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post #166 of 2956

Do you have some measurements of Stax impulse response then?

 

Also, when you say "accurate reproduction of a signal" are you saying the FR should be flat?  I remember reading articles on measurements and headphones that say a perfectly flat FR would sound horribly bright to the human ear.  Something to do with the proximity of the driver to our ears.  Then there's also loudness curves and HRTF to take into account.

 

I believe most Stax models have a largish soundstage due to the housings and driver size.  The Lambdas (which people seem to generalize as the electrostat sound) have a cool driver housing design, where the backside is actually sloped to help with increasing soundstage much like angled drivers.  The Sigma speaks for itself, and the SR Omega has massive drivers that are slightly angled which makes the soundstage large.  The O2 and small monitor headphones (SRX) are generally described as having smallish soundstages.  Then again, I've always took "airy" to be more related to the presence of highs rather than the size of the soundstage.

post #167 of 2956
Quote:
Originally Posted by Prog Rock Man View Post

Correct. We know some headphones have more bass than others and such measurements confirm this. As for scientific evidence of superiority, blind testing of components have often resulted in embarrassment for high priced kit. See the blind tests by Matrix Hifi Non 11 and DIY Audio Non 18 in the first post. Then the Carver blind test of amps shows that once line leveled and a bit of EQ, all amps can be made to sound the same. So I suspect that a series of blind tests of kit would result in various high end stuff being humbled, but a lot I am sure would shine through as the best.



I don't think you're getting the right things out of the Carver Challenge.  What Bob did was not just a little EQ'ing - in addition to near-perfect frequency matching, he corrected for phase shift, response under different impedance loads, and the differing response curves for different harmonic orders.

 

Basically, he made his solid state amp recreate within a 0.03% error exactly how the sample (tube) Conrad Johnson Premiere 4 amplifies.

 

The problem is that his circuits end up being far more complicated and susceptible to breakdown - whether changing in sound over time thanks or just plain electrical problems (compared to say, Adcom amps, Carvers are generally more liable to run in to issues).  There's a reason that Carver's amp design doesn't dominate the mid-end solid-state market, despite the excellent price/performance.

 

I went through and read it again, and I guess they never actually did any blind testing.  It almost sounded like they thought that they wouldn't benefit from doing such tests - but I'm not really sure.  You'd think that if anything they'd be biased towards hearing a difference, but then again, maybe after hearing/seeing the null tests they weren't expecting to hear any differences and thus did not.

 

Anyway, I've found the differences between similarly designed amps with enough power to be pretty small.  I can definitely tell the difference between the older solid state amps and receivers versus more modern ones and versus recent crappy, bright receivers - but I'm not sure I could pass a blind test between my Carver TFM-15CB (well, I have three of 'em) and my Adcom GFA-555 if they were gain-matched.  I think the Carver is warmer, but maybe it's just my mind playing tricks on me...

post #168 of 2956
Quote:
Originally Posted by BlackbeardBen View Post

but I'm not sure I could pass a blind test between my Carver TFM-15CB (well, I have three of 'em) and my Adcom GFA-555 if they were gain-matched.  I think the Carver is warmer, but maybe it's just my mind playing tricks on me...



Might be playing tricks on you. The Adcom GFA-555 is a solid and awesome amp with a very warm sound. I own one and have yet to find another one that beats it completely in terms of price and performance.

post #169 of 2956
Thread Starter 


 

Quote:
Originally Posted by n3rdling View Post

Do you have some measurements of Stax impulse response then?

 

Also, when you say "accurate reproduction of a signal" are you saying the FR should be flat?  I remember reading articles on measurements and headphones that say a perfectly flat FR would sound horribly bright to the human ear.  Something to do with the proximity of the driver to our ears.  Then there's also loudness curves and HRTF to take into account.

...........

That is right, the treble is toned down or else its proximity to the ear would make for a very bright sound. The flatter the FR for full sized speakers, the more natural and similar they sound.

post #170 of 2956
Thread Starter 


 

Quote:
Originally Posted by BlackbeardBen View Post





I don't think you're getting the right things out of the Carver Challenge.  What Bob did was not just a little EQ'ing - in addition to near-perfect frequency matching, he corrected for phase shift, response under different impedance loads, and the differing response curves for different harmonic orders.

