New Member - long time ML owner

[Brewnoser]

Just bought my second pair of MLs after over 30 years with Aerius i’s. ESL 9 Classic. Listened to the 11’s and loved them but budget and a desire to keep bi amping with my babies - restored McIntosh 240 and 275 - plus a killer deal on a low use demo pair got me here.

I do have a question I can’t find an answer to elsewhere. I’ve been bi amping the Aerius with the higher power to the panels and lower to the wooofer. Plus a Klipsch powered sub really throttled down to very low frequency.

It seems to sound better this way. The tech who last cleaned up the amps says the 275 is the better of them. So I’m going with that in the part of the sound that seems to demand quality.

Thoughts?

 

[Kermie]

Welcome!! Someone will be along with an answer for you shortly.

 

[Jazzman53]

Welcome to the forum, Brewnoser,

Just curious: What are you using for a crossover?

 

[Brewnoser]

Welcome to the forum, Brewnoser,

Just curious: What are you using for a crossover?

The speakers are designed to allow two kinds of bi amping. The crossover accommodates both.

 

[Jazzman53]

The speakers are designed to allow two kinds of bi amping. The crossover accommodates both.

OK I see; you are using the speaker's internal passive crossover.

My ESLs are DIY but I wasn't smart enough to design a passive crossover that works well with the ESL's radical impedance, so I took the easy but more expensive route and used a digital (DSP) crossover upstream of the power amps, which provides almost infinite tuning capability, in real time, and sounds wonderful.

I asked about your crossover because some ML owners are bypassing their speakers' internal passive crossovers in favor of bi-amping with an upstream DSP, and loving the results.

It's an option.

 

[Brewnoser]

OK I see; you are using the speaker's internal passive crossover.

My ESLs are DIY but I wasn't smart enough to design a passive crossover that works well with the ESL's radical impedance, so I took the easy but more expensive route and used a digital (DSP) crossover upstream of the power amps, which provides almost infinite tuning capability, in real time, and sounds wonderful.

I asked about your crossover because some ML owners are bypassing their speakers' internal passive crossovers in favor of bi-amping with an upstream DSP, and loving the results.

It's an option.

I can’t see myself doing this. The upstream to these is vintage McIntosh tube gear. Not one computer. Inserting something like that seems wrong. I’ve gotten to the point where stereo systems don’t get arguably better. Just different. Martin Logan owner for over 20 years and staying out of the boxes forever.

I’m more into room treatments now as my space is compromised until major renovations can happen.

 

[Brandon Hartwick]

You can do an electronic Xover on just the woofers, there's a lot of information on the forum about doing this and the dramatic improvement it makes. It might seem counterintuitive at first, but the results speak for themselves.

Any newer Martin Logan speaker uses an active crossover on the bass to prevent the overlap between the panels and woofers. The stock passive Xover on the Aerius is pretty lame and really muddies up the whole sound.

 

[Brewnoser]

You can do an electronic Xover on just the woofers, there's a lot of information on the forum about doing this and the dramatic improvement it makes. It might seem counterintuitive at first, but the results speak for themselves.

Any newer Martin Logan speaker uses an active crossover on the bass to prevent the overlap between the panels and woofers. The stock passive Xover on the Aerius is pretty lame and really muddies up the whole sound.

I bi-amped the aerius-i’s for a long time. A McIntosh 275 on the panels and a 240 on the bass with a separate powered sub set only to play below the ML range. Packed the woofer cabinets with dense fibre insulation.

The 240 had volume control so I could tune/balance.

You had to hear it. People who have great ears and sensibilities would come and love it. Some were people who would have liked to sell me other things but after hearing, didn’t try.

Now I have new EL-9’s and I’m in the play with them
To see what works mode.

 

[Brandon Hartwick]

I bi-amped the aerius-i’s for a long time. A McIntosh 275 on the panels and a 240 on the bass with a separate powered sub set only to play below the ML range. Packed the woofer cabinets with dense fibre insulation.

The 240 had volume control so I could tune/balance.

You had to hear it. People who have great ears and sensibilities would come and love it. Some were people who would have liked to sell me other things but after hearing, didn’t try.

Now I have new EL-9’s and I’m in the play with them
To see what works mode.

I'm not saying you're wrong, I'm saying there's room for improvement yet.

All the cool kids are doing it

 

[Brewnoser]

I'm not saying you're wrong, I'm saying there's room for improvement yet.

All the cool kids are doing it

So the cool kids are basically saying to the designers that their putting two sets of speaker terminals in on the crossover they use is wrong?

I don’t get it. The user manual goes to great depths to show different ways to connect one or two or even fours amps.
Yet the crossover isn’t well suited for that?

