|
Post by boomzilla on Apr 3, 2020 15:45:59 GMT -5
Man...am I going to have to try this at the office?! I'll need an XPA-4. Try two XPA-2s using one channel for each speaker?
|
|
klinemj
Emo VIPs
Honorary Emofest Scribe
Posts: 14,689
|
Post by klinemj on Apr 3, 2020 16:23:36 GMT -5
And bi-amp them all using a matched set of EIGHT PA-1s! Wretched excess... So, totally mono-a-mono...the Ultimate Monoblock Society Founder! As for mounting them up...just have Dan whip up some custom cabinets for you! Mark
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 3, 2020 16:48:40 GMT -5
...Quick questions, 1) do you currently have the Pendragons for an A B comparison and 2) are the Pendragons you listened or are listening to the updated versions? Hi 2shimei - No, I don't have my Pendragons anymore. I let them go to a friend who really wanted them. No, my Pendragons were not the updated versions. ...I enjoyed your write up on the Pendragons. What stuck out to me was when stating"If you choose to sit directly on the horizontal axis of the tweeter array and within its vertical envelope, you’ll hear any treble issues in the recording or in the upstream components. With high quality components and good recordings, this isn’t a problem." I find this very interesting because I've recently made component changes to my system [on my 3rd amp within 4 months now]. I understand 1 speaker may be more detailed thereby exposing any weakness in upstream components. However, perhaps you could take the time if convenient to touch upon why some speakers don't reveal component quality issues? And why do some speakers play pretty bad recordings/formats ok when other speakers expose issues in not only components but musical recording? Excellent questions, I'll give them my best shot, but others may differ... A speaker that I recently had that was very forgiving was a vintage Dynaco A25: The two-way Dynacos do most of their midrange with that woofer, and the lack of quick transient response just relaxes the entire presentation. The speakers image well, and sound sweet and rich, but they just aren't the last word in midrange resolution. If I had to pontificate on why some speakers are so analytical toward upstream components, I'd put my finger on the upper midrange to lower treble response. The "faster" a speaker responds in this particular frequency band (a range that the human ear is HIGHLY sensitive to), the greater the listener can hear "into the recording," but also the more you can hear recording flaws. Now some speakers present a "fast" impression in this critical range by overshooting the waveform and distorting or else by slightly emphasizing this "presence" range. THOSE speakers grate on the ears very quickly. And since it's a very difficult range to get right, lots of money gets spent on design there. It's difficult to get drivers that are both quick and have a wide bandwidth with uniform dispersion. All of those characteristics matter greatly. If you're trying to get a smooth blend between drivers, there are books written about balancing the critical factors - speed, bandwidth, and dispersion. One of the greatest speaker designers that ever lived, IMHO, was the late, great Jim Thiel. As a lot of people here probably know I own Tekton speakers, and I've struggled with them for some time until recently. I plan to write another page of my own amateur review on a different Tekton product but the issue of how telling or critical the speakers are is almost like them forcing a conversation and shifting the topic matter to the components upstream I think that the Tektons are probably getting better since I bought mine. In fact, if I ran across a used pair of Double Impact SE models, I'd be hard-pressed to resist. If I won the lottery, I might even consider some 1812s - But I digress... I'd think (speculating, here) that with a Tekton model using the midrange drivers, you'd get a much smoother frequency response (particularly in the critical midrange) than with the 10-inch, two-way models such as the Pendragon. But since I haven't heard either the newest Pendragons OR the new Tekton designs using the "circular tweeter array," I'm just guessing. Best of luck! Boom, First I'd like to thank you for inspiring an "arm chair reviewer" such as myself. And in helping me understand more and how to articulate what I'm hearing. Regarding this paragraph of what you writ: "If I had to pontificate on why some speakers are so analytical toward upstream components, I'd put my finger on the upper midrange to lower treble response. The "faster" a speaker responds in this particular frequency band (a range that the human ear is HIGHLY sensitive to), the greater the listener can hear "into the recording," but also the more you can hear recording flaws. Now some speakers present a "fast" impression in this critical range by overshooting the waveform and distorting or else by slightly emphasizing this "presence" range. THOSE speakers grate on the ears very quickly. And since it's a very difficult range to get right, lots of money gets spent on design there. It's difficult to get drivers that are both quick and have a wide bandwidth with uniform dispersion. All of those characteristics matter greatly. " My question regards upstream components of speakers that are designed with low mass etc in the extravagant MTM arrays we see from brands such as Tekton and dare I mention in the same sentence McIntosh. In case anyone doesn't know about the MTM arrays I refer I'm including a picture of a McIntosh array: My question is about amplifiers [upstream components]. If I understand correctly it seems that such "lightening quick" arrays demand some sort of "magic" from an amplifier. Perhaps you'd briefly