Tweeter replacement idea for Sansui SP-2500X’s

[Pretzelogic]

I’ve loosened up the surrounds on the woofers, replaced the old caps and tested every component in my old Sansui SP-2500X’s and it turns out my tweeters are fried. There are 4 identical tweeters, 2 for each speaker. Has anyone ever replaced 12 watt, 12ohm paired tweeters with a single 6ohm horn tweeter (assuming such a thing exists) in each speaker? Seems like my next best option to having the tweeters rebuilt, which I’m guessing is quite expensive for speakers that aren’t worth a whole lot. They do sound a helluva lot better since the recap but working tweeters would definitely take them one notch higher.

 

[homebrew]

Original Sansui T-138 12 ohm tweeters are essentially unavailable. These might do in a pinch.
https://www.parts-express.com/JZ2-677H-2-Paper-Cone-Tweeter-12-Ohm-69-289-2354?quantity=1

They probably will require some sort of adapter plate to fit your cabinet.

 

[Pretzelogic]

Would these work? Twist the two sets of black wires and the sets of white wires together and hook to one of these per speaker? https://www.ebay.com/itm/1156412605...=2349624&ssuid=&widget_ver=artemis&media=COPY

 

[homebrew]

Impedance is 6.5 ohms, your originals about twice that. Means you'll have to do some crossover modifications to maintain the same crossover frequency.

 

[Pretzelogic]

Impedance is 6.5 ohms, your originals about twice that. Means you'll have to do some crossover modifications to maintain the same crossover frequency.

Right but if I take the leads meant for 12ohm each and tie them together wouldn’t they be putting out roughly 6ohm load when paired together?

 

[Stuart Pedaso]

Would these work? Twist the two sets of black wires and the sets of white wires together and hook to one of these per speaker? https://www.ebay.com/itm/1156412605...=2349624&ssuid=&widget_ver=artemis&media=COPY

The speakers you linked to are midrange drivers -- may not give ideal high frequency performance for use as tweeters.

They measure ≈ 6.5Ω DC because they are 8Ω drivers.

It's interesting that someone measured stock "12Ω" T-138 tweeters at more than 12Ω DC:



That's consistent with a driver of 16Ω impedance rating and seems unusual for one rated at 12Ω. Though this suggests you may have success using a single 8Ω tweeter rather than 6Ω to maintain impedance load similar to the paralleled stock tweeters.

But if that's the case, why not use a couple of 4Ω tweeters in series per speaker system? Maybe something like this?



Whatever you use will need to fit in the space allowed -- magnet assemblies that fit in the baffle hole cutouts and outer flange diameter that clears other drivers around it.

Here's what appears to be the schematic for SP 2500X. Haven't confirmed accuracy 100%, but should be close.

 

[Pretzelogic]

The speakers you linked to are midrange drivers -- may not give ideal high frequency performance for use as tweeters.

They measure ≈ 6.5Ω DC because they are 8Ω drivers.

It's interesting that someone measured stock "12Ω" T-138 tweeters at more than 12Ω DC:

View attachment 2764796

That's consistent with a driver of 16Ω impedance rating and seems unusual for one rated at 12Ω. Though this suggests you may have success using a single 8Ω tweeter rather than 6Ω to maintain impedance load similar to the paralleled stock tweeters.

But if that's the case, why not use a couple of 4Ω tweeters in series per speaker system? Maybe something like this?

View attachment 2765163

Whatever you use will need to fit in the space allowed -- magnet assemblies that fit in the baffle hole cutouts and outer flange diameter that clears other drivers around it.

Here's what appears to be the schematic for SP 2500X. Haven't confirmed accuracy 100%, but should be close.

View attachment 2764811

WOW I replaced my old tweeters with those ones you put the link to, wired ‘em in series. NIGHT AND DAY!!! Thanks so much for the suggestion man! These old speakers now sound dang good for what they are.

 

[Stuart Pedaso]

WOW I replaced my old tweeters with those ones you put the link to, wired ‘em in series. NIGHT AND DAY!!!

Glad that worked out. It's always a gamble proceeding without detailed stock driver parameters for reference. Sometimes you get lucky.

 

[blkout50]

WOW I replaced my old tweeters with those ones you put the link to, wired ‘em in series. NIGHT AND DAY!!! Thanks so much for the suggestion man! These old speakers now sound dang good for what they are.

Resurrecting an old post.

I am having the same issue with my tweeters on my SP-2500X speakers.


A couple of questions;

1) Are these speaker replacements still working for you?

2) Did you make adapter flanges to mount the speaker replacements?

Thanks in advance,
Mike