And George, we can go through reams of posts where some one says :
"I heard a Class D amp and I liked Y about it"
well, moments later there you are trying to explain that they can’t like Y because 20 years ago some one measured something, so the poster’s experience must be wrong.
My original point George was that you never accept anyone's experience with Class D as valid, or just as important as yours, and that is a type of disrespect I really really wish you would stop demonstrating.
My original point George was that you never accept anyone's experience with Class D as valid
And why should I, if you search I've listened to plenty, I will go with what I hear and what independent measured results show about their ability into these sorts of loads, before I ever believe your subjective opinion on them, you've probably never used on on this sort of "evil load" speaker.
As history shows you keep starting Class-D threads to get some conformation or reco on what you hear yourself, because "maybe" your not too sure about Class-D
I've never seen you pass an opportunity to tell some one who says they like class D why they should not. If there is anything you are passionate about here it seems to be correcting people who like Class D.
And you never 'pass an opportunity' to dump on Pass Labs (or Spectral), so that makes you a hypocrite. Eric, people who live in glass houses shouldn't throw stones. If you can dump on Pass Labs or Spectral, than certainly George has every right to dump on Class-D. You cannot have it both ways...
Wow, huge difference in my dislike for particular brands, and being on a crusade.
I’ve never disrespected anyone for liking Pass. I’ve never told them they were wrong.
I have however said that Pass was not to my taste, for reasons I don’t fully understand, and honestly I write so little about Spectral I’m not sure what I said. It was probably something like I just didn’t do that much for me, but very glad there are readers like you here who track my writing so much. Kind of makes me blush.
Usually my comments about Pass are related to people asking for alternatives. In fact I have at times recommended people listen to Pass and Ayre as counterpoints and buy what they like.
Please point to where some one has asked for the best Pass amp, and I’ve been there telling them they were wrong.
Also, please point to a single post about anything where I tell some one their tastes were wrong. I may not agree with what you like, but I am nothing if not supportive of individuals buying what they like.
And that is a major place George and I are different. I think you should buy what sounds good. George on the other hand wants to pull out review after review proving to people what they like is wrong.
There’s nothing hypocritical there golf.
Further, I don’t attempt to bring out technical data (say distortion) and make a claim that the measurement automatically proves my like/dislike for a brand / model is because of it. In fact, that is kind of key. Sometimes Class D measures differently than a linear amp. That’s very different than saying it sounds better or worse, and that’s where George refuses to accept any of the countless suggestions from a’goners to show how one connects to the other.
Sometimes I know a measurement that is related to my tastes, or a listener’s experience, often I do not, or after listening find there is no correlation.
After multiple polite suggestions from many a’goners for George to stick to specifics. Specific models, specific experience, he has a real time doing that, and instead relies on tropes. Nothing wrong with George saying "I heard brand x model Y and I did not like it for these reasons." Would love to read that, because those Class D fans are making their cases with specific models, features and sound qualities, something George has pretty much ignored.
Another pattern I find useful is "Hey, for x amount of dollars, have you listened to Y brand? I really like them more." and if I am guilty of this, fine.
Here is an example of me being not George, after an A'goner asked for help with integrateds :
Luxman, Ayre and for budget comparison Arcam.
Pass, Luxman and Ayre
will give you distinctly different results, so I think they are worth
listening to. If you like tubes, I really like the latest gen ARC
integrateds.
Of course, I bought a Luxman and I stand by my decision. :)
If you think that sounds like me bashing Pass, I don't know what to tell you.
George, You said "This Stereophile’s JA’s statement, is the typical case where a 25w amp like the ML2’s with doubling capable wattage current will drive a pig of a load like these Alexia’s and the OP’s speaker "to a given level" with perfection better than any 3000w class-d can." OK, "drive" is the issue you are concerned with, to the exclusion of the much more important question of what an amp SOUNDS like. A more powerful engine will DRIVE a truck better than a smaller engine, but this is irrelevant to what people here care about. My Mytek Brooklyn will have problems DRIVING a very low impedance inefficient speaker to very loud levels. SO WHAT? At 1 to 100 watts, it kills the ML2 for resolution.