touch upon or comprehensively exhaust [if you'd like at your convenience ] as to what kinda manufacturer specifications may help in identifying amps that keep discipline of the speakers in which they are put in control over these kinda arrays? I acknowledge that initially I looked at the overall system the wrong way as I pieced it together over the years thinking, that each component works independently from one another. Recently, it is came to light that the amp/speaker combination may be more sensitive toward pairing than other components? You stated, " Now some speakers present a "fast" impression in this critical range by overshooting the waveform and distorting or else by slightly emphasizing this "presence" range." I suppose an equal culprit could also be the amplifier losing control of the speakers? For example, as I wiped the place clean from under the last amp and placed the new amp into place something immediately came into light during play. It was almost as someone reached out and seized the speaker's juggler while they tried to shake themselves free but without success. The treble area became so smooth I thought about going to the back of the speakers and unplugging them just to see if milk and honey were pouring out of the wires. Regarding the DI and 1812s I never heard them either. I almost purchased the 1812s but at the time stepping away from something furniture grade fashionable was a big giant leap for me. The Ulfs were not horrible looking, not that the 1812s are, but to me they look a little more DIY or a tower I'd expect to see in the corners of a fancy night club. Enjoy, William
|
|
|
Post by DavidR on Apr 3, 2020 16:49:40 GMT -5
My AR Towers of Power
AR10Pi + AR91
|
|
|
Post by thompson12 on Apr 3, 2020 19:02:50 GMT -5
The Pendragon speakers (PDs from here out to type less) had a BIG advantage in the bass. Their dual 10" drivers lorded it over the two 8s in the T2s. The PDs could also be equalized for slightly lower bass. The T2s just go so low and absolutely no lower. The PDs, being a far higher sensitivity speaker, could play more loudly with a lot less power. But there the PDs advantages end. And end abruptly. The T2s, being a 3-way speaker have a midrange driver that the PDs lack. That midrange driver makes the transition through the midrange absolutely seamless. I could always hear a slight softening of the PDs where those 10" woofers started to beam before the tweeters kicked in. And that change in definition and dispersion in the PDs critical midrange, once noticed, was impossible to ignore. You could sit directly on-axis with the PDs to reduce some of the crossover issues, but when you did, the tweeters were now too bright. You could sit off-axis to tame the tweeters, but when you did, the PDs crossover-range problems became more prominent. Since "the music lives in the midrange," I'd have to say that the T2s are the better speaker. But the dynamics and jump factor of the PDs were hard to leave. I've not heard the Tekton Double Impact. It would probably retain the virtues of the PDs and fix the PDs crossover issues, but I haven't heard any (and they cost 50% more than the PDs). A really dynamic front end gives the T2s some of the life and jump factor of the PDs - in fact my Auralic Vega (used as a DAC and digital preamp) seem to match the Emotiva PA-1s up with the T2s really, really well. But the PDs sounded their best with a much wider variety of amps and preamps. "Their best" of course, still being marred by their crossover issues. If you're a head-banger, the PDs are the speaker for you. If you want a mix of chamber music on up, the T2s are more versatile. Keeping in mind that the T2s are half the price of the PDs, they win the "value for the money" race by a mile. But lots of folks love their PDs. YMMV Boomzilla Wow nice Boom thanks for your detailed opinion much appreciated Mitch
|
|
|
Post by tchaik on Apr 3, 2020 19:58:26 GMT -5
reminds what we did with double advent speakers back in the early 70's. we couldn't afford two pair, but a buddy and I who each owned a pair tried them together a couple times. what fun we had.
|
|
|
Post by boomzilla on Apr 3, 2020 21:56:31 GMT -5
Hi @shimei and thompson12 - First, thank you for your kind words regarding my prose. But as I've said before, my opinion and a buck will get you a McCoffee at the drive through! LOL Take NOTHING that I say as any kind of gospel, but y'all are too smart to do that anyway. So regarding amplifiers, and more specifically, the amplifier-speaker interface. Again, books have been written about this stuff, and there are a LOT of folks on this Lounge who know more and understand better than I. But the majority of them ( KeithL excepted) generally aren't prone to long and detailed discussion of it. In fact, I could probably write a book on just the stuff that I've learned from KeithL, DYohn, klinemj, garbulky, and audiobill, just to name a few. Please forgive me if your name isn't in the previous list, but I'm coffee-deprived, and just shooting from the hip for the moment... So what do I think I know about speaker-amplifier combos? 