Martin Logan's can not be over-driven...

[Robin]

Did you know that ML speakers can not be over-driven by powerful amplification? It is true... ML's can not through mission of action, be over driven by amplifiers. In point of fact, if ML speakers / panels are ever, "verifiably" over-driven, ML wants to be informed, as this should never happen. Every ML speaker and panel is designed and built to only accept only the maximum rated watts / power for the individual ML speaker / panel.
It is very comforting to know our ML's are designed and built so well...

Comments anyone...

 

[jmschnur]

Is there a "fuse" or relay that protects both the bass section and panel from (for example) 1000 watts of low frequency or high frequency power? My 26 years old B&W's have a fuse for the woofer and a protective circuit for the mid ranger and tweeter.

For the B&W's the fuse would need to be replaced and the circuit would need to be reset ( a button is pushed).

In the case of ML's is there an automatic reset after the out of ilmits power goes away?

Joel

 

[kal_s]

Wondering about the same thing...

Hi Robin
Curiously, I was wondering about the same exact thing just today I am considering a Mark Levinson No.23, which is rated to output a MINIMUM of 400W into 4 ohms. My Aerius is rated at 4 ohms input impedance, with a max. input powe handling capacity of 200W per channel, and I sure don't want to blow it : so I am curious to figure out how this would work in case I hooked them up to a No.23. Anyone here tried this combination?
Thanks in advance,
---Kal

 

[twich54]

Hi Robin
Curiously, I was wondering about the same exact thing just today I am considering a Mark Levinson No.23, which is rated to output a MINIMUM of 400W into 4 ohms. My Aerius is rated at 4 ohms input impedance, with a max. input powe handling capacity of 200W per channel, and I sure don't want to blow it : so I am curious to figure out how this would work in case I hooked them up to a No.23. Anyone here tried this combination?
Thanks in advance,
---Kal

Check those specs again, I doubt very much it says 400 watts MIN, or if it does it's probably stated as it's Min. "capability". Besides there is no 4 ohm(nominal)speaker known to man that would require that much power as a min. !!!!
I'm curious, at normal listening levels do you know how much power is being feed to your speakers, outside of transient levels of course ?? Normal listening would fall well below 100 watts.

 

[DTB300]

I'm curious, at normal listening levels do you know how much power is being feed to your speakers, outside of transient levels of course ?? Normal listening would fall well below 100 watts.

Unless someone is a volume freek, most listening levels will run around 10 watts - again not including transient peaks. For Dave and Joey and their Vantage, 1 watt will produce 90+ dB's at 1 Meter - 90+ dB's is pretty loud. And to gain 3dB's you need to double your power...just do the math and you will see that unless we are significant volume freeks (100 dB+), we do not use too much continuous power. Most of it is transient peaks that the reserve power we have in our amps easily will handle - commonly refered to as Headroom.

Dan

 

[kal_s]

Re-checked User Manual Specs for Mark Levinson No.23...

Check those specs again, I doubt very much it says 400 watts MIN, or if it does it's probably stated as it's Min. "capability". Besides there is no 4 ohm(nominal)speaker known to man that would require that much power as a min. !!!!
I'm curious, at normal listening levels do you know how much power is being feed to your speakers, outside of transient levels of course ?? Normal listening would fall well below 100 watts.

Here is a quote, verbatim, from the ML No.23 manual, under "SPECIFICATIONS, RATED POWER":

"400 W minimum continuous sine wave power into 4 ohms with both channels driven from 20Hz to 20kHz with no more than .2% THD (FTC)".

 

[twich54]

Here is a quote, verbatim, from the ML No.23 manual, under "SPECIFICATIONS, RATED POWER":

"400 W minimum continuous sine wave power into 4 ohms with both channels driven from 20Hz to 20kHz with no more than .2% THD (FTC)".

EXACTLY........ as I said it relates to its MIN. CAPABILITY !!!! Does NOT mean that it STARTS there. Did you read Dan's post above ? Can you imagine how long a voice coil in one of your M/L speakers would last if it were feed continually a MIN OF 200 watts aand associated current...... not long !!

 

[DTB300]

Here is a quote, verbatim, from the ML No.23 manual, under "SPECIFICATIONS, RATED POWER":

"400 W minimum continuous sine wave power into 4 ohms with both channels driven from 20Hz to 20kHz with no more than .2% THD (FTC)".

This is just a specification for THD in a certain load at a certain output..

Your amp does not START at 400 Watts - as the "Minimum" may imply. This is why we have volume controls

Dan

 

[amey01]

Here is a quote, verbatim, from the ML No.23 manual, under "SPECIFICATIONS, RATED POWER":

"400 W minimum continuous sine wave power into 4 ohms with both channels driven from 20Hz to 20kHz with no more than .2% THD (FTC)".

This means its MAXIMUM capability is AT LEAST 400w.

Common sense will avoid blowing your speakers, not amplifier power. It is actually easier to blow a pair of cone speakers with too little power rather than too much power. Not sure about ML.