Your Mytec below measured by Stereophile, could even get it up into 2ohms at all.
Stereophiles JA’s summation, "practical use with speakers whose impedance doesn’t drop below 3 ohms." No good at all with the OP’s speakers we are talking about here.
245W into 8 ohms 315Wpc into 4 ohms when I tried to measure the clipping power into 2 ohms, the Mytek went into protection mode at 310W (18.9dBW),
Stereophiles JA’s summation, "practical use with speakers whose impedance doesn’t drop below 3 ohms." No good at all with the OP’s speakers we are talking about here.
245W into 8 ohms 315Wpc into 4 ohms when I tried to measure the clipping power into 2 ohms, the Mytek went into protection mode at 310W (18.9dBW),
@georgehifi You like to put up specs; now you have to also live with what they say. And what they are saying is: The Mytek can make about 300 watts into 2 ohms and therefore is able to double power from 75 watts into 8 ohms to 150 watts into 4 and finally 300 watts into 2 ohms. If we take @viber6 at his word, his amp plays nearly 5dB louder than yours into any load your amp can drive and sounds better at the same time. This assumes that the bass region is where the 2 ohm load occurs- where most of the musical energy lies.
But if the 2 ohm load occurs at 8 or 10KHz the story is quite different since so little power is used at that frequency. Then the Mytek would be able to play nearly **10dB louder** than your amp and sound better all the while if we take @viber6 at his word.
Quite simply an amplifier does not have to double power into 2 ohms from 4 ohms in order to behave as a voltage source. The only time this might be an issue depends on the impedance curve of the speaker and at the full power of the amp. If less than full power things are very different!
I have CS5i's and recapped the crossovers last year and made a MAJOR improvement to the driveability by going active on the subs. As part of the recap I drew out the huge crossovers and found that the 2 subs are done as augmentation woofers to 60hz where the 8" center woofer covers sub to 400. Basically all 3 are run in parallel at sub frequencies. There was only a single coil on the subs and it was super easy to wire them to a new binding post. I was able to single amp or biamp and the improvement is stunning. It also opened up them to using many other amps that did not need to cope with the 2 ohm bass load. I used an ICE amp on the subs and my ML 333 on the rest. SUPER dynamic now.
Great amp for these types of very hard loads, even if those figures below are a bit wishful, there are always losses. So exact doubling is impossible unless the 8ohm and 4ohm are understated to make the 2ohm look like it's doubling.
My vote goes to D-Sonic, I’ve had the opportunity to listen to them and they deliver. Built options available and Dennis stands behind his products. Give him a call... No affiliation here just had the privilege to attend a demo a i was positively impressed.
Admittedly those Chinese modules above, have been "tickled" a little by Pascal, http://www.pascal-audio.com/products/ like EVS "tickles" the IcePower 1200as modules, just so it takes away from being stock off the shelf.
From 6 Moons Jeff Rowland have been one of Pascal’s earliest customers among high-end manufacturers to release a few ‘entry-level’ products based on that module like the bridgeable 525 stereo power amp and the integrated Continuum S2. Red Dragon’s S500 beats with the same heart in a less high-end chassis for roughly half the price.
atmasphere, Of course you can take my word for anything I say I hear. Also, because I am not in the business I tell things like it is without concern for politics. Actually, I use an EQ to drastically boost HF because as a violinist hearing things under my ear, I tell you that all speakers are hopelessly veiled and muddy compared to that. I cannot make any system sound as natural and truthful as the real thing, but my EQ helps a lot. My speakers are aging Audiostatic 240, and I add the Enigmacoustics Sopranino super tweeters in parallel at the 8 kHz crossover setting. The net impedance of this combination is a little below 2 ohms in HF. In combination with my EQ I need lots of power into HF with the inefficient parallel stat speakers. The Mytek will rarely shut down for only unusual passages in classical music, even with my crazy (to most people) requirements. Even my little Bryston 2.5B SST2 which clips on probably merely 50 watts at 2 ohms since the power supply is skimpy, produces highly detailed, fast, clear sound within its limits. For classical music before Brahms, it is totally powerful enough and enjoyable. Even for Brahms which doesn't have any percussion, it is powerful enough, used at sensible volumes. The little Bryston is not powerful enough for Mahler and cymbal crashes, but the Mytek handles all classical music well.
erik_squires:"My original point George was that you never accept anyone's experience with Class D as valid, or just as important as yours, and that is a type of disrespect I really really wish you would stop demonstrating."
