800W, whereas mine are only 300W. Obviously the smaller subs have smaller amps built in.
The most affordable DefTech bipolar towers retails for $1200 a pair. Worth every penny, and you might be able to find a store that will deal with you like I did (SoundTrack in Colo Springs).
If you can't swing the bipolar towers, give a close look to their other models. They lack the D'appolito array, but still sound great, and can be had for $600 a pair.
I spent so much time on high frequencies because they make the main difference in overall sound, imho, assuming the rest of the speaker is pretty decent.
Think of BALANCE as you listen. Is there a frequency range that just sticks out?
I'd also recommend that you take a CD you are very familiar with for demo purposes. Listen to it though high-quality headphones and keep that sound in mind and a reference.
Justin
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