1. Speakers with low impedances (at ANY frequency) require amplifiers that can develop a lot of current. Some speaker-manufacturers seem to think that if their speakers' impedances don't have less-than-four-ohm dips in the middle of the audio range, then "any amplifier can drive them." This is a damned marketing lie. Electrostatic speakers, for example, have impedances that typically begin a precipitous decline at about 10KHz, and continue falling as the frequencies increase. The manufacturer claims that because the impedance doesn't get REALLY low until above 20KHz, that any amplifier can drive their speakers. They're wrong. I blew up a nice, high-quality and relatively expensive mono block amplifier into these electrostatic speakers with NO SIGNAL AT ALL going through. I turned on the amplifier and it instantly smoked. The worst part of all is that the amp was on loan to me from another generous Lounge member. Fortunately, the manufacturer fixed the amp under warranty - otherwise I'd have paid for it myself, of course, but I put the fault directly on the speaker impedance. The speaker company Apogee, back in the day, made ribbon speakers with impedances down below two ohms in the lower audio portion of the frequency response. The Apogees were famed as amplifier killers, and only the big Krell amps were reputed to be able to "arc-weld" sufficiently to drive the speakers. Even Magnepan speakers, with their mild four-ohm impedance want high current to sound dynamic. So I'd say that one of the first things to consider when choosing an amplifier is "does it have the current to make your speakers sing?" What amplifiers have high current? The Hegel brand is reputed to be a good high-current amp. The Crown PSA-2 amp (now discontinued), ditto. The Electron Kinetics Eagle 7a (also discontinued), ditto. And of course, the Krell amps, also historical artifacts, do good jobs with low impedance speakers. Now it must be said that almost any "pro" amplifier is designed to drive low impedances, and they will also do so for long time periods at high outputs without damage. But the price you (generally) pay is high fan noise and poorer sound quality. Curiously, the great equalizer for low impedance is an output transformer. Tube amps with two-ohm taps are damned near invincible (and sound good too). My rule of thumb is to select an amplifier rated for half the impedance your speakers are expected to be. Got eight-ohm speakers? Buy an amp rated for four-ohms. Got four-ohm speakers? Buy an amp rated for two, etc. 2. The complexity of the crossover makes a huge difference in the quality of the amplifier needed. Some cheap two-way box speakers use no inductor for the woofer at all, relying on the natural inductance of the woofer's voice coil to roll the woofer's frequency response off at some predictable frequency. The tweeter then gets a single, cheap capacitor to roll off the low frequencies from the tweeter and voilá - a salable box! If I remember right, the Thiel 5i crossover uses something like about 30 elements. This not only isn't cheap, but it also EATS amplifier power. All of those coils and resistors in the crossover dissipate audio wattage as heat. Additionally, the crossover elements modify the phase of the audio signal at the crossover frequencies and cause ferocious back EMF at some frequencies. Again, it takes a muscular, stable, and well-designed amp to deal with complex crossover topologies. 3. The sensitivity of the speaker, the size of your room, and your volume preferences all combine to have a LOT to do with the amp you'll need. The power to loudness curve is logarithmic, and it takes a LOT more power to get even a little more volume. Now the good news is that the vast majority of us listen at 90 decibels (dB) at our listening position or lower 99.5% of the time. The other 0.5% of the time, we’re trying to impress others with how loudly our system can play or else hosting parties where the guests expect rock-concert volumes. The vast majority of speakers produced these days can put out about 90 dB (plus or minus a tiny bit) with only ONE WATT of power. This means that the majority of your listening doesn’t really need much more than that. In fact, I have played difficult-to-drive speakers with my 12 watt tube amps, and (provided you don’t try stupid volumes) they suffice just fine, thank you. BUT - let a friend come over, and suddenly 10x or even 100x the power is needed for said friend to test the limits of the system and scare the cat. And if you’re a movie aficionado, then “movie theater volumes” are the norm, not the exception. Now if you do have “modern” speakers designed for “normal” sensitivity of 90 dB at 1 watt at one meter, then you can probably drive them OK with even an AVR. They may or may not sound good that way, but the speaker manufacturer knew that if their products weren’t capable of being driven by the AVR, they wouldn’t be selling many… And it takes some trade-offs to get that sensitivity. Usually what gets culled from the speaker budget first is bass response (after all, the schmuck who buys these will have a subwoofer, yes?). So it isn’t unusual these days to have really big boxes housing small, cheap drivers that just don’t have any bass to speak of below about 50 Hz. And while I’m on this rant, let me also opine (loudly) that if you believe ANY speaker manufacturer’s specs on bass extension, I’ve got this lovely bridge in Brooklyn that I can offer to you (only for today) at this AMAZINGLY low cash price! So back to the power amplifier / speaker interface. You know your ears, your friends, and your listening habits. You want volume? Bring watts! And finally, let’s cut to the chase. What brands do I think are the “dreadnaughts” of the amplifier fleet? And again, this is mine own opinion - you’re welcome to disagree… Near the top of the heap is McIntosh. Their premiere solid-state (and tube) amplifiers are fitted with an “autoformer” (Mac’s terminology) that transformer-couples to different speaker impedances in such a way that their output transistors see a semi-constant impedance. This allows the amplifier to effectively “loaf” most of the time, and results in consistent performance, cool operation, long service life, and high resale value. These puppies are NOT cheap - and they (in many situations) aren’t the last word