Nad t757 avr

[cpp]

I want all magazines to send in a square wave and measure the amp's output at low mid and high volume

that would be great, but as we all know all magazines and theses "testers" #1 do not conduct the same test #2, don't utilize the same measuring devices, software or music #3 do not have access to some products so all you get is stuff to cover a magazine page. #4 no anechoic chamber just a living/den/bedroom/garage/bathroom #5 don't listen to people on a forum

 

[AcuDefTechGuy]

I want all magazines tosent in a square wave and measure the amp's output at low mid and high volume. A square wave will tell tons about an amp's behaviour.

Hey AcuDefTechGuy

This is the third time I mention this in this thread. Those published noise specs are a misprint. If you look at the receiver industry as a whole and NAD's past performance numbers, do you honestly think NAD would risk putting anything out there that measures this poorly? Think about it.

You are probably right. I've also mentioned this possibility in other threads. PENG also mentioned this in this thread and other threads.

Perhaps my original point was, "Hey, doesn't this crosstalk of -58dB stick out like a sore thumb? Did HTM screw up (again)? "

But if other people think that a crosstalk of -58dB on a $1600 NAD is perfectly peachy, then never mind.

I'll just stick to pharmaceutical stuff.

 

[AcuDefTechGuy]

So here is another hypothetical question.

If 2 pre-pros have the same features and same price and have the same reliability record and have the same warranty and sold at the same dealer and have the same appealing aesthetics and are both reviewed by HTMag, which one would you buy?

NAD: crosstalk - 58db, THD 0.02%, SNR -105dB

Anthem: crosstalk -95dB, THD 0.0002%, SNR -120dB

Do you buy based on brand?

 

[GranteedEV]

I would pick neither one without xt32 + subEq

But hypothetically if i had to choose, I would still choose the NAD, because i trust it as a brand more like you said. I just don't feel comfortable with Anthem, Onkyo, or Pioneer electronics, as irrational as it sounds. But that's getting into fickle territory.

But if other people think that a crosstalk of -58dB on a $1600 NAD is perfectly peachy, then never mind.

Considering cross talk of speakers in an average room is prolly around -8db ;P

What IS crosstalk? A phantom replica of channel A leaking to channel B? If I listen at 100db peaks doesn't this mean crosstalk is at 52db peaks? Isn't that a great measurement considering masking effect...it's not like the crosstalk produces a sound distinct from the original sound....?

I say this as a guy who can hear crosstalk if I put my ear to my surround speakers during stereo. i've got an sr6003 and the very similar update sr6004;

www.audioholics.com/reviews/receivers/marantz-sr6004-1/sr6004-measurements

has crosstalk at 62db

So i'm not really concerned with crosstalk. I just want something i'll feel happy with and all else equal yes i would rather choose a brand name over those particular specidix measurements.

 

[markw]

Does it make any difference if you shoot a guy in the head with thirty bullets as opposed to only three?

 

[cpp]

mark

Does it make any difference if you shoot a guy in the head with thirty bullets as opposed to only three?

one worked for me when I served my country for 20 years. Its not how many bullets you have, it's what you do with the one that matters.

 

[3db]

Does it make any difference if you shoot a guy in the head with thirty bullets as opposed to only three?

Normally even one would be a waste of time

 

[markw]

I used three for a reason.

With some people I've run into, one might pass through without hitting any functioning area. Three triples the odds of it having the desired effect.

 

[PENG]

I want all magazines tosent in a square wave and measure the amp's output at low mid and high volume. A square wave will tell tons about an amp's behaviour.

I agree, keep in mind a square wave can be represented with an infinite series of sine waves of harmonic frequencies. May I remind you of the Fourier series. You may even have some old university/college math text books in your basement? Regardless, I also agree with you on this; and I often wonder why the high end guys (just the more common ones) such as Conrad Johnson, Krell, Audio Research, Boulder, etc., have not bothered demonstrating their superior measurements in those departments (Grant seemed to think they might excel in those things easy now Grant I said "seemed"...) I mean they should show they perform in those and compared theirs with the lower end products such as Parasound, Bryston, Anthem etc.

This is the third time I mention this in this thread. Those published noise specs are a misprint. If you look at the receiver industry as a whole and NAD's past performance numbers, do you honestly think NAD would risk putting anything out there that measures this poorly? Think about it.

