Hi all,
I just thought I would add a little of my personal experience to the idea of amp specs IMD, THD etc. and subjective listening impressions. I have been in development of a unique amp circuit that our designer chose to optimize with Mosfet output devices. As the circuit by design is extraordinarily resolving based on the speed of the circuit "slew rate" among other reasons which allows for easy subjective feedback to any changes to parts, bias setting, resonance control and the like, I'd like to share some specifics that may possibly be useful to this thread. As the design incorporates 4 output devices per channel producing 170 @ 8ohms and 280 into 4 ohms it will easily drive a flat 4 ohm load. But just "driving" a low impedance load isn't the real issue. A large contributor to the power rating is the result of the bias we choose to run. Higher bias gives greater output and stability into more difficult loads. The interesting thing with bias is that on a scope one of the most critical distortion measures to keep low is the second order harmonic. It is lowest with a lower bias setting. This is the distortion measurement most subjectively responded to as it effects mostly the critical mid and upper mid-range frequencies. In order get an optimally low second order harmonic we chose to sacrifice some power handling. So aside from "power handling" there are critical distortion characteristics that do matter a great deal within each design. Our second order harmonic along with the critical IMD which is a direct result of internal square wave function is spectacular down to 4 ohms "flat". If the 4 ohm nominal speaker has dips below 4 (which many do) the distortion characteristics change and the subjective emotional connection with the music may be compromised (If the speakers are of sufficient resolving power). But this is based on our design goals and cost to performance criteria. What ultimately matters most is your emotional response to the system in your space. If you look at the specs of THE most "realistic" sounding amps on the market i.e. Viola, Technical Brain, Audionet etc. their distortion specs are spectacular but the subjective sound quality is a result of subjective optimizing of everything based on their design goals. As most here know, specs alone certainly don't make a great amp but without great specs the potential isn't there. |
What I said earlier we sold and ues the Behringer in the past. Audyssey pro is superior in quality and in use. With the professional microphone you can measure a lot more information than with many other acoustic systems. Audyssey EQ and Volume give you more resolution and drive. This you loose with many other acoustic systems. We work at mm precisions. When you do not use like this, Audyssey is useless. For most people who have this as a hobby it is useless. I also use the targetcurves. I read a lot about human hearing. It did cost me a lot of info and tests to understand it. |
For that kind of money i'd look for a 2nd hand Modwright KWI-200 & put the spare change into some Stillpoints Ultra SS or Wave Kinetics A10-U8 feet. |
Yes, copper cables, bananas. Fan mod to add quiet fan. I use two Behringer amps, remove the jumpers on the B&Ws and amp the highs/lows separately. It sounds great. Also, I can recede the highs if I like via the gains. However, I don't. |
How do you connect the Behringer amps to the B&W's? Can you use regular speaker cables? |
I've had even the most agnostic audio enthusiasts be unsupportive of the fact that I love my Behringer ep4000 monoblocks. However, they would be my answer to this question (when paired with b&w n802). I've tried many brands and the Behringers are great. I just wish they were more expensive or had a better external case so that I would have some candy to go along with the musical presentation. However, I guess that's not really what its about and that is what has kept them in my equipment rack while 10 or more amps have come and gone. |
clever clock....relevant??? |
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Total Harmonic Distortion - irrelevant. Frequency Response - irrelevant. Slew Rate - irrelevant. Channel Separation - irrelevant. Intermodulation Distortion - irrelevant. |
Geoffkit,
To answer your question directly, a videophile certainly would want to see the specs and any videophile magazine test results before purchasing. And while not determinative, I always review specs on speakers, amps, pre's, CDP's and DAC's as well as read reviews with measurements prior to binding, if for nothing else to see if there is an anomaly I should be listening for.
My point is -- the objective and subjective both count.
Neal |
Geoffkit,
To answer your question directly, a videophile certainly would want to see the specs and any videophile magazine test results before purchasing. And while not determinative, I always review specs on speakers, amps, pre's, CDP's and DAC's as well as read reviews with measurements prior to binding, if for nothing else to see if there is an anomaly I should be listening for.