in bass control, but they make up for it elsewhere. One of the best sounding amps I’ve ever heard was a Vacuum-Tube Logic (“VTL”) Compact-100 tube mono block. The sound of these amps, paired with a vintage pair of Klipsch LaScalas was enough to bring tears to your eyes. But I wouldn’t recommend the VTLs at all. Their reliability is so poor (and replacement parts so impossible to find) that you’d be wasting your money. Hegel is another manufacturer with a reputation for being able to drive difficult speakers. I, personally, find the sound of their amps somewhat sterile, but many love them. Bryston is another “carriage-trade” manufacturer whose amplifiers supposedly do well with difficult speakers, but not having owned one in a long time, I couldn’t say what they sound like. Odyssey Audio, Audio by van Alstine, and Mark Levinson are also supposed to be good, but I’ve never heard an Odyssey, and haven’t heard a van Alstine or a ML in 30 years. Parasound’s big bruiser mono block amps are supposed to be da shiz, but I’ve not heard one of them either. So where does Emotiva stand among this herd? I was expecting the question, and must preface any comments by saying that many (most?) on this Lounge disagree with me. But here goes: Some of the Emotiva products are among the best I’ve heard at any price. But it depends (strongly) on the model. Among my personal all-time all-stars of Emotiva (and in order of sound quality AND the ability to drive difficult loads): First place - The Generation-2 XPA-1. Many will ask why not the XPR series, and having owned both I found the XPR to be less dynamic than the XPA models. The gen-2 XPA-1s just have unlimited power coupled with lively dynamics that make almost any speaker sound its best. Second place - The Class-D PA-1 amps with their B&O modules. These lack the power to drive difficult loads, but within their limits, they sound almost as good as the amp above. Third place - The Generation 2 XPA-2. Although not as muscular as the mono blocks, these are no slouches. More power than the PA-1 amps, but not quite as transparent, to my ears. Honorable mentions - Generation-1 X-series amps, mono or stereo (the multi-channel ones didn’t sound as good to me). Worst of Emotiva - If you own any of these, I apologize to you for this opinion, but I’m being honest… The XPA-1L models and any of the Generation-3 X-series. They just don’t belong in the category of Emotiva’s best, IMHO. Many love their sound; I don’t. OK - I’ve had my say - let the hate mail begin! LOL Happy amp shopping to you all - Boom
|
|
klinemj
Emo VIPs
Honorary Emofest Scribe
Posts: 14,689
|
Post by klinemj on Apr 3, 2020 22:13:48 GMT -5
Is there a magic code word I need to use to get my McCoffee?
Or, do I just pull up and say "Boom sent me"?
I'm retired and trying to save money...
And, thanks for the mention...tell your local Panera that you are a friend of Sarah's cousin Mark. She's a VP there and can hook you up.
Mark
|
|
|
Post by Perpendicular on Apr 3, 2020 22:17:25 GMT -5
Boom,
Didn’t the Emotiva Stealth Monitors use an XPA-1?
|
|
|
Post by boomzilla on Apr 3, 2020 22:19:36 GMT -5
Boom, Didn’t the Emotiva Stealth Monitors use an XPA-1? Since the XPA-1 was twice as large as the Stealth monitor and about three times as heavy, I doubt it - but as always, I could be wrong...
|
|
|
Post by Perpendicular on Apr 3, 2020 22:26:48 GMT -5
Boom, Didn’t the Emotiva Stealth Monitors use an XPA-1? Since the XPA-1 was twice as large as the Stealth monitor and about three times as heavy, I doubt it - but as always, I could be wrong... Well, hopefully, they didn’t included the outer chassis with the Stealth Monitors.
|
|
KeithL
Administrator
Posts: 9,901
|
Post by KeithL on Apr 4, 2020 0:01:32 GMT -5
The Stealth 8's do have dual Class AB amps... but they are not XPA-1's.
Boom, Didn’t the Emotiva Stealth Monitors use an XPA-1? Since the XPA-1 was twice as large as the Stealth monitor and about three times as heavy, I doubt it - but as always, I could be wrong...
|
|
KeithL
Administrator
Posts: 9,901
|
Post by KeithL on Apr 4, 2020 0:35:20 GMT -5
I agree with most of what Boomzilla had to say... with a few minor exceptions....
First off, you're absolutely right that some electrostatic speakers have impedances that drop ridiculously low at high frequencies (one notorious model drops to 0.6 Ohms at 20 kHz.) And, yes, if an amplifier tries to drive significant power into such a low impedance, and isn't designed for it, then it can definitely have serious problems. However, that is not why that amplifier you tried to use smoked itself when it wasn't being asked to drive significant power into that load. The reason is that many electrostatic speakers offer an extremely reactive load (you're talking about a panel, which is a pure capacitor, connected through a transformer). And that "nice quality expensive monoblock amplifier" was not stable into the very reactive load presented by the electrostats... so it oscillated...
The other thing you need to understand is that transformers don't actually deliver a constant impedance...
What a transformer does is to multiply or divide the load impedance by a fixed multiple. So, for example, regardless of whether the speaker is 2 Ohms or 8 Ohms, that McIntosh amp "sees" an output load of 4 Ohms. HOWEVER, if the impedance of the speaker varies, the impedance seen by the output stage will still vary proportionally. (And some transformers will do really odd things if they're presented with impedances they aren't designed for.)
There are two legitimate benefits of transformers.....
1)
They allow the internal amplifier circuitry to be optimized for a single output impedance while still being able to drive different impedance speakers.
