Yes, for a two way. I did look at 3 way, but don't remember what I found (if anything).
Interesting that dynamics tend to go together with tonal clarity .
I tend to think both are connected with low phase errors or low phase distortion.
This comes from experiences with bass rendition in home-built tube amplifiers, single-driver speakers ( in the midrange ) and some speaker wires I bought recently (!) .
ps. I haven't got any maths to back this up ....
I tend to think both are connected with low phase errors or low phase distortion.
This comes from experiences with bass rendition in home-built tube amplifiers, single-driver speakers ( in the midrange ) and some speaker wires I bought recently (!) .
ps. I haven't got any maths to back this up ....
Generally, this is where listening tests become confusing, especially when reading a description without being there together. I just went through some tuning of an amplifier. Looking at the rough simulations, mainly the difference was frequency response above 10KHz and the input impedance in that range as well. Now the real funny thing is, I could arrange the components in difference sequence between two points, and the sim would show the same thing because, but the consequences were totally different. In one case, the sound field was mixed up, the low notes of a cello was sort of distorted, in another case, the sound field was more well laid out, and you can feel the correct dynamics and timing associated with the performance.
My goodness, take a few days off to enjoy the Real World with family and friends, and the forum goes nuts!
It's been a good discussion though, and I thank Mr. Pimm and other unexpected contributors for their comments. Lots of good postings to think about.
There are things about perception of dynamics in loudspeakers that I find quite mysterious and have no explanation for, not even a likely hypothesis. For example: dynamic tracking in a multiway loudspeaker.
A number of commenters have noticed that perhaps the greatest virtue of horn systems is the way they play quietly ... low levels just sound more natural and true-to-life than low-efficiency loudspeakers. The little bitty microdetails just sound better, for some reason.
A more significant matter is the (subjective) failure of complex multiway loudspeakers to dynamically track at all levels. In other words, if a low-efficiency system is subjectively balanced at an average replay level of 85 dB (pretty common in the high-end biz), it sounds wrong at background-music levels of 50 dB, with dull, slow bass, murky midrange, and scratchy treble. You might think "Fletcher-Munson Effect" until you compare how an efficient loudspeaker sounds at the same 50 dB level ... the murk is all gone, and the more-efficient speaker sounds pretty much the same as it does at higher levels. Why?
This subjective mistracking is annoying enough that many former owners of complex and expensive 3 and 4-way systems have given up and gone the complete opposite direction, single-driver loudspeakers (typically with rear-horn loading).
I know from bitter experience that 3-way speakers are not fun to design, and 4-ways are just about impossible. It's easy enough to make them measure flat, and do the directivity dance that's in fashion now, but subjective integration is a real challenge. The commercially available high-end speakers fail the integration test dismally; what I hear at shows from the $20,000 to $100,000 vendors is disjointed and fatiguing sound.
The real test for an expensive high-end loudspeaker with a zillion drivers and a crossover of unknown complexity is simple: can it play background music at background levels? I'm serious here. Can the $100,000 speaker sound as good as a single-driver table radio at table-radio listening levels? Do you enjoy listening to it, or does it drive you away?
It's surprising how many high-end systems fail the background-music test ... in my experience, most do, with the complex multiway loudspeaker seeming to come completely apart, as if the different drivers are playing different tunes at different times. Play the reviewer-approved $100,000 system at audiophile levels with a 200-watt amplifier, and coherency returns, but turn it down, and the sound comes apart again.
Part of this is listener sensitivity. Like the annoying color-flicker of a slow LCD television, once you get sensitized, it's impossible to ignore. Some listeners give up and embrace the single-driver religion and never look back.
Other folks have noticed that high-efficiency loudspeakers are more consistent at low levels. An entry-level Klipsch speaker that might drive you out of the room at very high levels can sound pretty appealing at low levels, with a surprising dynamic clarity and openness to the sound.
This is all purely subjective talk, and I really don't have much of an idea why this problem of dynamic tracking seems to exist. But I do hear it ... it's the first thing I notice when I go visiting and hear a big, complex, high-dollar system. The desire to leave the room becomes very strong and I find myself making a diplomatic excuse to suddenly go elsewhere. Karna forgoes the diplomacy and just walks out; that's happened at more than one hifi dealer.
