Peculiar problem? Show me the light...

OK, I'm going to try and explain this as best as I can. I don't usually listen at mega volumes so this has not been noticed before. My Revel M20s can handle just about anything I put through them, and my subwoofer picks up the base inadequacies. There are some pieces of music that have tremendous base punch, and at very loud volumes I hear my Revels cracking up. Not my sub, but the M20s. Both speakers. If I turn down the volume gain from the neutral setting, on my subwoofer, the crackling goes away in the M20s. It's wierd. If I play the same piece of music with the sub off, I can play at prodigious volumes with no crackling at all. How can my self-powered sub, effect what's coming out of my speakers. I have it hooked up via the preout from my integrated. The sound, otherwise, is wonderful, but at the loudest levels with some powerful transient response type stuff, it'll crackle. I hope I'm explaining this properly. This is a very livable situation, for I just, in a blue moon, crank it up to satiate a sonic desire, sometimes. And it doesn't happen with most music. Anybody have any ideas? You might need more information, so hit me. Thanks in advance my audiophool friends. warren
Here's my system:
YBA Passion Integre
Micromega CDP
Sufire Architectural sub
Revel M20s
Audio Magic Stealth
Cardas GR Ics.
Sistrum Rack system
Sistrum Mini Monitor speaker stands
Sistrum Subwoofer stand
Now, I was told, from an astute audiophool, that this may be due to, believe it or not, subwoofer clipping. The signal can back up through the preout lines and do a number on the main speakers. Henceforth: crackling. Possible? Maybe that Sunfire sub just can't handle those killer, very-low- extension transients? Just thinking out loud. Sssgot to be something coming from the Ics via the preout. Maybe I've gotton a little volume, nuts? Make sense?

I don’t think the Revel produced the cracking noise. I believe your sub might have triggered some sort of vibration or resonance in the surrounding of the Revel, perhaps the join between the speaker and its stand, or the furniture nearby. The vibration was most likely airborne at very low frequency. That is why the cracking noise went away when you turned the sub down or ran the Revel by itself.

I had a similar problem a few months ago. After I upgraded to a pair of Vandersteen model 5, every time I played the Titanic CD track 1, the deep bass would cause my left speaker to buzz. At first, I thought the speaker was defected but when I walked close to it, the buzz disappeared, I then walked back to the listening chair and the buzz came back. It only happened on one or two CDs at certain volume level. I later put a pair of 16” Tube Trap at the front corners to control bass boom and the buzz went away forever. I still don’t know what was buzzing.

I hope this help.
I have not test the solution yet, but it makes so much sense that I'm embarrassed that I did not think of it. It took a tech guy over at YBA to explain what he thought it probably is. He said very simply that the Integre is clipping due to the sub and all my other stuff being on the same outlet. When cranking the music up the sub is drawing huge current and the Passion doesn't have enough to drive the M20s without clipping. When I shut off the sub-no problem, because the Passion has all the current it needs. The Integre is a very high current drawing amp, and the M20s very inefficient. That coupled with a thirsty subwoofer on one outlet: WAHLA! I'm going to go the sane root and keep my music at normal volumes. Makes sense now. I'll get a long extension cord and run the sub through another separate current-outlet, just to make sure, but that is the deal. Thanks again, warren

This is interesting. Now you got me thinking. I plugged both the Vandy 5 and a Theta Dreadnaught into a 20A line because the Vandies have less hums this way. Now I remember it did seem to be less dynamic than when the Vandies were in separate outlets. I am going to test it out tonight. The Integre must be very sensitive to voltage drop. You might want to install a 20A line just for it.

Thanks for sharing your experiences.
It makes perfect sense about power starvation pertaining to the dedicated verses shared lines.

Warrenh, like sidssp stated, you should notice at least some improvement in macro-dynamics or dynamic headroom when you take the sub off that line and put it on another. Even though you could hear the ill-affects at louder volumes due to absolute starvation, you are still potentially starving your amp even at lower volumes. Just not to the same degree but the difference is still usually audible.

It's amazing what sonic improvements one can experience by installing dedicated lines and it's the cheapest of upgrades. Anything containing an amplifier should idealistically have it's own dedicated 20 amp line and circuit and all other components should have 15 amp dedicated lines. And it's equally beneficial when one installs another dedicated line just for digital and yet another just for the pre.

And once you have dedicated lines installed, you will still benefit more when you install good quality power conditioners on those dedicated lines.

How does one go about having a dedicated line installed? How much can or does that cost? I have all my electronics plugged into my Audio Magic Stealth. Obviously, as you've heard, my Stealth is plugged into one outlet. I listen at, usually, low to moderate levels, and it's jazz that's my love, so I don't feel the dynamics are affected. There are times, however, as you've read, that I do like to crank it up. Stehno or anyone: info on dedicated lines. Thanks in advance.

I suggest you hire an electrician to do the job. The cost will vary depending on where you live and the complexity of your situation. I had one done for about $150 in New York area. But my installation was simple; the outlet and the circuit breaker were on the same side of the house and they were only 30 feet apart. The job was also part of a larger one and that saved me some label costs.

At a minimum, you should use 20A hospital grade outlet with #10 all copper wires. The next step up will be to put the wires in steel conduits or use shielded cables. I prefer steel conduit because it also protects the wires from harmful elements. You can also get some audiophile grade outlets but I don’t think it is essential.

Despite what others might suggest, do NOT install a separate ground rod for the dedicated line unless you are going to plug all the equipment to the same ac line. The potential ground loop problem caused by multiple earth grounds are very difficult to solve and might cause safety concerns.

BTW, I tried different outlets with the Vandies last night, the change in dynamic was hardly noticeable but the hums were. I decided to plug them back to the 20A line with the amp.

I hope this helps.
Thanks for the feedback. It seems that it should be a fairly inexpensive job, considering my home. The wall in question is on the same wall that leads into the garage where the circuit breakers are. Punch through the wall and you're there. Once I put my sub on its' own line, my clipping problems will be over. My electricity, with my Stealth is sssh..quiet. Just didn't have enough juice for my sub at mega volumes. The sub, not being plugged into the Stealth will hopefully not be a sonic negative. I believe, from what I've been told, that my Passion will run better, now, reagardless of volume (low and high). Sounds good. warren
Well, here's the next chapter in this saga. Seems, only myself and John are interested, but never-the-less I shall move on. I hook up my sub via an extension cord to another circuit. Sonic bliss. Everything's perfect. So, I figure, it's the dedicated line deal. Instead of plugging my sub back into the Stealth I plug it into the double wall outlet the Stealth is plugged into. I do the music test again, just to see if the clipping still happens. Lo and behold, sonic perfection. Mega volumes:no clipping/crackling, everything sounds perfect. Something going on in my Stealth? Anyone? Thanks for reading, at least...warren
Maybe your Stealth can't provide enough current. Its often recommended that amps not be plugged into power conditioners for this very reason. Not sure about the design of the Stealth. Maybe ask manufacturer.
Warren, thanks for the email. Swampwalker is most likely correct about the Stealth being limited on the current draw.

You might try using only the integrated on the Stealth, your source on the other outlet, and your sub on the extension cord again or even try moving the three around to see what improvements you may or may not hear.

That is just what I have done. Integrated and CDP in the Stealth (different outlets, though) and I plugged the sub into the same double outlet that the Stealth is plugged into. Wahla! Perfection. No crackling, quiet, black background. As it should be. Electricity is mystical, sometimes. It was a Stealth thing after all. I emailed, Jerry, the owner of Audio Magic, for some insight as to what the deal is with the Stealth. When I hear from him I'll post...thanks again guys for your help. warren