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Is the Benchmark AHB2, in mono mode, really better than my Mark Levinson No. 536 monoblocks?

avanti1960

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Speed and immediacy? Can you explain what you are talking about? My AHB2 reproduces the music with no distortion, it comes out at the same speed as any other amplifier. You sound like someone who likes the colored sound of whatever amp/speaker combo you own, (perfectly fine with me). Dynamics come from the music, the band/singer plays soft or loud, this has nothing to do with the amp.

If your speakers are hard to drive and the amp is losing power that is something else, but I do not think that is what you are talking about. Until the amplifier is clipping you are getting full dynamic sound.
Sure, I'll try. Admittedly it is more something that you have to experience, if someone tried to explain it to me before I heard it the words might be intriguing but would still fall flat.
My first class A amp ran up to 75 watts before it switched to class AB. The sound was actually too lively. too jumpy and frenetic. Notes would jump out, almost like a burst. Much more energy and big swings between loud and soft on a dime.
I sold it because it was too extreme, it over energized the music.
With my most recent class A amp I bought it on a whim and it was much nicer sounding than the first one. However I already had a very nice Class AB amp (Parasound a21+) that I liked but did not love. In order to decide which amp I wanted to keep I did some extensive A-B listening tests.
With a few select complex demo tracks it became obvious that the Class A amp was faster in keeping up with the changes that the music demanded, things stayed clear, focused and well organized. The Parasound lagged but still sounded pleasant, yet was not able to keep up with the complexities of the music, in that it lost focus and detail. Part of the music went missing in action.
I did not realize that amplifiers could behave so differently and never would have noticed if I hadn't compared them in such a way.
My speakers are not hard to drive, minimum impedance 6 ohms, 86db sensitivity. Has noting to do with coloration. This happened at moderate volume levels, no clipping involved.
The decision to sell the Parasound was easy after that comparison.
 

dualazmak

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Sure, I'll try. Admittedly it is more something that you have to experience, if someone tried to explain it to me before I heard it the words might be intriguing but would still fall flat.
My first class A amp ran up to 75 watts before it switched to class AB. The sound was actually too lively. too jumpy and frenetic. Notes would jump out, almost like a burst. Much more energy and big swings between loud and soft on a dime.
I sold it because it was too extreme, it over energized the music.
With my most recent class A amp I bought it on a whim and it was much nicer sounding than the first one. However I already had a very nice Class AB amp (Parasound a21+) that I liked but did not love. In order to decide which amp I wanted to keep I did some extensive A-B listening tests.
With a few select complex demo tracks it became obvious that the Class A amp was faster in keeping up with the changes that the music demanded, things stayed clear, focused and well organized. The Parasound lagged but still sounded pleasant, yet was not able to keep up with the complexities of the music, in that it lost focus and detail. Part of the music went missing in action.
I did not realize that amplifiers could behave so differently and never would have noticed if I hadn't compared them in such a way.
My speakers are not hard to drive, minimum impedance 6 ohms, 86db sensitivity. Has noting to do with coloration. This happened at moderate volume levels, no clipping involved.
The decision to sell the Parasound was easy after that comparison.

Really interesting, and I feel much concurrences with your subjective experience in amplifier selection/exploration.

I recently went through similar amplifier exploration (Class-AB, Class-A, Class-A[H]B, Class-D amps; the summary can be found here) in my multichannel multi-driver multi-way multi-amplifier stereo audio project, and learned a lot that we should carefully subjectively compare amplifiers, with our ears and brain, in our own individual room acoustic environments even if we would also pay much attentions on the catalog specs and objectively measured data for the amplifiers.
 