I just wanted to weigh in and state, based on my personal experience reading and participating on threads concerning class D amplification on numerous threads here on Audiogon over the past several years, that Erik's quoted statement concerning georgehifi/George above is completely accurate. On almost any thread concerning class D, George can be relied upon to post and express his unreasonable disdain for class D due to some sort of shortcoming, typically a shortcoming he has theorized but lacks empirical or convincing evidence for. I can't yet explain why George is so obviously and consistently anti-class D, but the real issue is that apparently, neither can he. At least, not convincingly. I also don't believe there's any validity to golfnutz claim that Erik has criticized Pass Labs or Spectral amps. In my opinion, Erik has been very respectful in all of the many posts of his that I've read. I think we should all refrain from making general critical claims about other members, especially without citing specific support for the claim.
I actually do have amps I like and amps I do not like, and if some one asks about them I'm happy to share my honest opinion about them and why I picked something else.
I hope I continue to do so in a way that is respectful of the preferences and experiences of others. Best,
I went looking, while there was 1 thread that was deleted, but still searchable, this is the harshest thing I could say about Spectral, and it was in 2016:
I've heard Spectral at Goodwyn's High End
in Waltham, MA ages ago. I missed the magic, but it has a very strong
following, what did I miss that others like about it?
I find it hard to believe that this is offensive, even less so that anyone remembers it. :D :D :D
@golfnutz, Give it up. Eric gave his opinion-Which is just as good as anyone's, even georgehifi. As to who I give higher credence, it would be Eric. Bob
@gdnrbob - I was commenting on a question made by noble100
I also don't believe there's any validity to golfnutz claim that Erik has criticized Pass Labs or Spectral amps.
Anyway, I didn't answer Erik previously about this because sure enough it would turn into a pissing match, and you didn't wait too long to make that happen. I've made my point, so yes, I'll give it up as you wish.
TBC: I’ve never claimed I have not said I prefer one amp /speaker/whatever over another.
Nothing wrong with having a personal preference, and expressing it when asked and appropriate. I mean, my god, if we didn’t have preferences, this entire web site would be 1 message long!!
My quote, above:
Wow, huge difference in my dislike for particular brands, and being on a crusade.
I’ve never disrespected anyone for liking Pass. I’ve never told them they were wrong.
And that is why I don’t see @golfnutz claims of my alleged hypocrisy valid.
The issue is not whether or not an A’goner likes a particular technology, it’s whether they respect the wishes of the OP or those who disagree with them.
So you seem to have quoted me, though I have not checked to be sure, lets go over the last two:
Spectral is a line I wanted to be impressed with, like Pass, and I just haven’t. They do not bring me joy.
On the opposite end of the spectrum is Pass. A sound I really don’t like.
First, @Golfnutz, I have to thank you. I’m pretty sure no one on earth has been paying attention to anything I write more than you, so as my biggest fan, I’m flattered.
Those comments and comments like them are fine.
Please point to a place where some one says "I love x" and I say they are wrong.
In fact, I make it clear, often but not perfectly, that I’m expressing my personal tastes, while not demeaning others for having different tastes. When George turns around and starts talking specific modern models, and characteristics he’s herard, instead of random statistics which may or may not have any correlation to a listening experience we’ll all be happy.
Also, while we are at it, can you please point us to the original threads? I'd love to show that my statements were in context, and contributing to a discussion.
Sorry Erik, I won’t be engaging in any more of this discussion.
Whew, there’s a load off! But it is a real shame because I can't imagine anyone on earth as interested in digging through my old posts like you have. I'll miss the closeness.
I guess you’re the only person that’s allowed to look at other members threads/posts.
Something I’ve never ever intimated. Hahahahha.
And for the record, Golf’s last quote was from a thread about DSP crossovers where I strongly suggested the OP stop reading and start doing to build a level of personal experience he won’t get from mere reading, but as predicted, the OP just started 3 more threads about DSP crossovers.
