The importance of component location...


I'm brand spankin new to the high end audio world, so I'm beginning my quest to someday call myself "knowledgable".

I've had the chance to look through the vast majority of systems on the gon. One thing I've noticed, at least from those postings that have pics, is that most people with dedicated listening rooms, have there amps located directly in the middle of the speakers ON THE FLOOR!!! Correct me if I'm wrong but I've always read is manuals NOT to place any component on the floor.

Now, just by looking at the pics, I can see that the amps location would reduce the long lengths of cable to the speakers. But does this location effect amp performace? If so, how?

Would this be the only reason to place the amp there?
As for myself, I don't have the option of placing my amp in this spot. Trust me, my wife would have a major objection, seeing my system is in the living room.

I guess the point I'm getting at is what would be the advatage of a system with its amp in the location over a system with its amp on an equipment rack?

Or is this what thing about amp location really a dead issue. Does it even matter.

Can anyone suggest a real world location to place the amp that would offer advantages in performance...outside of an equipment rack?

Thanks for you suggestions.
cdwallace

Showing 3 responses by nsgarch

Null1, I was going to reply to Bigjoe, but after receiving your very generaous vote of confidence, I think I'll just leave it at that. Thanks.

Wallace, re: your question about spkr cable vs. IC length. It seems counterintuitive doesn't it that long ICs and short spkr cables are the preferred configuration, but there are several reasons for it and I'll list three in decending order of importance (to me anyway),

1.) It all started with (woofer) damping and tube amps. Tube amps require the mediation of a (output) transformer in order to couple the load (speaker) to the current valve (the power output tube). You cannot just hook a speaker to a tube like you can with a transistor (if you want to know why, read.) Problem is, with transformers, there's an inherent "magnetic lag" sometimes called "hysteresis" between one set of windings being energised by the tube and magnetizing the iron core which (and here comes the lag) then creates a current in the output windings which drive the speaker. Most tube amps have a maximum damping factor of 10. Think of this as braking power, and the number 10 as the multiple of reverse force the amp can apply to the woofer when the audio signal wants it to stop and go the other way (the faster it can do that, the cleaner your bass), Even having say 20 feet of speaker cable instead of 10 feet can reduce that damping factor from 10 down to 8 at 10 feet and 4 at 20 feet (I'm not going into "why" here.) So that's one reason to keep speaker wire short and wire size fat with tube amps. With SS amps, it's not damping so much (they generally have damping factors of as much as 100) but even at that, the inductances built up over long speaker runs produce a reverse load on the amps (the moving speaker actually generates an electrical current equal and opposite to the one driving it -- called reactance) which creates harmonic distortion and other nasties. This phenomenon, from what I've read screws most w/ SS amps but I could never figure out why.

2.) The (small) currents that must be carried by ICs compared to those of speaker cable mean that inductance and capacitance don't build up as readily. And time smear is often handled easily with special alloys, or a few different size wire strands or extra twists, whereas with a long speaker cable, this problem could only be solved (if at all) with a lot more material (ie heavy and expensive wire every foot.)

3.) Economics. Foot for foot, of similar quality goods, ICs are cheaper than speaker cable. That's why speaker cable is often the last thing folks upgrade.

There are other lesser reasons, some of which other folks mentioned. Another practical one that comes to mind is the fact that you are more likely to have an electrical outlet behind your speakers that's on (or could be put on) a different circuit from your front end stuff to give your amp(s) clean unshared power. Etc., etc., etc.
If you re-check the pics, you'll see that amps only 'appear' to be on the floor. In fact they're on short amp stands that lift them a few inches off the floor. This keeps out most dust, and prevents acidental blocking of the cooling vents on the bottom of the unit (most instructions caution against setting equipment on carpet for this reason).

Short speaker cables and longer amp-preamp interconnects are generally the preferred layout (especially if using tube amps which have limited ability to control (damp) the woofers, resulting in less than terrific (sloppy/muddy) bass.

If your significant other objects to an amp right in the middle of the room, you should consider a pair of monoblock (1 channel) amps located next to, or even behind each speaker, rather than a stereo amp between them.
Bigjoe, could you explain the science, with respect to amplifier location, behind your pronouncement:

"there is no one location thats better than another,put your amps where they best suit your needs."

Thanks