My point is -- the objective and subjective both count.
Neal |
I think its safe to say amp specifications matter but do not tell the whole story. I agree. |
Just open your own ears and eyes :) |
I think its safe to say amp specifications matter but do not tell the whole story.
The TV analogy is a weak one that will not get anyone very far.
Everyone knows audio salespersons are much more forthright than their TV counterparts. They would NEVER do anything to lead a consumer to see things their way. :^) |
Nglazer, do folks demand to see the specs when buying a new TV? Of course not. That would be absurd, right? Only someone who hasn't quite figured out if he can hear the difference would be so interested in specs. Heck, people don't appear overly concerned with specs for turntables, stereo cartridges or even CD players. They ARE interested in how they sound. Do they have good bass, etc.? |
Zd542 wrote,
"Yes, but with TV's, the salespeople usually adjust the TV's they want to sell as best they can, and "detune" the other ones."
You get a gold star for the funniest post of the thread so far. |
Geoffkit,
Yes, I think I follow! The reason the specs matter even if an amp or other component sounds good in a showroom is because that is a limited time audition in an environment different from your home, and anomalous specs may tell you there will be dissatisfaction over the long term when you must live with a component. I expect that Stereophile runs detailed measurements and discusses them at length for just that reason. By your logic, they are wasting their -- and our -- time. I don't think so . . . .
Neal |
I owned 988 some years back, among dozens of other speakers.
You really don't want to compare experiences Bo.
You lose. |
It is not about age. I started when I was 6. I got a stereo tape recorder of Philips with tubes. In the beginning wenn I started in audio in 98 I was busy with it for 80 hours a week. It was that addictive for me. Audio is about understanding music and how to use audio to play music. I see you use the Quad 988. I sold Quad for over 6 years. Your speakers are ok, but mann you miss a lot to get the absolute sound in the time we live now. Time and technique go on and on. |
Listening to what.......Music....audio. This I do all my life. Today I went to a concert of Joe Bonamassa. Was really awesome!! |
Bo, you need to understand that some of us have been doing this far far longer than you.
And know more.
Stop talking and start listening. |
When are we talking about quality in audio? When is it good and when is it bad? Yess taste Always will be a very important part. For me music and also audio is emotion. I want to be touched. I want to feel the emotion in the music. A technical well measured amp does not say anything about the sound. This matters most. For an amp it is the same thing. The best amps can give a more realistic sound of instruments. When I listen to a violin in real the sound directly does something to your emotion. So when I listen to a set and the sound is so much different, It does not touch my emotion. That is why sound is the most important part in audio. Without it you will never become happy. Spatial resolution, how much detail can we hear. But it is not only how much we hear, where is the resolution coming from. The level of palpable image is important for the feeling. In real instruments and voices are extreme small and direct. So you need to place them blind where they are at the recording. The level of blacks is an important part how good the palpable image is in front of you. Depth is the part were music goes from 2-dimensional to 3-dimensional. Instruments suddenly stand free in the room but they even can vary in about 4-5 metres form eachother. This sets all the parts of the recording full free in the room. This is part where you see the big smiles on the faces of the people who are listening. That is the main reason why I only focus on a 3-dimensional sound. It is that simple! |
Springbok10, I agree 100 percent with your first post here. That is why I have asked in my first post here how does one alert the moderators about this guy. |
Bo1972:
"What can I say?"
