NHT SuperOne teardown and mod...

[MyNameIsJake]

So I recently got a pair 2nd hand for pretty cheap given there condition. I couldn't test them out but I bit the hook anyway. Here is what I got, and I think my hearing has been damaged by there sound

I opened up the cabs and discovered that the xovers have been burning??? The drivers themselves appear fine, so it's teardown and rebuild I go

[MyNameIsJake]

Here is a pic of the stuffing that is melted and the box.

I love the mirror finish the cabinet has after buffing. This is the finish I want for my subs when I finally get to buying the parts and building them.

The third of course is the pile of components I removed from the board. I'm going to experiment with the one cap & coil, but I might buy new parts depending on what I decide on what to do.

Thoughts and ideas are most welcomed

[MyNameIsJake]

BTW, would anyone happen to know what the value of the inductor is for this model?

[Brisso57]

Originally Posted by MyNameIsJake

BTW, would anyone happen to know what the value of the inductor is for this model?

If the inductor is not visually obviously scorched, just measure the inductance! Then measure the same component in the other speaker. If they are a close match then they may well be OK, as resistors and caps are - generally - more easily damaged by heat.

You might just be lucky!

cheers

Doug

[Brisso57]

Originally Posted by MyNameIsJake

BTW, would anyone happen to know what the value of the inductor is for this model?

Hi again - a second idea ...

If you can trace the XO circuit diagram and it looks like just a simple XO (i.e without a noth filter, etc) then just look at this:
2-Way Crossover Designer / Calculator

1. Choose a 2-way XO type and see if it looks like your circuit.
2. If it does, then make a guess at the XO freq and use the calculator to find the values of the components.
3. Compare the calc'd values to the real values and make a better guess at the real XO freq. Calc again. Repeat until you have matching values for the resistors and caps. Then just look at what the calc'd inductor value is.

cheers

Doug

[MyNameIsJake]

Thanks for your reply. I'll have to look in to how inductance is measured, as a refresher.

I took the other speaker apart and the xover in that looks to be in good health so I will be able to do a proper trace out and compare everything. It looks to me as the one in my pics decided that a party and bonfire was a good idea.

In the end, I will be designing a new xover and possibly replacing both drivers too (love the cabs).

The OEM used a 8mF and a 5.5mF cap, iirc 2-1ohm and a 3ohm resister. I'll have to check later.

Thx,

[Brisso57]

Originally Posted by MyNameIsJake

Thanks for your reply. I'll have to look in to how inductance is measured, as a refresher.



In the end, I will be designing a new xover and possibly replacing both drivers too (love the cabs).



Thx,

1. With a multimeter that measures inductance!

2. Stop now. Go buy a miniDSP. Go active and save on not having to replace any XO components. I also suggest that a miniDSP may get a better result from the same drivers, so you may be able to keep them also.

cheers

Doug

[pinkmouse]

Hi Jake

I've seen a lot worse looking crossovers than that still working from abused pro gear, so I suspect that the resistors and inductors will be okay. However the caps may well have suffered from the heat and should be replaced.

[MyNameIsJake]

Hi Pink,

Yes you are correct. The caps have been damaged. I did find that the one axial-cap is not even OEM.

Doug,

I like your idea with the miniDSP, but that isn't the route I was planning. But it is filed away for another idea I have

When I gets some time, I'll break out my woofer tester and take some measurements.