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Darkscience

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Sure, I'll try. Admittedly it is more something that you have to experience, if someone tried to explain it to me before I heard it the words might be intriguing but would still fall flat.
My first class A amp ran up to 75 watts before it switched to class AB. The sound was actually too lively. too jumpy and frenetic. Notes would jump out, almost like a burst. Much more energy and big swings between loud and soft on a dime.
I sold it because it was too extreme, it over energized the music.
With my most recent class A amp I bought it on a whim and it was much nicer sounding than the first one. However I already had a very nice Class AB amp (Parasound a21+) that I liked but did not love. In order to decide which amp I wanted to keep I did some extensive A-B listening tests.
With a few select complex demo tracks it became obvious that the Class A amp was faster in keeping up with the changes that the music demanded, things stayed clear, focused and well organized. The Parasound lagged but still sounded pleasant, yet was not able to keep up with the complexities of the music, in that it lost focus and detail. Part of the music went missing in action.
I did not realize that amplifiers could behave so differently and never would have noticed if I hadn't compared them in such a way.
My speakers are not hard to drive, minimum impedance 6 ohms, 86db sensitivity. Has noting to do with coloration. This happened at moderate volume levels, no clipping involved.
The decision to sell the Parasound was easy after that comparison.
Ultimately the important thing is your happy with your sound, and although most, (including myself), would say that your test is pure psychoacoustics because it needs to be blind etc to even begin with. Now that aside I do honestly believe that you did likely hear some difference and you just chose the one that sounded best to you, but those differences come from the "coloration" of the amp. In a perfect situation, to my understanding, all you want your amplifier to do is amplify whatever signal you feed it without adding distortion of any kind. This is something that can be measured and it is accomplished by feeding the amp a known signal and measuring the output compared to the known signal, (I am like you no expert and thats ok). That is really about it, like I said I have no doubt your system sounds good to you, but you are very likely hearing distortion and like someone else said some harmonic content, which I will not argue could very well make whatever music you like pleasing to you. My system has coloration too, because my speakers are not by any means Studio monitor quality and I like them still, but for the electronics I like knowing what I feed my speakers is as clean as possible so that what I am hearing is mostly the speaker coloration and my room. So in conclusion if your after a distortion free sound, I believe the AHB2 is king, atleast it was a couple yeara back when I bought it, and have no desire to ever change it out, its kind of like what I bought is basically the best there is. There is something called damping factor though and I think that is the only difference there is with the newer Purify amps but I have no researched if that is anything to care about, the other good thing about the AHB2 is it is extemeley well made, it is a bit of audio jewelry becuase of its price and build, but it backs it up with exceptional measurements. You do not need to spend that much if you go with a Purify.

You will need to get use to the fact that around here people are not interested in recommendations based on how you like the sound, we mostly only care about the measurements because that is the only way to know what we are hearing is proper.
 

Darkscience

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Ultimately the important thing is your happy with your sound, and although most, (including myself), would say that your test is pure psychoacoustics because it needs to be blind etc to even begin with. Now that aside I do honestly believe that you did likely hear some difference and you just chose the one that sounded best to you, but those differences come from the "coloration" of the amp. In a perfect situation, to my understanding, all you want your amplifier to do is amplify whatever signal you feed it without adding distortion of any kind. This is something that can be measured and it is accomplished by feeding the amp a known signal and measuring the output compared to the known signal, (I am like you no expert and thats ok). That is really about it, like I said I have no doubt your system sounds good to you, but you are very likely hearing distortion and like someone else said some harmonic content, which I will not argue could very well make whatever music you like pleasing to you. My system has coloration too, because my speakers are not by any means Studio monitor quality and I like them still, but for the electronics I like knowing what I feed my speakers is as clean as possible so that what I am hearing is mostly the speaker coloration and my room. So in conclusion if your after a distortion free sound, I believe the AHB2 is king, atleast it was a couple yeara back when I bought it, and have no desire to ever change it out, its kind of like what I bought is basically the best there is. There is something called damping factor though and I think that is the only difference there is with the newer Purify amps but I have no researched if that is anything to care about, the other good thing about the AHB2 is it is extemeley well made, it is a bit of audio jewelry becuase of its price and build, but it backs it up with exceptional measurements. You do not need to spend that much if you go with a Purify.

You will need to get use to the fact that around here people are not interested in recommendations based on how you like the sound, we mostly only care about the measurements because that is the only way to know what we are hearing is proper.
I want to add one more thing, trust me when I say I agree how it sounds to you is what matters in the end. I know it makes it sound like I am saying I only like the AHB2 because it measures well, but it also sounds really good to me. That is why my initial reaction was to ask what you meant about speed etc because I listen mostly to metal music and it is the really fast kind and the double kick bass drums sound amazing on my system. The elwctric guitars sound like the player is plugged into my speaker, all extremely clean and clear and detailed, with dynamics. But it is like you I just really like whatever coloration my speakers are doing because I know if I measured, it would not be pretty.
 

pogo

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There is something called damping factor though and I think that is the only difference there is with the newer Purify amps but I have no researched if that is anything to care about
This is one of the most important factors. Here is an interesting video in german from a sound engineer, who explains which technical data are actually relevant and audible nowadays: Link
You can also add a subtitle in your native language.