This is a big part of the reason I stick with 2-way systems, sometimes with "extensions" for very deep bass (below 50~80 Hz) or treble above 10 kHz. I never really liked the 3-ways I've designed, and the 4-ways were just outright failures. Getting things flat is pretty easy, and directivity control is pretty straightforward these days. If a speaker designed by somebody else is a flop, it doesn't bother me that much ... someone else's problem, not mine. But if it's my speaker that I can't stand to listen to, well, that's a big deal, and a pretty big signal I've gotten something very wrong.
It's been a good discussion though, and I thank Mr. Pimm and other unexpected contributors for their comments. Lots of good postings to think about.
There are things about perception of dynamics in loudspeakers that I find quite mysterious and have no explanation for, not even a likely hypothesis. For example: dynamic tracking in a multiway loudspeaker.
A number of commenters have noticed that perhaps the greatest virtue of horn systems is the way they play quietly ... low levels just sound more natural and true-to-life than low-efficiency loudspeakers. The little bitty microdetails just sound better, for some reason.
A more significant matter is the (subjective) failure of complex multiway loudspeakers to dynamically track at all levels. In other words, if a low-efficiency system is subjectively balanced at an average replay level of 85 dB (pretty common in the high-end biz), it sounds wrong at background-music levels of 50 dB, with dull, slow bass, murky midrange, and scratchy treble. You might think "Fletcher-Munson Effect" until you compare how an efficient loudspeaker sounds at the same 50 dB level ... the murk is all gone, and the more-efficient speaker sounds pretty much the same as it does at higher levels. Why?
This subjective mistracking is annoying enough that many former owners of complex and expensive 3 and 4-way systems have given up and gone the complete opposite direction, single-driver loudspeakers (typically with rear-horn loading).
I know from bitter experience that 3-way speakers are not fun to design, and 4-ways are just about impossible. It's easy enough to make them measure flat, and do the directivity dance that's in fashion now, but subjective integration is a real challenge. The commercially available high-end speakers fail the integration test dismally; what I hear at shows from the $20,000 to $100,000 vendors is disjointed and fatiguing sound.
The real test for an expensive high-end loudspeaker with a zillion drivers and a crossover of unknown complexity is simple: can it play background music at background levels? I'm serious here. Can the $100,000 speaker sound as good as a single-driver table radio at table-radio listening levels? Do you enjoy listening to it, or does it drive you away?
It's surprising how many high-end systems fail the background-music test ... in my experience, most do, with the complex multiway loudspeaker seeming to come completely apart, as if the different drivers are playing different tunes at different times. Play the reviewer-approved $100,000 system at audiophile levels with a 200-watt amplifier, and coherency returns, but turn it down, and the sound comes apart again.
Part of this is listener sensitivity. Like the annoying color-flicker of a slow LCD television, once you get sensitized, it's impossible to ignore. Some listeners give up and embrace the single-driver religion and never look back.
Other folks have noticed that high-efficiency loudspeakers are more consistent at low levels. An entry-level Klipsch speaker that might drive you out of the room at very high levels can sound pretty appealing at low levels, with a surprising dynamic clarity and openness to the sound.
This is all purely subjective talk, and I really don't have much of an idea why this problem of dynamic tracking seems to exist. But I do hear it ... it's the first thing I notice when I go visiting and hear a big, complex, high-dollar system. The desire to leave the room becomes very strong and I find myself making a diplomatic excuse to suddenly go elsewhere. Karna forgoes the diplomacy and just walks out; that's happened at more than one hifi dealer.
This is a big part of the reason I stick with 2-way systems, sometimes with "extensions" for very deep bass (below 50~80 Hz) or treble above 10 kHz. I never really liked the 3-ways I've designed, and the 4-ways were just outright failures. Getting things flat is pretty easy, and directivity control is pretty straightforward these days. If a speaker designed by somebody else is a flop, it doesn't bother me that much ... someone else's problem, not mine. But if it's my speaker that I can't stand to listen to, well, that's a big deal, and a pretty big signal I've gotten something very wrong.
