Crossover in Thiel CS 1.2

[linnmajik]

Hi guys,

I've been redesigning crossvers for a Thiel CS 1.2 I've just been using online crossover calcs and so far its been Ok. They are going to be used for a spare room and listening will be done at low volume.

The woofer X-0ver is a 2nd order starting at 2.2 Khz and the tweeter is a 1st order starting at 3.5khz I'm not using the original tweeter. I'm using an old Vifa softdome that gets its life sucked out everytime I've tried a 2nd order or above. The vifa woof (the original in the Thiel) gets very peaky when pushed close to the 3khz mark (which is why I used a 2nd order). I'm finally at my question:
If a 2nd order is used on the woof and a 1st order on the tweet, what is the phase relationship betweem the two? Am I 135 degress apart? (woofer is 90 one way, tweet is 45 the other???)

Thanks.

Greg

[Inductor]

Originally Posted by linnmajik

Hi guys,

I've been redesigning crossvers for a Thiel CS 1.2 I've just been using online crossover calcs and so far its been Ok. They are going to be used for a spare room and listening will be done at low volume.

The woofer X-0ver is a 2nd order starting at 2.2 Khz and the tweeter is a 1st order starting at 3.5khz I'm not using the original tweeter. I'm using an old Vifa softdome that gets its life sucked out everytime I've tried a 2nd order or above. The vifa woof (the original in the Thiel) gets very peaky when pushed close to the 3khz mark (which is why I used a 2nd order). I'm finally at my question:
If a 2nd order is used on the woof and a 1st order on the tweet, what is the phase relationship betweem the two? Am I 135 degress apart? (woofer is 90 one way, tweet is 45 the other???)

Thanks.

Greg

You can say there is a phase relation with the xover alone, but this is not the case because you have real drivers. (That's a common mistake). Also phase changes in frequency. You will have to measure the phase for the drivers and then simulate it with the xover. If you can not do that (measurements) for the time being, we can have a (very similar/other/parameters) speaker drivers simulation with your posted xover. Don't forget distance (between center of drivers/angle) is also important in this case for time alignment (see graph).

[speaker dave]

Nice picture attached. Hmmm, looks familiar.

David Smith
Designer of the JBL 4430

[Inductor]

Originally Posted by speaker dave

Nice picture attached. Hmmm, looks familiar.

David Smith
Designer of the JBL 4430

Always nice to know. Congratulations for your career. I was most introduced to the subject by Wayne Parham (...and his nulls).
(Sorry Dave... my favorite is the JBL 4350B)

[speaker dave]

Originally Posted by Inductor

(Sorry Dave... my favorite is the JBL 4350B)

Too big, I always wanted a pair of 4315s.

Here is where the diagram originally came from:

Improvements in Monitor Loudspeaker Systems

David

[Inductor]

More information to read about the THIEL - TIME RESPONSE & PHASE RESPONSE pdf
See some behavior of speaker drivers phases here on a previous post. Need some help with some bass
Stereophile: Thiel CS1.2 loudspeaker