A low/moderate DF is also a kind of distortion and can have different effects depending on the used speakers. See also my post #74.
 

pogo

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The DF is always an issue and it also does not mean that a very high DF is always suitable to please one's own taste or is required by the speakers. Therefore, amplifiers with switchable DFs are clearly in the advantage when adapting to different speakers.
 

Darkscience

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I think some Audiophiles are going to consider what I am about to say as blasphemy. I personally believe music sounds mostly the same to me through my laptop, car stereo, headphones etc. The only differences I can honestly hear is a difference in frequency response of the speakers, (headphones or live), the room I am listening in can affect the sound, and the one I personally care about the most, the distortion. I have pretty much figured out that music just sounds cleaner on my stereo, but the music, the notes, the rests, I can pretty much always hear, even on a bad sounding system, (like my car), I can still distinguish all 1/16 notes played at blistering BPMs found in most of what I listen to. But what listening on my stereo does is pretty much make it so I can crank it up louder and stay distortion free turning my living room into a live concert so to speak with the sound filling the room and a different perspective on sound stage due to the directivity of the speakers and room reflections.

A lot of Metal music, especially Black Metal is poorly recorded and listening on a clean system can make the music not as pleasing because the distortion added from listening on a poor system sometimes makes the music more pleasing by smoothing out, (with distortion), some of the spikey nature of the recording. But during the look through of some of those links about DF there was talk about dry sounding, wet sounding, there was talk about warmth, talk about hearing things in the recordings that were not there before. I just can’t come to believing any of that because like I said of my own experience of knowing that the music sounds the same to me on just about everything, I play it on. To me the benefit of the Stereo is mostly to get distortion free, room filling music through a wider frequency range, (I can’t always hear the bass player for example because my car speakers just do not have the range). My speakers are so far away from reference, but they sound great to me because they have their own coloration that I love and the AHB2 feeds them a clean, distortion free, noise free signal. I just can’t come to the belief that the sound of the music recorded could sound wet, dry, cold, warm by changing out the amplifier unless the amplifier happens to be adding distortion or noise, (harmonics?). It just sounds like the recording is all, with the full frequency response signature of my speakers and room.

I feel if there is anything I can possibly claim to my own hearing is that I believe I can hear distortion, I can tell if maybe there is too much or lack of bass/treble/mids, I can hear noise (in the form of hiss), and I can hear if there is something wrong with the speakers, (because they sound broken or something).

I have never been able to discern what is meant by speed of the notes, the only time that makes any sense to me is if I am playing my own electric guitar and I can hear a difference in how it sounds as I switch out the speakers, (we call them Cabs). In that scenario Cabs can sound muddy, loose, tight, and resonant, but in this case, it makes complete sense because it is a musical instrument, not a recording.

Anyways just some thoughts. Not saying any of it is correct, I likely got some of the more technical terms wrong, but I just…idk speed and decay don’t make sense to me in the world of reproducing recordings, just reproduce what was recorded no?
 

PGAMiami

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What has ones own taste got to do with it. DF has to be sufficient to ensure accurate driver control. We're not concerned about taste here.
Agreed. DF can surely affect how a system sounds as it’s the ratio of the speaker impedance vs the amplifier impedance. When that‘s a large number, then the amplifier is “in control” as it will start and stop the driver as intended. Additionally, if the DF is low and the speaker impedance varies by frequency, then this also causes aberrations in frequency response. Sometimes these aberrations will be synergistic and they may improve the overall response of the speaker/amp combo, but this is more luck than anything else, and it’s not a reliable way to put together a hi fidelity system. So all said, it’s better if the DF is high and for almost all solid state designs for voltage source amps, DF should not be a concern.

Note also it’s the DF as seen by the drivers that matters. A woofer in a box with a passive crossover will have at least one inductor in series with the amplifier, and this inductor will reduce the DF that the driver sees. This is one argument for why active crossovers can improve system performance.
 