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One of the simple questions may be is it the electronics running at extremely low levels that is causing the problem? We all should understand by now that at less than 1/3 power output things become quit difficult for many amplifier designs and I am wondering if this is some of the phenomena that we think we are hearing from the speakers themselves or are we hearing the amplifier distortion and increased noise floor? I am just thinking out loud here, not evidence but thinking what is going on in the rest of the system as we decrease that amplifier output.
That specific explanation doesn't make sense - it would have to be the opposite (sounding better at lower amplifier output). However, even though I've certainly noticed the correlation too, I'm not convinced there really are examples where simple in-room measurements don't explain an efficient speaker sounding better at low volumes than an inefficient one.
That can happen but it's not enough to explain what's going on in compression drivers, for instance. I run both Lynn's Ariels and the Azura AH425/GPA288H's with similar SE tube amps that are very good at low levels. The compression drivers work better at low listening levels , despite the amps working at VERY low signal levels on those with 109db/w.
I have a suspicion that there are mechanical threshold/hysteresis effects that start to swamp the signals at very low levels of motion in cone speakers, that don't happen with compression drivers where the diaphragm is moving on metal or mylar flexures, with very low hysteresis and 'clean' elasticity .
It does also seem this is supported by speakers with heavy rubber/foam roll-surrounds being more 'dead' at low sound levels than those with pleated/concertina surrounds. the Supravox 285GMF for instance has lovely realistic bass and presence at low signal levels.
I have a suspicion that there are mechanical threshold/hysteresis effects that start to swamp the signals at very low levels of motion in cone speakers, that don't happen with compression drivers where the diaphragm is moving on metal or mylar flexures, with very low hysteresis and 'clean' elasticity .
It does also seem this is supported by speakers with heavy rubber/foam roll-surrounds being more 'dead' at low sound levels than those with pleated/concertina surrounds. the Supravox 285GMF for instance has lovely realistic bass and presence at low signal levels.
Thanks Lynn. Does it still sound good when you turn it down, or does it "come alive"when you turn it up? Two common problems that were demonstrated to me almost 30 years ago in Paris. I still don't understand why, either.But it certainly is a common phenomenon.
My own gear is pretty well-behaved in this respect ... but then again, it's all Class A vacuum-tube throughout the signal path, with the number of coupling caps kept to a minimum (two in the Monarchy DAC, and one in the tweeter crossover). I was a bit surprised to find that sigma-delta digital converters tend to sound dull on low-level material, while the better-quality ladder/R2R converters (Philips TDA 1541, Burr-Brown PCM63, 1702, and 1704) have quite noticeably better dynamics.
The drivers in the Ariel don't drop into the murk as readily as more modern audiophile drivers ... different spider and surround, or better magnetic design? The AH425 and Radian 745Neo and Altec/GPA 288 have sterling low-level resolution and tonality, no problems there at all.
Tonality and resolution at low levels was one of the big differences between the JBL 2226 and the GPA 416-Alnico. The JBL sounded flat and dull, while the 416-Alnico had the trademark Alnico sparkle to the sound, and most noticeably at low levels. If you want to hear the difference between magnet materials, and overhung vs underhung voice coils, low-level listening is where it is most apparent. IslandPink, please tell us more about the sound of the Supravox 285GMF, especially how it compares to prosound drivers.
If the sound goes dead at low levels, that's a sign that something's wrong ... it doesn't happen with live acoustic music, where playing quietly has a special beauty all its own. The sound of a harpsichord is a travesty on most high-end audio systems, but is really quite beautiful on a 5~7" full-range speaker, or a high-efficiency system with the right magnet design. In real life, the instrument has an amazing shimmery sound that only rarely makes it through the recording and playback process. I've heard Bosendorfer pianos sound like that, too ... an almost bell-like sonority that almost never comes through on recordings.