Maybe a tad less, perhaps? |
There was a time when amplifier measurements varied greatly, and some claimed specs were less than (let's be generous and say) accurate. Then when specs were actually measured, they started to become way more consistently accurate. Just when the specs started to become little more than academic fodder, some manufactures started a specs war with specs marketing becoming the driving force, even surpassing their reason for being; sound quality. Even though many specs (though not all) taken out of context offer the consumer little insight into how an amp might actually sound, I'd rather not throw the baby out with the bathwater and return to the bad old days. I say keep measuring, keep it in context, and maintain some semblance of quality. Perhaps in the future we'll have better diagnostic tools to help guide us in the vast sea of choices. Even the crude measurements we currently have still offer us a bit of insight into system compatibility. |
Exactly. There is merit to the subjective approach. Specs only tell part of the story. You don't listen to specs, you listen to sound and music. |
The key point in that last post is "best picture." Who decides what is the best picture? YOU DO...and tastes differ. Julian Hirsch pretty much always said the same things so he was sort of boring compared to modern "objectivist" reviewers who aren't necessarily more accurate, but have the florid and long winded descriptions we all know and are sometimes entertained by. Also, room correction gizmos merely hand over parts of your rig to paramaters decided on by somebody else, applies those paramaters to everything you listen to regardless of what might be on the recording, thus taking you out of the driver's seat, so to speak. Do you want a robot adjusting your video screen for you? How about salting your food? Picking out your wine? Man up (or Woman up) and join the fight against evil Room Correction Devices (RCDs) or all esthetic choice will be marginalized! |
I did not bash Wilson Audio. I wrote that there speakers need a lot of attention before you get a decent level for the money you paid. That is not the same as bashing a product. I even wrote that I love the looks and how it is build. But you need big rooms, often with treatment to get a good level out of it. And you need the right amps to control them and get a muscial sound of it. Stop with the bullshit talks about bashing. Read before you say this kind of nonsense! |
Maybe houses are bigger in the US? When I see the pictures of Wilson Audio speakers here at Audiogon I see bigger rooms. Often special audio rooms and room acoustic treatment. What I said earlier; speakers which need a lot of attention. I never was bashing the brand. Just read better!! |
We also asked to naim people why people should pay so muc money for 2 dimensional sound. They had no answer for it. For me it is a normal question. We Always go to shows with a few people. We have our own music with us. We go to the dealer day. Often the day after the consumer days. Most of the people I worked with, friends or other people in this business have the same way of thinking I have. Maybe it is typical dutch, I don't know!! |
Bo1972, we are a cynical society, since very often hobbyist and commerce collide and the hobbyists feel insecure, uncertain and preyed upon......as by dealers/sellers who use the fora to promote their goods and slam others. So, why not follow the advice of very respected sellers/manufacturers, like Duke, Ralph Karsten, Bill Feil and tread that line so carefully that you never give offence. You have crossed that line. You make me uncomfortable. Moderators: how about EVERY post by a commercial vendor is
Always, in each post, followed by the disclaimer, in bold: I SeLL x (if he is espousing x or trashing y). Then we can choose to ignore the post or take it with healthy skepticism. When Ralph Karsten responds, he NEVER pushes his product or rankles any feathers, so he would be exempt because he has no history of conflict. He answers in generalities and technicalities. Bo1972 exceeds the comfort zone. Restrict him in the sense that he should disclose everything every time. It's a tough call, but that's why they pay you the big bucks to moderate:) |
Yes, but with TV's, the salespeople usually adjust the TV's they want to sell as best they can, and "detune" the other ones. |
Paraneer, IMO the brand that Bo is trashing the most is Wilson. Apparently, they are not good for the typical Dutch house and Wilson Audio is not informing the people about this. =)) Regarding your comment Keep them coming Bo because I can't stop laughing either. I for one, I am not sure whether I want to start laughing or crying. |
Just having my morning coffee and signed on to get my daily dose of Bo...
Another excerpt from our resident audio god...
"At shows I Always asked the people of naim why it is so 2D. To be honnest many people who even work for distributers there knowledge is limited. Often they do not know a lot about music. What can I say!"
Perhaps when you get ask this question to a manufacturer Bo, you do not get an answer because they can't stop laughing.
Keep them coming Bo because I can't stop laughing either. |
Julian hirsch
Mglazer wrote,
"It was Julian Hirsch (RIP), a highly respected reviewer for decades. He did not say that amps (or any other compnents) that measure the same, sound the same. What he did say was that if the measurements of two amps were very good and close to each other, both will sound very good and then it is a matter of personal taste which one prefers. In other words, he established the objective, so the buyer could apply his/her subjective taste. Most reviewers today only focus on the subjective."