If you read the fine print of this thread you will know that you, me and at least someone else had said simular things about misprint/typo possibilities and Mark also said "Who care", I guess meaning we should just ignore it anyway in that case. By the way, fwiw we are not even the first and second who said anything about misprint/typo.

 

[3db]

I agree, keep in mind a square wave can be represented with an infinite series of sine waves of harmonic frequencies. May I remind you of the Fourier series. You may even have some old university/college math text books in your basement?

beeeeeeeeeeecause a square wave is much easier to generate than gathering an armful oif infinite sine waves. Yep I remember my Fourier series.

If you read the fine print of this thread you will know that you, me and at least someone else had said simular things about misprint/typo possibilities and Mark also said "Who care", I guess meaning we should just ignore it anyway in that case. By the way, fwiw we are not even the first and second who said anything about misprint/typo.

Errm what is fwiw?

 

[PENG]

beeeeeeeeeeecause a square wave is much easier to generate than gathering an armful oif infinite sine waves. Yep I remember my Fourier series.





Errm what is fwiw?

Just yanking your chain, I did say I agree with the square wave tests. That said, Fourier is really cool, it is a tough thing to swallow when presented with the fact that any periodic waveforms, square, triangular, anything, and factually be represented with an infinite series of sine/cosine harmonics plus fundamental. Without him we may still not be enjoying our modern communication technologies and noise analysis. Also, his transforms, Fourier transforms, make it easy to flip between the time and frequency domain. Even Audyssey benefits from it.

 

[3db]

that would be great, but as we all know all magazines and theses "testers" #1 do not conduct the same test #2, don't utilize the same measuring devices, software or music #3 do not have access to some products so all you get is stuff to cover a magazine page. #4 no anechoic chamber just a living/den/bedroom/garage/bathroom #5 don't listen to people on a forum

Feeding a square wave to an amp is dirt simple and cheap. Measuring it costs a little more so there is no reason why standardizing on tests shouldn't be the goal of these audio rags out. Furthermore,the reviewers are still able to pollute the science with their subjective golden ear voodoo. Testing an amplifier requires no anoechic chamber; just a square wave generator, an oscilliscope to measure slew rates and a spectrum analyzer to look for harmonics. Everything else can be calculated from the information garnered from these instruments.

 

[AcuDefTechGuy]

what is fwiw?

For What It's Worth.

 

[cpp]

3bd, I 'm addressing all test in general.. as you noted

Furthermore,the reviewers are still able to pollute the science with their subjective golden ear voodoo

exactly, I agree with that statement

 

[Greg Stidsen]

The crosstalk spec quoted is the for the multi-channel decoder, NOT the stereo spec. Dolby spec is 55dB which the T 757 exceeds. The stereo crosstalk spec is 79dB which is good for a multi-channel amp.

 

[3db]

Once you move beyond the point of audibility for a spec, there is no reason to improve upon the design to drive the spec even further past inaudibility. At that is point the laws of diminishing returns really kicks into high gear.

 

[AcuDefTechGuy]

The crosstalk spec quoted is the for the multi-channel decoder, NOT the stereo spec. Dolby spec is 55dB which the T 757 exceeds. The stereo crosstalk spec is 79dB which is good for a multi-channel amp.

So why even bother measuring since a $200 AVR will exceed a crosstalk of -55dB.

That's it, I'm cancelling my HTM subscription as soon as it ends. Totally worthless measurements and totally worthless audiofool fine food subjective reviews that do nothing but advertise.

 

[3db]

So why even bother measuring since a $200 AVR will exceed a crosstalk of -55dB.

That's it, I'm cancelling my HTM subscription as soon as it ends. Totally worthless measurements and totally worthless audiofool fine food subjective reviews that do nothing but advertise.

yeah but you still need to see the feature list

 

[AcuDefTechGuy]

yeah but you still need to see the feature list

We can get that from all the free reviews on amazon, yahoo, best buy, Crutchfield, etc.

 

[cpp]

Originally Posted by 3db View Post
yeah but you still need to see the feature list
We can get that from all the free reviews on amazon, yahoo, best buy, Crutchfield, et

trouble is your right