I like techno and electronic music as much as anyone ... there certainly was some terrific stuff at the last ETF I attended ... but there are musical instruments have ravishingly beautiful sound when you hear them in person, standing or sitting a few feet away. It takes a very special system to get even an approximation of the beauty of the live performance.
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The Monarchy N24, with Burr-Brown 1704 converters, which support 44.1/16, 88.2/24, and 96/24 PCM through the coaxial S/PDIF input. The current/voltage conversion is passive, followed by a 6DJ8 SRPP gain stage, an output RCA in parallel with a volume control, which drives a 6DJ8 SRPP line stage. This directly drives the input of the Karna amplifiers.
My somewhat controversial articles about DACs are here: Part One, and Part Two. The Monarchy is still my favorite, but have not heard the Metrum HEX or Audio-GD Reference 10.32 yet.
Just checked the Supravox prices. The 285 and 400 Alnico (2000 series) and field-coil (EXC) prices are seriously up there, but they are pretty famous in Europe, based on the conversations I had many years back at the ETF.
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Many amplifiers have THD curves that increase as volume decreases. In my (limited) experience it's caused by me not having designed in enough bias current, combined with device characteristics that change as the devices turn off.
thoglette,
I think that it is more common than most think that the distortion numbers actually increase with decreasing output, and especially below the 1/3 output level. This is the reason that long term power handling is checked at 1/3 power output as this is commonly where the most heating of the output devices occurs. I know most people think that the problems are at high power but that is not really the case if the amplifier is not clipping the outputs. The THD is lower at higher output, but it also is dependent on the speakers impedance curve how this all works out.
Lynn you are saying that you are using vacuum tube class A amplification but you don't say whether this is SE or not? I am not a real fan of extremely low output tube amplifiers though I have used some Cary amps this way but only for the upper frequencies driving compression drivers that were crossed over at 1.6Khz and above. I gave up on tubes amplifiers when I sold my old McIntosh amps, not the nice chrome models,. but ones that ran on 6BG6 power tubes. Not the best sounding amps to say the least.
I think that it is more common than most think that the distortion numbers actually increase with decreasing output, and especially below the 1/3 output level. This is the reason that long term power handling is checked at 1/3 power output as this is commonly where the most heating of the output devices occurs. I know most people think that the problems are at high power but that is not really the case if the amplifier is not clipping the outputs. The THD is lower at higher output, but it also is dependent on the speakers impedance curve how this all works out.
Lynn you are saying that you are using vacuum tube class A amplification but you don't say whether this is SE or not? I am not a real fan of extremely low output tube amplifiers though I have used some Cary amps this way but only for the upper frequencies driving compression drivers that were crossed over at 1.6Khz and above. I gave up on tubes amplifiers when I sold my old McIntosh amps, not the nice chrome models,. but ones that ran on 6BG6 power tubes. Not the best sounding amps to say the least.
Dumptruck,
I guess the question becomes do people who are using high efficiency speakers also use lower power amplifiers better matching the devices? Otherwise I can say I have no idea why this would be so. The mass of a dome tweeter isn't any higher than a compression driver diaphragm so that isn't the cause, magnetic energy in the gap can be similar in both cases so that shouldn't matter either. I know what you are saying about clean sound out of a compression driver at low output and perhaps it has more to do with the actual loading or coupling of the device to the air with a proper horn than anything else? The impedance match to the air is obviously better with the compression driver and that is a good an argument as any I can think of right now.
I guess the question becomes do people who are using high efficiency speakers also use lower power amplifiers better matching the devices? Otherwise I can say I have no idea why this would be so. The mass of a dome tweeter isn't any higher than a compression driver diaphragm so that isn't the cause, magnetic energy in the gap can be similar in both cases so that shouldn't matter either. I know what you are saying about clean sound out of a compression driver at low output and perhaps it has more to do with the actual loading or coupling of the device to the air with a proper horn than anything else? The impedance match to the air is obviously better with the compression driver and that is a good an argument as any I can think of right now.
Thanks, Lynn.
