There seems to be some confusion as to what Time-Alignment is.
Simply put, it is the aligning of the woofer and tweeter acoustic phases at the crossover frequency.
If the two drivers are not aligned, the result is phase cancellations at the crossover region. When the woofer and tweeter are time-aligned, it will eliminate smearing and improve stereo imaging.
All Time-Aligned speakers like Thiel, Dunlavy and others do this. Sometimes, it's called Time-Coherence or Phase-Coherence. They all mean the same thing. A clean handover between the woofer and the tweeter. As an example, the illustrations below show a crossover frequency of 2kHz.
Time-Alignment doesn't mean 20Khz and 20Hz reach the ear at the same time. That is not possible with inductors and capacitors because one will introduce phase lag and the other phase lead.
Simply put, it is the aligning of the woofer and tweeter acoustic phases at the crossover frequency.
If the two drivers are not aligned, the result is phase cancellations at the crossover region. When the woofer and tweeter are time-aligned, it will eliminate smearing and improve stereo imaging.
All Time-Aligned speakers like Thiel, Dunlavy and others do this. Sometimes, it's called Time-Coherence or Phase-Coherence. They all mean the same thing. A clean handover between the woofer and the tweeter. As an example, the illustrations below show a crossover frequency of 2kHz.
Time-Alignment doesn't mean 20Khz and 20Hz reach the ear at the same time. That is not possible with inductors and capacitors because one will introduce phase lag and the other phase lead.
There seems to be some confusion as to what Time-Alignment is.
Simply put, it is the aligning of the woofer and tweeter acoustic phases at the crossover frequency.
If the two drivers are not aligned, the result is phase cancellations at the crossover region. When the woofer and tweeter are time-aligned, it will eliminate smearing and improve stereo imaging.
All Time-Aligned speakers like Thiel, Dunlavy and others do this. Sometimes, it's called Time-Coherence or Phase-Coherence. They all mean the same thing. A clean handover between the woofer and the tweeter. As an example, the illustrations below show a crossover frequency of 2kHz.
Time-Alignment doesn't mean 20Khz and 20Hz reach the ear at the same time. That is not possible with inductors and capacitors because one will introduce phase lag and the other phase lead.
That is a highly theoretical conception of "time aligned". In the real world, it's very difficult to get the tweeter and woofer to aligne perfectly. You could get them to "time aligned" at a specific frequency but not at "all frequencies". At the end, you have to compromise.
And by the way, "time aligned" is just one aspect of speaker design. There are all sorts of variables when it comes to the final results. Just having "time aligned" does not automatically mean you have a good sounding speakers.
Yes, time alignment is not a guarantee of good sounding speakers. But if you have a pair of good sounding speakers, they will be even better when the woofer and tweeter are time-aligned.
Time alignment refers to aligning the acoustic phases at the crossover frequency. It does not mean all frequencies from 20Hz to 20kHz reach the ear at the same time. To do that, you'll have to use digital technology like FIR filters.
Yes, it is a single point in space. Usually, time alignment is done on the tweeter axis with the mic on a stand 1 meter away. So, as long as you are exactly on the tweeter axis, you're fine. If you move left, right, up, down, it will not be perfectly aligned.
It doesn't mean they will align. More often than not, they don't. This is because the acoustic centers of the woofer and tweeter are not aligned.
But at least electrically they will align before you start worrying about the physical side. Its easier to work with one variable than two.
Time alignment is acoustic time domain. Electrical phase is totally different.
Electrical phase is about power amplifiers. Power amps work best when the load is resistive. Unfortunately, a speaker with a crossover is a reactive load. This causes electrical phase to shift. When that happens, the power amp has to work harder. A speaker with minimal electrical phase shift is a friend to a power amplifier.
This is one of my speakers with good electrical phase. You can see there are no wild fluctuations at the crossover region.
Unfortunately, the real world does not know the difference between mechanical and electrical characteristics. In filter theory, they are the same. Therefore when a network such as an L/R is used which is electrically aligned, the mechanical side also needs to be aligned. As I think you are saying, you can treat both issues independently to arrive at your target
Typical asymmetric filters are a good case where two wrongs make a right. The filter's asymmetry compensates for the mechanical misalignment over the narrow crossover zone. You can't separate one from the other.
This is one of my speakers with good electrical phase. You can see there are no wild fluctuations at the crossover region.
Looks like a ported box.
~52 hz tuning.
Port tuning is lower than the fs of the driver.
Probably 8 ohm speaker.
As I gain experience with FIR processing it's getting easier and easier to achieve excellent alignment throughout the spectrum...even through the sub range if overall latency can be tolerated.
New world...it makes the opening alignment example seem almost primitive...
(not to disparage it 🙂
Yeah, pretty good. Excellent mids. The only issue I have with this driver is the bass. It's not loud enough unless I tune the box higher up.
What you describe is called phase alignment. Time alignment is something else. The term is used for loudspeakers applying any method to change the acoustic center of a driver, such as a tilted or a stepped baffle, a waveguide or a delay network in the crossover.
Loudspeaker time alignment - Wikipedia
I have a spanner to throw in here.
And for me it's an honest and serious question.
In regards to time alignment, and phase and baffle diffraction, and all the other things that everyone seems to get so, calculating, about.
In the real world, where any given room is different from everyone else's.
Do any of these alignment issues actually matter ?
Lets go a step further.
If I set up my speakers, and room, and chair, so that all parameters are perfect.
I then move the chair, isn't that then going to make the alignments etc invalid ?
And for me it's an honest and serious question.
In regards to time alignment, and phase and baffle diffraction, and all the other things that everyone seems to get so, calculating, about.
In the real world, where any given room is different from everyone else's.
Do any of these alignment issues actually matter ?
Lets go a step further.
If I set up my speakers, and room, and chair, so that all parameters are perfect.
I then move the chair, isn't that then going to make the alignments etc invalid ?
The idea is to get multiple drivers to as nearly as possible appear as one. The effect of moving your chair will mainly be governed by the directivity and reflectivity of the speaker/room set-up
So if a speaker is designed and built to have perfect everything in the designers room.
It will obviously change in the customers room.
Doesn't that render some or more of the designers efforts useless ?
It will obviously change in the customers room.
Doesn't that render some or more of the designers efforts useless ?
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