 

[Jazzman53]

You can do an electronic Xover on just the woofers, there's a lot of information on the forum about doing this and the dramatic improvement it makes. It might seem counterintuitive at first, but the results speak for themselves.

Any newer Martin Logan speaker uses an active crossover on the bass to prevent the overlap between the panels and woofers. The stock passive Xover on the Aerius is pretty lame and really muddies up the whole sound.

To my ears, the most noticeable effect of active bi-amping (i.e. splitting out the bass and mid/treble frequencies from the line-level signal upstream of the power amps) is significantly tighter, more accurate bass, which I attribute to removing the passive inductor coil from between the amp and woofer. Thus directly coupled; the amp exerts tighter control over the woofer.

Without getting into an analog versus digital debate; I would just point out that upstream active bi-amping can be done using either an analog op-amp type crossover or a digital (DSP) crossover.

I've done it both ways and both sound great. I ultimately went with the DSP for its auto-EQ functionality and practically infinite tuning flexibility-- all in real-time from my listening position. I'm completely spoiled now

 

[Brandon Hartwick]

So the cool kids are basically saying to the designers that their putting two sets of speaker terminals in on the crossover they use is wrong?

I don’t get it. The user manual goes to great depths to show different ways to connect one or two or even fours amps.
Yet the crossover isn’t well suited for that?

This was the technology available at the time, high end active crossover networks weren't really a thing when this era of ML speakers were made. If you go look at any new ML speaker they're doing exactly what @Jazzman53 is talking about, because that's the technology we have today.

Nobody trying to say your doing anything wrong. Biamping is great, I do it, we're saying the woofer crossover is lacking in older ML speakers. If you're happy there's no need to mess with anything though.

 

[Brewnoser]

This was the technology available at the time, high end active crossover networks weren't really a thing when this era of ML speakers were made. If you go look at any new ML speaker they're doing exactly what @Jazzman53 is talking about, because that's the technology we have today.

Nobody trying to say your doing anything wrong. Biamping is great, I do it, we're saying the woofer crossover is lacking in older ML speakers. If you're happy there's no need to mess with anything though.

Oh I understand with the Aerius. But I have a new pair of ESL 9’s. Apparently the crossover on these is set quite differently from the older ones.

With the Aerius I did have the ability to tweak the sound by having one amp that was volume adjustable. So I could sit and have someone move it until things fell into place.

I still do. Though right now I’m not doing that as things sound pretty good with both running as power amps only. Tubes change will affect that though.

 

[Brandon Hartwick]

Oh I understand with the Aerius. But I have a new pair of ESL 9’s. Apparently the crossover on these is set quite differently from the older ones.

With the Aerius I did have the ability to tweak the sound by having one amp that was volume adjustable. So I could sit and have someone move it until things fell into place.

I still do. Though right now I’m not doing that as things sound pretty good with both running as power amps only. Tubes change will affect that though.

Yeah so I actually had to look this up on Martin Logan's website, but apparently they don't give you the fancy DSP enabled class D amps with electronic Xover on the woofers until you move up to the ESL 11 or larger. So the ESL 9 still uses a passive crossover network on the bass, what exactly is different about it I'm not sure.

 

[Brewnoser]

Yeah so I actually had to look this up on Martin Logan's website, but apparently they don't give you the fancy DSP enabled class D amps with electronic Xover on the woofers until you move up to the ESL 11 or larger. So the ESL 9 still uses a passive crossover network on the bass, what exactly is different about it I'm not sure.

Well for one thing you can’t bi amp the 11’s. So there’s that.

The crossover for the 9’a is much lower than for the Aerius-i And I’m sure it’s an updated circuitry.

 

[Jazzman53]

For the benefit of anyone unfamiliar with active bi-amping, and how crossovers work;

A passive crossover splits the high-level (already amplified) signal into separate bass and mid/treble bands, which then separately drive the woofer and ESL panel.

A low-pass filter, consisting of a series inductor (a coil of small diameter wire many feet in length) with a resistor in parallel, blocks high frequencies and passes only low frequencies to the woofer.

(as an aside; it kills me how audiophiles spend huge money on big fat speaker cables, only to connect them to a passive crossover where the signal has to pass through a 120' coil of small diameter wire-- it's like coupling a fire hose to a soda straw).

A high-pass filter, typically consisting of a series capacitor and a parallel resistor, blocks low frequencies and passes only mid/high frequencies to the ESL panel.

When passively splitting an already-amplified signal (downstream from the amp), significant signal power is lost to heat as the signal is pushed through the filters. Also, the amplifier's ability to control driver motion is somewhat impaired by the passive components between them.