 

Basically, he made his solid state amp recreate within a 0.03% error exactly how the sample (tube) Conrad Johnson Premiere 4 amplifies.

 

The problem is that his circuits end up being far more complicated and susceptible to breakdown - whether changing in sound over time thanks or just plain electrical problems (compared to say, Adcom amps, Carvers are generally more liable to run in to issues).  There's a reason that Carver's amp design doesn't dominate the mid-end solid-state market, despite the excellent price/performance.

 

I went through and read it again, and I guess they never actually did any blind testing.  It almost sounded like they thought that they wouldn't benefit from doing such tests - but I'm not really sure.  You'd think that if anything they'd be biased towards hearing a difference, but then again, maybe after hearing/seeing the null tests they weren't expecting to hear any differences and thus did not.

 

Anyway, I've found the differences between similarly designed amps with enough power to be pretty small.  I can definitely tell the difference between the older solid state amps and receivers versus more modern ones and versus recent crappy, bright receivers - but I'm not sure I could pass a blind test between my Carver TFM-15CB (well, I have three of 'em) and my Adcom GFA-555 if they were gain-matched.  I think the Carver is warmer, but maybe it's just my mind playing tricks on me...


I was summarising as the point is if you make different amps sound the same, well what have you really achieved?

post #171 of 2956
Quote:
Originally Posted by Prog Rock Man View Post


I was summarising as the point is if you make different amps sound the same, well what have you really achieved?

 

That's a painful question for many.  If it's not painful, then it's at the minimum... difficult. 

 

However, go to your local amp dealer and there will be tons of reassurance and distraction from such a question.  In a while, the difficulty disappears and the question loses significance and may be even entirely forgotten.  The thought! 
 

post #172 of 2956
Quote:
Originally Posted by Prog Rock Man View Post


 


I was summarising as the point is if you make different amps sound the same, well what have you really achieved?



 

You are assuming that amps should by default sound different. This speaks to what High Fidelity is or might be really about. In the dark ages (70s/80s) the objectivist camp had an expression for the ideal amp, it was a wire with gain, viz an amp should not add any character of its own - it should just accurately transmit the input signal but louder.

 

In Masters and Clark's blind tests in  "Do All Amplifiers Sound The Same" they found that if properly level matched amps costing $230 and $12000 were actually very hard to tell apart.

 

Nowadays we are bombarded with copy that has the working assumption that all amps are different, but this is seldom verified in anything like unbiased tests. Audio mags like Stereophile are populated with sighted reviews where the reviewer knows the price, appearance and design of the components in advance and thus have expectations of sound, generally the more expensive or more boutiquey or pretty the more they like it, there are exceptions of course. Yet these golden eared reviewers are often incapable of detecting apalling products such as the wire that adds several % distortion or the CD/DAC combo that has 25% distortion below 100hz and apallingly uneven FR.

 

post #173 of 2956
Quote:
Originally Posted by nick_charles View Post

Audio mags like Stereophile are populated with sighted reviews where the reviewer knows the price, appearance and design of the components in advance and thus have expectations of sound, generally the more expensive or more boutiquey or pretty the more they like it, there are exceptions of course. Yet these golden eared reviewers are often incapable of detecting apalling products such as the wire that adds several % distortion or the CD/DAC combo that has 25% distortion below 100hz and apallingly uneven FR.

 

 

Yes, that's true.  Instinctively I don't feel that home audio is important enough for life-or-death testing, and sighted audition doesn't offend me greatly.  But I think some basic standards should be upheld - some mental precautions taken, if you like - and they aren't.  Over the years you see a basic correlation between physical appearance - even color - and the reported SQ.

