@joysjane
Old Infinity speakers were tuned without much regard to impedance. I'm not sure which speakers you have, but I've seen a number of crossover upgrades for them you should consider which fixes these issues.
Good as they originally sounded, they were designed without the tools we have today which would allow for simultaneous optimization of frequency and impedance.
Best,
E
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Hi George,
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.
Best,
Erik
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Hey OP. 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. Take a look at the very first plot from this review: https://www.stereophile.com/content/conrad-johnson-premier-twelve-monoblock-amplifier-measurementsand you'll see how this happens with tubes, with notoriously high impedance outputs. 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. |
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.
Best,
E
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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. Best, Erik |
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. Best, Erik |
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 Best, Erik |
Thanks for those kind words, @noble100
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,
Erik
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Hi @golfnutz 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. Best, Erik |
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.
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I'm sorry George, let me restate that.
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.
Even when an OP specifically asks detractors of Class D to go elsewhere, becuase they wan to read about relative differences between Class D amps, well, in moments there you are, telling them why they need to wait for a tech no one has heard of, or consider a linear amp instead.
And in terms of style, you have routinely characterized others and projected your own patterns onto posters, especially me.
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I am funny as hell, sad the moderators don't think so.
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Hi DSPer,
There are a lot of linear amps which are also not great for low impedance loads. Like those, many Class D modules are designed for more normal loads.
Some however, like Hypex, have been rated down to 2 and will do a very good job.
Just kind of depends. Where Class D tends to have more of a problem with speaker loads is at the top end. Think ESL's with dropping impedances, but again, a lot of linear amps have the same issues.
Above all, assuming they are rated for the speaker, you should listen. You never know what serendipity will bring you.
Best,
E
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My guess is that amps with low impedance around 100-150 Hz sound more discerning
Sorry if it wasn't clear, but I meant: "My guess is that _SPEAKERS_ with low impedance around 100-150 Hz.... " Apologies for any confusion, I hope that to most it would have been clear I made that mistake. Erik |
That’s just adding series resistance to the perceived load to make it
look higher to the amps output stage so it doesn’t complain, and what
that does is lower the damping factor and raise the output impedance as
seen by the amp
@georgehifi - You literally have no idea what I was talking about, so your reply is wrong in the specific and wrong in the general. Best, E |
I have seen some commercial speakers from Focal introduce a 2 Ohm low deliberately in the crossover. Took quite a number of caps and resistors too.
My guess is that amps with low impedance around 100-150 Hz sound more discerning, more snobbish of amplifiers. "Look at me, I can only be driven by high current amps, so I must be better."
I have also seen designs from Infinity which were an utter part crap fest. My guess for them is that at the time they were designed good simulation and measurement tools were far too expensive, and they reached their sound empirically with no concern for the amps. You may think "well, nothing wrong with voicing by ear" but the designs I’m talking about could easily have achieved equivalent results with easier to drive impedances.
Kudos to Joseph Audio for going the other way, and actually adding crossover components which make them easier to drive by a wider range of amps.
Best,
E
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