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Darkscience

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Ok so Benchmark has a whole article on DF, and I found it extremely informative. The information all appeared legit to me link.
They provide the equations pre-built into a spreadsheet. They instructions say to enter the nominal, min and max impedance of your speaker.
Capture.JPG

If I did this correctly below are the results I got, (Basically a max attenuation of .10 dB with an error of .09 dB, or as they describe this, beyond the inaudible threshold of a proper A/B/X test.)

Is this accurate? (Also the only testing I found for my speaker is in another language but I think I can read it).
Capture3.JPG

The results seem to suggest everything is ok?
 

Darkscience

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Maybe I should have used 4 and 22? But either way the results are almost identical. (Max =.10, Min = .02 Error = .08)
Capture5.JPG
 

sq225917

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I've never understood speed either. If a speaker can reproduce the correct frequency by definition its managing the speed, that's all speed is frequency. I've never heard a good explanation of the term. Attack, shimmer, decay, all that I get, but speed seems meaningless
 

PGAMiami

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I've never understood speed either. If a speaker can reproduce the correct frequency by definition its managing the speed, that's all speed is frequency. I've never heard a good explanation of the term. Attack, shimmer, decay, all that I get, but speed seems meaningless
It’s not just about frequency response, it’s also about how quickly the driver stops once the signal goes to zero. A bell will keep ringing long after it’s hit. That’s what you don’t want your speakers to do.

Speaker designers expect your amplifier to be a ideal voltage source, meaning it has zero output impedance or an infinite DF. When the output impedance of the amp gets closer to the impedance of the speaker, then you have problems with the frequency response as the impedance of the speaker varies.

The Benchmark article explains this better than I can. But there is one more point to be made that is not in the article, which is that the output impedance of an amplifier varies with the output voltage and current. The output impedance is not the same at 1 watt as it is near the amplifier’s maximum output. At a low level, the power supply is not stressed and the output impedance will be mostly determined by the output stage design. However at high output levels the power supply of the amplifier starts to limit the current that is available to the output stage and this effectively increases very significantly the output impedance.

One way to explain this is to think of the electrical output of your amplifier as if it was water, the output stage is a valve the modulates this flow of water. But the water is coming from a power supply which you can think of as a pump. The output stage simply cannot allow more water to flow than the pump can provide.

Typically it’s the bass frequencies that need most power. So bass is typically where the stiffness of the power supply matters most. Almost all amplifiers have unregulated power supplies, so when the output stage calls for a lot of current and cannot produce that much, the voltage sags. Most designers deal with this by putting in a large but unregulated power supply. Very few amplifies have regulated power supplies with active controls that hold their voltage at a specified level, and these are usually monster amps like the Levinson 32. AHB2 is one of the very few amplifiers with a regulated power supply.
 

PGAMiami

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You can think of your speaker like a motor and a generator, both at the same time. When it’s perfectly driven by the voltage of the amp, it’s a motor. When the speaker keeps moving on it’s own due to mechanical inertia or ringing, it’s a generator producing voltage and current. You want your amplifier to be the unaffected by this back emf coming from the speaker. A low DF will not allow the amplifier to control the speaker. But it’s the total DF at the speaker terminal that matters, and this includes the passive crossover and its inductors.
 

sq225917

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Assume I understand the electricalworkings of a speaker and the effects of amp damping factor. What I'm asking for is an agreed meaning to the subjectivist use of the term speed, something I can measure.
 

PGAMiami

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Assume I understand the electricalworkings of a speaker and the effects of amp damping factor. What I'm asking for is an agreed meaning to the subjectivist use of the term speed, something I can measure.
Use REW to measure the speakers in your room and look at the distortion and waterfall graphs
 

dualazmak

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Assume I understand the electricalworkings of a speaker and the effects of amp damping factor. What I'm asking for is an agreed meaning to the subjectivist use of the term speed, something I can measure.

