Separates are no better than AV Receivers, Objectively

[fmw]

Depends on who you buy power from. If you buy a big amp from a consumer retailer, yeah, pony up sucker. If you buy from someone like QSC or Crown, it's not so bad. For the price of one high powered consumer amplifier, I can buy three or four entry level pro-amps that will probably blow it out of the water. I mean, if Dynaudio told me I only needed 20 watts I'd probably still have a pro-amp because they are affordable and durable. In other words, I'm not on the defensive of my past purchases.




I'm not niave to how business works. But, as an engineer I know that even though companies are money driven, their engineers are still interested in building the best product they can. There is passion, even though it's not at the top.

It makes sense why an amplifier company would tell you that more power is needed, but not speaker companies. Unless they are just part of the gang.



I know I don't have golden ears, but, I'm pretty sure that power helped my system. I could be wrong though. My problem with the tests we are talking about is that I have no idea of the credibility of the testers. I'm sure they are nice guys and that they are trying to teach us, but, I don't have any idea if they actually know what they are doing. So, I'm just listening and taking everything into account and being appreciative they are taking the time to talk to me about their findings.

It has me thinking, so, I'm going to do some checking on my own... I'm going to ask some of my electrical engineering friends who certainly would know about this or could find out for me. Us ME's know some EE's.

I mean, that's all we can really do when it comes to the Internet. Get some ideas and then check 'em out on your own. In my industry, for example, there are forums that talk about our products... and many people on the forums are completely out of their element. That's why I try to keep an open mind on this stuff. On the 'net, people can have incredible knowledge, or they could be completely over their head and not know it.... but it's awesome they are talking to us about it so we can check it out on our own!

I hope that makes sense and doesn't offend anyone.. I'm appreciative of everyones input!

There you go. Nothing wrong with some skepticism. Go do the tests yourself. Then you will know.

 

[fmw]

Best of luck to you with it CB!

In the meantime so long as the testers stop trying to tell me & those of us who are interested in getting amps or that already have them that we don't need/shouldn't want amplifiers whenever the subject comes up I'll be happy.

Live & let live. They can test to their hearts content & I'll enjoy my unscientific but great sounding system provided by my amplifiers power!

I don't have a problem with that at all. After all, I was a high end audiophile once in my life. Live and let live is fine. The only problem is assigning audible differences with no regard to the fact that the audible differences could be generated by placebo effect rather than the products themselves. The issue we objectivists have is that the high end industry has built itself entirely on this issue and we'd like people to know the truth. That's it.

By the way, all amplifiers do not sound the same. Neither do all cables. That's been proven in bias controlled tests as well. Our group and others have proved this.

We're not trying to keep people from enjoying equipment. We enjoy it too. We are just trying to have people understand that subtle differences are sometimes not differences at all because our brains process what our ears sense. One should be aware of that. Again, if you want to make a truly effective argument, then go do the bias controlled listening tests and come back with that knowledge and experience. Otherwise you are just clinging to beliefs.

 

[AcuDefTechGuy]

By the way, all amplifiers do not sound the same. Neither do all cables. That's been proven in bias controlled tests as well. Our group and others have proved this.

Are there published studies on this?

Are there actual published blinded studies that proved amplifiers with similar power ratings, THD, frequency response, crosstalk, and output impedance sound differently from each other?

Are there actual published blinded studies that proved audio cables & wires sound differently from each other? In other words, Monster Cable will sound differently from AudioQuest from Kimber Kable from Vampire Wire from Blue Jeans Cable?

 

[avaserfi]

Are there published studies on this?

Are there actual published blinded studies that proved amplifiers with similar power ratings, THD, frequency response, crosstalk, and output impedance sound differently from each other?

Are there actual published blinded studies that proved audio cables & wires sound differently from each other? In other words, Monster Cable will sound differently from AudioQuest from Kimber Kable from Vampire Wire from Blue Jeans Cable?

