Realistic Nova 7B with unknown modification

[dekejones]

I recently picked up a set of Realistic Nova 7Bs and a Realistic STA-77A receiver from facebook marketplace and speakers need some work. I've learned from the threads I need to recap them, planning on using these https://www.parts-express.com/Dayto...0V-Polypropylene-Capacitor-027-432?quantity=1, but when I took it apart there is an unknown modification on one of the 3" drivers in each cabinet. There is a small capacitor and a part I have no idea what it is wired in line and searching in the forums I haven't seen this mentioned anywhere and unable to tell if these came like this from factory, or they were modified by an owner sometime during its lifespan. I've attached pictures to see if anyone can identity what this modification is and whether I should replace these parts as well while I'm working on it.

I think these parts are there to limit the range to one of the drivers to turn it into a tweeter, but pretty new to this. Also, somewhere along the line one of the drivers was replaced with a different realistic part that looks like one of their bullet drivers. Pics attached.

I got this set up to listen to Sturgill Simpson's new album as Johnny Blue Skies and want to make it sound as great as possible, while retaining as much of the characteristics of the original as I can. Very excited to hear it once I get it up and running again.

 

[Lavane]

It looks like a cap and inductor was added. The tweeter has been replaced with a Radio Shack super tweeter.
I've done a similar crossover mod to mine. The second from the last picture is the factory wiring drawing, and the last picture is the modified crossover drawing. Yours is probably something similar to the last drawing picture.
Just replace the caps with some polypropylene film caps.

 

[Lavane]

What the modified crossover does is add a 1mh coil to the woofer to force it to roll off where it should. The factory crossover had the woofer running full range and roll off naturally. Also a second capacitor was added across the woofer. It's the same value as the other capacitor in the crossover.

 

[dekejones]

What the modified crossover does is add a 1mh coil to the woofer to force it to roll off where it should. The factory crossover had the woofer running full range and roll off naturally. Also a second capacitor was added across the woofer. It's the same value as the other capacitor in the crossover.

Thank you so much for the response! How has your modification altered the sound? It looks like my parts list for the modification/upgrade would be 4 poly caps and two 1mh coils. That's very reasonable to me.

 

[Lavane]

Yup, that's it. They sound a little more coherent. The midrange is more detailed too. The bass sounded a little less boomy also. It does make them a little less efficieant though. Also notice, the tweeters are wired out of phase to the woofer in the modified crossover. I didn't get fancy with the cap that goes across the woofer. Something like a cheap Dayton polypropylene film cap will do in that position. P.E. sells a few different 1mh coils. I went with the one with 22ga wire if I remember right. No need to go with heavy gage wire here. The coil will be physically bigger, and more expensive.

 

[dekejones]

Yup, that's it. They sound a little more coherent. The midrange is more detailed too. The bass sounded a little less boomy also. It does make them a little less efficieant though. Also notice, the tweeters are wired out of phase to the woofer in the modified crossover. I didn't get fancy with the cap that goes across the woofer. Something like a cheap Dayton polypropylene film cap will do in that position. P.E. sells a few different 1mh coils. I went with the one with 22ga wire if I remember right. No need to go with heavy gage wire here. The coil will be physically bigger, and more expensive.

Thank you again for your advice and guidance! Much appreciated and I can't wait to get these singing.

 

[Lavane]

Thank you again for your advice and guidance! Much appreciated and I can't wait to get these singing.

Here is the link to the thread I used to modify mine. There may be some more information for you.

A full crossover for the Realistic Nova 7B....I did it.

I originally posted a version of this in another thread but thought I'd flesh it out more with some pictures and start a new topic to get more eyes on it. I've owned a pair of Nova 7B's for almost 30 years now. They belonged to my in-laws, and my wife and I got them during one of their moves...

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