My New Three-way Crossover System with Ethos

[wensean]

Hello Everyone, I am new here, I am trying to build a new active crossover system with my Martin Logan Ethos......​

img1 is a simple 3-way hybrid crossover system. (Phase I)​

I plan to stick with this setup for at least 3 months before moving on to the Phase II setup. This way I will be able to clearly determine how much the 3-way active crossover affects the system.

img2 is a 3-way active crossover system with network streamer that I am going to build. (Phase II)​

Any commend will be very appreciated. Thank you.

img3 is the opening diagram of Ethos​

full story here
http://vincent.vcih.com/2023/09/23/my-new-3-way-active-crossover-system/

 

[JonFo]

This looks like a cool project. I will follow along closely.

Your phase 1 doubles up on bass from 20 to 80Hz, with both the Ethos and HSU covering that region. Adjusting the gains on both will help, but you'll still wind up with excess bass unless the DIO or the laptop software can run some form of EQ to mitigate that.

Phase 2 is cool, the thing to figure out is the exact point in the Ethos XO to inject the high-passed signal from the new active XO.

Same for the bass XO, as you do want to leverage the built-in amp, but feed it from the external XO and bypass the built-in active bass XO. That probably means your external controls on the Ethos will be inoperable unless the gain directly affects the Amp and not the built-in XO gain stages.

Keep us posted, and good luck.

 

[wensean]

Jonathan, thank you for your invaluable advice that is full of knowledge, and for fully considering the pros and cons of my two approaches. You are right, I need to figure out the crossover point. On the Ethos menu, the crossover point is set to 475Hz, so I may try +-100Hz crossover around it.

As for the bass XO, I really don't have a clue. 80Hz is just what I'm attempting. What do you think?

By the way, what a fine home theater and hi-fi system you have!

 

[JonFo]

As for the bass XO, I really don't have a clue. 80Hz is just what I'm attempting. What do you think?

80Hz is a good place to start. For reference, my rig uses an 80Hz crossover from the woofers to the subs.

XO slopes are another subject to consider, and I highly recommend 24/dB Octave (fourth order) Linkwitz-Riley for both the woofer to panel and the woofer to sub.

So the topology I'd recommend is:

Panel: high-pass 24/dB Oct. LR @475Hz (+/-)
Woofer: Band-pass low 24/dB Oct LR @80Hz, high 24/dB Oct. LR @475Hz
Sub: low-pass 24/dB Oct. LR @80Hz

BTW- before building anything, you might find that learning what works best for your system can best be accomplished with a single digital crossover with 2 in and 6 (or more) outs. We've discussed several models in threads on adding active bass for legacy speakers.
I tweaked my settings plenty at the beginning and, even over the years, made minor changes here and there based on measurements.

Speaking of measurements, do you have and use REW ?

Anyone doing an active XO mod on their speakers should use this tool. Software is free, and the Mic is ~$100

 

[jtucker]

One thing I would be concerned about: The Ethos uses DSP in its internal crossover. My opinion is that the DSP is what allows the phase response for the woofer and panel to be close to the same at crossover. This is what makes the woofer and panel integration work better than on older models. I would probably stick with a two way crossover between sub and ethos.

 

[wensean]

XO slopes are another subject to consider, and I highly recommend 24/dB Octave (fourth order) Linkwitz-Riley for both the woofer to panel and the woofer to sub.

So the topology I'd recommend is:

Panel: high-pass 24/dB Oct. LR @475Hz (+/-)
Woofer: Band-pass low 24/dB Oct LR @80Hz, high 24/dB Oct. LR @475Hz
Sub: low-pass 24/dB Oct. LR @80Hz

Your advice is excellent and that's exactly what I'm going to do. I downloaded REW and have been studying it. The parts to make the XO are on the way.

 

[wensean]

One thing I would be concerned about: The Ethos uses DSP in its internal crossover. My opinion is that the DSP is what allows the phase response for the woofer and panel to be close to the same at crossover. This is what makes the woofer and panel integration work better than on older models. I would probably stick with a two way crossover between sub and ethos.

To bypass all Ethos excellent internal crossover seems not a wise idea. But I was inspired by Mr. Linkwitz's 4-way XO concept. So I have always wanted to try to use a pure Linkwitz-Riley XO in conjunction with an electrostatic panel.

 

[wensean]

It's been almost 6 month since I posted this project.
This week I finally started building my new XO system with Martin Logan Ethos.

img01: Drilling 6 outputs ( 2x of High, Mid, Low ) and 1 network sockets.
img02: two 3way XO board and a Arylic DAC /network streamer on the right, power supply on the left.
img03: connect them together.

 

[wensean]

img01: Disassembling of Martin Logan Ethos ESL panel.
img02: Disassembling ICE 200W D class Amp and control unit.
img03: replace volume control with XO Mid channel (300Hz~80Hz) input.
img04: First, bypass the active xo on the control panel and reconnect it directly to the D amplifier input. and leave the original input sensitive switch unchanged. Second, Bypass ESL panel passive xo.
img05: Disconnecting ESL panel passive xo. Look, what a beautiful xo board!
img06: Turn off the xo on Subwoofer too.
img07: System diagram
img08: (video with sound) Put everything back and see how it sounds!

My first impression of the new XO setup is that it is more dynamic and transparent, yet still maintains the most natural sound of the ESL speakers! I will keep the other speaker the un-changed and then compare the two for at least a month!

 

[wensean]

https://www.martinloganowners.com/t...ive-crossover-modification.19996/#post-212947