As I pointed out nearly one hundred posts ago the audibility thresholds for these specifications have been determined using scientific method. I even offered some articles, but you completely ignored the point maybe this time will be different.

http://forums.audioholics.com/forums/showpost.php?p=379405&postcount=6

To simplify if the audibility threshold for crosstalk is -80dB then it doesn't matter if the specification is -80dB or -1,000,000dB there will be no audible difference one just happens to be technically better than the other.

This large lack of understanding and ability to correlate any/all specification to perception is how most high end manufactures justify their product along with a healthy dose of the placebo effect.

 

[fmw]

Are there published studies on this?

Are there actual published blinded studies that proved amplifiers with similar power ratings, THD, frequency response, crosstalk, and output impedance sound differently from each other?

No, if you ask the question that way. What I said was all amplifiers do not sound alike. I didn't suggest they all have the same measurements. A good example is on the Stereophile website. They compared a $500 SS amp to a multi thousand dollar tube amp and got a statistically significant audible difference. It was subtle but statistically significant. The test was properly conducted, bias controlled and valid. Are the measurements of the two amps the same? Almost certainly not. I tested a $4500 Audio Research tube amp against a B&K solid state amp and did not get a statistically significant audible difference. I guess that says something positive about ARC's ability to design a tube amp. The tube amp in the Stereophile test was a VTL. I'm sure it is also a great amp, but an expensive one and not entirely transparent.

Are there actual published blinded studies that proved audio cables & wires sound differently from each other? In other words, Monster Cable will sound differently from AudioQuest from Kimber Kable from Vampire Wire from Blue Jeans Cable?

Yes, if you want to accept what I have published on this forum and others. There are a small number of interconnect cables that do color sound. Generally they have very high inductance. Some of them have little boxes included with them that have the basics of a tone control inside them. Just look for the models that included black boxes. In our test we had one such interconnect pair out of 15 total pairs of cables. Will Monster and Audioquest sound different from Blue Jeans? Probably not. We did have a Monster pair in the test and a Kimber PBJ and an Audioquest in the test. They were all in the 14 pairs that didn't have an audible difference. Blue Jeans didn't exist in those days and Vampire wasn't one of the tested cables.

Cable tests are really easy to do because you don't even need to balance levels. One person connects cables. The other person votes and scores. Try some for yourself.

 

[AcuDefTechGuy]

As I pointed out nearly one hundred posts ago the audibility thresholds for these specifications have been determined using scientific method. I even offered some articles, but you completely ignored the point maybe this time will be different.

http://forums.audioholics.com/forums/showpost.php?p=379405&postcount=6

To simplify if the audibility threshold for crosstalk is -80dB then it doesn't matter if the specification is -80dB or -1,000,000dB there will be no audible difference one just happens to be technically better than the other.

This large lack of understanding and ability to correlate any/all specification to perception is how most high end manufactures justify their product along with a healthy dose of the placebo effect.

Yeah, I get the point that we can only hear so much. I knew that before reading any papers. I knew that before obtaining my doctorate degree. It's common sense. Human beings are limited.

On a previous post, fmw very casually and lightly said that some amps and cables do sound differently from each other, which I agree to a point.

My question was, "Are there any published blinded-studies to prove that amps and cables sound differently?"

My question was NOT, "Can we hear a difference between a crosstalk of -80dB vs -140dB, or THD of 1% vs 0.0001%, or frequency response of +/-0.00dB vs +/-3dB, or SNR of -140dB vs -80dB.

There are always differences. Sometimes we can distinguish them, and sometimes we cannot. I personally thought there was a significant audible difference in sound clarity when I compared my analog line-stage preamp vs receiver vs pre-pros. I was just trying to see if there were an easy way to prove with specs, but perhaps there is not an easy way. Looking at the specs of $300 receivers vs $10,000 pre-pros, I cannot see a significant difference. But surely, most of us believe that there should be an audible difference in sound clarity between a $10,000 pre-pros + $10,000 amp vs a $300 receiver, right?

So if the specs can't tell us, then what?
Blinded studies as suggested by fmw...

