Lose out on sound using amp without 2 ohm rating?

[elpablo]

I have a Hafler Pro 505 amp rated at 255 watts at 8 ohms and 400 watts at 4 ohms and plan on purchasing the ElectroMotion ESL speakers. Will I lose out on any sound because this amp doesn't provide any specs for 2 ohms? Any feedback is greatly appreciated, thanks!

 

[Hocky]

Not necessarily. As long as it has sufficient power supply to handle the low impedance swings, it will be OK. And the swing are very high frequency, too, where there isn't as much energy. I would try it out and see how it works.

 

[elpablo]

Good to know, thanks for your input Hocky!

 

[amey01]

I have a Hafler Pro 505 amp rated at 255 watts at 8 ohms and 400 watts at 4 ohms and plan on purchasing the ElectroMotion ESL speakers. Will I lose out on any sound because this amp doesn't provide any specs for 2 ohms? Any feedback is greatly appreciated, thanks!

No two ways about it - you need a good amp to drive MLs. For a balanced system, you need to spend more on your amp (proportional) than you may normally have to.

I'm not familiar with the Hafler, but those specs look reasonable - and if the overall tonal quality is to your liking, then you should find it okay. That's not to say it will be - any amp and any pair of speakers can make a good or bad synergistic match.

 

[elpablo]

Thanks for your input amey01!

I would hope this amp drives the ElectroMotion ESLs pretty well
overall considering it is higher end and a
a couple different ML sales reps told me that any amp/receiver rated at 100 watts at 8 ohms would drive them fine even without a 6 ohm rating. I understand that there is more to an amp than it's specs as far as sound quality is concerned however.

 

[amey01]

I understand that there is more to an amp than it's specs as far as sound quality is concerned however.

Absolutely!

Just remember though - many highly regarded amps don't work well with MLs due to the highly reactive load presented.

The fact that it is not rated at 2-ohm doesn't mean it performs badly at 2-ohm - there is not much energy present at 20,000Hz anyway.

Have a look through the system pages to see what sorts of amps we are using.

 

[elpablo]

Thanks again Amey01!

I will spend some time on forum checking out member configurations.

 

[Guitarist]

ML's site makes it plain that most modern AVRs can easily drive their speakers, so it makes me wonder about the wisdom of buying some expensive super-amp to drive them! (However, I wouldn't mind a reasonably priced one, such as a Parasound 5250 and use my AVR as a pre/pro.)

 

[Hocky]

ML's site makes it plain that most modern AVRs can easily drive their speakers, so it makes me wonder about the wisdom of buying some expensive super-amp to drive them! (However, I wouldn't mind a reasonably priced one, such as a Parasound 5250 and use my AVR as a pre/pro.)

You really don't need a super expensive amp, you just need something that puts out clean power and is able to handle the low impedance dips of MLs. There are some cheap amps that do it well and some expensive amps that do it poorly.

 

[Gordon Gray]

ML's site makes it plain that most modern AVRs can easily drive their speakers, so it makes me wonder about the wisdom of buying some expensive super-amp to drive them! (However, I wouldn't mind a reasonably priced one, such as a Parasound 5250 and use my AVR as a pre/pro.)

Hi Guitarist,

Not too sure about that general statement regarding user experience.

You may want to do some more research.

As always, YMMV.

GG

 

[Guitarist]

Hi Guitarist,

Not too sure about that general statement regarding user experience.

You may want to do some more research.

As always, YMMV.

GG

This is from their site:

Do MartinLogan speakers require big or expensive amplifiers?
Absolutely not. MartinLogan speakers are quite efficient and are capable of providing from 89-91 dB output from only 2.83 volts of input. This makes them suitable for use with a wide range of discrete and integrated amps, receivers, and A/V receivers. Our hybrid designs will perform well with either a tube or transistorized amplifier, and will reveal the sonic character of either type.

Will amplifiers rated at 6 or 8 ohms work with MartinLogan electrostatic speakers?
All MartinLogan speakers are compatible with receivers rated at 4, 6 or 8 ohms. We have tested several mainstream, high quality receivers and have found all are more than capable of driving 4 ohm speakers. The limitations of an amplifier rated at 6 or 8 ohms only becomes obvious at extremely high sound volumes over a very extended time period. For most every other application an amplifier rated at 6 or 8 ohms will perform perfectly with MartinLogan speakers.


I'd think they'd have a lot of p***ed off customers if those statements were untrue! Anyway, my 130 watt/channel Sony STR 6400ES works just fine with my Theos. As I said, I plan to upgrade to a more powerful/stable amp (one that doubles its 8 ohm rating when driving 4 ohms), but until then, I'm satisfied.

 

[Rich]

Guitarist, it all depends on what your expectations are. A lot of the folks using the modern MLs in a home theater environment aren't as picky about the sound as many experienced audiophiles. Do you seriously believe any speaker manufacturer would say that their speakers won't work as well with certain amps? Marketing hype is just that. I wouldn't take it too seriously.

Martin Logans are efficient speakers and can be driven by most amps and receivers. But they also have wildly varying impedance swings, dropping down to less than two ohms at the higher frequencies. With a lesser amp, this can result in rolling off of the high frequencies or sonic compression, or even tripping the amp's protective circuits. Lots of people won't notice these issues. But someone with a good ear and plenty of high end audio experience will notice it immediately. If you think you are satisfied with your current Sony, just wait until you upgrade to a decent amp. You will be surprised at the difference. A lot of people don't even realize how good Martin Logans can sound until they hear them with a quality front end, and then they are just floored.

As for the Hafler, I expect it is sufficient. The ideal is to have an amp that can double its output with every halving of impedance, and according to the specs elpablo published for the Hafler it is at least close to that.