 

But re your second point quoted above: to be pedantic, I think the golden ears sometimes are detecting distortion and uneven FR ... and liking it.  Given that recording processes are "bent wires with distortions and compression" it's no surprise that replay chains featuring euphonic colorations and tilted FRs can sound nice.  In many ways the arguments in this hobby happen because we're not really sure if the "Dark Ages" are over yet ... are we still interested in the straight wire with gain, or not?  It's a vexing question ... and I have to say that if someone gave me a black box to plug in - like a guitar pedal - and it made my system sound exactly like I wanted it to, in my wildest dreams ... then I'd take it, and I'd love it, and I wouldn't care if the wires inside were straight or bent like pretzels.  You?
 

post #174 of 2956
Quote:
Originally Posted by Prog Rock Man View Post
 


Just wanted to add that this is a tremendously important thread.

 

Keep up the good work!

 

And, many thanks for the DiffMaker!  It's a real show stopper! 

 

USG

post #175 of 2956


 

Quote:
Originally Posted by n3rdling View Post

Do you have some measurements of Stax impulse response then?

 

Also, when you say "accurate reproduction of a signal" are you saying the FR should be flat?  I remember reading articles on measurements and headphones that say a perfectly flat FR would sound horribly bright to the human ear.  Something to do with the proximity of the driver to our ears.  Then there's also loudness curves and HRTF to take into account.


You can find impulse response measurements at Ryumatsuba's site.  As for the horribly bright comment, I'd like to see the article you're referencing.  Last but not least, loudness curves are a moving target as is the HRTF.  A band wouldn't adjust their performance for you due to these, why should your headphones?

post #176 of 2956
Quote:
Originally Posted by LFF View Post

Might be playing tricks on you. The Adcom GFA-555 is a solid and awesome amp with a very warm sound. I own one and have yet to find another one that beats it completely in terms of price and performance.


Well, I am using it to power notoriously difficult to drive and typically neutral-to-bright sounding big Infinity speakers (Kappa 8 and the woofers of my Renaissance 90).  I've never so much as heard the Adcom as having a reputation for a warm sound, but I have heard that of the Carver.  In terms of warmth, both of them pale in comparison to my dad's McIntosh 6100 and Polk Monitor 7s.  I've got my own pair of the same Polks and with either the Carver or Adcom they didn't sound nearly as invitingly warm.

 

I like the Adcom a whole lot more though - it's much more damage tolerant and has so much more power in reserve.  The Carvers also emit some kind of a very faint buzzing sound at all times - not loud enough to hear unless you stick your ear up to the tweeter, but it's there.  Nothing of the sort with the Adcom, and I would be willing to bet that it is a result of interference within the components.  Actually, when I took the cover off of one that was buzzing worse than the others and moved one of the wires (can't remember which one), the buzzing sound was affected and I was able to minimize it with a specific placement.  Of course, later it seemed to revert back to the same...  I guess my point is that I find the Adcom's simplicity, reliability, and versatility appealing.  It's ability to supply the big woofers with gobs of current is great.
 

Quote:
Originally Posted by Prog Rock Man View Post

I was summarising as the point is if you make different amps sound the same, well what have you really achieved?


The perfect amp?  : D

 

Differences in power handling make a big difference.  Probably the only really noticeable difference among good transistor amps.

 

Quote:
Originally Posted by nick_charles View Post

You are assuming that amps should by default sound different. This speaks to what High Fidelity is or might be really about. In the dark ages (70s/80s) the objectivist camp had an expression for the ideal amp, it was a wire with gain, viz an amp should not add any character of its own - it should just accurately transmit the input signal but louder.

 

In Masters and Clark's blind tests in  "Do All Amplifiers Sound The Same" they found that if properly level matched amps costing $230 and $12000 were actually very hard to tell apart.

 

Nowadays we are bombarded with copy that has the working assumption that all amps are different, but this is seldom verified in anything like unbiased tests. Audio mags like Stereophile are populated with sighted reviews where the reviewer knows the price, appearance and design of the components in advance and thus have expectations of sound, generally the more expensive or more boutiquey or pretty the more they like it, there are exceptions of course. Yet these golden eared reviewers are often incapable of detecting apalling products such as the wire that adds several % distortion or the CD/DAC combo that has 25% distortion below 100hz and apallingly uneven FR.