 

[AcuDefTechGuy]

They compared a $500 SS amp to a multi thousand dollar tube amp and got a statistically significant audible difference. It was subtle but statistically significant...The test was properly conducted, bias controlled and valid. Are the measurements of the two amps the same? Almost certainly not. I tested a $4500 Audio Research tube amp against a B&K solid state amp and did not get a statistically significant audible difference....In our test we had one such interconnect pair out of 15 total pairs of cables. Will Monster and Audioquest sound different from Blue Jeans? Probably not. We did have a Monster pair in the test and a Kimber PBJ and an Audioquest in the test. They were all in the 14 pairs that didn't have an audible difference.

Yeah, I agree that there may be some SUBTLE differences, and I think it's good enough for me. For most people, a slight subtle difference is NOT worth $20,000, but when you have the money (which I don't), any subtle difference is great. You want the best.

So bottom line, most amps and cables (equal measurements) sound the same, but some amps and cables (lesser measurements) may not sound as good.

 

[avaserfi]

Perhaps you realized certain things such as there are limitations to our hearing etc...Perhaps if you took the time to read the articles I originally cited you would realize how these thresholds were and are determined, but since it seems unlikely here are some cliff notes: Properly controlled ABx (a form of double blind) studies are often used to determine human thresholds for hearing.

The reason I previously stated: "Just as with speaker specification/measurements with electronics it is necessary to understand what each measurements means and how to correlate it with human perception to get the whole story" is because you must understand fully what the specifications mean and their thresholds in regards to human perception to understand if/when there would be an audible difference depending on the actual measured numbers.

With this in mind lets think for a second. The human threshold for hearing specification X is a certain number. That means any value technically, and truly, better than this will have no audible differences, but if the specification is lowers or worse than this value there will be audible differences hence my previous posts. I didn't think it needed to be spelled out, but I guess it does.

Lastly, it is important to note that just because there is a difference does not necessarily mean good. These differences are often coloration which can be added via an equalizer actively rather through a passive method such as an amp or cable. A properly designed* amplifier or cable acting within its limits will be completely transparent.

*There are many cases when due to design choices amplifiers and cables are not transparent sometimes on purpose and other times due to poor design.

 

[fmw]

So if the specs can't tell us, then what?
Blinded studies as suggested by fmw...

Specs will tell you a lot. If two amplifiers have basically the same specifications you can bet money that they won't have audible differences in a blind test.

From experience I can tell you that the most "colored" components are usually the in the high-priced audiophile category. The manufacturers sometimes modify what would be a clean design in order to add some euphonic character to the component. The term they use for it is "voicing." The VTL amp in the Stereophile test would be an example of that. Tube amplifiers do not need to be colored just because they use tubes. ARC makes tube components that are transparent, for example. A cable with high enough inductance to roll off high frequencies would be another example like the unmentionable cable pair in our test. You won't find this kind of monkey business in the mid fi world because those customers aren't looking for euphonics. They are usually looking for clean specifications. Actually, you won't find much of this funny business in the high end audiophile world either.

The reason colored components are bad is that they aren't adjustable or defeatable. You get the coloration whether you want it nor not. If you want colored sound it is better to use something like a tone control or equalizer. Then you can adjust it or defeat it.

 

[B3Nut]

Amplifiers *can* sound different, but the causes of the verifiable sonic differences are *quantifiable*, ie they can be measured as well as heard. With an easy-to-drive/efficient speaker, the amp section in a receiver and a separate power amplifier, assuming both meet basic hi-fi standards and are not allowed to clip, will sound identical in a level-matched test. Throw an inefficient or otherwise difficult speaker (low-impedance or wildly-fluctuating impedance curve, drastic phase angle shifts, etc.) into the mix and you will conceivably stress the receiver's amplifier beyond its design limits resulting in various nonlinearities (compression and clipping being the most obvious) resulting from the power supply's inability to source the required current. Not only is this audible, it shows up glaringly on the scope and distortion analyzer. This is why objectivists qualify the statement on amplifier sound as follows: Any two amplifiers, given (1) flat frequency response, (2) THD and IM below audible limits, (3) sufficiently-low noise floor (S/N ratio), (4) high input impedance and low output impedance (true of all modern solid-state hi-fi amps, not always true of older designs, bad/voodoo designs, or vacuum-tube amplifiers), and (5) operated below the point of clipping will sound identical in a level-matched bias-controlled test.

