Axiom Home Page Forums General Discussion Advice from Axiom Owners Balanced XLR cables

Charles, what's the story on your new EP600? You are keeping us in suspense.

I'm keeping myself in suspense, too. I really haven't played around with positioning much, or on trim and phase settings. I just set them to half and 0, and it's sitting on the side of the couch, along the wall that doesn't have an opening. I calibrated it to the same SPL as my speakers, and I've bumped it up in the receiver a few times just to see how much I could feel it. Then I set it back down. It's certainly different than subs I've used in the past (all wimpy). I was watching a couple of concert DVDs today, and I never knew they had that much low end. It was nice.

But yeah, the replacement amplifier was a little different than the one I shipped back. It actually looked like the illustration on the site. I also have it hooked into a Panamax power conditioner, though I don't know why that would be necessary. It was just lying around, so I put it to use.

I will try playing with positioning when I have some friends over. One of my coworkers offered her sons' help (they're college age), and I think that's probably wise. I'll try out the sub crawl and have them help me move it around to try out any promising locations.

Overall, I'm happy with the performance. I'd like to experiment with bass traps, but not in the current room. I'm not sure I fully understand the concept of bass traps, either. I'll have to read more. People say the low bass likes to hang out in the corners, but then they put bass traps there, which sounds kind of like putting flypaper around a turd.

I understand that Peter is very big(tall, that is), so his claim is credible.

While we're back on this, Mike, it isn't distance alone, but a combination of distance with lots of external electromagnetic interference working over that distance(e.g. such as often exists in professional use)which might make a balanced XLR connection preferable. The balanced cable uses two central conductors(typically tightly twisted, although this isn't essential to the process)rather than one as in a coaxial cable. The balanced output device sends out a voltage signal on each of the conductors, but inverts one by 180 degrees with respect to the other. The balanced input device re-inverts one by 180 degrees so that both voltages are in phase and instead of cancelling each other they add and the resulting voltage is 6dB higher(a doubling of voltage is a 6dB increase, rather than the 3dB for a doubling of power). Typically the balanced input circuit has a 6dB lower gain than the unbalanced coax input to compensate for this. So what does all this back-and-forth inverting, winding up the same, accomplish? Any external electrical noise that hits the two conductors is of the same phase and nearly of equal strength if the conductors are very close to each other; when the inversion occurs in the receiving device, this puts the two noise voltages 180 degrees out of phase with each other and therefore the external noise is cancelled.

Nice explaination John. Thanks.