Yes, he was highly respected by those that believe you can assess how an amp will sound by measuring some parameter or another. Those who do not believe in such things found out a long time ago that parameters that Julian Hirsch held dear, you know, things likeTHD and frequency response and slew rate, had little or no bearing on the subjective sonics of the amp. In fact, what we actually found out was that amps with extremely low THD sound very much worse than amps with relatively high THD. And amps with very high slew rates did not sound as good as amps with relatively low slew rates.
When you go to buy a TV you walk into the store and pick the one you can afford with the best picture, right? Why shouldn't you pick amplifiers the same way? Follow? |
Musical Fidelity there amps are musical and very well controled. The sound has become warmer the last years. There is some depth, but not in the league of Pass Labs. In the past I gave shows for the distributer of MF. Compared to Naim the focus of instruments is a lot sharper. Naim is more focussed on sound and drive. The Naim amps do not give a sharp individual focus like instruments and also voices sound like in real. The other point is ther is almost no depth. At shows I Always asked the people of naim why it is so 2D. To be honnest many people who even work for distributers there knowledge is limited. Often they do not know a lot about music. What can I say! |
I don't wanna disrespect the dead, but Julian Hirsch was a quack, imo. |
What Musical Fidelity products are you talking about Bo1972. A few years ago, I tried a MF A3.5 integrated. I was very surprised with it. No question that is is a very powerful amp. It will drive just about anything. Also, the sound was very fast. If you like what the Naim does with the quick pacing or PRAT, the MF did it better. In my opinion, though, it went too far. The highs were a bit harsh and there was no body or fullness to the sound. Kind of like old Krell but without the good midrange. Not 2D but not 3D. Maybe 2.5D. I thought I would like it but it was just OK. Not great. It was one of the first units to come from Asia and not the UK. Maybe that was the problem. |
Johnmc67- I own a pair of B&W 802D. I have spent many hours and years looking for the right amp. About a year ago I found what I feel is one of a few worth owning, the Veritas by Merrill Audio. However it is beyond your stated budget. But just in the last few days the Merrill has announced an entry level amp. It is the Thor made by Merrill Audio. It lists for $4,000 per pair but he is running deals on it for a limited time so it can be had for less. It is based on a trickle down tech of the Ncore amps.
I have not heard it yet but hope to sometime after the RMAF show next week. I believe Merrill will have them setup at the show if you live nearby and can make it. On aside he will be pairing the Veritas with a pair of TED E1 speakers and Andrew from Pioneer might assist in the setup. I wish I could be able to hear that combo.
Also there was someone on the Audio Circle selling his Veritas because he is going with an all active setup. |
All the demo's in the past with the 802N and the 800 Signature with Mark levinson were often dissapoiting. The best options I think are:
Musical Fidelity, Pass labs X0.5 series and Krell |
Last year I talked with Pass Labs about the idea of creating a new roomacoustic system in there pre-amps. Because the highend brands still do not make a good room acoustic system. Mctosh is using the old dated version of Tact. This is not usable for highend. |
I sold Tact in the past, also there room acoustic system. We were not a fan of it. The sound is far from natural. And it sounds even clinical. The demos they give are most of the time dissapoiting these days. I recently sold the Millenium Tact of a friend of mine. It was quite easy to get a much better sound and stage compared to the Millenium. I had sold him this one new in the past. I even see this as a fault of myself. Soon I will receive the new Audioquest Wild dog subcable wenn it comes out. It is a pure silver subwoofer cable with DBS72. This will give a better timing and speed. But also a big advantage in the freq range from 80-140hz. Time and technique go on and on, that is why audio is a never ending story. |
Geoffkit,
It was Julian Hirsch (RIP), a highly respected reviewer for decades. He did not say that amps (or any other compnents) that measure the same, sound the same. What he did say was that if the measurements of two amps were very good and close to each other, both will sound very good and then it is a matter of personal taste which one prefers. In other words, he established the objective, so the buyer could apply his/her subjective taste. Most reviewers today only focus on the subjective.
