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Setting up an active crossover using Roon

manisandher

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Recently, quite a few people have asked me how I've gone about setting up active crossovers just using Roon alone. I thought I'd start a thread to discuss the process. I'm just going to dump a number of screenshots, which are hopefully fairly self-explanatory (if you know Roon, at least). We can then go into more details should people have further questions.

Process to follow shortly.

Mani.
 

ahofer

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EQ/DSP and multi-point casting?
 
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manisandher

manisandher

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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:
1. Channel Mix 1.JPG
2. Channel Mix 2.JPG

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:
3. LF 1.JPG

Assign to output channels 3 and 4:
4. LF 2.JPG

3. Set up mid channel

Set up pass-band:
5. Mid 1.JPG
6. Mid 2.JPG

Assign to output channels 5 and 6:
7. Mid 3.JPG

4. Set up HF channel

Set up high-pass filter:
8. HF 1.JPG

Assign to channels 7 and 8:
9. HF 2.JPG

5. Set up time delays

10. Speaker Delays.JPG

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.
 
Last edited:
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manisandher

manisandher

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ahofer

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What do you mean by 'multi-point casting'?
Multiple endpoints. Never mind, I've never used multi-channel before and that's where you separate each driver's EQ. Cool. I presume you could do subs that way as well, but I don't think you could adjust time/phase delay.
 
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manisandher

manisandher

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I presume you could do subs that way as well, but I don't think you could adjust time/phase delay.

I have subs in my 4-way main system. It's the exact setup as above, but with output channels 1 and 2 assigned to the subs. Yep, I'm adjusting the time delay there too.
 

Dathzo

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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.
Great, thank you! This is very informative! I have ordered mi Motu MK5, but delivery times are long. I will certainly get back to it. I understand you also have the Okto Pro. Which of the 2 DACs you prefer @manisandher?
 
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Savi

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Really nice to share. One day I would like to try the same setup.
There is also a excellent thread with rpi4+camillaDsp solution, any opinion on pros and cons of the two solutions ?
Maybe it is a stupid question but with this setup you are limited to listen music with roon ? Ones a week I use my speakers to watch a movie, or to listen to a podcast... You confirm that there is no solution for this ?
Thxs
 
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manisandher

manisandher

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I understand you also have the Okto Pro. Which of the 2 DACs you prefer @manisandher?

I haven't compared them directly, but would be amazed if they sounded very different from each other. One major difference though is that the Okto works plug 'n' play with Linux, whereas the MOTU doesn't (at least with kernel 5.10 and earlier). And of course, that the MOTU has an ADC!

Mani.
 
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manisandher

manisandher

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There is also a excellent thread with rpi4+camillaDsp solution, any opinion on pros and cons of the two solutions ?

I haven't tried that. I have to say that I've been able to achieve everything I wanted just using Roon, so haven't looked elsewhere. It's a very straighforward solution.

Maybe it is a stupid question but with this setup you are limited to listen music with roon ?

Yes, that's the limitation in using Roon's DSP - you have to use Roon.

Mani.
 

Dathzo

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I haven't compared them directly, but would be amazed if they sounded very different from each other. One major difference though is that the Okto works plug 'n' play with Linux, whereas the MOTU doesn't (at least with kernel 5.10 and earlier). And of course, that the MOTU has an ADC!

Mani.
Thanks a lot! I’m aware that one user from the Roon forum (Burkhardt_Petermann), had some issues with the Okto and Linux (RPi), so may be tricky in some cases, perhaps different firmwares. But it seems that the Motu is a great unit for its price at this moment.
Thank you again!
 

Nspace

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This looks interesting. However without wanting to derail this thread, maybe someone who has gone to this length may explain what is fundamentally difficult to yet stopping the use of in the box software to do the crossover interfacing before Ultralite Mk5...

One would think that with nowadays CPUs, RAM, etc. induced latency wouldn't be significantly different with or without this extra software step, provided everything would be done internally without no additional conversion.
Then is the potential issue of "Accidentally low-passing a tweeter with a high power" as you put it manisandher, which would require careful set up, and possibly some emergency measure? in case something gets off limits.

Am I missing something? Or is just a case of finding the vst-container/standalone software to be added before Cuemix?
 

dadregga

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I've been using this for about a year in a MCH 5.1 setup into a HDMI AVR input as well (bypassing AVR sub crossover and room correction stuff with Roon crossver + Roon DSP using REW filters) - works fine.

People object to the cost, which is understandable, but Roon has a pretty remarkable DSP engine, and if you use that + the multi-room endpoint stuff + room correction, the cost begins to look more reasonable - and it means I need fewer boxes (since I already have a home server) and a simpler output chain.
 
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