'Time-Aligned' Speaker Drivers
Mar 26, 2019 at 3:02 PM Thread Starter Post #1 of 14

TheSonicTruth

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They've been out a long time, and I've heard the difference. So why aren't most consumer-oriented loudspeakers built as show in my diagram? (Apologies in advance for crude graphics!)

Loudspeakers - Time-Alignment - Compact.jpg
 
Mar 26, 2019 at 5:33 PM Post #2 of 14
Mar 26, 2019 at 6:49 PM Post #3 of 14
There are two ways to "time-align" drivers: the physical way that you described, and an electronic method that phase shifts the tweeter a little. It could be (I'm not saying that it is) that speaker manufacturers mostly use the second method, which might explain why you never see speakers set up like that.

See: https://en.wikipedia.org/wiki/Loudspeaker_time_alignment
 
Mar 26, 2019 at 9:15 PM Post #4 of 14
Interesting stuff. Time or phase alignment is one of the more significant advantages of active speakers over passive implementations.

In particular, having the crossover at line level enables higher order crossovers (up to 8th order with some of the Linkwitz products) which greatly reduces phase differences between the drivers.
 
Mar 27, 2019 at 1:43 AM Post #5 of 14
They've been out a long time, and I've heard the difference. So why aren't most consumer-oriented loudspeakers built as show in my diagram? (Apologies in advance for crude graphics!)

a few random remarks on the top of my head:
1/
I've heard the difference
:rage:
this puts you in trouble in here and brings no benefit. whatever you tried had obviously more variables affected than just time shift between drivers due to placement. so your subjective experience of a change may at best show correlation, but you have no evidence of causality and shouldn't suggest that you do.
chart.jpg

2/ physical placement is only one of the relevant variables(also I'd imagine that things are most important at the listener position, so vertical alignment with tilted front could probably achieve the same effect if that's really important? I'm a total noob when it comes to speaker design so maybe I'm saying something dumb?). anyway, as soon as we're involved with crossover, some freqs are probably going to be out of phase in the signal. so it might be a good idea to consider the entire system instead of just the drivers? I'm also guessing that the relative position of the tweeters on each pair of the stereo system is more important than the relation between tweeter and low freq driver, as to limit phase shift/cancellation. but again that's educated guess, I'm a speaker noob.
2.1/ DSPs!!! I imagine that anybody perfectionist enough to worry about this is going to measure stuff around his listening position, spend a lot of time placing his speakers, and use fancy calibrating tools to improve what can be. nowadays we have several ways to skin a phase cat. electric, acoustic, digital.

4/ I'm sitting in front of a pair of JBL LSR308 right now and the tweeter is recessed like in C. am I lucky or what? the drivers being vertically aligned never crossed my mind before I read your post right now.
 
Mar 27, 2019 at 2:48 AM Post #6 of 14
I have KEF speakers that have nested drivers to supposedly time align them. They sound fine, but for the life of me, I can't discern the difference between them and regular speakers. By the time it gets out into a typical living room, my guess is that all bets are off. I think it's just gilding the lilly. They do have really good dispersion, but I don't know if that is due to their physical layout.
 
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Mar 28, 2019 at 10:56 PM Post #7 of 14
Time-aligned speakers sound silly to me. What if I move my head 6 inches up, down, to the left, or to the right? What if I tilt my head back or forward? How am I supposed to hold my head in the first place? Doesn't relative position of the head change each driver's position relative to my ears, so that the sound takes more or less time to get to them from each driver? Are the speakers designed for a head held perfectly vertically with ears the shape of perfectly flat boards on the sides at some angle? Shouldn't the drivers be attached to my ears by strings of precise lengths with adequate tension so that the drivers move to keep the same time alignment relative to my ears, all on a platform of precisely arranged and perfectly silent perpetual gyroscopes?
 
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Mar 28, 2019 at 11:07 PM Post #8 of 14
Time-aligned speakers sound silly to me. What if I move my head 6 inches up, down, to the left, or to the right? What if I tilt my head back or forward? How am I supposed to hold my head in the first place? Doesn't relative position of the head change each driver's position relative to my ears, so that the sound takes more or less time to get to them from each driver? Are the speakers designed for a head held perfectly vertically with ears the shape of perfectly flat boards on the sides at some angle? Shouldn't the drivers be attached to my ears by strings of precise lengths with adequate tension so that the drivers move to keep the same time alignment relative to my ears, all on a platform of precisely arranged and perfectly silent perpetual gyroscopes?
I think that is a different issue. Time alignment of speaker drivers is important to minimise phase shifts, mainly from the crossover, and for accurate reproduction of timbres around frequency change over points between the drivers.
 
Mar 29, 2019 at 4:22 AM Post #9 of 14
It’s alignment of the drivers relative to each other, not the line Steiner. But I still think it’s overstated.
 
Apr 27, 2019 at 8:36 PM Post #10 of 14
I think that is a different issue. Time alignment of speaker drivers is important to minimise phase shifts, mainly from the crossover, and for accurate reproduction of timbres around frequency change over points between the drivers.
Right...physical alignment is wasted without a phase correct crossover.Incremental as it is.
 
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May 2, 2019 at 7:08 PM Post #12 of 14
the dark moments in the video might get censored by utub for using passages of the latest episode of GOT.
 
May 2, 2019 at 8:08 PM Post #13 of 14

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