 

[Dezoris]

My cables sound amazing.

 

[AcuDefTechGuy]

...Perhaps if you took the time to read the articles I originally cited you would realize how these thresholds were and determined...ABx...double-blinded...

No, really? Geez, I thought someone just picked a number out of thin air and we all just believed it.

And I highly doubt that any of these studies were DOUBLE-BLINDED. They were mostly single-blinded, meaning the person who administered the study knew which one was which. Double-blinded means the person who administered the study doesn't even know which one was which. This is usually done in the medical field with human trials of medications.

...you must understand fully what the specifications mean and their thresholds in regards to human perception to understand if/when there would be an audible difference depending on the actual measured numbers....

What? Crosstalk? Freq. Resp? THD? SNR? What do they mean? So they tell us that crosstalk of -20dB is inaudible? That THD 1%, Freq Resp +/-3dB, SNR -80dB is inaudible?

You mean a crappy $100 receiver with crosstalk of -20dB, THD 1%, Freq Resp. 20Hz-20kHz +/-3dB, SNR -80dB will sound just as good as a $20,000 pre-pros with a crosstalk of -140dB, THD 0.0001%, Freq Resp 20Hz-20kHz +/-0.000dB, SNR -140dB?

With this in mind lets think for a second. The human threshold for hearing specification X is a certain number. That means any value technically, and truly, better than this will have no audible differences, but if the specification is lowers or worse than this value there will be audible differences hence my previous posts. I didn't think it needed to be spelled out, but I guess it does.

Geez, is that what threshold means? I had no idea.

And since when do we let someone else tell us that what we perceive isn't TRUE? That there is this golden threshold number carved in stone by the spec gods?

Let me guess...their double-blinded studies were absolutely flawless and their results are gold standards?

Lastly, it is important to note that just because there is a difference does not necessarily mean good.

Yes, that's right, Andrew. Keep on telling yourself that the $40,000 Mark Levinson may sound differently than a $300 receiver, but it doesn't necessarily mean it will actually sound better than the $300 receiver.

 

[fmw]

But can those cables serve you coffee or get the mail?

 

[AcuDefTechGuy]

My cables sound amazing.

You should listen to my braided cables!

They are the bomb.

 

[avaserfi]

While I realize I am wasting my time I will reply to your clearly ignorant posts one last time. This post concludes my participation in this thread.

And I highly doubt that any of these studies were DOUBLE-BLINDED. They were mostly single-blinded, meaning the person who administered the study knew which one was which. Double-blinded means the person who administered the study doesn't even know which one was which. This is usually done in the medical field with human trials of medications.

Since you aren't familiar with the ABx testing procedure I will explain it to you as it seems reading an article is too much work. When completing an ABx test the participant listens to Unit A and then Unit B. Once this occurs they listen to Unit Y and Unit X. Now it is up to the participant to then make the relation between X/Y and A/B. After completing this many times the results can be statistically analyzed.

Now this comparison between A/B and X/Y have no need for a researcher since it can all be done with a pre-programmed switch box controlled fully by the participant. The only time a researcher would need to be in the room would be prior to the participants comparisons while setting up the system. The issue of having X and A (or any other combination of the 2 pairs) be the same between each trial can be fixed by out of room, randomly assigned, replacement of wires.

I personally have set up multiple studies like this for various topics in such a manner.

What? Crosstalk? Freq. Resp? THD? SNR? What do they mean? So they tell us that crosstalk of -20dB is inaudible? That THD 1%, Freq Resp +/-3dB, SNR -80dB is inaudible?

If you had true interest in this data you could read the article yourself instead of randomly quoting specifications.

And since when do we let someone else tell us that what we perceive isn't TRUE? That there is this golden threshold number carved in stone by the spec gods?

