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Post by Talley on Dec 31, 2017 20:42:45 GMT -5
With modern electronics the computer can handle all that but it cant change its own oil LOL You can stock the pantry with food but you can’t get the wife to cook it |
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Post by socketman on Dec 31, 2017 20:43:45 GMT -5
You can make coffee but its never in the fridge.
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Post by rtg97229 on Jan 1, 2018 22:32:40 GMT -5
Some amps and other products have a "house sound" that people find pleasant. I don't want to make it seem that I am calling out any given manufacture because there are some very credible brands that would have to go on the list and I think that if people enjoy the sound they should buy it. I even own some colored gear in some of my setups so it is not an insult. That said I find Emo products to be very natural or uncolored and I doubt that slew rate is an issue with either of the amps being discussed.
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Post by rtg97229 on Jan 1, 2018 22:46:51 GMT -5
I should add that some speakers can have a less than ideal impedance curve or provide a capacitive load that could be less than ideal for some if not most amps designed for an 8 or 4 Ohm resistive load. I would consider that a rare case but we are audio enthusiasts and we sometimes do strange things, and its often fun when we do.
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Post by leonski on Jan 2, 2018 0:39:11 GMT -5
Some amps and other products have a "house sound" that people find pleasant. I don't want to make it seem that I am calling out any given manufacture because there are some very credible brands that would have to go on the list and I think that if people enjoy the sound they should buy it. I even own some colored gear in some of my setups so it is not an insult. That said I find Emo products to be very natural or uncolored and I doubt that slew rate is an issue with either of the amps being discussed. I was dissed' for 'suggesting' that MC had a 'house sound'. As for your remarks about speaker impedance? Speakers MIGHT be resistive at some few frequencies, Other than that? They are ALL a mix of inductive and/or capacitive 'reactance'. The real rare case would be a speaker which is very low reactance. All speakers are reactive loads to one extent or another. I might add that HT stuff, designed for less robust amps, also tends to be an easier load for the partnering amp to drive. Some HT receivers are AWFUL amps and fail at lower impedances and certainly at higher phase angles. Phase angles are when current leads or lags voltage. They are NEVER in lock-step except when measured into a resistor. And yes, that's exactly why I've been harping on a REAL amp measurement standard, other than a resistor. Speaker dummy loads which mimic the reactance of a real speaker can be fabricated for a couple bucks. One company, 'Audiograph' makes a dummy load which stresses amps with capacitive phase angles of up to 60degrees and the same with inductive phase angles. This is one of the major reasons why 2 amps which might measure identicallly into a resistor simply don't compare into a 'real' speaker. Off hand, I don't know that it is possible to fabricate a speaker which is a pure resistive load. audiograph.se |
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Post by Talley on Jan 2, 2018 8:38:23 GMT -5
Interesting...
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Post by Bonzo on Jan 2, 2018 10:21:44 GMT -5
It's threads like these where I realize I'm just not a super duper nerdy end all of audiophiles. I'm easily the biggest audiophile of all my friends and co-workers, but compared to the uber geeks out there (here), I'm nothing. Wow.