So, for example, if the amplifier puts out the most power into a 4 Ohm load, it will see both 4 Ohm speakers and 8 Ohm speakers as a 4 Ohm load ("matched" by the transformer). This enables it to output its maximum rated output power into both 4 Ohms and 8 Ohms (or into whatever impedances the transformer has taps for). (So, instead of 200 watts/8 Ohms and 400 watts/4 Ohms, it can deliver 400 watts into either. This was a very big deal when amplifier power was a limited commodity.)
2) True transformers do not pass DC current from primary to secondary. So, even if the output stage of the amplifier shorts to one of the rails, it will never apply DC to your speaker and damage it. Note that McIntosh does not use true transformers... they use autoformers... which are not fully isolated. However, if the output stage were to short, the autoformer would present a low impedance to the resulting DC, and ensure that a fuse would blow VERY quickly. The down-side is that even the best transformers cause some amount of distortion and phase shift. This makes it more difficult to design amplifiers with transformers for a variety of related reasons.
It also takes VERY large, heavy, and expensive transformers to limit these to acceptable levels.
Incidentally, and interestingly, the ICEpower modules we use in the PA-1 are rated to deliver maximum short term power into a 2.7 Ohm load.....
Hi @shimei and thompson12 - First, thank you for your kind words regarding my prose. But as I've said before, my opinion and a buck will get you a McCoffee at the drive through! LOL Take NOTHING that I say as any kind of gospel, but y'all are too smart to do that anyway. So regarding amplifiers, and more specifically, the amplifier-speaker interface. Again, books have been written about this stuff, and there are a LOT of folks on this Lounge who know more and understand better than I. But the majority of them ( KeithL excepted) generally aren't prone to long and detailed discussion of it. In fact, I could probably write a book on just the stuff that I've learned from KeithL , DYohn , klinemj , garbulky , and audiobill , just to name a few. Please forgive me if your name isn't in the previous list, but I'm coffee-deprived, and just shooting from the hip for the moment... So what do I think I know about speaker-amplifier combos? 1. Speakers with low impedances (at ANY frequency) require amplifiers that can develop a lot of current. Some speaker-manufacturers seem to think that if their speakers' impedances don't have less-than-four-ohm dips in the middle of the audio range, then "any amplifier can drive them." This is a damned marketing lie. Electrostatic speakers, for example, have impedances that typically begin a precipitous decline at about 10KHz, and continue falling as the frequencies increase. The manufacturer claims that because the impedance doesn't get REALLY low until above 20KHz, that any amplifier can drive their speakers. They're wrong. I blew up a nice, high-quality and relatively expensive mono block amplifier into these electrostatic speakers with NO SIGNAL AT ALL going through. I turned on the amplifier and it instantly smoked. The worst part of all is that the amp was on loan to me from another generous Lounge member. Fortunately, the manufacturer fixed the amp under warranty - otherwise I'd have paid for it myself, of course, but I put the fault directly on the speaker impedance. The speaker company Apogee, back in the day, made ribbon speakers with impedances down below two ohms in the lower audio portion of the frequency response. The Apogees were famed as amplifier killers, and only the big Krell amps were reputed to be able to "arc-weld" sufficiently to drive the speakers. Even Magnepan speakers, with their mild four-ohm impedance want high current to sound dynamic. So I'd say that one of the first things to consider when choosing an amplifier is "does it have the current to make your speakers sing?" What amplifiers have high current? The Hegel brand is reputed to be a good high-current amp. The Crown PSA-2 amp (now discontinued), ditto. The Electron Kinetics Eagle 7a (also discontinued), ditto. And of course, the Krell amps, also historical artifacts, do good jobs with low impedance speakers. Now it must be said that almost any "pro" amplifier is designed to drive low impedances, and they will also do so for long time periods at high outputs without damage. But the price you (generally) pay is high fan noise and poorer sound quality. Curiously, the great equalizer for low impedance is an output transformer. Tube amps with two-ohm taps are damned near invincible (and sound good too). My rule of thumb is to select an amplifier rated for half the impedance your speakers are expected to be. Got eight-ohm speakers? Buy an amp rated for four-ohms. Got four-ohm speakers? Buy an amp rated for two, etc. 2. The complexity of the crossover makes a huge difference in the quality of the amplifier needed. Some cheap two-way box speakers use no inductor for the woofer at all, relying on the natural inductance of the woofer's voice coil to roll the woofer's frequency response off at some predictable frequency. The tweeter then gets a single, cheap capacitor to roll off the low frequencies from the tweeter and voilá - a salable box! If I remember right, the Thiel 5i crossover uses something like about 30 elements. This not only isn't cheap, but it also EATS amplifier power. All of those coils and resistors in the crossover dissipate audio wattage as heat. Additionally, the crossover elements modify the phase of the audio signal at the crossover frequencies and cause ferocious back EMF at some frequencies. Again, it takes a muscular, stable, and well-designed amp to deal with complex crossover topologies. 