Looking for direction on how to modify a crossover from single to bi-amp input

Hello DiyAudio,

I recently acquired a pair of Duntech Sovereigns (mid-west US) and am trying to figure the feasibility to convert them from single to biamp inputs. Attached are a few pics. While I have done some basic repairs, I have limited experience with crossovers having this many components. Yikes, they are even on drawer slides.

My wife and I collect equipment from the Sov's era, back when I was school-aged, when seems all the cool kids in the magazines had more than one amp. I have some amp pairs that are not easily bridgeable that I'd love to use with the Sovereigns.

Ask any questions. I'll do my best to respond. Thanks in advance for any input.

MnM
DS Backplate.jpg
DS Backplate Open.jpg
DS Input 1.jpg
DS Output.jpg
DS Crossover 1.jpg
DS Crossover Underside.jpg
 
Hello

Sure you want to modify them? If they are in good shape and it's your first time doing this might want to use something else.

Wow the drawer is a great idea you have a schematic? Can you determine the component values? Looks like the caps are all painted. If you are talking full up Bi-amp you need to know what the voltage drives are and be prepared to make changes. If you remove 1/2 of a bandpass circuit you will typically need to make adjustments to the remaining half.

Rob 🙂
 
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I assume you want to passively bi-amp this speaker.
Please unplug the 2 red wires and 2 black wires connected to the binding posts, measure the relative resistance of all four connectors on the crossover board with an ohmmeter and post the results.
In this way, it should be possible to determine which pair of connectors belongs to high-frequency and which pair of connectors belongs to low-frequency.

DS Input 1.jpg
 
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I have some amp pairs that are not easily bridgeable that I'd love to use with the Sovereigns.
Using two amp sides per speaker won't gain much (if any) headroom, the peak power demands are still the same for a given SPL.
The woofers are crossed ~300Hz, where most of the highest peak (and sustained) power is required.
Ask any questions. I'll do my best to respond.
What amps do you have, and what are you hoping to achieve?
 
I assume you want to passively bi-amp this speaker.
Please unplug the 2 red wires and 2 black wires connected to the binding posts, measure the relative resistance of all four connectors on the crossover board with an ohmmeter and post the results.
In this way, it should be possible to determine which pair of connectors belongs to high-frequency and which pair of connectors belongs to low-frequency.

View attachment 1459966


Sorry that wont work.
If you look at the copper side, the two reds share a common trace, as with the two blacks also sharing a common trace. Doh.
Would've made it super nice and easy otherwise .
 
  • Thank You
Reactions: chrisng
You reallly wanna mess with this? For one thing you'll likely blow its value.. and it's hard to tell what it will sound like. It looks like they went a long way to design and make this speaker.

http://duntech.com/products/sovereign.html

The crossover is a highly complex, first order type with high power handling. The fibreglass printed circuit board is mounted in it's own separate cavity. Polypropylene capacitors are used for their stability, high voltage, low loss and low inductance, together with aircore inductors. Resistors are high powered ceramic type.
 
Yes, you start by figuring out the XO. Then you create separate inputs for the ranges you wish to amplifier separatly. Onlyworks if XO is parallel.

What you want to do is passive bi-amping, you need 2 identical amplifiers (or at least same gain). does not have the advantages of active bi-amping.

dave
 
I see it as a chance for someone to earn a lot of 'internet credits' by doing the reverse work up.
You don't even need to know the component values, just where they sit in the schematic.
It might want a few more detailed photos, different angles and parts that aren't easy to see. It's no fun starting one of these and getting stumped half way through.
 
Hello

Sure you want to modify them? If they are in good shape and it's your first time doing this might want to use something else.

Wow the drawer is a great idea you have a schematic? Can you determine the component values? Looks like the caps are all painted. If you are talking full up Bi-amp you need to know what the voltage drives are and be prepared to make changes. If you remove 1/2 of a bandpass circuit you will typically need to make adjustments to the remaining half.

Rob 🙂
Hi Rob,

I am on the fence, whether or not to mess with them. Having read some of the other posts in this thread, I am definitely leaning towards leaving well enough alone. And you confirmed one of my biggest fears, separating the subs from the rest of the array will ultimately require additional changes. Not as simple a mod as I had hoped.

Thanks for your response,

Mike