And the self appointed forum cop has spoken. golfnutz from his very few posts (25) had more knowledge than either of you. Audiogon's loss if he leaves.
This thread should have been finished after the 5th
post. I think your response nailed it perfectly. Class-D and speakers < 2ohms just don't work, with maybe the exception of some of the latest offerings that cost just as much as a good quality Class A amp.
Of course you can take my word for anything I say I hear. Also, because
I am not in the business I tell things like it is without concern for
politics.
I didn't doubt you :)
This thread should have been finished after the 5th
post. I think your response nailed it perfectly. Class-D and speakers
< 2ohms just don't work, with maybe the exception of some of the
latest offerings
With class D amps the older amps were limited by their output filters- not their current. With newer amps that can switch faster, the output filter can be set to a higher frequency and so 2 ohms isn't the concern it used to be. 2 ohms requires more current of course. Most output sections can handle the current; we're using devices rated at 30 amps each which is double the current capacity required for our prototype to make full power into 2 ohms. The problem isn't the class D so much as it is whether the heatsinks provide adequate cooling (important even for GaNFET-based output sections into that sort of impedance) and whether the power supplies have adequate current to support the power. So like any other amp: some do some don't. Simply inquire with the manufacturer. Yes- just that simple... 5 pages later.
By all means please show the do’s in Class-D, hopefully independently tested, impedance v rms wattage all at just before clipping into 8, 4 and 2ohms, the same distortion figures.
By all means please show the do’s in Class-D, hopefully independently
tested, impedance v rms wattage all at just before clipping into 8, 4
and 2ohms, the same distortion figures.
Ha! That's pretty funny!
**No** amplifier will have the same distortion figures. All amps regardless of technology used have higher distortion into lower impedances. This has been seen over and over again in tests by JA at Stereophile, Bascomb King and others all over the world.
And right here might be the simple salient fact to the pointlessness of the inquiry: If you want the best results from your amplifier investment dollar, that dollar will be best served by a speaker load of higher impedance ***IF HIGH QUALITY SOUND IS YOUR GOAL***. (Sorry about the caps- I was looking for emphasis, not shouting). This is where that magical line in the sand occurs- the difference between the results sounding like real music or just a really good hifi.
Plain and simple low impedance speaker loads are a Bad Idea and it doesn't matter if you can weld with your amplifier- it simply will make more distortion into that lower impedance, and that distortion will be audible as less detail and harsher. Doesn't matter if the amp can double power or not- the higher distortion will be there nonetheless. Again- its easy to see in the specs and independent measurement. The story of Sisyphus is there as a teaching moment and applies directly to the the task of driving lower impedances.
Atmasphere, While you and Ric Schultz are technically correct that higher impedance speakers get better performance from amps than low impedance speakers, this ignores the overwhelming superiority of low impedance electrostatics for most musical criteria, except in large SPL dynamics where the conventional dynamic speaker excels. If someone designed a higher impedance stat, that would be great, but the disadvantage of somewhat higher distortion (and it is still fairly low) into their very low impedance is vastly outweighed by their superior transient response, clarity, coherence, less coloration, etc. The old dictum is still true--the speaker is the most important element in the chain, with the possible exception of source quality. Get the best speaker you can afford, then get the best amp that will drive that speaker.
Sez you, some of the very best are insanely hard to drive, and why class-d, OTL and you have a problem with that.
Sez the specs of all amps. Obviously this statement is misleading; George is cherry picking. On the one hand he likes to trot out Stereophile ratings to support his claims but when that same source doesn't support his claims then its ignored.
Some of the very best speakers are also very **easy** to drive. The issue is simple: Do you want the sound of a good hifi or the sound of real music?? If the latter, then you will want a speaker that is both state of the art and easy to drive since distortion is what separates the men from the boys.
