New Member - long time ML owner

[Robert D]

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 the setup works like this (no line level input from the owner's preamp required):

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 capablity (you have to live with what the passive crossover gives you).

Yeah, that's what my guess was. That's too bad. The Sanders speakers sold have active crossovers. He knows it's superior. Right now my Prodigies sound great, but I feel confident using active crossovers will improve the sound.
How pronounced is the change when you switch over? The speakers end up getting a stronger signal also, so more volume?
Would running active crossover on the 11s or higher end up causing problems, since the woofer is already going through an active crossover? I guess you'd need to bypass it too?

 

[Jazzman53]

Yeah, that's what my guess was. That's too bad. The Sanders speakers sold have active crossovers. He knows it's superior. Right now my Prodigies sound great, but I feel confident using active crossovers will improve the sound.
How pronounced is the change when you switch over? The speakers end up getting a stronger signal also, so more volume?
Would running active crossover on the 11s or higher end up causing problems, since the woofer is already going through an active crossover? I guess you'd need to bypass it too?

Actually, I am only comparing the sound of my fully active speakers to other hybrid ESLs which use passive crossovers.

My speakers were not changed from passive to active, as they never had a passive crossover. For a DIY speaker, it's way easier to use an active crossover than spend months trying to dial in a passive crossover, and it sounds much better anyway.

I initially bi'amp'd them-- feeding the analog out from a Carver C1 preamp into an op-amp driven DBX 223 analog crossover, upstream of a pair of Carver TFM-25 power amps.

Later I changed my setup to 6-channel stereo, by adding a pair of RiPol subs and a third amp. I also replaced the analog crossover with a Behringer DCX 2496 and added a Behringer DEQ2496 digital EQ. It sounded really good but the Behringers' user interfaces were seriously outdated. I couldn't use their computer interfaces becuse they used a serial ports, which newer laptops don't have, so I had to use the clunky front panel interface. Additionally, the DEQ's auto-EQ used obnoxious pink noise, and it wasn't at all user friendly.

Finally; I replaced the Behringer's with a DBX Driverack Venu 360, which sounds fabulous and uses a very sexy Ipad control interface.

Several of my friends who I built speakers for use a DBX Driverack PA2, which has basically the same features as Venu 360 except for digital ins (balanced analog XLR inputs only), and the PA2 is half the price. They all love the PA2.

I opted for the Venu 360 because it's digital inputs allowed me omit the analog preamp and use my Logitech Transporter's digital preamp instead. I'm feeding the Transporter's digital out to the digital in on the Venu 360. In this way, multiple D/A & A/D conversions are elminated and I have only a single D/A conversion, at the output of the Venu 360, to the amps.

LOVE IT!

 

[Robert D]

Actually, I am only comparing the sound of my fully active speakers to other hybrid ESLs which use passive crossovers.

My speakers were not changed from passive to active, as they have always used an active crossover.

I initially bi'amp'd them-- feeding the analog out from a Carver C1 preamp into an op-amp driven DBX 223 analog crossover, upstream of a pair of Carver TFM-25 power amps.

Later I changed my setup to 6-channel stereo, by adding a pair of RiPol subs and a third amp. I also replaced the analog crossover with a Behringer DCX 2496 and added a Behringer DEQ2496 digital EQ. It sounded really good but the Behringers' user interfaces were seriously outdated. I couldn't use their computer interfaces becuse they used a serial ports, which newer laptops don't have, so I had to use the clunky front panel interface. Additionally, the DEQ's auto-EQ used obnoxious pink noise, and it wasn't at all user friendly.

Finally; I replaced the Behringer's with a DBX Driverack Venu 360, which sounds fabulous and uses a very sexy Ipad control interface.

Several of my friends who I built speakers for use a DBX Driverack PA2, which has basically the same features as Venu 360 except for digital ins (balanced analog XLR inputs only), and the PA2 is half the price. They all love the PA2.

I opted for the Venu 360 because it allowed me omit an analog preamp and use my Logitech Transporter's digital preamp instead. I'm feeding the Transporter's digital out to the digital in on the Venu 360. In this way, multiple D/A & A/D conversions are elminated and I have only a single D/A conversion, at the output of the Venu 360, to the amps.

LOVE IT!

I'd like to hear it!