I never ceased to be amazed by the wild claims of differences in sound when dealing with such similar (and all near-perfect) amps, CD players, DACs, etc.  Maybe I just don't have enough experience.  But changing speakers has always resulted in a definite difference in sound and capabities.


 

Quote:
Originally Posted by InnerSpace View Post



 

Yes, that's true.  Instinctively I don't feel that home audio is important enough for life-or-death testing, and sighted audition doesn't offend me greatly.  But I think some basic standards should be upheld - some mental precautions taken, if you like - and they aren't.  Over the years you see a basic correlation between physical appearance - even color - and the reported SQ.

 

But re your second point quoted above: to be pedantic, I think the golden ears sometimes are detecting distortion and uneven FR ... and liking it.  Given that recording processes are "bent wires with distortions and compression" it's no surprise that replay chains featuring euphonic colorations and tilted FRs can sound nice.  In many ways the arguments in this hobby happen because we're not really sure if the "Dark Ages" are over yet ... are we still interested in the straight wire with gain, or not?  It's a vexing question ... and I have to say that if someone gave me a black box to plug in - like a guitar pedal - and it made my system sound exactly like I wanted it to, in my wildest dreams ... then I'd take it, and I'd love it, and I wouldn't care if the wires inside were straight or bent like pretzels.  You?
 


I agree - people like some distortion of particular sorts - some people more than others.

post #177 of 2956
Quote:
Originally Posted by InnerSpace View Post

But re your second point quoted above: to be pedantic, I think the golden ears sometimes are detecting distortion and uneven FR ... and liking it.  Given that recording processes are "bent wires with distortions and compression" it's no surprise that replay chains featuring euphonic colorations and tilted FRs can sound nice.  In many ways the arguments in this hobby happen because we're not really sure if the "Dark Ages" are over yet ... are we still interested in the straight wire with gain, or not?  It's a vexing question ... and I have to say that if someone gave me a black box to plug in - like a guitar pedal - and it made my system sound exactly like I wanted it to, in my wildest dreams ... then I'd take it, and I'd love it, and I wouldn't care if the wires inside were straight or bent like pretzels.  You?
 


Indeed, I guess my point was that the golden eared should know when something is out of whack, they are of course free to prefer it like anyone else but that they interpret the terrible as "accurate" as in the examples I alluded to is different.

 

Hmmm tricky....I guess I would allow for speakers/headphones to conform to personal taste but for the chain up to that point to be accurate, since speakers/headphones have far more variability than electronics it makes sense to put the variations at that point ?

 

 

post #178 of 2956
Thread Starter 


 

Quote:
Originally Posted by upstateguy View Post





Just wanted to add that this is a tremendously important thread.

 

Keep up the good work!

 

And, many thanks for the DiffMaker!  It's a real show stopper! 

 

USG


post #179 of 2956
Quote:

Originally Posted by Shike View Post


And, just for giggles compares to a portapro


I just wanted to add that the PortaPro, PX100 ... measurements aren't the best to do comparisons with since they have a huge spike (over 10 dB) in the treble that pushes down the rest of the frequencies in the waterfall plot. And who knows, maybe ryu had to turn down the volume for these headphones to prevent any clipping in those resonant regions.

 

And notice the ringing in the impulse response. I have a PX100 lying around here and without EQ (bad treble peaks, bad!) I would certainly not enjoy using them.


Edited by xnor - 10/12/10 at 12:40pm
post #180 of 2956
Quote:
Originally Posted by Shike View Post


 


You can find impulse response measurements at Ryumatsuba's site.  As for the horribly bright comment, I'd like to see the article you're referencing.  Last but not least, loudness curves are a moving target as is the HRTF.  A band wouldn't adjust their performance for you due to these, why should your headphones?


http://www.headphone.com/learning-center/about-headphone-measurements.php

 

I believe the following also has mention of it, but I haven't read it in a long time:

http://www.stereophile.com/features/808head/

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