 

[jmschnur]

My hafler that I built 30 years ago has done well with my Vantage speakers for the last 5 years (DH200).


J

 

[JayGee]

I have 2 McIntosh MC601's driving CLX's from the 8ohm tap and a 601 driving the Stage from the 4ohm tap. These were the suggested settings from M-L. No problems.

 

[Guitarist]

Rich, I used to be a professional classical recording engineer, so I think I have pretty good ears and high expectations! FWIW, I used to have a pair of ML ReQuests driven by a Mark Levinson No.334 and a 380S preamp! I had to sell all of that in order to consolidate my audio/video system and reduce the "visual blight" when I got married. Someday (in about 6 months, I hope!), I'll get a better amp. Regardless, the Theos sound so much better than the previous B&W 804s that I'm in comparative audio heaven!

 

[amey01]

I'd think they'd have a lot of p***ed off customers if those statements were untrue! Anyway, my 130 watt/channel Sony STR 6400ES works just fine with my Theos. As I said, I plan to upgrade to a more powerful/stable amp (one that doubles its 8 ohm rating when driving 4 ohms), but until then, I'm satisfied.

It'll "work" - yes. A lot of other electrostatics (eg Soundlab, Quads) would turn an amp like that to smoke and cinders. So in that respect, MLs are somewhat easier on an amplifier and the statement ML makes is correct.

Will it be optimal? No way. Is the Sony receiver be able to deliver its maximum capability?......my bet would be no as well.

There are posts on this forum where people trade good dynamic speakers for ML without a concurrent amplification upgrade, then post here saying how disappointed they are with the ML sound. I wonder why?

 

[elpablo]

It is my understanding the all electrostatic speakers aren't very efficient and that just has to do with the technology. While the ESL spec sheet does note the nominal speaker impedance is 6 Ohms it also notes it they go as low as 1.6 Ohms @ 20 kHz. The spec sheet also recommends up to 300 watts per channel.

Once I get my ESLs I look forward to comparing a Denon receiver rated up to 115 watts at 6 Ohms to the Hafler. I see that the Pro 505 I have is very similar to the DH-500 and you can purchase mod kits on line to upgrade the sound. I'm not sure I'll ever do this however.

Once again I understand that amp power alone doesn't provide quality sound and also know this amp is far from some of the real high end ones others own. There are also many other factors that play into sound quality such as a good DAC etc. Regardless I'm expecting this amp to give these speakers an extra punch that most receivers wouldn't be able to provide. Hopefully it will also be a good match for overall sound quality as I'm looking for an end result that is more that just volume!

 

[Rehan Azim Hashmi]

Subjectively speaking and with deep respect for every ones opinion on this thread i say an amplifier with 2 ohm rating may be an amplifier which has a high power rating. To get the best sound or unleash the full potential of Martin Logans a powerful amplifier is necessary. Especially for ML models which have estimated 1 ohm resistance at 20 khz frequency.

I have owned two integrated amplifiers both with maximum 4 ohm rating. The sound subjectively speaking from the MOSFET Sony was very good and for the UHCMOS Denon was between good and very good. A point to keep in mind is that i had the Sony when my CLS were recently acquired and the Denon after some time. One reason for the good sound with low power amplifiers is that the resistance of CLS is 1.6 ohm at 20 Khz. The CLX at high frequencies has a resistance of 0.6 ohms and needs very powerful amplifiers to sound its best.

To conclude, the lower the electrostatic panel resistance response at high frequencies the more powerful, more expensive and thus better sounding, higher quality with premium audiophile grade parts, amplifier required. Subjectively speaking and i may be mistaken that for top octave response from a low resistance electrostatic panel, that gives the aural impression of air, a 1 or 2 ohm rating amplifiier is required.

 

[gmartan]

Subjectively speaking and with deep respect for every ones opinion on this thread i say an amplifier with 2 ohm rating may be an amplifier which has a high power rating. To get the best sound or unleash the full potential of Martin Logans a powerful amplifier is necessary. Especially for ML models which have estimated 1 ohm resistance at 20 khz frequency.

I have owned two integrated amplifiers both with maximum 4 ohm rating. The sound subjectively speaking from the MOSFET Sony was very good and for the UHCMOS Denon was between good and very good. A point to keep in mind is that i had the Sony when my CLS were recently acquired and the Denon after some time. One reason for the good sound with low power amplifiers is that the resistance of CLS is 1.6 ohm at 20 Khz. The CLX at high frequencies has a resistance of 0.6 ohms and needs very powerful amplifiers to sound its best.

To conclude, the lower the electrostatic panel resistance response at high frequencies the more powerful, more expensive and thus better sounding, higher quality with premium audiophile grade parts, amplifier required. Subjectively speaking and i may be mistaken that for top octave response from a low resistance electrostatic panel, that gives the aural impression of air, a 1 or 2 ohm rating amplifiier is required.

Inaccurate. While a powerful amplifier certainly controls the bass better, even for those ML speakers with powered woofers, they won't make the high end sound much better. Any clean, modern amplifier that is direct coupled, in otherwords with no output transformers, will work just fine. It's not the power, it's the ability to match the impedence at all frequencies. Direct coupled amps can do that. Amps with output transformers can't. Lesser amps, including most A/V receivers, will sound grainy. Older amps often don't have the extended and airy top end that makes the panels so delicious to listen to. Lastly, even if you can't hear above 10K you will still get hooked when you hear the difference that using a capable amp provides.

 

[Rehan Azim Hashmi]

gmartan thanks for your response and accurate feedback.

I will make it a point to keep in mind the above information.

Once again, thanks for the amendment.