Making Stacked KEF 103 Speakers full active threeways

[bencat 2,263]

Okay Keith has very kindly let me loan a Behringer DCX2496LE to use which is great but I am clueless on how this is set up and used . So anyone who has used this can I ask for help .

What I want to do is set the Behringer to accept an XLR Digital input and then set Crossover points to Six XLR outputs one for Left Speaker and one for Right Speaker . As a starting point I have decided to use the following . The Mid and Treble crossover points will remain as they are as they are what KEF state . The Low Bass Crossover will start at the level indicated but I will be trying different settings to see what sounds best . What I need to know is first how do I set this up on the A XLR input for Digital In ? Is it an automatic thing that once it gets a digital signal in it sets itself for that .

After that I need to set the input as A and the outputs to all six XLR's . Once that is done I then need to set each of the outputs as follows

1 - Low Bass - Right Speaker - CR Cut off point 200Hz  - 2 - Mid Filter - 200Hz - CR Cut off point 3000Hz - 3 - High Filter - 3000Hz - CR Cut off point - 15000kHz

4 - Low Bass - Left Speaker - CR Cut off point 200Hz  - 5- Mid Filter - 200Hz - CR Cut off point 3000Hz - 6 - High Filter - 3000Hz - CR Cut off point - 15000kHz

So how do I go about this either through connection with my PC or on the unit itself ?

I will not get the 6 XLR to RCA adapters till later this week so I want to use my time by being able to set the above and ensure it is saved to the unit so that my drive units are safe when I make all the connections and switch on .

To be clear the front end to this will be a Raspberry Pi + Digihat sending an SPDIF signal to a MiniDSP DDRC 22D which will allow me to add the DIRAC Live Filter to that digital signal and then send the filtered signal via XLR out to the Behringer DCX which will then perform the CR split as outlined above .

Any help is appreciated will send pics of settings if needed .

Edited Wednesday at 13:09 by bencat

[MF 1000 1,615]

As I recall Andrew Julian included the lead to enable you to connect the unit to your laptop which will help in the setup ...never tried it in ‘digital in’ mode myself 

[bencat 2,263]

Just now, MF 1000 said:

As I recall Andrew Julian included the lead to enable you to connect the unit to your laptop which will help in the setup ...never tried it in ‘digital in’ mode myself 

Hi Keith yes he did include the lead but to be honest I am still confused as when I try and set the cr points it gives an error message . I know it is just me being unfamiliar with it but need to start at the basic setting up of input A to Outputs 1,2,3,4,5,6, first and then move on . Can you just set the unit back to Factory Default ?

[MF 1000 1,615]

As it was set for Jules it should be input A (LHS) fir outputs 1,3,5 and B for 2,4,6 

so 1&2 are bass, 3&4 are mids, 5&6 are tweeters

Edited Wednesday at 13:59 by MF 1000

[greybeard 5,578]

Unfortunately my version is the lite, and does not have the digital input or th PC connection so i will not be much help I'm afraid. 

[greybeard 5,578]

Andrew Google DCX tutorial, that should get you started.

[bencat 2,263]

Okay let's start with first principals how do I make input A into Stereo output ? Once I have that I should be able to then assign the right output to 1,2,3 and then the left output to 3,4,5 . Can anyone suggest how this can be done.

[MF 1000 1,615]

I’ve only done this on the DCX unit itself Andrew but you select each channel then scroll through the menu till you get the connection diagram ....then you can select if it’s a or b input 

[greybeard 5,578]

I think you will need to assign them 1,3,5 & 2,4,6. That is what i do, and I think that was a pre selected mode in setup. Have you got the manual Andrew? if not here is a scan https://imagescdn.juno.co.uk/manual/624251-01U.pdf

[bencat 2,263]

Keith in my case there is no B input as that would be analogue and I do not have a second input. I will be using input A as a stereo digital input and then using the input as a stereo output splitting left and right and then assigning each side to the three outputs to low mid and high . Will have to sit and read the manual and see if this gives me the information I need. 

[bencat 2,263]

Right I think I have got this worked out a little . Under Set Up I have changed Input A to AES / EBU and the output to Mono . I have then set up the crossovers as follows

Output 1 - 20hz - 200hz - Output 2 - 200hz - 3000.1hz Output 3 3000.1hz - 15000HZ  - Right Channel

Output 4 - 20hz - 200hz - Output 5 - 200hz - 3000.1hz Output 6 3000.1hz - 15000HZ - Left Channel

According to the manual when AES/EBU is chosen then Input A is the defined input for all channels and you can then assign the outputs from 1 to 6 using either a single out put or as in my case six outputs and all will be mono feeds .

Given the above I have stored this and so can recall it . As far as I can tell this is now set to input one digital stereo signal in to Input A and that has now been manually set up by me to output the filtered signals above . I should be able to when the Adapters arrive take two feeds Hi / Mid and Hi to two stereo amps which will then feed the correct signal to to each speaker . The last two feeds will go to the left and right for the Low Bass amplifier and feed Left and right accordingly .

Given my lack of knowledge of this item it would be great to have someone who knows how to check settings go over it but the only option i can see to do that is to take a photo of the screen settings and let people view them . Might do that tomorrow and see what you all think .

[greybeard 5,578]

What crossover have you chosen eg, LR (Linkwitz riley) AB (acoustic Butterworth) and you can choose between 6db upto 48 db slopes.

As I stated earlier mine is set up with 1,3,5 left and 2,4.6 right as the output channels, but I know there are various configurations you can choose, so what you have chosen may well be correct.

[bencat 2,263]

Colin I chose the LR 48 db  for all the cr points prefer a nice smooth tail off. I think the issue I have is the Digital input is single while all of you use two analogue inputs . The unit automatically switches to mono which is.Not ideal but will see what the results are. 

Another option is to use an additional DAC  with balanced out feed the DIRAC signal in to the DAC then use the XLR analogue left and right in to the DCX and then set it as you say for right and left . All I really want to be sure is that having set each channel up that the drivers will be okay.

[greybeard 5,578]

Yes but all digital inputs are single, co-ax, optical, AES EBU but the signal is in stereo (or even dts surround), not mono,which is the bit that is confusing me.

I also use the LR 48db as it is my preference too.

[MF 1000 1,615]

Unless you have very sensitive speakers the background hiss that can occur with DCX units shouldn’t be an issue ....analogue input seems a far easier option to implement