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Setting up an active crossover using Roon

Notwist_tsiwtoN

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WARNING: I am assuming that you have played around with digital or active analogue crossovers before, and that you are familiar with the characteristics of your drivers (optimal bandwidth, power handling, etc.). Accidentally low-passing a tweeter with a high power beyond its capabilities may permanently damage it.

I'm going to take you through how I set up the active crossovers in my office system. The chain is:

Music Server (with Roon Core) -> ethernet -> Win 10 PC (with Roon Bridge) -> USB -> MOTU UltraLite-mk5 -> 6x Neurochrome 286 mono amps -> 3-way speakers

The speakers are a pair of old Impulse H2s, popular in the UK in the '90s. They are particularly good for going active because they have 3 sets of binding posts on the rear. They have a recessed horn-loaded mid, and a rear horn-loaded bass. Roon's DSP allows time alignment, which I found particularly useful.

I've ripped out the internal passive crossovers, and have hardwired each driver to a pair of binding posts. So, each mono amplifier's output is connected directly to a driver.

1. Set up channel mix

Here, you assign the 2 input channels to the DAC's output channels:
View attachment 178538
View attachment 178539

I have assigned input channel 1 to the UltraLite's output channels 1, 3, 5, 7, and input channel 2 to the UltraLite's output channels 2, 4, 6, 8. I have reserved output channels 1 and 2 for headphone listening, where I want to bypass the crossovers.

Also, you can see that I'm level-matching by setting the gain/attenuation for each driver. I've determined this by measuring each driver nakedly using a 20Hz-20kHz sweep. You may have you own preferred way of doing this (e.g., REW, etc.).

2. Set up LF channel

Set up the low-pass filter:
View attachment 178543

Assign to output channels 3 and 4:
View attachment 178544

3. Set up mid channel

Set up pass-band:
View attachment 178545
View attachment 178546

Assign to output channels 5 and 6:
View attachment 178547

4. Set up HF channel

Set up high-pass filter:
View attachment 178548

Assign to channels 7 and 8:
View attachment 178549

5. Set up time delays

View attachment 178550

And that's pretty much it! Feel free to ask questions.

And the end result (taken with my old phone, so not great SQ quality):

Mani.
After you setup the crossover, does Motu still need to be connected to the PC, are the settings stored in Motu or in the software on PC? Can I turn the PC off and use another source while crossover still being active?
Also I have an ADI-2 PRO, can I: PC->ADI-2->MOTU->Speakers&Sub, can I still record guitar on my PC when it's set this way?
Thanks much in advance. Sorry if the questions are a bit silly, I don't know much about it.
 
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manisandher

manisandher

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After you setup the crossover, does Motu still need to be connected to the PC, are the settings stored in Motu or in the software on PC? Can I turn the PC off and use another source while crossover still being active?

Sorry, very quick reply for now...

Once set up (via CueMix), the MOTU does not have to remain connected to a PC - it stores the settings internally. I use a SOtM sMS-200 streamer as a Roon Endpoint with my MOTU.

But if you want to use the MOTU as a recording device also, then you'll need a PC with recording software.

Also I have an ADI-2 PRO, can I: PC->ADI-2->MOTU->Speakers&Sub, can I still record guitar on my PC when it's set this way?

I don't know.

Here, are you using the MOTU as a mic preamp and the RME as an ADC? In which case, it should work.

But I suspect most people here will tell you that the MOTU and RME will sound the same... because these people are certain that all modern DACs and ADCs should sound the same based on the way they measure ;).

(I don't subscribe to this, BTW. It's simply not what I hear. But I can no longer be bothered to try to convince others who are secure in their certainty - the antithesis of true 'science'.)

Mani.
 

Notwist_tsiwtoN

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Sorry, very quick reply for now...

Once set up (via CueMix), the MOTU does not have to remain connected to a PC - it stores the settings internally. I use a SOtM sMS-200 streamer as a Roon Endpoint with my MOTU.

But if you want to use the MOTU as a recording device also, then you'll need a PC with recording software.



I don't know.

Here, are you using the MOTU as a mic preamp and the RME as an ADC? In which case, it should work.

But I suspect most people here will tell you that the MOTU and RME will sound the same... because these people are certain that all modern DACs and ADCs should sound the same based on the way they measure ;).

(I don't subscribe to this, BTW. It's simply not what I hear. But I can no longer be bothered to try to convince others who are secure in their certainty - the antithesis of true 'science'.)

Mani.
Im using CueMix 5 but it looks different than your screenshots and don't have the same options. I don't have slope option for low pass/high pass filters etc. What am I doing wrong?
 

Brucemck2

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It’s unclear to me how to set up a straight two way to a sub in Roon. Can someone send a narrative or screen shots?

I’d like to take native two channel in, and then send that to L/R high passed at 60Hz and the L+R (mono) low passed at 60Hz to the LFE channel. It’s unclear to me how to create a mono output (L+R) at the proper volume level. Roon would be feeding a Trinnov with its crossover functionality turned off (so that Roon was doing the crossover functionality) and it’s also unclear to me how to configure the LFE volume setting in the Trinnov.
 
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