You (we) can measure the transient characteristics (i.e. kick-up and fade-off of the cone/dome movements) using 8-wave and 3-wave tone burst excitation signals and measurement microphone, then you may analyze using Adobe Audition. If you would be seriously interested in such measurements, please refer to my recent posts on my project thread;
Measurement of transient characteristics of Yamaha 30 cm woofer JA-3058 in sealed cabinet and Yamaha active sub-woofer YST-SW1000: #495, #497, #503

Also the relative time alignments (in 1 msec and 0.1 msec precision) between the SP drivers, which can be measured and adjusted, greatly contribute to the "speed" (and disappearance) of entire SPs in our (stereo) audio system;
- Precision measurement and adjustment of time alignment for speaker (SP) units: Part-1_ Precision pulse wave matching method: #493
- Precision measurement and adjustment of time alignment for speaker (SP) units: Part-2_ Energy peak matching method: #494
- Precision measurement and adjustment of time alignment for speaker (SP) units: Part-3_ Precision single sine wave matching method in 0.1 msec accuracy: #504, #507
- Perfect (0.1 msec precision) time alignment of all the SP drivers greatly contributes to amazing disappearance of SPs, tightness and cleanliness of the sound, and superior 3D sound stage: #520

In case if you would like to perform these measurements using the test tone signals I prepared, please contact me by PM system for possible sharing of the test signals.
 
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Lsc

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I think some Audiophiles are going to consider what I am about to say as blasphemy. I personally believe music sounds mostly the same to me through my laptop, car stereo, headphones etc. The only differences I can honestly hear is a difference in frequency response of the speakers, (headphones or live), the room I am listening in can affect the sound, and the one I personally care about the most, the distortion. I have pretty much figured out that music just sounds cleaner on my stereo, but the music, the notes, the rests, I can pretty much always hear, even on a bad sounding system, (like my car), I can still distinguish all 1/16 notes played at blistering BPMs found in most of what I listen to. But what listening on my stereo does is pretty much make it so I can crank it up louder and stay distortion free turning my living room into a live concert so to speak with the sound filling the room and a different perspective on sound stage due to the directivity of the speakers and room reflections.

A lot of Metal music, especially Black Metal is poorly recorded and listening on a clean system can make the music not as pleasing because the distortion added from listening on a poor system sometimes makes the music more pleasing by smoothing out, (with distortion), some of the spikey nature of the recording. But during the look through of some of those links about DF there was talk about dry sounding, wet sounding, there was talk about warmth, talk about hearing things in the recordings that were not there before. I just can’t come to believing any of that because like I said of my own experience of knowing that the music sounds the same to me on just about everything, I play it on. To me the benefit of the Stereo is mostly to get distortion free, room filling music through a wider frequency range, (I can’t always hear the bass player for example because my car speakers just do not have the range). My speakers are so far away from reference, but they sound great to me because they have their own coloration that I love and the AHB2 feeds them a clean, distortion free, noise free signal. I just can’t come to the belief that the sound of the music recorded could sound wet, dry, cold, warm by changing out the amplifier unless the amplifier happens to be adding distortion or noise, (harmonics?). It just sounds like the recording is all, with the full frequency response signature of my speakers and room.

I feel if there is anything I can possibly claim to my own hearing is that I believe I can hear distortion, I can tell if maybe there is too much or lack of bass/treble/mids, I can hear noise (in the form of hiss), and I can hear if there is something wrong with the speakers, (because they sound broken or something).

I have never been able to discern what is meant by speed of the notes, the only time that makes any sense to me is if I am playing my own electric guitar and I can hear a difference in how it sounds as I switch out the speakers, (we call them Cabs). In that scenario Cabs can sound muddy, loose, tight, and resonant, but in this case, it makes complete sense because it is a musical instrument, not a recording.

Anyways just some thoughts. Not saying any of it is correct, I likely got some of the more technical terms wrong, but I just…idk speed and decay don’t make sense to me in the world of reproducing recordings, just reproduce what was recorded no?
I understand what you are saying. Adele for example sounds like Adele in all of your devices - clock radio, boom box, radio in the car, home stereo etc.

To distinguish where this hobby leads some people…and sometimes it becomes an obsession…How loud can you play that Adele song on the clock radio? Play that same song in a $50k system at realistic levels. If you experienced the difference, does that make you to want to go out and spend the money to replay that experience that you heard in a $50k system (arbitrary $ selected)?

If not, you are in the same camp as my 2 well off bros and wife who doesn’t care enough to spend their hard earned money on a high end system while I have cared for 20 years and have steadily improved my system to a point where now spending much more money doesn’t seem to make sense anymore because I now have to spend a lot more money for tangible improvements.

This is the simplest I can explain what this pursuit is. How good of a sound system is good enough? We have passion constraints and/or budget/value constraints.
 
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