3. The sensitivity of the speaker, the size of your room, and your volume preferences all combine to have a LOT to do with the amp you'll need. The power to loudness curve is logarithmic, and it takes a LOT more power to get even a little more volume. Now the good news is that the vast majority of us listen at 90 decibels (dB) at our listening position or lower 99.5% of the time. The other 0.5% of the time, we’re trying to impress others with how loudly our system can play or else hosting parties where the guests expect rock-concert volumes. The vast majority of speakers produced these days can put out about 90 dB (plus or minus a tiny bit) with only ONE WATT of power. This means that the majority of your listening doesn’t really need much more than that. In fact, I have played difficult-to-drive speakers with my 12 watt tube amps, and (provided you don’t try stupid volumes) they suffice just fine, thank you. BUT - let a friend come over, and suddenly 10x or even 100x the power is needed for said friend to test the limits of the system and scare the cat. And if you’re a movie aficionado, then “movie theater volumes” are the norm, not the exception. Now if you do have “modern” speakers designed for “normal” sensitivity of 90 dB at 1 watt at one meter, then you can probably drive them OK with even an AVR. They may or may not sound good that way, but the speaker manufacturer knew that if their products weren’t capable of being driven by the AVR, they wouldn’t be selling many… And it takes some trade-offs to get that sensitivity. Usually what gets culled from the speaker budget first is bass response (after all, the schmuck who buys these will have a subwoofer, yes?). So it isn’t unusual these days to have really big boxes housing small, cheap drivers that just don’t have any bass to speak of below about 50 Hz. And while I’m on this rant, let me also opine (loudly) that if you believe ANY speaker manufacturer’s specs on bass extension, I’ve got this lovely bridge in Brooklyn that I can offer to you (only for today) at this AMAZINGLY low cash price! So back to the power amplifier / speaker interface. You know your ears, your friends, and your listening habits. You want volume? Bring watts! And finally, let’s cut to the chase. What brands do I think are the “dreadnaughts” of the amplifier fleet? And again, this is mine own opinion - you’re welcome to disagree… Near the top of the heap is McIntosh. Their premiere solid-state (and tube) amplifiers are fitted with an “autoformer” (Mac’s terminology) that transformer-couples to different speaker impedances in such a way that their output transistors see a semi-constant impedance. This allows the amplifier to effectively “loaf” most of the time, and results in consistent performance, cool operation, long service life, and high resale value. These puppies are NOT cheap - and they (in many situations) aren’t the last word in bass control, but they make up for it elsewhere. One of the best sounding amps I’ve ever heard was a Vacuum-Tube Logic (“VTL”) Compact-100 tube mono block. The sound of these amps, paired with a vintage pair of Klipsch LaScalas was enough to bring tears to your eyes. But I wouldn’t recommend the VTLs at all. Their reliability is so poor (and replacement parts so impossible to find) that you’d be wasting your money. Hegel is another manufacturer with a reputation for being able to drive difficult speakers. I, personally, find the sound of their amps somewhat sterile, but many love them. Bryston is another “carriage-trade” manufacturer whose amplifiers supposedly do well with difficult speakers, but not having owned one in a long time, I couldn’t say what they sound like. Odyssey Audio, Audio by van Alstine, and Mark Levinson are also supposed to be good, but I’ve never heard an Odyssey, and haven’t heard a van Alstine or a ML in 30 years. Parasound’s big bruiser mono block amps are supposed to be da shiz, but I’ve not heard one of them either. So where does Emotiva stand among this herd? I was expecting the question, and must preface any comments by saying that many (most?) on this Lounge disagree with me. But here goes: Some of the Emotiva products are among the best I’ve heard at any price. But it depends (strongly) on the model. Among my personal all-time all-stars of Emotiva (and in order of sound quality AND the ability to drive difficult loads): First place - The Generation-2 XPA-1. Many will ask why not the XPR series, and having owned both I found the XPR to be less dynamic than the XPA models. The gen-2 XPA-1s just have unlimited power coupled with lively dynamics that make almost any speaker sound its best. Second place - The Class-D PA-1 amps with their B&O modules. These lack the power to drive difficult loads, but within their limits, they sound almost as good as the amp above. Third place - The Generation 2 XPA-2. Although not as muscular as the mono blocks, these are no slouches. More power than the PA-1 amps, but not quite as transparent, to my ears. Honorable mentions - Generation-1 X-series amps, mono or stereo (the multi-channel ones didn’t sound as good to me). Worst of Emotiva - If you own any of these, I apologize to you for this opinion, but I’m being honest… The XPA-1L models and any of the Generation-3 X-series. They just don’t belong in the category of Emotiva’s best, IMHO. Many love their sound; I don’t. OK - I’ve had my say - let the hate mail begin! LOL Happy amp shopping to you all - Boom
|
|
KeithL
Administrator
Posts: 9,901
|
Post by KeithL on Apr 4, 2020 0:42:08 GMT -5
The "speed" of even the lightest tweeter is orders of magnitude slower than the speed of the electronics in an amplifier. And, if you add up the total moving mass in all those tweeters, you'll find that they aren't especially light either.
(Their main benefit is a large and controlled radiating area.)
Any decent solid state amplifier with even reasonably good transient response will drive them very well. And, if you want an amplifier with "good control", then you want an amplifier with a high damping factor.
