tweeter polarity help.

[joaoveludo]

Hi!
My mission 763 have a 1st order filter for bass and 2nd order filter for tweeter, so the phase will be woofer at 90º and tweeter at 180º. i'm i right?
I unsoldered old tweeters without seeing if they were reversed or not.
For what i've been reading, and in this particular case, it won't matter if i reverse the polarity of the tweeter or not because the mid-bass and the tweeter will always be 90º off phase (45º off phase on crossover freq.). I'm i right?

I'm waiting for your answer to finish the replacement

Since i'm replacing original tweeters with different ones (originals not available) should i change the value of the hi-wattage resisitor on the tweeter filter? It

thanks!

 

[Willitwork]

You're not right

This mixed order Xover is commonly found on many British two-way speakers and on all those I have seen tweeter and woofer are connected with the same polarity for both drivers. I believe this is done for time alignment purposes and you will definitely hear the difference if you reverse tweeter polarity, it just sounds awful.

You have to keep in mind that in many cases speaker manufacturers who design their own drivers don't need to resort to complex crossovers since their driver's behavior is already tailored to their specific need. This may account for apparent Xover phase oddities. In some high-end speakers the midbass and/or bass drivers don't use any filtering other than the cabinet's mechanical acoustical filtering characteristics. I have seen this done in some Heybrook and Rega speakers with amazing results.

 

[sreten]

Hi,

The phase depends on the acoustic order of the roll-offs not the
electrical order of the crossover. It will very likely matter which
way round it is connected unless its a poor crossover design.

/sreten.

 

[qatlas]

Hi I a same type of speaker MISSION 673 the xover is broken and needs a makover .
Does any of you have a suggestions for a replacment filter.

qatlas

 

[qatlas]

By the way I have a link to similar speakers and the manual

Mission763

http://oldsite.mission-hifi.com/archive/76series/6i_series.pdf

qatlas



qatlas

 

[Inductor]

Hi I a same type of speaker MISSION 673 the xover is broken and needs a makover .
Does any of you have a suggestions for a replacment filter.

qatlas

You can repair it (is anything broken? or just makeover). Usually people post a picture to see were they can improve. Also helps to have a schematic of said xover. Quality parts always come to mind. Does it sound, or was it good before or does it need some improvement.
(attention to the reader, this was an old post)

 

[qatlas]

Mission 763 cross over ( HP filter )

Thanx Inductor
The sound is not as it was before the tweeter was gone.
Trough faultfinding ( by means bypassing the C1 and R1) tweeter is back but the sound is no good I found the capacitor is broken and needs to be replaced ,but I can not find the size and type. Find the schematics attached.

Qatlas

 

[Charles Darwin]

You're not right

This mixed order Xover is commonly found on many British two-way speakers and on all those I have seen tweeter and woofer are connected with the same polarity for both drivers. I believe this is done for time alignment purposes and you will definitely hear the difference if you reverse tweeter polarity, it just sounds awful.

There is one exception I know of and that's (older) Tannoys.
Although there are other differences: The bass has a second order low pass while the HF runs off a first order hp. With the AlNiCo drivers (up tp HPDs) the tweeter coil is exactly a quarter wavelength behind the bass coil which results in an in-phase response as long as the tweeter is inverted. They sound awful if the tweeter is NOT inverted.

 

[sreten]

Hi,

You should maintain the same relative phase for the tweeter.
for the broken capacitor replace it, if really stuck measure the other
capacitor that works in the other speaker. Tweeter sensitivity,
impedance, and roll-off need to be similar for a substitute.

/sreten.