time align the seas a26 kit ?

[norman bates]

Since woof is run wide open and tweet is single capped, it seems to me that if the tweet was moved back you could be time/phase aligned.

https://www.loudspeakerbuilding.com...2013/April-2013/_Seas-A26_8563,en,900995,5693

near the bottom of this link, you see the tweet firing more than .5mS before the woof. ug, that would be like 6" I think to line up the centers............



And the ringing at 1,600hz and 2,500hz is pretty evident in the woof.


Norman

 

[rayma]

you see the tweet firing more than .5mS before the woof.
ug, that would be like 6" I think to line up the centers.

How about speaker stands with a backward-tilt?

 

[eriksquires]

Hi Norman,

That's a great site with plenty of data. I'd grab Xsim and the data from the link and try to simulate it. 🙂

I suspect that without a HP filter on the woofer your going to create a lot of destructive interference by merely time-aligning the tweeter, but that's what XSim is for. 🙂

Best,

Erik

 

[norman bates]

So an inductor on woof would help for the time alignment versus just running the woofer wide open ?


I don't understand.

 

[Juhazi]

In combined response graph we can see no summation at 4kHz. Acoustic slopes are not symmetrical and that makes it problematic to analyze step response. I might try just reversing tweeter polarity.

 

[eriksquires]

I never analyze a step response. I just simulate it. 🙂

The OP's goal however was perfect time alignment, so I assume that means he/she wants to keep positive polarity on both drivers.

Best,

Erik

 

[eriksquires]

Here, I imported all the data into XSim for the A26. It's a little rough, but I estimate the delay closer to around 2".

Let us know what you find. 🙂

One thing I noticed however is that the step response for the woofer doesn't jive with the FR. It's not nearly as sharp.


Erik

 

[norman bates]

I couldn't get my tablet to unzip. (lol, that can go so many ways !)

So, you can't get time alignment with a woofer run wide open and a single cap on a tweet ?

And yes, I'm chasing the 6db time alignment setups like classic thiel speakers (I've owned 2).

Thanks for the help.

 

[eriksquires]

The file is in XSim, which is Windoze only.

 

[eriksquires]

Norman,

Do you know how phase alignment works in crossover slopes? I think that's the part you are missing. 🙂

Drivers must complement each other in amplitude and phase. If you have proper alignment with a 2" delay it won't be right at 0.

Check out my blog on testing driver distances to help understand the issue.

Best,


Erik

 

[eriksquires]

Let me restate. You can get perfect time alingment by moving the tweeter, or delaying the signal digitally.

However, you will no longer have the same phase alignment, so you'll create both constructive and destructive interference where the two drivers outputs overlap.

Of course, this only happens because crossovers are not perfect. There's no brickwall filter at 2,000.00000 Hz that separates the tweeter and woofer. If there were, then no problem. 🙂

Best,


Erik

 

[Face]

And yes, I'm chasing the 6db time alignment setups like classic thiel speakers (I've owned 2).

FYI, their crossovers are far from simple.