(Which, I hate to tell you, rules out virtually all tube amps, and all amps with transformers.... just check that "damping factor" spec for yourself.)
Hi 2shimei - No, I don't have my Pendragons anymore. I let them go to a friend who really wanted them. No, my Pendragons were not the updated versions. Excellent questions, I'll give them my best shot, but others may differ... A speaker that I recently had that was very forgiving was a vintage Dynaco A25: The two-way Dynacos do most of their midrange with that woofer, and the lack of quick transient response just relaxes the entire presentation. The speakers image well, and sound sweet and rich, but they just aren't the last word in midrange resolution. If I had to pontificate on why some speakers are so analytical toward upstream components, I'd put my finger on the upper midrange to lower treble response. The "faster" a speaker responds in this particular frequency band (a range that the human ear is HIGHLY sensitive to), the greater the listener can hear "into the recording," but also the more you can hear recording flaws. Now some speakers present a "fast" impression in this critical range by overshooting the waveform and distorting or else by slightly emphasizing this "presence" range. THOSE speakers grate on the ears very quickly. And since it's a very difficult range to get right, lots of money gets spent on design there. It's difficult to get drivers that are both quick and have a wide bandwidth with uniform dispersion. All of those characteristics matter greatly. If you're trying to get a smooth blend between drivers, there are books written about balancing the critical factors - speed, bandwidth, and dispersion. One of the greatest speaker designers that ever lived, IMHO, was the late, great Jim Thiel. I think that the Tektons are probably getting better since I bought mine. In fact, if I ran across a used pair of Double Impact SE models, I'd be hard-pressed to resist. If I won the lottery, I might even consider some 1812s - But I digress... I'd think (speculating, here) that with a Tekton model using the midrange drivers, you'd get a much smoother frequency response (particularly in the critical midrange) than with the 10-inch, two-way models such as the Pendragon. But since I haven't heard either the newest Pendragons OR the new Tekton designs using the "circular tweeter array," I'm just guessing. Best of luck! Boom, First I'd like to thank you for inspiring an "arm chair reviewer" such as myself. And in helping me understand more and how to articulate what I'm hearing. Regarding this paragraph of what you writ: "If I had to pontificate on why some speakers are so analytical toward upstream components, I'd put my finger on the upper midrange to lower treble response. The "faster" a speaker responds in this particular frequency band (a range that the human ear is HIGHLY sensitive to), the greater the listener can hear "into the recording," but also the more you can hear recording flaws. Now some speakers present a "fast" impression in this critical range by overshooting the waveform and distorting or else by slightly emphasizing this "presence" range. THOSE speakers grate on the ears very quickly. And since it's a very difficult range to get right, lots of money gets spent on design there. It's difficult to get drivers that are both quick and have a wide bandwidth with uniform dispersion. All of those characteristics matter greatly. " My question regards upstream components of speakers that are designed with low mass etc in the extravagant MTM arrays we see from brands such as Tekton and dare I mention in the same sentence McIntosh. In case anyone doesn't know about the MTM arrays I refer I'm including a picture of a McIntosh array: My question is about amplifiers [upstream components]. If I understand correctly it seems that such "lightening quick" arrays demand some sort of "magic" from an amplifier. Perhaps you'd briefly touch upon or comprehensively exhaust [if you'd like at your convenience ] as to what kinda manufacturer specifications may help in identifying amps that keep discipline of the speakers in which they are put in control over these kinda arrays? I acknowledge that initially I looked at the overall system the wrong way as I pieced it together over the years thinking, that each component works independently from one another. Recently, it is came to light that the amp/speaker combination may be more sensitive toward pairing than other components? I bring this up because of what I enjoy from you [encourage you to persist in ], that is, your control of the English language by which to convey your points. You stated, " Now some speakers present a "fast" impression in this critical range by overshooting the waveform and distorting or else by slightly emphasizing this "presence" range." I suppose an equal culprit could also be the amplifier losing control of the speakers? For example, as I wiped the place clean from under the last amp and placed the new amp into place something immediately came into light during play. It was almost as someone reached out and seized the speaker's juggler while they tried to shake themselves free but without success. They never say a peep unless the strong arm while in control allows them to inhale or exhale. The treble area became so smooth I thought about going to the back of the speakers and unplugging them just to see if warm milk and honey were pouring out of the speaker wires. This syrupy chocolate sound must of released a tremendous amount of endorphins because I heard the difference of a component that kept on freely giving. In contrast the cold water and "ringing" iced cubes hitting the glass were no longer audible. Regarding the DI and 1812s I never heard them either. I almost purchased the 1812s but at the time stepping away from something furniture grade fashionable was a big giant leap for me. The Ulfs were not horrible looking, not that the 1812s are, but to me they look a little more DIY or a tower I'd expect to see in the corners of a fancy night club. Enjoy, William