Neal |
Ok here is the second part of my write-up: To realize why room correction softwares yields a superior soundstage it is important to realize that: On one hand, one does not want to excite room modes as that will lead to nasty bass resonances and nulls. Therefore, it is desirable to NOT place the speakers symmetrically with respect of the walls in the room. This is exactly what Wolf_Gargia has pointed out. However, on the other hand, to achieve a perfect soundstage, one has to place the speakers symmetrically with respect to room walls as one wants identical acoustic paths. Consequently, one is always faced with a dilemma to optimize the speaker position for the best bass response or for the best stereo image. (In the case of small speakers with limited bass output the situation is most often not critical and acceptable compromises can always be found. In the case of large speakers with healthy bass, however, this becomes problematic. In this second case, one's priority is always to optimize the position of the speaker to obtain the best bass response. Thus, having nor a "perfect" soundstage.) Now, the reason Bo obtains a much better soundstage is because room correction systems, can actually optimize both issues mentioned above at the same time. Moreover, if one used two speakers and a subwoofer, the contradictory issue above is completely removed by sending all low frequencies to a separate subwoofer which can be placed anywhere in the room (e.g. the place that gives the best bass response). This is why Bo is crossing over his sub very high, I believe at 140 Hz or so. This in turn explains why REL subs are too slow for him - they are not design to play that high. Please also note that a similar approach is used also by Lyngdorf in their room correction procedure, i.e. in Lyngdorf system the subwoofers are crossed over at even higher frequencies, i.e. 250 - 300 Hz or os. The opinions are very divided here. Some argue that when crossing over the sub so high one can get rig of most room resonances, while other argue that it is not a good thing as our ear will be able to detect the source of the low frequency. Since I simply do not know what is the right thing to do, I will just give both camps the benefit of the doubt and acknowledge that room correction has come a very long way. I too use a room correction system, not a home-cinema Onkyo like Bo, but an Accuphase stereo unit that can not account for a sub and which most likely is not as advanced as the Audyssey Pro. While I had very few lab rats in my room (as I am not in the business like Bo) I too can attest that stereo purists (even very experienced ones), are extremely impress by the three dimensional and holographic stage obtained when using such softwares. This happens because they are not much aware of these "home theater tricks". They know they have done their homework at home and positioned the speakers correctly and in some cases even added acoustic treatments. However, they simply do not know/understand how crucial it is to have almost identical phases and frequency responses at the listing position from the two speakers and/or how easy is to perturb these parameters. (I find this perfectly normal since as humans, i.e. we are not waves, we have very little feeling for phenomena like interference. I am a physicist and I have spent countless hour in the lab aligning and tuning lasers. While I am fully aware of how crucial is to have an exact phase and/or wavelength in the lab, I too was very surprised the first time I have heard a truly holographic sound stage - not surprizing given the fact that in the lab I was using an oscilloscope, i.e. not my ears.) What I have found very interesting and funny at the same time is the fact that home-theater geeks, are much less impressed, if at all, to hear this holographic soundstage. They typically comment something like "big deal
you have used something like Audyssey XT with your Accuphase system to obtain a three dimensional static image
my home cinema system makes things flying around me ". The first time I was told this I was perplex. My friend's answer took me totally by surprise. . :) Regarding timber and room correction software: My experience (with the unit that I use) is that to obtain an accurate timber when using room correction softwares, it is crucial to use the room correction software as little as possible. That is, one has to place the speakers (and subwoofer if applicable) in the best place possible, so only minimal corrections need to be applied. It is very easy to screw things up, and suck the life out of the music, especially if one is naive enough to think that you can place the speakers randomly in the room and let the software take care of everything else. (Most likely, I am not the only one here who has heard room correction softwares sucking the life out of the music while at the same time giving a perfect holographic soundstage.) Now, it seems to me that Bo here, is one of those home-theater-tech-guys that sets up Audyssey based systems in people's home - a rather common thing in the home theater business, I might add. Therefore, he most likely knows what he is doing and as a result most of the time he obtains a satisfying timber along with the holographic soundstage. I am very sure that timber accuracy is the reason why Bo insists that Pass Labs amps are so important in his set