Axiom Home Page Forums General Discussion Hearing Things AVR vs Seprerate- Measured

Someone at AVS came up with an idea of how the differences in the low frequency response was being created. They were preout signal related. When I boosted the preout levels of the 2 mains to match the other channels I was also unintentionally boosting the output to the subs below the sub crossover frequency. With stereo content this resulted in an increase of about 2db below 100hz, and was audible but subtle.

Here are the new graphs. They are virtually identical once the subs are out of the equation by removing it in the AVR settings.

R\L channels powered by AVR. 1/12 octave averaged pink noise. 5db divisions. Towers ran full range, no sub.



R\L channels powered by Seperate amplifier. 1/12 octave averaged pink noise. 5db divisions. Towers ran full range, no sub.



Matt, I still think it is genuinely possible for amps to make a difference in sound quality. I think it has more to do with the ability to play without distortion or tonal shift as spl increases. As for frequency response, both these amplifiers measure the same so far as the graphs show at a pink noise output of 75db.

And as a scientist i can appreciate that some people don't seek a proven truth when it comes to this hobby.
Sometimes the magic is in looking at a new piece of gear and thinking you are creating something cool and amazing sounding.

I personally like to shop for different amps even though i am generally in the camp of "all properly designed amps sound the same". I just like the aesthetics of the some of the pricier options.
I hate black.
It is just some cool ass gear to look at while listening to good music.

There would have to be a technical difference for amps to sound difference such as SPL out of the range of the amp specs (e.g. distortion) or a specific reason why some limitation was applied to an amp that may change the sound (e.g. some kind of filter or super thin internal wiring, etc.).
Otherwise within specs, all amps should be designed to produce the most accurate sound which is to say in a frequency sweep the amp produces nothing but a ruler flat line.
This is most common in virtually any measurement i've seen from competent SS amp builders.

I have a friend who for the longest time was a stereophile. Collects vintage gear for decades now and knows his electronics specs! Was always a stalwart believer in amps sounding different until his guru electronics friend built an instantaneous switcher and they did some playing around with different amps in A/B testing.
Now admittedly if there are differences between amps, they are so small that they are virtually unnoticeable. SPL still needs to be applied which their switcher does not do, and as such, by eliminating that last piece of the variables, the nonconvertible may have been converted simply by doing a more controlled test.

Is the magic gone?
Maybe a little.
But they still like the bling and being able to crank up a 500W /ch amp to its max!
There's always still fun to be had.

Chess, the more I learn about all this stuff, by reading and measuring and pondering, the more I have to say I agree with you.

I'm starting to view SS amps less as audio gear, and more as lab gear. The differences originally measured and heard were due to my user error. Dang preout settings!

Spoken exactly like a scientist, an evil scientist.

You dastardly demon!

Never!

My first record player was a small, vinyl-covered pressboard box. It played only 78's. As children's recordings, they were made in bright (bilious) yellow, They had an LP-sized hole in the center.

When I wanted to play and sing along with the theme from "The Jetsons," I turned a knob that started the table turning with my selection positioned on it. I gently placed the 17 oz. plastic "tone arm" down on the lead-in slips. I'd watch and wait for the needle (which was no more than the nail-end of a pencil compass) to be drawn into the first groove. Then the magic started.

As the nail became ever-more sophisticated, then so did The Jetsons. Now the nail was a "stylus," tipped with really expensive shit. The Jetsons became The Beatles and the process never stopped, like most things in the modern world.

How a nail on a piece of plastic with grooves (OK, one groove) cut (OK, pressed) into it, could play drums and pianos and trumpets and strings and people singing through a speaker(s), was stupefying.

Still the best magic trick I've ever seen (with eyes wide shut)!

The Jetsons B-side? The B-side was a rockin' little diddy sung by the Judy character's voice over artist. It was called "Oop, Eek, Orc, Ah-Ah, Than Means You're the End." When I say "little diddy" I mean it. That title was the entire chorus. Bite me, Katy Perry.

And now the magic is even more real and louder and bigger; much, much louder, and much, much bigger.

If the magic goes with me, and only me, then so be it.

Come to think about it, this Forum is entirely for seeing images, writing and reading ABOUT hearing. Move along, folks, there's nothing to hear, here.

Do not look at that man behind the curtain! Stop looking! When you close your eyes, it IS magic. Where else does size matter so much only with your eyes closed? If that's not magic...


(Oh, that collection of about 100 78's with original sleeves? Umm, when we had graduated to lp's, we used them for Frisbee toss/brick wall games. The ones that didn't "make it" were gathered up, then we'd move the throw-line about 6 feet (2m) closer each time. As it turns out, it's a rather quick process.)

Nah. Maybe science has let the magic smoke out of that black box known as an amplifier, but pot legalization has doubled down and injected the smoke directly into the listener.

Of course the real magic still resides where it always has. With the composer.

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Is the magic gone?

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Nope!

https://www.facebook.com/AxiomAudio/phot...3177446/?type=3

You bet there is more fun to be had! where's my calculator!

Hopefully this nerdy stuff I do spares you guys from doing it yourselves. It is fun though.