|
|
|
Post by boomzilla on Apr 4, 2020 1:49:25 GMT -5
Hi KeithL - Mr. Levkoff, as always in my experience, is technically correct. Transformer-output-coupled amplifiers are heavy and inherently expensive. They also do not have as good a damping factor as do amplifiers that drive the load without an intervening transformer. So in theory, even an AVR (lacking an output transformer) would outperform a McIntosh power amplifier. But despite their "handicaps," the big McIntosh amps sound like no AVR ever made. Given the choice of an equally expensive McIntosh amp with and without their output "autoformers," I'd pick the latter every single time in full confidence that the performance would be audibly superior. I wouldn't automatically extend that idea to other amplifiers, but McIntosh seems to be the exception. After decades and decades of autoformer design, perhaps they've just come up with a set of design parameters that works. But this brings up another (and very important) concept - the amplifier with the better measured specifications is not always the better-sounding one. This is a hard (VERY hard) idea for a technical mind like Keith's to swallow, but I'm convinced that it's true. Those VTL Compact-100 tube amps that sounded so good to me, for example, definitely measured not just worse but significantly worse than the cheapest 100 WPC AVR. But hearing them both side-by-side, I think that even Keith would prefer the sound of the VTLs. So my tip to you is "don't buy an amplifier based on its published specifications." You need to listen. Boomzilla
|
|
|
Post by boomzilla on Apr 4, 2020 1:58:23 GMT -5
I agree with most of what Boomzilla had to say... with a few minor exceptions.... First off, you're absolutely right that some electrostatic speakers have impedances that drop ridiculously low at high frequencies (one notorious model drops to 0.6 Ohms at 20 kHz.) And, yes, if an amplifier tries to drive significant power into such a low impedance, and isn't designed for it, then it can definitely have serious problems. However, that is not why that amplifier you tried to use smoked itself when it wasn't being asked to drive significant power into that load. The reason is that many electrostatic speakers offer an extremely reactive load (you're talking about a panel, which is a pure capacitor, connected through a transformer). And that "nice quality expensive monoblock amplifier" was not stable into the very reactive load presented by the electrostats... so it oscillated... Thank you kindly for clearing that up. I appreciate it. My follow-up question is not asked out of antagonism, but out of curiosity. Amplifiers these days are well-protected from damage. If the load impedance is too low, the amp disconnects - if the components become too hot, the amp shuts down, etc. Why aren't amps protected from potentially damaging reactive loads? In other words, don't amps have protection against oscillation? Thanks - Boomzilla
|
|
|
Post by boomzilla on Apr 4, 2020 5:00:47 GMT -5
An idea for you @shimei -
Try a tube amplifier with your Tekton speakers. You might fall in love. See if you can borrow the tube amp from a friend? Tekton speakers definitely (in my experience) are "tube friendly," due to their high sensitivity.
Boomadooma
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 4, 2020 11:23:47 GMT -5
An idea for you @shimei - Try a tube amplifier with your Tekton speakers. You might fall in love. See if you can borrow the tube amp from a friend? Tekton speakers definitely (in my experience) are "tube friendly," due to their high sensitivity. Boomadooma I definitely won't pass up the opportunity should one arise. As is now the amp I'm using is rated Class A first 7-10 watts. After a week or so of listening I don't think I've explored outside of that range. The THX specifications are set on my Pre-Pro at 82% volume on the dial. I've never gone beyond that. The Tekton Ulfs are rated 96 db sensitivity. 2 watts 99db 4 watts 102 db. Nope, pretty sure I haven't stepped to the AB side of the amp as of yet. I have zero experience with tube amps outside of guitar playing but wouldn't mind hearing one connected to the Tektons. Thanks Boom and Keith, Enjoy, William
|
|
|
Post by garbulky on Apr 4, 2020 14:05:11 GMT -5
An idea for you @shimei - Try a tube amplifier with your Tekton speakers. You might fall in love. See if you can borrow the tube amp from a friend? Tekton speakers definitely (in my experience) are "tube friendly," due to their high sensitivity. Boomadooma I definitely won't pass up the opportunity should one arise. As is now the amp I'm using is rated Class A first 7-10 watts. After a week or so of listening I don't think I've explored outside of that range. The THX specifications are set on my Pre-Pro at 82% volume on the dial. I've never gone beyond that. The Tekton Ulfs are rated 96 db sensitivity. 2 watts 99db 4 watts 102 db. Nope, pretty sure I haven't stepped to the AB side of the amp as of yet. I have zero experience with tube amps outside of guitar playing but wouldn't mind hearing one connected to the Tektons. Thanks Boom and Keith, Enjoy, William Which amp is class a that You are using?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 5, 2020 10:33:02 GMT -5
I definitely won't pass up the opportunity should one arise. As is now the amp I'm using is rated Class A first 7-10 watts. After a week or so of listening I don't think I've explored outside of that range. The THX specifications are set on my Pre-Pro at 82% volume on the dial. I've never gone beyond that. The Tekton Ulfs are rated 96 db sensitivity. 2 watts 99db 4 watts 102 db. Nope, pretty sure I haven't stepped to the AB side of the amp as of yet. I have zero experience with tube amps outside of guitar playing but wouldn't mind hearing one connected to the Tektons. Thanks Boom and Keith, Enjoy, William Which amp is class a that You are using? Parasound Halo A 31
|
|