Whereas; an active crossover splits the line-level music signal coming out the preamp (upstream of the amps)-- sending bass frequencies to a separate amp powering the woofer, and mid/treble frequencies to a separate amp powering the ESL panel.

In this case the amplifiers are directly coupled to the drivers, resulting in practically no power loss, and more control over driver motion. This is particularly noticeable in the bass band.

Additionally; active crossovers can use steeper slopes (up to 24db for op-amp analog types or 48db for digital) without introducing significant distortion. This allows greater flexibility in selecting crossover frequencies, and allows playing to higher volume levels before there is risk of driving the diaphragm into a stator.

Passive crossovers are typically limited to 12db/octave of slope, as steeper slopes done passively would incur excessive power loss and audible distortion. The upside is cost, as a single stereo amp can then drive a pair of multi-driver speakers.

It should be noted however, that passive crossovers often include shelving and/or notch filters to tamp down resonances and/or tune the speaker's frequency response, and if so, this tuning would be lost when bypassing the passive crossover. Accordingly; EQ'ing may be required when changing from a passive to an active crossover.

Most active analog crossovers lack EQ capability, in which case a separate graphic or parametric EQ may be needed for tuning.

A DSP crossover resolves all problems, and most have Auto-EQ capability, which plays test tones through the system that are picked up by a microphone, and the DSP then automatically overlays parametric EQ's to bring the frequency response to whatever pre-selected curve the user chooses.

Provided the speakers have the basic capabilities, a DSP can make them sound anyway one likes...it's bloody marvelous!

 

[Robert D]

For the benefit of anyone unfamiliar with active bi-amping, and how crossovers work;

A passive crossover splits the high-level (already amplified) signal into separate bass and mid/treble bands, which then separately drive the woofer and ESL panel.

A low-pass filter, consisting of a series inductor (a coil of small diameter wire many feet in length) with a resistor in parallel, blocks high frequencies and passes only low frequencies to the woofer.

(as an aside; it kills me how audiophiles spend huge money on big fat speaker cables, only to connect them to a passive crossover where the signal has to pass through a 120' coil of small diameter wire-- it's like coupling a fire hose to a soda straw).

A high-pass filter, typically consisting of a series capacitor and a parallel resistor, blocks low frequencies and passes only mid/high frequencies to the ESL panel.

When passively splitting an already-amplified signal (downstream from the amp), significant signal power is lost to heat as the signal is pushed through the filters. Also, the amplifier's ability to control driver motion is somewhat impaired by the passive components between them.

Whereas; an active crossover splits the line-level music signal coming out the preamp (upstream of the amps)-- sending bass frequencies to a separate amp powering the woofer, and mid/treble frequencies to a separate amp powering the ESL panel.

In this case the amplifiers are directly coupled to the drivers, resulting in practically no power loss, and more control over driver motion. This is particularly noticeable in the bass band.

Additionally; active crossovers can use steeper slopes (up to 24db for op-amp analog types or 48db for digital) without introducing significant distortion. This allows greater flexibility in selecting crossover frequencies, and allows playing to higher volume levels before there is risk of driving the diaphragm into a stator.

Passive crossovers are typically usable up to about 12db/octave of slope. Beyond that; there would be excessive power loss and audible distortion. The do however, allow driving a pair of hybrid speakers using a single stereo amp.

It must be noted however, that passive crossovers often include shelving and/or notch filters to tune the speaker's frequency response, and if so, this tuning would be lost when bypassing the passive crossover. Accordingly; EQ'ing may be required when changing from a passive to an active crossover.

Most active analog crossovers lack EQ capability, in which case a separate graphic or parametric EQ may be needed for tuning.

A DSP crossover resolves all problems, and most have Auto-EQ capability, which plays test tones through the system that are picked up by a microphone, and the DSP then automatically overlays parametric EQ's to bring the frequency response to whatever pre-selected curve the user chooses.

Provided the speakers have the basic capabilities, a DSP can make them sound anyway one likes...it's bloody marvelous!

Great explanation, thanks! Id like to do this, but havent made the leap yet. My setup as it is now really doesnt have the room for the extra equipment. Im thinking this is something I will do in the future.
It sounds like the new ML ESL 11 and up have an active crossover? So if I were to get one of those later on, id not need to mess with doing this external crossover or are those passive as well?

 

[Jazzman53]

Great explanation, thanks! Id like to do this, but havent made the leap yet. My setup as it is now really doesnt have the room for the extra equipment. Im thinking this is something I will do in the future.
It sounds like the new ML ESL 11 and up have an active crossover? So if I were to get one of those later on, id not need to mess with doing this external crossover or are those passive as well?