 

[roberto]

One thing is power output and other thing is power heat dissipation

Hola guys...you are mixing two different values...one thing is the power output of an amplifier without distortion, and another is the heat dissipation of the speaker... to dissipate the heat, it is in watts like a resistor or an iron...two differnt things. The amplifier is to have that power output in watts with the less distortion, the signal applied remains the less touched the better specification. On the other hand, it`s the capability of the speaker to disipate the heat when the power is applied...both in watts, but different in measurement. It is saying that both should be in or around the same in value, but it is easier to burn a speaker with a small amplifier than a bigger one. why? Because as an example, the specs of the amp is up to, lets say 50 Watts continuous with a distortion of not less than 0.5 THD (total harmonic distortion) at 8 ohms load, and after those 50 watts the amplifier starts to clipping (DC pulse in the upper and lower part of a sinusoidal wave) and this is a lot of distortion, capable to distroy any 200 Watts pure sinosoidal wave applied to the speaker. If you apply a pure wave of 200 watts to the spakers that it is capable to dissipate, then no problem...it is a little more complex than what I´m trying to explain...but you might get the idea...happy listening,
Pura vida,
Roberto.

 

[miljac]

Clipping and power handling

AFAIK, when the amp clips then the speakers see a huge amount of higher frequency energy. This HF energy is routed to the tweeters by the crossover. For classical speakers this means that the tweeters melt after some (not so long) time. This also means that if the design is proper, it is way much easier to destroy the loudspeakers by an amp that is too weak then with a too strong one. As for electrostatics, it all depends from the voltage applied - the foil too close to stators, arc and probably silence. However, I think that the MLs have quite a good headroom built in, e.g. Ascent - 90 dB/2.83V = 2W @ 4 ohm, power rating 200 W -> some 111/112 dB of sound pressure. So it is likely that anyone but a loudness freak would not reach the max power rating - and there is still a family/neigborhood corrective factor for most of us .
I have driven my 2 x 200W McIntosh into soft clipping only once playing loud some Wagner's orchestral piece, in the beginning when I wanted to know how loud the system can play without distortion and boy was it loud. Nowadays I listen to them seldom very loud, usually coming to 100 dB or little over on symphonic orchestra's forte fortissimo, this going to max 20W or so, hardly a challenge both for the amp and speakers.

Much depends on the clipping characteristics of the amp too. Again, "hard" clipping means a *lot* of HF energy that is not even shown on the spl meter. May be even well below the max power rating and still ruin the tweeters. Probably not a problem with the electrostatic panels though, these have no coils that melt.

 

[Robin]

ML will repair or replace, no questions asked...

Is there a "fuse" or relay that protects both the bass section and panel from (for example) 1000 watts of low frequency or high frequency power? My 26 years old B&W's have a fuse for the woofer and a protective circuit for the mid ranger and tweeter.

For the B&W's the fuse would need to be replaced and the circuit would need to be reset ( a button is pushed).

In the case of ML's is there an automatic reset after the out of ilmits power goes away?

Joel

Joel,

I have been assured, ML will repair or replace any of it's speakers, which fails due to being over-driven. IMHO, now that is a company ready to stand behind it's products... Of course ML would want it returned to understand why it happened, what failed etc., because the fact remains ML's are made so this doesn't happen.

It was explained to me using a water flow analogy, even if you have a fire hydrant of water (watts from your amp.) going to your ML speakers, only so much water (watts) will be accepted by ML speakers (maximum rated / channel watts), only so much water can fit through your garden hose connection (ML speakers) and no more.

Regarding fuses, ML's electrostatics's do not have fuses as far as I know, but my ML Descent subwoofer does. Because the Descent has it's own built-in amplifier, so I would assume that the Vantages and the Summits could have fuses for their built-in subwoofer amplifiers too.
ML uses other watt regulation electronics in their electrostatic speakers, though I do not know, what specifically those electronics would be.

Again, if it were possible to ever manage to blow a ML speaker, ML would want it back to see why it blew, no questions asked...
HTH

 

[jmschnur]

Thanks!

I would assume that the cones for the hybrid (woofer and/or tweeter) (NAC-Cinema i etc )would need something that would disengage. There are many times when a spike could ruin alot if that were not the case.

Perhaps I wil call ML and ask.

Joel

 

[stesom]

Its interesting this thread comes up today since I though I had blown one of my new Summits. I was playing the Sheffield Drum Record at what I consider realistic volume. Imagine sitting 6 feet from a full drum kit being played with gusto. I have done this many times with no problem and all of a sudden my amp goes into protection mode. After letting it sit for a little bit, I powered it back up but the right channel was gone. The speakers never came close to showing distress or compression nor did the amp until thwack it went down.

Anyway these speakers can take a lot of power. Good thing I have a couple of backup amps or my life would be so sad without music. Now the problem is getting 130LBs of dead weight back to Classe for repair. Anyway as this thread states, I have no doubt these speakers can sink a lot of power. I love em and am grateful to have em.......Steve

P.S. I have melted the glue off the voice coils and their formers in the past on both a set of Thiels (midrange) and Audio Physics (woofer) .