While you and Ric Schultz are technically correct that higher impedance
speakers get better performance from amps than low impedance speakers,
this ignores the overwhelming superiority of low impedance
electrostatics for most musical criteria, except in large SPL dynamics
where the conventional dynamic speaker excels. If someone designed a
higher impedance stat, that would be great, but the disadvantage of
somewhat higher distortion (and it is still fairly low) into their very
low impedance is vastly outweighed by their superior transient response,
clarity, coherence, less coloration, etc. The old dictum is still
true--the speaker is the most important element in the chain, with the
possible exception of source quality. Get the best speaker you can
afford, then get the best amp that will drive that speaker.
Electrostats are a bit of an exception. Their low impedance derives from a capacitance and is at the upper frequency extreme where very little energy exists! So you don't need a powerhouse to drive them. Sound Labs are a great example and some of the very best ESLs ever made. We have lots of Sound Lab customers- about 80-85% of all our MA-2s go to Sound Lab owners. IMO, the Sound Lab is one of the top 5 speakers made price no object. Even Martin Logans don't need that much power- we've driven them with our M-60s (and a set of ZEROs) no worries.
But I don't agree about the 'best speaker you can afford' thing! The reason is simple- you may find that you have a preference for an amplifier technology- tubes for example- and if that is the case buying an incompatible speaker will simply be money down the loo. So- if you know what kind of amp you prefer, then get the best **compatible** speaker you can for it.
I just saw the impedance curve. Wow, that's pretty brutal. I would love to see the schematics for this beastie and see if it can be made more amplifier friendly.
On another note, one thing I've found about amps and low impedance in the bass:
- Amps can be more susceptible to sounding weak due to low impedance than you'd think. - This is easily audible. Basically pick the amp that produces the deepest tightest bass. :) - Sometimes speakers have horrible impedance issues for lack of better simulation tools (i.e. old speakers designed empirically) and sometimes they get there to make them seem more demanding. Audiophiles often equate a demanding speaker with a better speaker.
To the OP: Buy what you like, I think the impedance issue, so long as it meets the amps minimum impedance requirements, will be something you can 100% hear for yourself, either way.
I just saw the impedance curve. Wow, that’s pretty brutal.
They do do this for laughs do they?. Put it this way, what advantage is there for a speaker manufacturer like Wilson, Thiel, ML esl’s, MBL, Sonus Faber JM labs ect ect ect ect to make their speakers so hard to drive, because complexity of design, complex xovers used, that you have to spend big bucks on an amp with enough current to be able drive them.
THE ANSWER IS NONE!! They do it to make them as close to perfect as possible, and reward is reaped when driven right with as little compromises as possible. If you want a gutless amp then look for a speaker to suit, they in most cases won’t be designed like the ones above.
If you want a gutless amp then look for a speaker to suit, they in most cases won’t be designed like the ones above.
@georgehifi I ask you to provide a list of amps that have guts. I request this, despite it possibly being beneath your dignity.-But, only to provide those less knowledgeable valuable information. B
Ideally, amplifiers are pure voltage sources. That is, the voltage at the speaker terminals is 100% determined by the input from your sources. Usually there's a multiplier, around 20. So, 1 V in ---> 20V out.
But as the impedance of the amplifier rises, and the impedance of the speaker drops, this drops: 1 V in --> 18 V out.
And it can be frequency dependent, because the speaker's impedance is frequency dependent.
This is not the whole story though, as amplifier feedback matters, so it may be that the amps can keep up but only to a certain current limit.
That's why I was strongly encouraging you to listen. If your Class D amp is rated for 2 Ohms, go by your hearing, not spec or class. If it has an actual issue you'll hear it.
Of these only the Thiel is really difficult to drive. We have customers with Wilson, Martin Logan and JM Labs. And we make tube amps that don't double power or even act as a voltage source. The mbls aren't that hard to drive either; just have a bump (not dip) in the upper midrange driver that can make an amp with no feedback sound bright. But the mbls are easy to drive; most of their 'inefficiency comes from the simple fact that they are omni-directional.
I’m glad you are branching out to opine on something besides Class D amplifiers, I think that shows real progress in you participating constructively with others on a broad range of topics.
In regards to your reply to me, please just imagine me rolling my eyes around and guffawing repeatedly, in a very very respectful manner.
