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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

Showing 1 response by gregm

gregm
3,411 posts
 

Time alignment has nothing to do with instruments placement in an orchestra, that will (or sould) show up in the recording of said orchestra.

Remember, we are reproducing the recording of the orchestra and that recording includes cues as to where the sound of each instrument originated at the time of the recording.

Also, the speed of sound doesn’t change with frequency --

As mentioned above, time alignment in speakers has to do with the sounds coming out of different drive units. Take a guitar for example and a two-way speaker. Assuming that some of the notes of that guitar are reproduced by the tweeter and some by the woofer, you realise that a delay in the sound emanating from the woofer will sound odd --

As mentioned above, Wilson (and others) tries to minimise delays by aligning the drive units vertically - for example, the back of a tweeter with the back of a woofer, meaning the woofer cone will seem to be well in front of the tweeter.

The rest of the delay compansation has to be done in the xover -- a very difficult task and AFAIK very few speaker manufacturers attempt it.

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