up - he needs to inject some life into an otherwise rather sterile/cold system (Onkyo and Monitor Audio Platinum) - my opinion of course. Therefore, knowing the reactions of my few audiophile friends to the 3D soundstage in my room, I have no doubt that Bo is impressing many of his clients big time with his demos. However, people should realize two important things. First, most recordings (and especially the rock ones) do not contain much, if any, holographic three-dimentional information encoded on them. (I am talking about 3D not 2D soundstage). Therefore, while impressive in a demo (with specific songs), such systems will most likely not be as impressive when playing one's entire album collection. Some specific recordings will certainly sound very impressive but only a very small percent of one's collection. Secondly, one can not conclude that because of its significantly superior soundstage a system with room correction is clearly superior to a system without room correction. As it turns out (see the quotes below), this is exactly what Bo is doing when drawing conclusions about many of the components he is trashing. This should be very clear from his post above: 6 months ago I listend to the latest 800D. The image was almost flat at the show. I was at the same show and I had a very deep and wide stage with the same music. Similarly, in the thread: Why are subwoofers so polarizing?he writes: What I do is I send clients to shops were they sell Velodyne. It is not my responsibility how they do there demo. This is a very easy way to convince. I never heard a demo of a Velodyne at a show that I was thrilled. I Always have my own cd's with me. I let you draw your own conclusions. |
Don't forget the initial question of this topic! Give some brand names and stop arguing to know who has the bigger P...
Everything you say about optimization is right. Using an Audissey pro is the easiest way.
Amps are of course too different to be affirmative on the final result and you also need to try them on your specific speakers to get the perfect synergy.
So the question is too twisted to be answered : Best amp do not really exist without the rest of the system! |
I am glad we have a discussion about audio again :) |
The advantage of Audyssey pro compared to most other acoustic systems for amps is sound realism and more drive and resolution. With many you loose a lot of drive and resolution. Some were talking about the difference between the left and right speaker. because when one is in the corner and the other one is free. Often you will hear the focus is more forwared to the speaker in the corner. With Audyssey Pro you do not have this problem anymore. It adapts to the right volume a speaker gives at the place were it is set. I measure at different places and hights because I want to measure the best dynamics possible. This gives a huge improvement over the Audyssey way of measuring. With Audyssey EQ and volume I also get more resolution. With the Pass Labs XP-20 I did not have the clear level of words endings at sss, ttt or th for example. Most acoustic problems you get in the lowest freq. With Audyssey Pro they're gone and you hear more layers of the low freq. Because the acoustic problems covered these layers. |
Brands do not say a lot about what the properties/talents are of there amps, sources, cables and speakers. What we Always do is burn it in and then listen. Since I do this work you compare all the time. This how you learn the differences in sound, the way the image is projected, the speed and timing, the weight and layers in the low freq. and how much resolution there is. This you do with your ears. I listend a lot to clasical live music. I use the way I heard voices and instruments to be played in the right proportion. The first thing I Always do wenn I visit people for the first time is changing the position of the speakers. So the voice is in the middle and the instruments and voices have the right proportion. I also create a better balance focused on the acoutics of the room. I always use tape to make small changes to hear what will be the right place. Even with cables you can change a lot to the spound, drive, resolution, deptha nd control of the amp. |
Mapman and Wolf, I am only bouncing ideas.
My point is that if speakers placement has been optimized properly, one should still be able to detect small differences in soundstage when changing amp because of the reasons I have stated above. Of course, we talk about small differences. Further, because each amp controls the subwoofer of speaker differently, the speaker position might also need to be slightly changed when changing amps. Therefore, because most of these small differences are cause by the interactions between amp, speakers and room, IMO it is basically impossible to determine them by performing measurements on a single component (except maybe for point 3). One has to try the various amps in his room.
Wolf, some example: left channel has slightly higher distortions/volume then the right channel. I clearly stated that I do not know I significant/large such differences can be. Thus, it should have been clear that I was only a guess.
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Who was the bullet headed reviewer dude at Stereo Review way back when who swore up and down that amps that measure about the same sound about the same? Lots of laughs! |
