A Question About Time Alignment


I was reading a review of the Wilson Alex V on Stereophile recently. (Published just in time. I’m thinking about picking up a pair. Maybe a couple for the bedroom, too.) And it raised a long-standing question of mine, one that I hope the wiser minds on this site can answer. 
 

Wilson’s big selling point is aligning the different frequencies so they all reach your ear simultaneously. As I understand it, that’s why they have minute adjustments among the various drivers. The woofers put out bass notes that move slowly thanks to their long sound waves while the tweeters are playing faster moving, high frequency notes with short waves. Wilson lets you make adjustments so that they all arrive at the ear at once. 
 

It seems to me, however, that live music isn’t time aligned. Suppose I’m playing the piano and you’re sitting across the room. When I stretch out my left hand to hit the low notes, those notes travel along the same long, slow wavelengths as the notes from Wilson’s woofers. Similarly, the treble notes I play with my right hand move quickly through the short wavelengths. The notes from the piano are naturally out of alignment. If Wilson’s goal is to achieve a lifelike sound, aligning the frequencies doesn’t seem like the way to do it. 
 

Wilson has been selling lots of zillion dollar speakers for lots of years and people continue to gobble ‘em up. Something must be wrong with my line of reasoning. Would someone please point out where I’ve gone wrong? Nicely?

paul6001

Be sure to not confuse time alignment with linear phase. Wilson speakers are time aligned, not linear phase, fundamentals and harmonics do not arrive at the same time. What time alignment is concerned with is when seperate drivers play the same frequency at the same time. You want those frequencies to arrive at the ear at the same time. That's time alignment and it occurs at and around the crossover frequencies between two drivers and or when two drivers are acoustical mirrors of each other such as dual mid ranges, both of which circumstances occur in Wilson speakers. And this is what is solved, albeit best for one seat, in Wilson speakers. There are compromises such as aligning voice coils but they are not as accurate as Wilson's adjustable enclosures. I suspect time alignment is important especially in speakers where the many other problems are well handled. Just keep in mind what time alignment is and what it isn't and what it does and what it doesn't do.

P6001,

Before you go buy the two pair of Wilsons I suggest

you read up a bit. Plenty of reference material for audiophiles

available. 

Not too long ago I sat in large listening room that featured the Wilson ($700K)

speakers.+ the Perry subs.  I heard 4 different speakers. Now they must have been 

poorly setup. But this dealer claims to sell more Wilson than anyone.

Later I was invited to listen to the same speakers in a customers home-

Different city- Only these were powered by Spectral instead of Burmeister.

Whole different coherent sound. 

Without correct time alignment the sound will never be right. 

 

 

 

 

I once did an experiment and replaced one of my Skogrand cables (12 meteres long, btw) with a simple 14 gauge wire from Home Depot, but cut to the precise length, and when I played the first song ("Thunder Kiss '65" by White Zombie) the difference in the music's arrival at my ears was so disorienting, I got nauseated and lost my lunch of Beluga caviar. It was dreadful. (sarcasm for the humour impaired).

 

I'll go with what the actual physicist says about sound waves in post 2.

  

Related is the issue of keeping your speaker wires the same length. The lengths we use are very small relative to signal speed, but, I still follow the rule. Makes a big difference using expensive cable.

I am pretty sure that the speed of sound is relatively constant at a given temp.

The speed of light is also a constant, and the speed of electricity is usually a bit slower than the speed of light for most cables.

The main reason to keep the cables the same length is more for resistance and the other electrical parameters like inductance and capacitance.
It has nothing to do with the shorter cable getting the sound to the speaker faster, slower or at an equal speed as the longer cable.

You also have to take the room  size , and  room treatment or lack of 

for 1st reflections ,bounce reflections  and hard surfaces ,as well of bass nulls n the room ,setup and damping ever more so effecting the sum ,Everything counts !!