anyone with a rsp-1068/rmb-1075 combo quick question

[boxer82003]

if you turn everything on and turn up the volume to 75 or 80 most noticeable at this level with nothing playing do you notice a buzz comming through the speakers is this normal?

i ask because i can hear it if i mute my tv at normal listening volume 50 to 60 and walk up to the speaker approx 1 to 2 ft away i hear a faint buzz i have tried diconnecting my cable but its still there.

[Kevin D]

Perfectly normal. There's some manufacturers that put muting circuits to counteract that, but it can take away from the sound.

Pretty much any noise that's not audible at the listening position, or any at a high volume level with no source is fine.

Kevin D.

[PhotoRobot]

This is true, it's there but inaudible when the system is being used and only when you get 1-2 ft away with the ear tilted. Is this just a power hum loop?

[BassThatHz]

Sorry to say but this isn't a new discovery... :P this very phenomenon has been studied and kicked around various scientific and mathematical fields dating 300-60 years ago.

Here is a small list of some of those people...
Harry Nyquist, John Johnson, Carl Gauss, Heinrich Hertz, Max Planck, Albert Einstein, Hermann Helmholtz, Claude Shannon, Nikola Tesla, Ludwig Boltzmann.

They all contributed to some degree in sound, noise, power, heat and electro-magnetic radiation (quantum/thermodynamics).

Every atom in the known universe emits/transfers energy and noise at various bands of frequency (ie background radiation).

E=M*C^2
Nobody really understands exactly, but to keep it simple, the idea is if you trap energy (and something to do with electro-magnetics/gravity) you get mass (particles).

For the most part, when these particles (with charge) move in space/time they can influence each other by electro-magnetic fields (electric field).

Electrical energy occurs when this electric field is transmitted (flows) by or in an electrical conductor. Anything that prohibits conduction of electrical energy is considered resistance (mostly thermal radiation, and is a type of noise). Not all of these electro-magnetic fields being transmitted is "good" energy; unwanted or wasted energy is considered noise.

Transistors function mostly by way of resistance.

"Power hum" is the effect of these conductive particles resonating with the frequency of the alternating electrical field (AC), typically 60-50hz. If and when the resonating particles displace air particles, you get this humming sound. If the power is great enough (high-power lines) you can hear this effect from a fair distance away.

I guess it doesn't help any that speakers are designed specifically to convert these electrical fields (even the unwanted ones) into magnetic fields, which cause the magnets to apply force on the voicecoil and therefore create cone motion.

Without an input signal the system has nothing to amplify but the noise itself, and so the higher the volume knob goes, the more noise gets pre-amplified and set off to the power amp; which of course adds more noise to the signal and then amplifies all that from low-level to high-level.

In most cases there will be a threshold of where the power amp makes more noise than the pre-amp and another where this will be audible by the human ear at some given distance.

Those that have been in an anechoic chamber say that the human brain/ear will generate its own sound to listen to when there isn’t anything else to pick up on; basically like tinnitus.

[bigburner]

if you turn everything on and turn up the volume to 75 or 80 most noticeable at this level with nothing playing do you notice a buzz comming through the speakers is this normal?

Hi boxer,

In my system I consider that a small amount of hiss is normal, hum indicates that I have a ground loop, and buzz indicates that my interconnects are situated too close to power cables.

Do you and I have the same definitions for hiss, hum and buzz? I don't know, but I do know that I eliminated a nasty buzz by separating my interconnects from my power cables.

Nigel.

[Stevebez]

Its a good point to distinguish between hiss, buzz and hum ...

"Hiss" in this context is what I think is what is referred to by BassThatHz's very interesting explanation.

[boxer82003]

i think its more like a hum or buzz then a hiss.

when you say interconnects you mean the cables from the 1068 to the 1075?

[PhotoRobot]

Thanks for the great response BassThatHz's. I think that summs up hizz...

I've always wondered why.

PRobot

[boxer82003]

so this is all normal then i can stop worring