Yes; the published info indicates the ESL 11 has a built in class D bass amp, and a DSP with room correction, probably using parametric EQ's, and possibly with auto-EQ functionality.

What I can't determine from the published info is how the signal is split and fed to the amp(s).

A typical DSP crossover requires a line-level input but if the owner's amp is used to drive the panel, I don't see how it could be done using the high-level output from the owner's amp as an input to the DSP.

Unless ML has tech I don't know about, I can imagine only three scenarios for their ESL 11:

1) The high level output from the owner's amp goes through a passive crossover, and only the bass band gets split out and EQ'd by the DSP.

2) The DSP is a separate outboard unit that takes a line level input from the owner's receiver or preamp, then splits out the bass and mid/treble bands, and feeds the line-level signal back into the owner's preamp or receiver to power the panel, and sends a line level signal to the built in bass amp.

3) The DSP is built in, and receives a line level input from the owner's receiver or preamp, then splits out the bass and mid/treble bands, and feeds the line-level signal back into the owner's preamp or receiver to power the panel, and sends a line level signal to the built in bass amp.

Scenario #1 just makes no sense to me at all (why bother if only the bass is gets EQ'd), whereas #2 seems the smartest, and #3 would be functionally equivalent to #2, at a lower cost.

Perhaps someone on this forum has an ESL 11 and can clarify it's configuration.

 

[Brewnoser]

Yes; the published info indicates the ESL 11 has a built in class D bass amp, and a DSP with room correction, probably using parametric EQ's, and possibly with auto-EQ functionality.

What I can't determine from the published info is how the signal is split and fed to the amp(s).

A typical DSP crossover requires a line-level input but if the owner's amp is used to drive the panel, I don't see how it could be done using the high-level output from the owner's amp as an input to the DSP.

Unless ML has tech I don't know about, I can imagine only three scenarios for their ESL 11:

1) The high level output from the owner's amp goes through a passive crossover, and only the bass band gets split out and EQ'd by the DSP.

2) The DSP is a separate outboard unit that takes a line level input from the owner's receiver or preamp, then splits out the bass and mid/treble bands, and feeds the line-level signal back into the owner's preamp or receiver to power the panel, and sends a line level signal to the built in bass amp.

3) The DSP is built in, and receives a line level input from the owner's receiver or preamp, then splits out the bass and mid/treble bands, and feeds the line-level signal back into the owner's preamp or receiver to power the panel, and sends a line level signal to the built in bass amp.

Scenario #1 just makes no sense to me at all (why bother if only the bass is gets EQ'd), whereas #2 seems the smartest, and #3 would be functionally equivalent to #2, at a lower cost.

Perhaps someone on this forum has an ESL 11 and can clarify it's configuration.

All i can tell you is that when i checked last there was only one set of binding posts on the back of the ESL 11’s. My 9’s have two.

 

[Jazzman53]

All i can tell you is that when i checked last there was only one set of binding posts on the back of the ESL 11’s. My 9’s have two.

I've been racking my brain trying to figure out how ML could use the high-level output from the owner's amp as an input for a DSP, which seemed impossible to me.

I couldn't find any info on the ML 11 but I found a PDF of the ML ESL 11a Owner's Manual, wherein the following excerpt explains [almost] everything:

"PoweredForce™ bass technology results in immense bass dynamics
and precision beyond the reach of traditional passive box systems.
Additionally, room correction and low-frequency equalization capa-
bilities allow precision calibration for optimal room integration.
Featuring an advanced crossover topology, each crossover uses preci-
sion audiophile-grade polypropylene capacitors, toroidal transformers,
and high-purity air-core and iron-core coils."

So now we know that the crossover is indeed passive, and only the bass band receives line-level DSP room correction, which is applied to the low-level signal feeding the built in bass amps.

The mids/highs receive no DSP correction.

Toroidal transformers would not typically be used in a passive crossover, which leads me to believe they are there to provide a line level bass signal for the DSP engine (eliminating the need for a line level input from the owner's preamp).

I think it works something like this:
A passive crossover splits out the bass and mid/treble bands, and routes the mid/treble band power to the ESL panel.

The spit-out bass band then feeds into dual transformers which steps down the signal voltage (in two steps) to provide a line-level input for the DSP. The DSP then applies room correction and feeds the corrected singal to a pair of Class D bass amps powering the dual 8" woofers.

This setup likely improves any issues with bass/room interactions, and also provides plenty of power for bass output. This is a pretty goon compromise which allows using the owner's amp to power the panel.

However, this setup is less effective or desirable than a fully active setup, insofar as the already-amplified music signal is pushed through a power-robbing passive crossover, and there is no real-time tuning capability for the ESL panel (you have to live with what the passive crossover gives you).