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Post by Talley on Jan 2, 2018 10:25:23 GMT -5
It's threads like these where I realize I'm just not a super duper nerdy end all of audiophiles. I'm easily the biggest audiophile of all my friends and co-workers, but compared to the uber geeks out there (here), I'm nothing. Wow. I wouldn't classify me as an audiophile. I just want the best I can get but I started from the source... my isolation transformer then worked my way down through the system. Bought some stuff to get started and did some mild treatments on the acoustics and will now be ready to really dial it in. My uncle is the severe end of the audiophile group. |
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Post by Bonzo on Jan 2, 2018 10:34:47 GMT -5
It's threads like these where I realize I'm just not a super duper nerdy end all of audiophiles. I'm easily the biggest audiophile of all my friends and co-workers, but compared to the uber geeks out there (here), I'm nothing. Wow. I wouldn't classify me as an audiophile. I just want the best I can get but I started from the source... my isolation transformer then worked my way down through the system. Bought some stuff to get started and did some mild treatments on the acoustics and will now be ready to really dial it in. My uncle is the severe end of the audiophile group. It's not the original topic of your thread, it's what others have contributed. Your thread topic is a very valid question. I guess it warrants the answers and discussions posted. But it's just stuff way over my head. Not that I couldn't "learn" it to understand it, if I had time, but it's stuff I personally just couldn't give a rats a$$ to care about. But I'm glad there are people out there that care, because without them, low end audiophiles like me wouldn't get the stuff we have. I'm very appreciative, but wow I'm glad I'm not that far gone.  |
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DYohn
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Post by DYohn on Jan 2, 2018 11:05:31 GMT -5
No dynamic loudspeaker is a purely resistive load. A voice coil impedance changes constantly with the frequency of the signal, generally ranging from a net impedance of 2-ohms up to several thousand ohms. A dynamic loudspeaker cannot become a capacitive load, by the way, although some electrostatic systems can. When a loudspeaker is rated at "4-ohms" or "8-ohms" that refers to the "nominal" or lowest average over a given frequency range. A typical "4-ohm" dynamic loudspeaker impedance curve looks like this:  |
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Post by mgbpuff on Jan 2, 2018 11:45:57 GMT -5
So, this says to me that an electromagnetic cone type speaker should be driven by an amplifier that is essentially current regulated vs voltage regulated and the voltage available should be adequate to force the current required. Maybe an electrostatic speaker should be voltage regulated instead. The only pure current regulated amp I have encountered is Nelson Pass's First Watt F1. Pass says this amp must be used on a single full range type dynamic cone speaker.
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Post by Talley on Jan 2, 2018 12:04:38 GMT -5
I was just reading on that first watt amp too
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DYohn
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Post by DYohn on Jan 2, 2018 12:18:39 GMT -5
No, it means that there is no single impedance for loudspeakers. As far as pairing with amplifiers, I will leave that to the tweakers who think such things are important, but in my experience you may use any amp with any loudspeaker. Performance may not be optimal and in some cases the user must be careful not to overload the amp or overdrive the speakers, but there really is nothing wrong with using any amp and any speaker.
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Post by mgbpuff on Jan 2, 2018 12:33:20 GMT -5
No, it means that there is no single impedance for loudspeakers. As far as pairing with amplifiers, I will leave that to the tweakers who think such things are important, but in my experience you may use any amp with any loudspeaker. Performance may not be optimal and in some cases the user must be careful not to overload the amp or overdrive the speakers, but there really is nothing wrong with using any amp and any speaker. I am getting used to your responses of no, false, and wrong to almost anything I write. If an amplifier driving a single dynamic coil type speaker were to be current regulated, then the varying impedance of the speaker would be a non issue. This is all I am saying. |
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KeithL
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Post by KeithL on Jan 2, 2018 12:45:34 GMT -5