Have you heard either the AMR CD-777 CD player (which I own) or the AMR DP-777 DAC?
good explanation about the compression driver, providing the amp does not have crossover distortion as described by thoglette
The McIntosh amps, for reasons known only to them, were biased pretty far into B, with very little A. This resulted in quite a lot of low-level distortion compared to other Class AB tube amps of the day. It was partially masked by local cathode feedback derived from a tertiary winding on the output transformer, but the drawback of that technique are tricky stability issues that can arise from interwinding capacitance.
The Karna and Amity amplifiers, although PP, are pretty much the opposite in every other respect. The output tubes are very low-distortion direct-heated triodes, which have about 10~20 times lower upper-harmonic distortion than pentodes. The quiescent bias is actually higher than an equivalent SE amplifier, around 70 to 85 mA per tube, which puts the amplifiers into extra-deep Class A. I found that raising the bias from the usual recommended 60 mA (for 300B's) to 70~85 mA reduced the distortion by half, with the greatest improvement for upper harmonics. This removes the need for global or local feedback, which makes the amplifier unconditionally stable with any load.
Another unusual feature is that each output tube is driven by a symmetric pair of Class A PP driver tubes, instead of the usual one-driver-per-output of conventional RC-coupled designs. This means when the output tubes go into the grid-current region, or HF content has to drive the 60~70 pF Miller capacitance of the output tube, or the driver section needs to overcome the somewhat nonlinear grid-load of the power tube, it can do so with very low distortion and accurate summation of the Class A PP pair. The distortion of the driver section is about 5x lower than an equivalent RC-coupled amplifier, and has enough power to drive the output tubes into Class A2 or AB2 (about 20 to 30V of positive grid drive is available).
A subtle improvement is also provided by the transformer input, which prevents system-wide ground loops by breaking the (ground-side) galvanic connection between the amplifier and the source components, as well as filtering off any RFI interference that might get into the input section.
Power output is 15 watts at less than 0.1% distortion (Class A1), or 30 watts at 3% distortion (the A2 or AB2 region, depending on the current draw). The input & driver sections have completely independent B+ supplies from the output section, which runs around 500 to 550V. There are no electrolytic filtering capacitors in the power supply, so voltages above 500V are acceptable. Since all stages in the amplifier are balanced, there are no turn-on thumps or bangs, or turn-off transients.
Subjectively, it does not sound like "Golden Age" PP-pentode amplifiers from the Fifties, or modern versions with similar circuitry, nor does it sound like 2 to 8-watt SET amplifiers with RC-coupled circuits. Transparency and tonality are similar to 45-based SET amplifiers, although with about 10~15 dB more headroom.
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No, I have not. I have corresponded with Thorsten and have a lot of respect for his designs, although we part company about our favorite converters ... he's a TDA 1541 guy, and I like the Burr-Brown family the best. Both are really, really good, though.
Thorsten uses the TDA 1541 ladder converter for 44.1/16 Red Book CD's, and a sigma-delta converter for high-res content. Considering how fantastic the Burr-Brown ladder converters sound with 88.2/24 and 96/24 content, I find this an odd choice, but Thorsten's the expert here.
I have noticed that audiophiles who like DACs that use sigma-delta converters listen to Class AB transistor amps, usually with low-efficiency loudspeakers, while the ladder/R2R enthusiasts often have moderate-power valve amplifiers, typically in the 3 to 30-watt range.
This preference can be seen two ways: folks who believe that tube amps are "euphonious" may think that the 2nd and 3rd-harmonic distortion of the tube amplifiers conceals the gritty-sounding monotonicity errors of ladder/R2R converters, and a sigma-delta converter allied with a Class AB transistor amplifier is more "accurate".
I fall in the other camp. I don't find Class AB transistor amplifiers "accurate" sounding at all; most of them sound very electronic and artificial-sounding to me, and are definitely not as transparent and revealing as the Karna and Amity amplifiers.
With the amplification I use, the majority of the sigma-delta converters sound drab and dynamically compressed, almost as if the PCM source had suffered MP3 compression. The ESS Sabre 9018 seems to be the exception, but every DAC I've auditioned with the ESS 9018 used opamps in the signal path, leaving me wondering what the 9018 really sounds like.
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