Let me guess...their double-blinded studies were absolutely flawless and their results are gold standards?

There is a reason peer reviewed publications are essential. This means that there wasn't just one study, but the results were/are repeatable - the sign of any properly conducted research.

As far as differences between high end amps/pre-pros and receivers there are technical ones and the possibility of audible ones. Assuming both a receiver and amp/pre-pro are designed to be transparent and are functioning completely within their limits (not driven to clipping etc...) they will sound exactly the same which is not at all. The area where this amp/pre-pro combination will sound different is likely when using a lower sensitivity speaker especially if it has a lower nominal impedance as this would be far harder to driver and most typical receivers are not up to the challenge, but in this case it is being driven beyond its limits. FMW is also very right in pointing out that the majority of esoteric brands are designed to color sound in a certain way. I would avoid this at all costs for the same reason he and I have previously mentioned - why use a passive solution when you can do the same thing in a controlled fashion with an EQ. It is also important to note that it has been shown through credible perceptual research that a gradual roll off of the high end is preferred by listeners due to current recording techniques. This is why so often these esoteric designs are perceived as sounding better.

 

[AcuDefTechGuy]

Specs will tell you a lot. If two amplifiers have basically the same specifications you can bet money that they won't have audible differences in a blind test.

So looking at the attached table in the first post, if we used the same speakers and external amps, would those pre-pros and receivers sound "equivalent"?

Which specification, do you feel is the most important and makes the most difference?

 

[AcuDefTechGuy]

...Assuming both a receiver and amp/pre-pro are designed to be transparent and are functioning completely within their limits (not driven to clipping etc...) they will sound exactly the same which is not at all.

What? Exactly the same which is Not at all?

Yeah, let me know when you do your first professional product review for Audioholics, Home Theater Magazine, or Sound & Vision. I might read it then.

 

[mtrycrafts]

And the other side of that reality is that no one listens to just 1 channel so why only test that?

Everybody is speaking a separate language in this whole mess. The manufacturers speak one, the magazines speak another, and us poor consumers are left trying to figure who to believe & WTH both are talking about.

Since it starts with the manufacturers and what they print for specs which is ACD then the magazines should follow suit.

I am willing to put more trust into independent magazines then I am the maker of the receivers so if I get close matches on 1 & 2 channels driven but get a totally different lower number for ACD then what the manufacturer quotes (Which is what most consumers look at) I'll believe the magazine.

Until standardization becomes a reality, some should do the best they can to give us uniform information. S & V has at least started to do so by posting a more accurate ACD number. Whether it's reality or not, it is what the manufacturers print for the specs of the receivers. So it is matching apples to apples.

That one channel measurement is meaningful in that one channel can go to max power delivery by itself without a 2nd ch doing so. So, that can be very useful unlike ACD that is so far not known to do so as there is yet such a disc pressed with all channels maxing out at the same instant.

So, it is more useful than the ACD.

 

[mtrycrafts]

It's an endless useless battle Emig5m. They aren't going to change thier minds & we aren't going to change ours.

So far you have not presented any credible evidence for some of us to change minds on this issue. But we can, in case you doubt it, with evidence.

But what irritates me alot is the implication that we are supposedly hearing something that is not there. We are either delusional or liars. That is what I truly resent.

You mean everything you think you hear is in reality real sound that is hitting your eardrums and registers in your brain? I suppose you never asked anyone to repeat something just to be told, nothing was said in the first place?
Perception can be unreliable.

Why can't you control test people accept that there just might be people out there that have very good hearing and can tell the difference? When you can give us credit for that, I might be more willing to give your tests more credit.

Of course there may be. But, so far no one has taken the seat under bias controlled conditions to show off their talents.

 

[mtrycrafts]

Are you kidding? You would be the next AUDIO CRITIC.

I think there are more people who want the statistical proven truth than people who just want thin opinions.

If there were so many, as you suggest, The Audio Critic, Audio, et al, would still be publishing with the largest subscriptions. No, those folks are in the minority, that is why Stereopile is so successful, lots of gullible folks