Atmasphere, You said, "But I don't agree about the 'best speaker you can afford' thing! The reason is simple- you may find that you have a preference for an amplifier technology- tubes for example- and if that is the case buying an incompatible speaker will simply be money down the loo. So- if you know what kind of amp you prefer, then get the best **compatible** speaker you can for it."
I say that no speaker is "incompatible" with any amplifier. A 5 watt tube amp may make great music up to 105 dB with an efficient horn speaker. But driving a 75 dB efficient electrostatic with small panels, it can make beautiful chamber music at SPL of 75 dB, which is the natural level of a string quartet, for instance. Suppose the listener wants to hear sweet mellow sound from the string quartet, then the more "compatible" higher powered neutral/accurate SS amp is not for him.
The more general point is that the sound character is largely determined by the speaker, closely followed by the recording. Most good amps today have superb specs and sound fairly close to each other. Any of them are much closer to theoretical perfection than any speaker available today, all of which sound hopelessly veiled compared to the real thing, although I come much closer with my electrostatic and EQ. The real advances in high fidelity should be in speaker design rather than amp design. Produce better electrostatic designs, rather than inferior huge curved panels of Sound Lab and Martin Logan which smear HF and bloat images. It is interesting how the new smaller Maggie LRS is creating a sensation. I haven't heard it yet, but the size is right. How about plasma drivers crossed over to electrostatic panels for lower freq. I heard the Plasmatronics speaker by Dr. Alan Hill in the early 80's. Too bad most of the market cares about big dynamics instead of accuracy and finesse, which is why these plasma and stat transducers are largely ignored.
The more general point is that the sound character is largely determined
by the speaker, closely followed by the recording. Most good amps
today have superb specs and sound fairly close to each other.
@viber6 Actually this isn't true. It is true that speakers have a lot of sound character (as does the room) but amps don't sound the same at all, nor do all amps interface correctly with all speakers.
One example is how solid state generally doesn't work well with full range ESLs. Full range ESLs have about a 9 or 10:1 range of impedance from the bass to 20KHz. For example a Sound Lab is 30 ohms in the bass and between 1.5 to 3 ohms at 20KHz depending on the position of the Brilliance control (if the control were removed it would simply be 3 ohms). (BTW, Sound Lab solves this issue to some degree by having a bit of adjustability to their speakers- bass settings, midrange settings (IIRC) and the Brilliance control.)
Now most solid state amps are designed to work as a voltage source, which is to say they maintain the same voltage regardless of load. This is the idea of doubling power as impedance is halved or halving power as impedance is doubled. So If the solid state amp makes 100 watts into 8 ohms, On a Sound Lab ESL with 30 ohms in the bass it will make only about 26 watts but with the same level signal applied at 20KHz will make 300 watts- over a 10:1 difference! The problem here is that unlike a box speaker with a driver in it, the ESL's impedance curve is based on capacitance rather than a base impedance influenced by resonance. Put more simply, it **has the same efficiency regardless of impedance**. This causes solid state amps to be bright on top and unable to make power in the bass. Martin Logan gets around this by simply having a super low impedance at high frequencies and most solid state amps (tube amps to a greater degree) can't make power into that impedance and so they tone down the brightness. In a nutshell, ESLs are not Voltage driven; they are Power driven. For more on this see http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php
Conversely a B&W 802 is designed for a voltage source amp (solid state) and so tube amps have a very difficult time making bass on this speaker.
But put even more simply, we've been getting spec sheets from amplifier manufacturers for 60 years, but we can't tell what the amp sounds like. So we have to audition the amp on our speakers to see if it satisfies! This simple fact is common knowledge with all audiophiles.
Of course we have to examine what is considered 'superb specs'; the simple fact of low THD doesn't mean the amp will sound uncolored or musical to the human ear- in many cases quite the opposite! This is why tubes are still around 55 years after being declared 'obsolete'. Its complex, due to how the human hearing perceptual rules work; how we perceive sound pressure (the presence of higher ordered harmonics, FWIW), how the ear converts distortion into tonality and the masking principle all play a role.
Because some manufacturers want their amplifier to conform more closely to the human perceptual rules, they are willing also to have 'inferior' specs. Its a simple fact that as our current regime of test and measurement goes, we're not always measuring the right things.
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