 

[amey01]

Its interesting this thread comes up today since I though I had blown one of my new Summits. I was playing the Sheffield Drum Record at what I consider realistic volume. Imagine sitting 6 feet from a full drum kit being played with gusto. I have done this many times with no problem and all of a sudden my amp goes into protection mode. After letting it sit for a little bit, I powered it back up but the right channel was gone. The speakers never came close to showing distress or compression nor did the amp until thwack it went down.

Anyway these speakers can take a lot of power. Good thing I have a couple of backup amps or my life would be so sad without music. Now the problem is getting 130LBs of dead weight back to Classe for repair. Anyway as this thread states, I have no doubt these speakers can sink a lot of power. I love em and am grateful to have em.......Steve

P.S. I have melted the glue off the voice coils and their formers in the past on both a set of Thiels (midrange) and Audio Physics (woofer) .

You must listen at some mighty levels to melt drivers in your Audio Physics and Thiels! Then to blow your Classe amp as well.

I've never had this probelm, but let me know what happens with your amp repair. I also have a Classe amplifier (CA-101) and have noticed it goes into Protection fairly easily - much easier in fact than any other amp I have owned. Occasionally I have had a lapse in concentration and turned the amp on first - then simply when the preamp comes out of protection it is enough to put the Classe into Protection. Never had a probelm with it not firing backup again though! Good luck!

 

[stesom]

You must listen at some mighty levels to melt drivers in your Audio Physics and Thiels! Then to blow your Classe amp as well.

I've never had this probelm, but let me know what happens with your amp repair. I also have a Classe amplifier (CA-101) and have noticed it goes into Protection fairly easily - much easier in fact than any other amp I have owned. Occasionally I have had a lapse in concentration and turned the amp on first - then simply when the preamp comes out of protection it is enough to put the Classe into Protection. Never had a probelm with it not firing backup again though! Good luck!

I must admit that when listening to rock I do tend to get carried away. The one thing I can say is Classe has always provided excellent customer service and has made any repair I have needed for free. So no complaints just really hate to have to lug 130LBs of dead weight around.

I have found that the input board is sensitive to DC as I am sure most amps would be. Maybe even overly sensitive since you say yours will go into protection mode when you switch on your pre after the amp. That can signal that your pre is putting out a little DC on startup.

I was playing an LP at the time with the pre-amp almost maxed out. I expect that there was some persistent subsonic content that finally overwhelmed the input side of the amp since this is where the fuses blew.

Anyway I do know you can overheat/melt a cone drivers voice coil, but in both cases the manufacturer did not blame me, they blamed the glue that was used to secure the coil to the former. I did not fry the coil itself just detached it from the former.

In the end, I have hooked up a Rotel RB1090 to the Summits and it is doing a very good job. Going to also try the Classe CA100 and have some fun listening to the differences while waiting for may amp to go to Canada and back.......Steve

 

[twich54]

Steve, did the lights dim ??

 

[risabet]

I have found that the input board is sensitive to DC as I am sure most amps would be. Maybe even overly sensitive since you say yours will go into protection mode when you switch on your pre after the amp. That can signal that your pre is putting out a little DC on startup.

I can't quite understand how/why amplifier manufacturers still make amps with
DC coupled inputs, there is no reason I can fathom except specsmanship, DC to light response is unncessary and lowers reliability. A judiciously selected input cap solves the problem with little if any detriment to the sound.

 

[JonFo]

I'd have to agree that it's hard to overdrive the panel section.
I solve the amp load question by having 15 channels of amplification in the rig, 12 of which are for the ML's

Each Monolith Panel has over 800 w going into it with no distress ever.

Never had a volume problem (can hit 115db clean & easy) or any discernable distortion. The infinite baffle sub can noticeably change the air pressure levels in the room.

Of course, my normal listening levels are moderated for long-term hearing survival

 

[Robin]

ML's are tough, well make speakers...

I'd have to agree that it's hard to overdrive the panel section.
I solve the amp load question by having 15 channels of amplification in the rig, 12 of which are for the ML's

Each Monolith Panel has over 800 w going into it with no distress ever.

Never had a volume problem (can hit 115db clean & easy) or any discernable distortion. The infinite baffle sub can noticeably change the air pressure levels in the room.

Of course, my normal listening levels are moderated for long-term hearing survival

Jonathan,

It is amazing about your Monolith panels having over 800 watts available to them and no problems ever. I think that is the general experiance with ML speakers they are just built so well, while sounding so great at the same time...

So far on this thread no one has replied, stating they ever had a ML speaker fail by being over-driven / over-powered. I think that speaks volumes as to the quality of ML's product through out the market... Our ML Club has a good size member ship and an excellent cross section of divercified users, all over the world (just see Flapper map) and so far no reported problems being over-driven... A testiment to the wonderful ML speakers we own, wouldn't you agree...