Three way electronic crossover

grapplesaw

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#1
Hello Everyone

This thread may not go far or supersede Jene’s 400 build thread, OMG if that happen.

so to get started this is to describe how to set up and how not to set up a three-way electronic crossover system. I had grand ideas of how I was going to build this using isolation transformers for converting RCA to balance then balanced back to RCA many steps have been taken and I have a pretty good understanding of how to do it

The issue is it hasn’t worked out the way I thought. I have used Rane balance buddies for doing the conversion of RCA to XLR balanced system. At this time using these transformers I am getting a hum. This is causing much frustration in getting the deemed to be best practises type of install to work. I can get great continuity with no noise using our Pam style converters I have also purchased a Tascam balance to unbalance converter box which has it channels if I can’t get my dear balance buddies to work

before we dive into my nagging problems with the balance buddies I’d like to describe what goal is stop a few of us on the form have purchased DBX Drive rack PA2‘s to set up a true balanced system this is the electronic crossover which converts analogue to digital then back to anolog. It’s a tool I will use to set up and balance the system for equalization , crossover points phase balancing and the like. I hope to end up with a Rane AC23 crossover using the settings the PA2 comes up with.

so final goal is to have these setup including a switcher box to use both xlr and unbalance to feed as balanced inputs to the crossover 8E2B99D6-777F-47E7-92F3-792D8494B165.jpeg 81C0C102-3A8E-484A-A92A-1671D52494D8.jpeg 953A3437-E0DA-4D1B-BABA-26E7D8D4EF8C.jpeg 33E9F5CA-3711-416D-93A7-92A107A87BA7.jpeg BED6C7E4-F503-4947-AEC8-BD3BB644E1AF.jpeg A8BFE48C-982C-4FBD-9C95-E66F37A64FD8.jpeg 2363F0A6-E5CC-42EA-BB22-F06252E444C9.jpeg
 

grapplesaw

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#3
as I am using a combination of unbalanced and balanced components it’s best to read up on there difference and best practices in the attached links.

These Balance Buddies are basic In Design

1678554724322.jpeg

My issue as it stands , and need to be solved defore going on to a great build , is the noise when connecting the Rane balance buddies isolation transformers to the rca inputs on the amps. we have noise. When one or two rca are plugged into the BB. With or without xlr’s also plunged in.

when the rca plug are both installed without the xlr’s and I touch the plug case the noise goes away. So ground fault is the issue, or is it. Reading Jensen documents I have tried putting a resistor on various resistant across the rca hot and ground As in this.

1678554923905.png


I can make the connection fro balanced to unbalanced through a electronic ic box with no noise , perfect.

the goal is to use isolation transformers as they are passive and are claimed to not pass noise. Read the articles to see these claims

how to solve this inductive noise, ground fault or what.
ideas are needed.
 

laatsch55

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#8
I've been looking for one with the same slope as the Al K's Extreme Slope crosses, but so far no dice. The Extremes are 96 db/octave...
 

grapplesaw

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#9
I've been looking for one with the same slope as the Al K's Extreme Slope crosses, but so far no dice. The Extremes are 96 db/octave...
Lee you may need to build one. Options are using design tool

i have not realy looked at this but may be of interest

https://rephase.org/

rePhase is a free FIR generation tool for building fully linear-phase active crossovers with arbitrary slopes.
It also let you manually compensate for the phase shifts of your loudspeakers and existing crossovers, be it active or passive.
 

gene french

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#10
I've been looking for one with the same slope as the Al K's Extreme Slope crosses, but so far no dice. The Extremes are 96 db/octave...
isnt that steep of a slope parasitic??
or is that just for passive crossovers....
that is built in to my dsp....but active
dont laugh....just trying to learn more....
 

grapplesaw

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#11
Gene this is a good place to answer at lot of questions. I got more questions on this whole subject that answers.
 

grapplesaw

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#13
About ready to start up the AP and test these transformers as standalone. I’ve read so many white papers on this subject and no one has given a step by step procedure only this concept or that
Ugh!!!
 

grapplesaw

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#14
Setup both AP analizers

drove both direction as stand alone and pairs 1K and virtually no distortion. Drive to get either .77volts in and out on the balanced cables. My understanding this is the 0 dbv porotocal

so my issue is ground loops and how to deal with them.

ideas anyone

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