However, you are still assuming that the differences between the Emotiva and Krell amps will result in the Krell amp sounding better. And you seem to be basing that assumption on two other assumptions: 1) that Krell will use better parts 2) that the better parts they use will result in an audible difference - for the better - in sound quality To be honest, since I haven't heard the Krell amp, and certainly haven't heard it compared directly to ours, I don't know either way.... However, I'm certainly not going to ASSUME that it will sound better - based on two other unsubstantiated assumptions.... or based on the name of the manufacturer. The Krell amp might sound better than ours... or it might sound exactly the same... or it might even sound worse... not having heard it I just plain don't know. And, even if you're sure, one way or the other, I would advise that you avoid crediting the difference to factors that may in fact not have anything to do with it.... which is a tendency we all have. (It might sound better - but the difference could have nothing whatsoever to do with parts quality.) For example, one very common misconception is that "better parts will sound better". The reality is that, in many cases, "better" means that they have a longer service life, or better tolerance to abuse... but may NOT mean that the part delivers better audio performance. For example, certain low cost capacitors have excellent high frequency response, and exceptional service life, but also have serious nonlinearities at audio frequencies and low voltages. This makes them "excellent" parts for bypass capacitors in power supplies.... but really "poor" parts for audio signal applications. (And some "better" parts don't perform better at all - but are simply better able to withstand the abuse encountered in certain manufacturing techniques.... like wave soldering - which makes them cheaper to use.) Many audio equipment manufacturers also cheerfully use "better" parts for reasons other than sound quality or production considerations. (They may just use them to impress people who've heard of the name.... for example, people who've "just read that teflon capacitors are better") Better watts sound better. I doubt there is a SINGLE spec which will be the smoking gun, but maybe a bunch of specs taken together will point in the right direction. The rule? All things that can be measured don't matter. AND All things which matter can't (yet, I'll add) be measured. Krell might use 'better' parts in some areas. Selecting and matching transistors, for example, can have audible beneifits. Certian types of capacitors may have a different 'sound'. Different dielectrics in capacitors have can have different 'sounds'. Teflon is good, but some swear by ($$$$) Oil Filled Silver Mundorf Supreme. (or whatever) Fillm resistors are generally better than CARBON resistors. Circuit board layout matters. Circuit board MATERIAL matters. Grounding scheme (look up Star Ground) might matter. The Krell is a large number of small differences. Some differences cost ZIP while other differences DO have a $$ cost. Even if EMO made the SAME amp from the same schematic, but priced at the EMO level, it wouldn't sound as good as the Krell. |
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DYohn
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Post by DYohn on Jan 2, 2018 12:54:34 GMT -5
No, it means that there is no single impedance for loudspeakers. As far as pairing with amplifiers, I will leave that to the tweakers who think such things are important, but in my experience you may use any amp with any loudspeaker. Performance may not be optimal and in some cases the user must be careful not to overload the amp or overdrive the speakers, but there really is nothing wrong with using any amp and any speaker. I am getting used to your responses of no, false, and wrong to almost anything I write. If an amplifier driving a single dynamic coil type speaker were to be current regulated, then the varying impedance of the speaker would be a non issue. This is all I am saying. Sorry, not going after you, just striving for accuracy. The varying impedance of a loudspeaker is a non-issue with any amplifier, mainly because it cannot be otherwise. If you desire constant power into any load, the regulation you need is in the amplifier power supply not in the outputs, which is one reason why the newest Emotiva P/S designs are interesting. |
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Post by amped on Jan 2, 2018 14:21:01 GMT -5
I figured it out! I have got it...
Confucius say...
"The Krell sound better to you then the Emo...because you like the sound of the Krell better than Emo.."
POW! You're welcome thread!
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KeithL
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Post by KeithL on Jan 2, 2018 14:24:13 GMT -5
I've got to comment on your last statement..... because, even though it seems to make sense, it is actually far from true in practice. The VERY BASIC theory that suggests it would make sense goes as follows... - The force applied to the speaker cone depends on the current through the voice coil and the magnetic field strength. - Therefore, if we used a current drive amplifier (where the output current depends on the input voltage) the current would be unaffected by things like resonance. - So, since we've removed resonance and other frequency effects from the equation, our speaker should be more linear. Now, here's why that idea doesn't really usually work... - All speakers have resonances, and usually a single major primary resonance. - At the resonant frequency both the impedance and the mechanical efficiency go up. - With our current drive amplifier the current will remain constant (proportional to the input voltage) - even at the resonant peak. - As a result, the drive force will remain constant at the resonant frequency (which seems like a good thing... except...) - Because the drive force is the same at the resonant frequency, BUT THE MECHANICAL EFFICIENCY IS HIGHER, there will be a peak in the mechanical output (audio). - In contrast, with a normal voltage drive system, at resonance, while the mechanical efficiency goes up, the drive power goes down, and the two tend to partially cancel out. A normal voltage drive amplifier delivers less current, and