Yamaha RX-V1400 Delay Question

[Mudcat]

I have the Yamaha RX-V1400 (see my thread in MEMBER SYSTEMS "My what a nice rack"). Anyway, my question is this. With the set up routine of the RX-V1400, is speaker cable length important? Now let me expound a little. My viewing/listening room is 12.5 feet wide and 25 feet long, as can be seen from the above mentioned post my equipment is rack mounted and seperate from the TV/monitor. I would like the TV centered on the narrow wall which would force me to have the rack equipment along an adjacent wall. Instead of trying to make all speaker cables of equal length and having a jumble of wires all over the floor behind the rack, can I make them only as long as necessary? The speakers (Front A, Surround, Surround Back, and Subwoofers)are driven by seperate amps - though I am driving one pair through the Front B connections, and one pair through the Presence connections. Will the Yamaha set up routine, which determines speaker distance to the listening position take into account the different cable lengths and make the necessary corrections? I've been through the cable articles posted here and have search other threads too, but cannot find the answer.

[Edit: Added link to your thread - HawKe]

 

[Unregistered]

Speaker cable length will not matter

The idea behind having all speaker cables the same length is to attempt to ensure that the *signal* reaches each speaker at the same time. But electrons travel down the wire near the speed of light so for all intents and purposes it won't make one single bit of difference if the cables are of different lengths - cut them to the appropriate lengths to minimize the mess. The signal will arrive at each speaker at the same time.

The distance set up for receivers is to ensure that the *sound* from each speaker arrives at your ears at the same time. Sound travels ~1foot/millisecond. Neither your Yamaha, nor any other receiver, takes into account the length of the cables as it is irrelevant.

You need to measure the actual physical distance (in meters or feet) from the ideal listening position to each speaker and input those distances into the speaker distance setup in your receiver's menus. The receiver will then calculate the delay required to achive the objective of all sounds reaching your ears at approximately the same time.

Note that the delay calculation really cannot account for characteristics of your room, like when the first reflection from a nearby wall occurs, but in practice it doesn't matter anyway - even if your distances are off by a few feet you likely will not notice any difference from setting the exact distance. The absolute minimum audible delay that I have ever seen proven is 6ms (thus a distance error of 6 feet) and that is only with pure tones, not music or movie soundtracks.

YPAO and other systems like it will attempt to take into account characteristics of your room and try to eq the sound to make it 'right'. I have no experience with that, but others have said that it does a pretty good job.

Nice setup. I guess you are firmly in the 'too much is never enough' camp.

 

[Unregistered]

sorry to dig this out of the field, but:

electricity (electrons) DO NOT conduct through a wire (or wires) at ANYTHING NEAR the speed of light.

quote:
As for copper, the time interval between collisions is 5.26e-45 seconds and average drift velocity is,

4.62e-3 (m/s) / (v/m).
It means that when 1V voltage is put on both ends of 1m long copper wire, the velocity of free electrons to length direction is 4.62 mm/s. It seems amazingly slow but since electric charge of electrons is -1.6e-19c, 12.6A electric current flows in the 0.5mm copper wire with this speed. You see how large the number of free electrons is.

quote:

from here:

http://www.cartage.org.lb/en/themes/Sciences/Physics/Electromagnetism/Electrostatics/ElectricCurrent/Mysteryofelectric/Mysteryofelectric.htm

now this isn't a "be all" answer. the speed will vary with voltage (potential) and conductor size. but in no way will it EVER approach the speed of light: 299 792 458 m / s, the electrons flow at about 1.5 m / s.

 

[Unregistered]

1.5 m/sec?

If the electrons flowed as slowly as 1.5 m/sec, then, by your calculations, the sound from a 1.5 meter wire hooked up to a speaker that is directly next to another speaker that is connected using 4.5 meters of speaker wire would arrive two seconds after the first signal....

What kind of crap math is that? I think that all of us have wired speakers that were considerablly different distances from the receiver source with considerably different wire lengths, and not noticed this massive delay that would apparently exist in your calculation.

Also, if the electron speed was so slow, there would be perpetual syncing problems with video displays.

While your math and physics knowledge probably impresses chicks at bars, it defies every logical bone in my body....Either you've forgotten to carry a one, or you're full of crap.

I challenge you to rethink your claims, show your math, or state your conclusion in simple terms the rest of us "uneducated" mass can understand.

 

[Unregistered]

electrons and current!

Hehe.. hey guys... just to clarify a few things... he's right about the electron speed. Electrons don't flow anywhere close the speed of light, but instead have a pretty slow drift velocity through the medium which they flow.

However, the speed of current through the same medium can be considered to be close to the speed of light, because current can be MODELED as the flow of electrons, but is really a flow of CHARGE and not honest-to-god ELECTRONS from point A to point B. Current can be likened to an impulse, and the electrons likened to impulse carriers. The electrons themselves move very slowly, but transmit the current impulse through the medium REALLY quickly by transferring charge and shifting around.

Hope that helped clarify a few things. I actually came online here to find some reviews about the HTR5790 coz I just got one.. hehe.. dunno how I got pulled into this discussion though