so less power, at the resonant frequency; a current drive amplifier delivers the same current, and so MORE voltage, and so MORE power, at resonant frequency. However, the mechanical efficiency is higher at the resonant frequency; the voltage drive amplifier tends to partially cancel out this effect, while the current drive amplifier potentiates it. As a result, at least with most real-world speakers, a current-drive amplifier will actually produce a worse peak in the acoustic output at resonance. No, it means that there is no single impedance for loudspeakers. As far as pairing with amplifiers, I will leave that to the tweakers who think such things are important, but in my experience you may use any amp with any loudspeaker. Performance may not be optimal and in some cases the user must be careful not to overload the amp or overdrive the speakers, but there really is nothing wrong with using any amp and any speaker. I am getting used to your responses of no, false, and wrong to almost anything I write. If an amplifier driving a single dynamic coil type speaker were to be current regulated, then the varying impedance of the speaker would be a non issue. This is all I am saying. |
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Post by Talley on Jan 2, 2018 14:26:24 GMT -5
Keith, As I said before in my first post the krell has better midrange sound and cymbals to my ears. I need to do some more comparisons but again without an a/b box it's hard to do. But each time I go back and forth its the same story. The bass actually sounds tighter on the xpa-7 over the krell. Right now I just need one amp... not two. I only have two because my krell had some damage caps and started distorting... so I got the xpa-7 to fill in while I waited for the krell to get repaired. Now it's repaired so not sure what to do. However, you are still assuming that the differences between the Emotiva and Krell amps will result in the Krell amp sounding better. And you seem to be basing that assumption on two other assumptions: 1) that Krell will use better parts 2) that the better parts they use will result in an audible difference - for the better - in sound quality To be honest, since I haven't heard the Krell amp, and certainly haven't heard it compared directly to ours, I don't know either way.... However, I'm certainly not going to ASSUME that it will sound better - based on two other unsubstantiated assumptions.... or based on the name of the manufacturer. The Krell amp might sound better than ours... or it might sound exactly the same... or it might even sound worse... not having heard it I just plain don't know. And, even if you're sure, one way or the other, I would advise that you avoid crediting the difference to factors that may in fact not have anything to do with it.... which is a tendency we all have. (It might sound better - but the difference could have nothing whatsoever to do with parts quality.) For example, one very common misconception is that "better parts will sound better". The reality is that, in many cases, "better" means that they have a longer service life, or better tolerance to abuse... but may NOT mean that the part delivers better audio performance. For example, certain low cost capacitors have excellent high frequency response, and exceptional service life, but also have serious nonlinearities at audio frequencies and low voltages. This makes them "excellent" parts for bypass capacitors in power supplies.... but really "poor" parts for audio signal applications. (And some "better" parts don't perform better at all - but are simply better able to withstand the abuse encountered in certain manufacturing techniques.... like wave soldering - which makes them cheaper to use.) Many audio equipment manufacturers also cheerfully use "better" parts for reasons other than sound quality or production considerations. (They may just use them to impress people who've heard of the name.... for example, people who've "just read that teflon capacitors are better") |
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Post by mgbpuff on Jan 2, 2018 14:31:24 GMT -5
I am getting used to your responses of no, false, and wrong to almost anything I write. If an amplifier driving a single dynamic coil type speaker were to be current regulated, then the varying impedance of the speaker would be a non issue. This is all I am saying. Sorry, not going after you, just striving for accuracy. The varying impedance of a loudspeaker is a non-issue with any amplifier, mainly because it cannot be otherwise. If you desire constant power into any load, the regulation you need is in the amplifier power supply not in the outputs, which is one reason why the newest Emotiva P/S designs are interesting. A dynamic coil moves in response to current flowing through it, not necessarily voltage across it. So if the current is regulated and by regulation I mean closed loop feedback controlled so the the current output of the amp is forced to follow the current input of the reference signal, then the varying impedance of the speaker is not a factor anymore. The voltage across the speaker terminals may look like it is going to hell sometimes under such current controlled conditions, but that is of no significance since the coil responds in movement only to the current flowing through it. Just any amplifier can not do this with the displacement accuracy that a current controlled one could. Such an amplifier would probably have to be used on each dynamic coil in a multi cone speaker. |
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